Release v0.6.24: smart shapes, rotation and canvas zoom

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.24)
-project(KSwitcher VERSION 0.6.19 LANGUAGES CXX RC)
+project(KSwitcher VERSION 0.6.24 LANGUAGES CXX RC)
 if(NOT WIN32)
   message(FATAL_ERROR "KSwitcher uses native Windows APIs")
 endif()
@@ -17,6 +17,8 @@ set_target_properties(KSwitcherConfig PROPERTIES OUTPUT_NAME "KSwitcher.Config")
 target_compile_definitions(KSwitcherConfig PRIVATE KS_CONFIG_APP)
 target_link_libraries(KSwitcherConfig PRIVATE kscore)
 add_executable(KSwitcherTests tests/tests.cpp)
+add_executable(KSwitcherScrollTests tests/scroll.cpp)
+target_link_libraries(KSwitcherScrollTests PRIVATE kscore)
 target_link_libraries(KSwitcherTests PRIVATE kscore)
 add_executable(KSwitcherIntegration tests/integration.cpp src/screenshot_launcher.cpp src/screenshot_activation.cpp src/app.cpp src/screenshot_notifications.cpp src/screenshot.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
 target_link_libraries(KSwitcherIntegration PRIVATE kscore)
@@ -39,7 +41,7 @@ endif()
 add_executable(KSwitcherOcrTests tests/ocr.cpp src/screenshot_launcher.cpp src/screenshot_activation.cpp src/app.cpp src/screenshot_notifications.cpp src/screenshot.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
 target_link_libraries(KSwitcherOcrTests PRIVATE kscore)
 if(MSVC)
-  set_property(TARGET kscore KSwitcher KSwitcherConfig KSwitcherScreenshot KSwitcherTests KSwitcherIntegration KSwitcherInputTests KSwitcherOcrTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+  set_property(TARGET kscore KSwitcher KSwitcherConfig KSwitcherScreenshot KSwitcherTests KSwitcherScrollTests KSwitcherIntegration KSwitcherInputTests KSwitcherOcrTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
   target_compile_options(kscore PRIVATE /W4 /utf-8)
   target_compile_options(KSwitcher PRIVATE /W4 /utf-8)
   target_compile_options(KSwitcherConfig PRIVATE /W4 /utf-8)
@@ -49,14 +51,17 @@ else()
   target_link_options(KSwitcherConfig PRIVATE -municode -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherScreenshot PRIVATE -municode -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherTests PRIVATE -static -static-libgcc -static-libstdc++)
+  target_link_options(KSwitcherScrollTests PRIVATE -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherIntegration PRIVATE -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherInputTests PRIVATE -static -static-libgcc -static-libstdc++)
   target_link_options(KSwitcherOcrTests PRIVATE -static -static-libgcc -static-libstdc++)
 endif()
 enable_testing()
 add_test(NAME native-regressions COMMAND KSwitcherTests)
+add_test(NAME scroll-regressions COMMAND KSwitcherScrollTests)
 add_test(NAME input-regressions COMMAND KSwitcherInputTests)
 add_test(NAME screenshot-ui-regressions COMMAND KSwitcherScreenshotUITests)
+add_test(NAME screenshot-save-regressions COMMAND KSwitcherScreenshotUITests --save-only)
 add_test(NAME updater-regressions COMMAND powershell.exe -NoProfile -ExecutionPolicy Bypass -File "${CMAKE_CURRENT_SOURCE_DIR}/tests/update.ps1" -Executable "$<TARGET_FILE:KSwitcher>")
 set_tests_properties(native-regressions PROPERTIES WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 install(TARGETS KSwitcher KSwitcherConfig KSwitcherScreenshot RUNTIME DESTINATION .)

README.md

@@ -90,6 +90,10 @@ broker can load them even when the profile directory is inaccessible to it.
 Notifications expire after 24 hours. Cache cleanup runs on capture/open; each cache is bounded to
 40 files and 256 MiB. Expired or evicted notifications cannot reopen their screenshot.
 In the editor, **Ctrl+C** or **Enter** copies the current result without closing the window.
+**Save… / Ctrl+S** saves the full-resolution image and annotations as PNG. The first save asks
+for a file; later saves update that file. **Ctrl+Shift+S (Save As…)** always asks for a new
+destination. Saving keeps the editor open and leaves the clipboard unchanged. Further edits
+must be saved or copied again before closing without a warning.
 The editor starts with **Pencil / Freehand (F)** for drawing. Choose **Pointer (V)** to select objects, move them, and edit geometry, thickness and
 other properties using handles and controls. Clicking empty space clears selection; dragging empty
 space adds nothing. Choose a drawing tool to create objects, then return to **V** to edit them.
@@ -107,10 +111,10 @@ change its diameter. Wheel up increases the size; wheel down decreases it. These
 and update linked arrows. **Ctrl+D** clones the selected object with a small offset. A cloned number
 gets the smallest available positive number, just like a newly placed number: gaps left by deletion
 are filled first, without renumbering existing objects. A cloned arrow keeps its style but starts without endpoint links.
-Arrow and line endpoints can attach to numbered markers, rectangles, circles, ellipses, text blocks,
+Arrow and line endpoints can attach to numbered markers, rectangles, circles, ellipses, triangles, trapezoids, text blocks,
 and other arrows or strokes. In Arrow or Straight line mode, hold **Ctrl** and drag from one object
 to another to draw over them and automatically attach both endpoints. Without Ctrl, existing objects
-can still be selected and edited as before. With Pointer, drag an existing endpoint onto a target to attach it. Attached endpoints follow movement and resizing; text attachments
+can still be selected and edited as before. With Pointer, drag an existing endpoint onto a target to attach it. Attached endpoints follow movement and resizing; shape and text attachments
 also follow rotation. Arrow-to-arrow attachments retain their relative position along the target line.
 Clicking a connector or adding/editing its caption preserves its links. Moving the whole connector
 intentionally detaches its endpoints; moving one endpoint detaches only that end. Deleting a target
@@ -158,7 +162,34 @@ resize; circles keep equal width and height. Move shapes by their outlines, adju
 the mouse wheel or side handle, recolor, clone with Ctrl+D, and undo/redo as with other objects.
 Hold Ctrl to start drawing over an existing object. Line style applies to outlines; Ends is disabled
 for shapes.
+**Canvas zoom:** use **Ctrl++ / Ctrl+-** (including numpad keys) or **Ctrl+mouse wheel**.
+Each step changes the view by 25%; the wheel zooms around the cursor, keyboard shortcuts around
+the viewport center. **Ctrl+0** restores the initial fit. Drag with the **middle mouse button**
+to pan an enlarged image. Zoom ranges from 0.1× to 16× the initial fit; the status bar shows the
+actual image scale. Zoom and pan do not change annotations, export resolution or undo history.
+The wheel without Ctrl still adjusts the object under the cursor.
+
 **Freehand line (F)** draws an opaque curve by following the mouse. The curve is one object:
+after mouse release, light smoothing reduces jitter. Confidently recognized closed outlines become
+rectangles, circles, ellipses, triangles or trapezoids (including tilted outlines), stored as shape objects.
+Drag either bounding-box corner handle to resize the entire recognized outline; circles keep equal
+width and height. Shapes can also be moved, recolored and cloned.
+Every shape has a round rotation handle above its outline. Drag it to rotate around the center;
+hold **Shift** for 15-degree steps. The handle works for toolbar shapes and recognized shapes,
+including triangles. Resize handles and attached connectors follow the rotation; Ctrl+Z/Ctrl+Y
+undo and redo it. The square handle still controls outline thickness.
+**Triangle (G)** is also available directly on the toolbar: drag to create a triangle.
+Both drawn and recognized triangles have three independent vertex handles instead of bounding-box
+resize handles. Drag any vertex to reshape the triangle while keeping the other two fixed, even
+after rotation. Vertex edits support undo/redo, and the rotation and thickness handles remain available.
+**Trapezoid (B)** on the toolbar creates a trapezoid with parallel bases. Pencil recognition also
+fits nearly parallel, unequal bases into a clean trapezoid. Trapezoids support bounding-box resizing,
+rotation, styling and undo/redo; Ctrl+Z after recognition restores the original pencil stroke.
+Oval fitting tolerates uneven contours and small closing gaps or overlaps; broad open arcs and
+repeated loops remain freehand strokes.
+Press **Ctrl+Z** once to restore the original stroke, again to remove it; **Ctrl+Y** reapplies the improvement.
+Small strokes, strokes linked to other objects, and any stroke drawn partly with Shift are left unchanged.
+Ambiguous shapes are only smoothed. To edit the resulting curve,
 move it, change its color or thickness, clone it, or drag its endpoints. Hold Ctrl to start a new
 stroke over an existing object. Hold **Shift** while drawing to constrain the current segment
 to a horizontal, vertical or 45-degree diagonal line; release Shift to resume freehand drawing in the same stroke.
@@ -168,7 +199,7 @@ released repeatedly within one stroke. The **Line style** selector supports Soli
 Dash-dot; **Ends** supports an arrow at the end, start, both ends, or no arrows. These settings
 apply to selected straight/freehand lines and set defaults for subsequent lines. Both are disabled
 for numbered markers and highlights unless a line drawing tool is active. Undo/Redo includes style changes.
-The window close button asks for confirmation before discarding an uncopied screenshot.
+The window close button asks for confirmation before discarding changes that have not been saved or copied.
 **Escape** cancels region selection or inline text edits; it does not close the editor. Copy keeps the editor open and publishes the image
 at its original pixel size, ready to paste. The preview fits the window without changing export size.
 The shortcut is configurable in Settings under **Screen capture**.
@@ -220,6 +251,10 @@ thumbnails and source labels aligned with the scaled fonts and spacing.
 ## Implemented
 
 - Installed Windows keyboard layouts, configurable cycle/order and direct shortcuts; IMEs are switch-only.
+  Text conversion cycles skip layouts that leave the text unchanged and use the next enabled layout
+  that changes it. If none changes the text, the operation keeps the text and advances one layout.
+  Partial copied suffixes can be reselected with paced keys; replacement still requires verification
+  of the complete expected text. Browser/editor compatibility depends on its handling of simulated input.
 - Selection conversion and verified recent input (physical scan codes, 2-second typing-run boundary).
 - Same-process clipboard ownership plus verified WebView2 descendants, including the Teams fix.
 - Teams recent-word conversion uses a single word-selection command and validates the copied range.
@@ -278,6 +313,12 @@ existing saved shortcuts are preserved. While KSwitcher runs, this binding opens
 
 History controls: Enter to paste, Shift+Enter for plain text, Ctrl+1…9 for quick paste,
 Ctrl+P to pin/unpin, Delete to delete, Ctrl+O for the full item, Escape to hide.
+For an image, **Edit image**, **Ctrl+O**, or **Edit image in screenshot editor**
+in the context menu opens the original image in the built-in screenshot editor.
+Annotate it there, then copy the result. Opening the editor leaves the
+clipboard and original history entry unchanged. Text items still open as text;
+Enter and double-click still paste the selected item.
+
 Pressing the history shortcut a second time pastes the second-most-recent item.
 
 ## Data and migration
@@ -379,6 +420,8 @@ protect already valid input, and ambiguous alternatives remain unchanged regardl
 **My dictionary** provides separate English, Ukrainian and Russian fields for correct words missing
 from the bundled dictionaries. Enter words separated by commas or new lines, then click OK and Save
 in Settings. Case and duplicates are normalized automatically; no file editing or ranks are needed.
+The v0.6.23 bundled Ukrainian dictionary includes `поточні`. The updater preserves existing dictionary files;
+if upgrading from an older dictionary, add this word in My dictionary → Ukrainian and click OK → Save.
 These entries are stored in settings and survive dictionary updates. They protect correct input and
 are eligible as correction targets at any frequency limit. The language and target layout must still
 be enabled. **Never correct these words** is a separate exception list and takes precedence.

Release/README.md

@@ -1,21 +1,23 @@
 # Latest Windows release
 
-## v0.6.19 — 2026-10-31
+## v0.6.24 — 2026-11-01
 
 ## Changes
-- Retry a silently dropped Ctrl+C up to three total attempts, only while the transaction clipboard remains unchanged and the original input context is still valid. Failed snippet verification preserves the trigger and following input without sending Enter.
+- Smooth pencil strokes and recognize rectangles, circles, ellipses, triangles and trapezoids, including tilted contours. Ctrl+Z restores the original stroke; Ctrl+Y reapplies the improvement.
-- Exclude temporary transaction clipboard contents from Windows clipboard history and cloud synchronization. The original clipboard snapshot is still restored after the operation when ownership permits.
+- Recognized outlines become editable shapes. Add Triangle (G) and Trapezoid (B) toolbar tools; triangles have three independently draggable vertices.
-- Fix snippet integration test isolation: restore a multiline editor after earlier single-line scenarios, reset layout/correction state, coordinate test-editor clipboard access and disable unrelated background update checks.
+- Rotate all shapes with their round handle, with Shift snapping to 15-degree steps. Resizing, cloning, connector attachments and PNG export follow shape rotation.
-- Add deterministic coverage for one dropped copy and exhausted retries. Keep exact assertions for Enter ordering, buffered typing, clipboard restoration and subsequent auto-correction.
+- Zoom with Ctrl++ / Ctrl+- or Ctrl+mouse wheel, reset with Ctrl+0 and pan with middle-button dragging. Zooming does not change image resolution or undo history.
 
 ## Validation
-The fixes passed 230 native regression checks, 472 input/UI checks, screenshot editor UI and notification registration checks, 48 updater checks and updater progress checks. The full editor integration suite passed all 63 assertions; conversion-specific diagnostics also passed. The final snippet suite passed 20 consecutive runs, including injected copy failures and the three-attempt limit. The v0.6.19 staged Release build also passed the native, input/UI, screenshot and updater checks; the installed application was not replaced or restarted.
+423 native regressions, 473 input/UI checks, shared wheel handling, screenshot editor and shape/zoom regressions, PNG save regressions, notification registration, 48 updater checks and updater progress checks passed.
 
 ## Limitations
-The fix does not retry paste blindly: an editor may already have changed its selection or text. Clipboard contention, editor capabilities and input privileges can still prevent an operation. Existing accessibility readback limitations and problem-only diagnostic logging remain unchanged.
+Shape recognition is heuristic: ambiguous outlines may remain smoothed strokes or require Ctrl+Z to restore the original. Small, linked and Shift-constrained pencil strokes are not automatically improved. Triangle vertices are edited independently; trapezoids use bounding-box resize handles. Canvas zoom is limited to 0.1×–16× the initial fit. PNG exports are flattened images, not editable projects.
+
+Existing browser-selection verification and clipboard/accessibility limitations remain unchanged. The bundled Ukrainian dictionary includes `поточні`; updates preserve existing dictionaries. If missing, add it under Settings → Auto-correction options → My dictionary → Ukrainian, then OK → Save.
 
 **Upgrade:** choose Update in the tray menu. Legacy v0.3.0–v0.4.1 clients first receive the v0.4.2 compatibility bridge, then the current full release. v0.2.3 and earlier require manual installation.
-For manual installation, exit KSwitcher and extract the entire ZIP into its installation folder. Keep personal `data/` and customized dictionaries.
+For manual installation, exit KSwitcher, close screenshot editors and extract the entire ZIP into its installation folder. Keep personal `data/` and customized dictionaries.
 
 Download **KSwitcher-win-x64.zip** with **SHA256SUMS.txt**. The package contains all three executables, a release manifest, offline dictionaries, documentation and license notices. It contains no personal settings, clipboard history, Tesseract installation or language models.
 

Release/SHA256SUMS.txt

@@ -1 +1 @@
-8b2008e97ca625b7eebdf509c038d6d1f6c5c853dce6da1b939abaa18223e26d  KSwitcher-win-x64.zip
+5976c1363e4342830f503cba6d17b3ec1386741f636932117d9b08f55004af92  KSwitcher-win-x64.zip

build.ps1

@@ -10,6 +10,8 @@ $outDir = Join-Path $root 'build'
 New-Item -ItemType Directory -Force $outDir | Out-Null
 $executablePath = if ($Stage) { Join-Path $outDir 'staged\KSwitcher.exe' } else { Join-Path $outDir 'KSwitcher.exe' }
 New-Item -ItemType Directory -Force (Split-Path $executablePath) | Out-Null
+Set-Content -LiteralPath (Join-Path $outDir '.local-dev') -Value 'Local development build' -Encoding ascii
+Set-Content -LiteralPath (Join-Path (Split-Path $executablePath) '.local-dev') -Value 'Local development build' -Encoding ascii
 Push-Location $root
 try {
     $common = @('-std=c++20','-Os','-DNDEBUG','-DUNICODE','-D_UNICODE','-DWIN32_LEAN_AND_MEAN','-DNOMINMAX','-D_WIN32_WINNT=0x0A00','-Wall','-Wextra','-Wno-missing-field-initializers','-Isrc','-Ivendor','-ffunction-sections','-fdata-sections')
@@ -39,6 +41,10 @@ try {
     if ($LASTEXITCODE) { throw 'Screenshot link failed' }
     Copy-Item -LiteralPath $screenshotPath -Destination build/release/KSwitcher.Screenshot.exe -Force
     if ($Test) {
+        & $compiler @common tests/scroll.cpp @libs -static -s -o build/KSwitcherScrollTests.exe
+        if ($LASTEXITCODE) { throw 'Scroll test build failed' }
+        & .\build\KSwitcherScrollTests.exe
+        if ($LASTEXITCODE) { throw 'Scroll tests failed' }
         & $compiler @common tests/tests.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o @libs -static -s -o build/KSwitcherTests.exe
         if ($LASTEXITCODE) { throw 'Test build failed' }
         & .\build\KSwitcherTests.exe
@@ -51,6 +57,8 @@ try {
         if ($LASTEXITCODE) { throw 'Screenshot UI test build failed' }
         & .\build\KSwitcherScreenshotUITests.exe
         if ($LASTEXITCODE) { throw 'Screenshot UI tests failed' }
+        & .\build\KSwitcherScreenshotUITests.exe --save-only
+        if ($LASTEXITCODE) { throw 'Screenshot save tests failed' }
         $registrationTest = Join-Path (Split-Path $executablePath) 'KSwitcherRegistrationTests.exe'
         try {
             & $compiler @common tests/screenshot_registration.cpp build/core.o build/platform.o @libs -static '-Wl,--gc-sections' -s -o $registrationTest

dictionaries/README.md

@@ -17,7 +17,7 @@ replace counts with original frequency ranks, sort lexically. Reproduce with
 hashes. The lists contain word forms from subtitles, not a complete spelling
 or grammar dictionary. Recognition can miss names, jargon and uncommon forms.
 
-Supplemental Ukrainian vocabulary: `реліз`. These additions use rank 50001,
+Supplemental Ukrainian vocabulary: `реліз`, `поточні`. These additions use rank 50001,
 after the upstream 50k list, rather than claiming a measured corpus frequency.
 They are included with the default unlimited rank setting and recorded in sources.json.
 

dictionaries/sources.json

@@ -9,11 +9,12 @@
   "uk": {
     "source": "https://raw.githubusercontent.com/hermitdave/FrequencyWords/525f9b560de45753a5ea01069454e72e9aa541c6/content/2016/uk/uk_50k.txt",
     "sourceSha256": "9548b79a608d33f39c5546037a69117d679730b1fda08dd0ce67c043dbf3335a",
-    "words": 42550,
+    "words": 42551,
-    "bytes": 898227,
+    "bytes": 898248,
-    "sha256": "c94605e6be676d2d64f89a3bc16f92b9128f9977d226a97b103cf22a3e6835e3",
+    "sha256": "caeb097749d4afc84b68ad96b3d7dfb6a6569561cd32ccce0bee94a13b43ba86",
     "supplementalWords": {
-      "\u0440\u0435\u043b\u0456\u0437": 50001
+      "\u0440\u0435\u043b\u0456\u0437": 50001,
+      "\u043f\u043e\u0442\u043e\u0447\u043d\u0456": 50001
     }
   },
   "ru": {

dictionaries/uk.txt

@@ -27337,6 +27337,7 @@
 поторопись	9062
 поторопитесь	20656
 поторопиться	15390
+поточні	50001
 потрапив	4168
 потрапила	7383
 потрапили	6631

resources/app.rc

@@ -9,8 +9,8 @@ IDC_SCREENSHOT_PENCIL CURSOR "icons/lucide/pencil.cur"
 1 RT_MANIFEST "app.manifest"
 201 RCDATA "update.ps1"
 1 VERSIONINFO
- FILEVERSION 0,6,19,0
+ FILEVERSION 0,6,24,0
- PRODUCTVERSION 0,6,19,0
+ PRODUCTVERSION 0,6,24,0
  FILEOS VOS_NT_WINDOWS32
  FILETYPE VFT_APP
 BEGIN
@@ -20,7 +20,7 @@ BEGIN
   BEGIN
    VALUE "FileDescription", "KSwitcher — native keyboard and clipboard utility"
    VALUE "ProductName", "KSwitcher"
-   VALUE "FileVersion", "0.6.19"
+   VALUE "FileVersion", "0.6.24"
   END
  END
  BLOCK "VarFileInfo"

src/app.cpp

@@ -227,7 +227,8 @@ class Transaction
         return selectPrevious(n, [&] { return valid(); });
     }
     std::wstring copyRange(size_t count, const std::wstring &wordCandidate,
-                           const std::function<bool(const std::wstring &)> &matches)
+                           const std::function<bool(const std::wstring &)> &matches,
+                           const std::function<bool(const std::wstring &)> &suffixMatches = {})
     {
         // WebView word boundaries are only candidates; exact verification is mandatory.
         if (needsSelectionDelay(target) && !wordCandidate.empty() &&
@@ -247,7 +248,25 @@ class Transaction
                 return {};
             Sleep(25);
         }
-        return select(count) ? copy() : std::wstring{};
+        auto text = select(count) ? copy() : std::wstring{};
+        // Chromium editors can apply only part of a burst of Shift+Left events.
+        // Extend only a verified suffix; never replace a partial or unrelated range.
+        if (valid() && !matches(text) && !text.empty() &&
+            (suffixMatches ? suffixMatches(text) : newlines(wordCandidate).ends_with(newlines(text))) &&
+            caretSteps(text) < count)
+        {
+            const auto missing = count - caretSteps(text);
+            diagnosticEvent(L"Selection: extending verified suffix by " + std::to_wstring(missing));
+            for (size_t i = 0; i < missing; ++i)
+            {
+                if (!valid() || !chord(VK_LEFT, MOD_SHIFT))
+                    return {};
+                Sleep(25);
+            }
+            text = copy();
+            diagnosticEvent(L"Selection: suffix recovery match=" + std::to_wstring(matches(text)));
+        }
+        return text;
     }
     bool paste(const Clip &clip)
     {
@@ -433,7 +452,7 @@ void App::addTray()
     icon.uCallbackMessage = TrayMessage;
     icon.hIcon = (HICON)LoadImageW(instance, MAKEINTRESOURCEW(IDI_KSWITCHER), IMAGE_ICON,
                                    GetSystemMetrics(SM_CXSMICON), GetSystemMetrics(SM_CYSMICON), LR_SHARED);
-    wcscpy_s(icon.szTip, L"KSwitcher — keyboard layouts & clipboard");
+    wcscpy_s(icon.szTip, localBuildTitle(L"KSwitcher — keyboard layouts & clipboard").c_str());
     Shell_NotifyIconW(NIM_ADD, &icon);
     icon.uVersion = NOTIFYICON_VERSION_4;
     Shell_NotifyIconW(NIM_SETVERSION, &icon);
@@ -1138,7 +1157,9 @@ void App::transform(int command, int snippet)
                 {
                     text =
                         tx.copyRange(recent.keys.size(), recent.keys, [&](const std::wstring &candidate)
-                                     { return recent.match(candidate, available, physicalLayout()) >= 0; });
+                                     { return recent.match(candidate, available, physicalLayout()) >= 0; },
+                                     [&](const std::wstring &candidate)
+                                     { return recent.matchSuffix(candidate, available, physicalLayout()) >= 0; });
                     hint = recent.match(text, available, physicalLayout());
                     diagnosticEvent(L"Recent verification copied=" + std::to_wstring(text.size()) + L" keys=" +
                         std::to_wstring(recent.keys.size()) + L" match=" + std::to_wstring(hint));
@@ -1155,6 +1176,7 @@ void App::transform(int command, int snippet)
                          previous->version == version)
                 {
                     expected = previous->result;
+                    diagnosticEvent(L"Previous result expected=" + diagnosticText(expected));
                     text = tx.copyRange(caretSteps(previous->result), previous->result,
                                         [&](const std::wstring &candidate)
                                         { return newlines(candidate) == newlines(previous->result); });
@@ -1202,11 +1224,7 @@ void App::transform(int command, int snippet)
                                     chord(VK_RIGHT);
                                 return;
                             }
-                            int source = detect(text, available, hint);
+                            to = nextConversionLayout(text, available, cycle, hint);
-                            if (source < 0)
-                                source = hint;
-                            auto it = std::find(cycle.begin(), cycle.end(), source);
-                            to = it == cycle.end() || ++it == cycle.end() ? cycle.front() : *it;
                         }
                         result = convertTo(text, available, to, hint);
                     }

src/app.h

@@ -120,6 +120,7 @@ class App
 };
 void showHistory(App &, bool visible = true);
 void launchScreenshot(App &);
+void launchScreenshotEditor(App &, const Clip &);
 void refreshHistory(App &);
 void showSettings(App &, bool visible = true);
 void showLogs(App &);

src/core.cpp

@@ -148,6 +148,26 @@ std::wstring convertTo(const std::wstring &text, const std::vector<Layout> &layo
     }
     return best < 0 ? text : convert(text, layouts[best], to);
 }
+int nextConversionLayout(const std::wstring &text, const std::vector<Layout> &layouts,
+                         const std::vector<int> &cycle, int hint)
+{
+    if (cycle.empty())
+        return -1;
+    int source = detect(text, layouts, hint);
+    if (source < 0)
+        source = hint;
+    auto it = std::find(cycle.begin(), cycle.end(), source);
+    size_t start = it == cycle.end() ? 0 : (size_t(it - cycle.begin()) + 1) % cycle.size();
+    // Compare every candidate with the original input, never an intermediate conversion.
+    // Bound the search so digits, whitespace and identical layouts cannot loop forever.
+    for (size_t offset = 0; offset < cycle.size(); ++offset)
+    {
+        int target = cycle[(start + offset) % cycle.size()];
+        if (target != source && convertTo(text, layouts, target, hint) != text)
+            return target;
+    }
+    return cycle[start];
+}
 std::wstring cycleCase(const std::wstring &text)
 {
     if (text == upper(text))
@@ -459,6 +479,14 @@ void Run::backspace(HWND w, ULONGLONG now)
         keys.pop_back();
     at = now;
 }
+int Run::matchSuffix(const std::wstring &text, const std::vector<Layout> &layouts, const Layout &physical) const
+{
+    if (text.empty() || text.size() >= keys.size() || overflow)
+        return -1;
+    Run tail = *this;
+    tail.keys = keys.substr(keys.size() - text.size());
+    return tail.match(text, layouts, physical);
+}
 int Run::match(const std::wstring &text, const std::vector<Layout> &layouts, const Layout &physical) const
 {
     if (text.size() != keys.size() || overflow)

src/core.h

@@ -24,6 +24,8 @@ std::wstring upper(std::wstring text);
 std::wstring convert(const std::wstring &, const Layout &, const Layout &, bool force = false);
 int detect(const std::wstring &, const std::vector<Layout> &, int preferred = -1);
 std::wstring convertTo(const std::wstring &, const std::vector<Layout> &, int target, int hint);
+int nextConversionLayout(const std::wstring &, const std::vector<Layout> &,
+                         const std::vector<int> &cycle, int hint);
 std::wstring cycleCase(const std::wstring &);
 std::wstring transliterate(const std::wstring &);
 struct Snippet
@@ -92,5 +94,6 @@ struct Run
     void record(wchar_t, HWND, HKL, ULONGLONG);
     void backspace(HWND, ULONGLONG);
     int match(const std::wstring &, const std::vector<Layout> &, const Layout &physical) const;
+    int matchSuffix(const std::wstring &, const std::vector<Layout> &, const Layout &physical) const;
 };
 } // namespace ks

src/history_preview.h

@@ -0,0 +1,17 @@
+#pragma once
+#include <map>
+#include <set>
+#include <string>
+
+namespace ks {
+// Keep the visible working set even in unusually tall windows. Never evict a
+// visible preview to admit another visible preview: that creates a paint loop.
+template<class T>
+void trimHistoryPreviews(std::map<std::wstring,T> &cache,
+                         const std::set<std::wstring> &visible, size_t limit=32)
+{
+    for(auto it=cache.begin(); cache.size()>limit && it!=cache.end();)
+        if(!visible.contains(it->first)) it=cache.erase(it);
+        else ++it;
+}
+}

src/ocr.cpp

@@ -186,6 +186,43 @@ Pixels decodeImage(const Clip &clip, UINT maxWidth, UINT maxHeight)
     check(converter->CopyPixels(nullptr, pixels.width * 4, (UINT)pixels.bgra.size(), pixels.bgra.data()));
     return pixels;
 }
+Bytes encodePng(const Pixels &p)
+{
+    if (!p.width || !p.height || uint64_t(p.width) * p.height * 4 != p.bgra.size() ||
+        p.bgra.size() > UINT_MAX || p.width > UINT_MAX / 4)
+        throw std::runtime_error("Invalid PNG image dimensions");
+    Com<IWICImagingFactory> factory;
+    check(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER,
+                           IID_PPV_ARGS(factory.out())));
+    Com<IStream> stream;
+    check(CreateStreamOnHGlobal(nullptr, TRUE, stream.out()));
+    Com<IWICBitmapEncoder> encoder;
+    check(factory->CreateEncoder(GUID_ContainerFormatPng, nullptr, encoder.out()));
+    check(encoder->Initialize(stream.p, WICBitmapEncoderNoCache));
+    Com<IWICBitmapFrameEncode> frame;
+    check(encoder->CreateNewFrame(frame.out(), nullptr));
+    check(frame->Initialize(nullptr));
+    check(frame->SetSize(p.width, p.height));
+    auto format = GUID_WICPixelFormat32bppBGRA;
+    check(frame->SetPixelFormat(&format));
+    if (format != GUID_WICPixelFormat32bppBGRA)
+        throw std::runtime_error("Unsupported PNG pixel format");
+    check(frame->WritePixels(p.height, p.width * 4, (UINT)p.bgra.size(),
+                             const_cast<BYTE *>(p.bgra.data())));
+    check(frame->Commit());
+    check(encoder->Commit());
+    STATSTG stat{};
+    check(stream->Stat(&stat, STATFLAG_NONAME));
+    if (stat.cbSize.QuadPart > UINT_MAX)
+        throw std::runtime_error("PNG image is too large");
+    check(stream->Seek({}, STREAM_SEEK_SET, nullptr));
+    Bytes bytes((size_t)stat.cbSize.QuadPart);
+    ULONG read{};
+    check(stream->Read(bytes.data(), (ULONG)bytes.size(), &read));
+    if (read != bytes.size())
+        throw std::runtime_error("Cannot read encoded PNG image");
+    return bytes;
+}
 Format imageDib(const Pixels &p)
 {
     BITMAPINFOHEADER h{};

src/ocr.h

@@ -9,6 +9,7 @@ struct Pixels
 };
 Pixels decodeImage(const Clip &, UINT maxWidth = 0, UINT maxHeight = 0);
 Format imageDib(const Pixels &);
+Bytes encodePng(const Pixels &);
 std::wstring recognizeText(const Clip &);
 std::wstring recognizeText(const Clip &, const Settings &);
 std::filesystem::path tesseractExecutable(const Settings &);

src/platform.cpp

@@ -396,13 +396,14 @@ bool chord(WORD key, UINT mods)
 bool needsSelectionDelay(HWND target)
 {
     const auto name = lower(processName(target));
-    return name == L"ms-teams" || name == L"msedgewebview2";
+    return name == L"ms-teams" || name == L"msedgewebview2" ||
+           name == L"chrome" || name == L"msedge";
 }
 bool selectPrevious(size_t count, const std::function<bool()> &valid)
 {
     if (count > 100000)
         return false;
-    // Teams' WebView editor applies selection changes asynchronously. A burst of
+    // Chromium and Teams' WebView editors apply selection changes asynchronously. A burst of
     // Shift+Left events can all use the same caret position and select only one
     // character. Give each change time to settle before sending the next one.
     const auto target = GetForegroundWindow();

src/platform.h

@@ -8,6 +8,16 @@
 
 namespace ks
 {
+inline std::wstring localBuildTitle(const std::wstring &title)
+{
+    static const bool development=[] {
+        wchar_t path[32768]{};
+        if(!GetModuleFileNameW(nullptr,path,std::size(path))) return false;
+        std::error_code error;
+        return std::filesystem::exists(std::filesystem::path(path).parent_path()/L".local-dev",error);
+    }();
+    return development?title+L" [LOCAL DEV]":title;
+}
 using Bytes = std::vector<unsigned char>;
 struct Format
 {

src/screenshot.cpp

@@ -1,4 +1,5 @@
 #include "screenshot.h"
+#include "stroke_improvement.h"
 #include "ocr.h"
 #include "../resources/resource.h"
 #include <algorithm>
@@ -28,8 +29,8 @@ bool confirmScreenshotClose(HWND owner)
     dialog.hMainIcon=icon;
     dialog.dwCommonButtons=TDCBF_YES_BUTTON|TDCBF_NO_BUTTON;
     dialog.pszWindowTitle=L"KSwitcher";
-    dialog.pszMainInstruction=L"Close without copying?";
+    dialog.pszMainInstruction=L"Close without saving or copying?";
-    dialog.pszContent=L"Your latest screenshot changes have not been copied to the clipboard.";
+    dialog.pszContent=L"Your latest screenshot changes have not been saved to a file or copied to the clipboard.";
     dialog.nDefaultButton=IDNO;
     dialog.lpCallbackData=(LONG_PTR)owner;
     dialog.pfCallback=[](HWND window,UINT notification,WPARAM,LPARAM,LONG_PTR data)->HRESULT {
@@ -53,7 +54,7 @@ bool confirmScreenshotClose(HWND owner)
     // If Windows cannot display the confirmation, keep the screenshot open.
     return SUCCEEDED(result) && button==IDYES;
 }
-constexpr int ToolIds[]{27,10,11,22,23,24,25,21,19,26,20,12,18,13};
+constexpr int ToolIds[]{27,10,11,22,23,24,25,36,37,21,19,26,20,12,18,13};
 struct Surface
 {
     HDC dc = CreateCompatibleDC(nullptr);
@@ -123,7 +124,7 @@ bool chooseTextFont(HWND owner,Mark &m)
     m.fontWeight=font.lfWeight; m.fontItalic=font.lfItalic!=0;
     return true;
 }
-constexpr int CursorTools[]{10,11,22,23,24,25,19};
+constexpr int CursorTools[]{10,11,22,23,24,25,36,37,19};
 HCURSOR makeToolCursor(int tool,int size)
 {
     // Monochrome AND/XOR cursor: white outline keeps the glyph visible on dark images.
@@ -148,6 +149,8 @@ HCURSOR makeToolCursor(int tool,int size)
         case 23: Rectangle(dc,x(17),y(18),x(30),y(29)); break;
         case 24: Ellipse(dc,x(17),y(17),x(30),y(30)); break;
         case 25: Ellipse(dc,x(16),y(20),x(31),y(28)); break;
+        case 36: { POINT p[]{{x(23),y(17)},{x(31),y(30)},{x(16),y(30)},{x(23),y(17)}}; Polyline(dc,p,4); break; }
+        case 37: { POINT p[]{{x(20),y(18)},{x(27),y(18)},{x(31),y(30)},{x(16),y(30)},{x(20),y(18)}}; Polyline(dc,p,5); break; }
         case 19:
             line(18,25,25,18); line(25,18,29,22); line(29,22,22,29);
             line(22,29,18,25); line(18,25,17,30); line(17,30,22,29); break;
@@ -179,12 +182,18 @@ struct Capture
     COLORREF customColors[16]{};
     Mark stroke{};
     bool strokeConstrained{};
+    bool strokeUsedConstraint{};
     size_t strokeAnchor{};
     int strokeAxis{}; // 0 = not chosen, 1 = horizontal, 2 = vertical, 3/4 = diagonals.
     bool strokeAxisSettled{};
     std::vector<POINT> strokeMotion;
     POINT start{}, end{};
     RECT selection{}, view{};
+    RECT canvas{};
+    double zoom=1,panX=0,panY=0;
+    bool panning=false;
+    POINT panOrigin{};
+    int zoomWheelDelta=0;
     std::vector<Mark> marks;
     ScreenshotHistory history;
     HWND editor{}, inlineText{};
@@ -208,6 +217,7 @@ struct Capture
     int hoveredTool=0;
     MarkPart hoveredPart=MarkPart::None;
     std::wstring statusText;
+    std::filesystem::path savedPath;
     explicit Capture(ScreenshotHost &a) : app(a), autoOpenEditor(a.autoOpenEditor) {}
     ~Capture() {
         if(pencilCursor) DestroyCursor(pencilCursor);
@@ -239,11 +249,13 @@ void updateStatus(Capture &c)
         if(c.hoveredTool==30) text=L"Line style: solid, dotted, dashed or dash-dot";
         if(c.hoveredTool==31) text=L"Line ends: start, end, both or no arrowheads";
         if(c.hoveredTool==35) text=L"Arrow caption: F2 / double-click to edit; drag to reposition";
+        if(c.hoveredTool==28) text=L"Save (Ctrl+S) | Save As... (Ctrl+Shift+S)";
     }
     else if(c.inlineText) text=L"Text: Enter = new line | Ctrl+Enter = apply | Esc = cancel";
-    else if(part==MarkPart::Rotation) text=L"Drag to rotate text | Hold Shift for 15-degree steps";
+    else if(part==MarkPart::Rotation) text=L"Drag to rotate | Hold Shift for 15-degree steps";
     else if(part==MarkPart::Thickness) text=L"Drag to change thickness | Mouse wheel over object = size";
     else if(part==MarkPart::Radius) text=L"Drag to resize the number | Mouse wheel = diameter";
+    else if(part>=MarkPart::Vertex0 && part<=MarkPart::Vertex2) text=L"Drag triangle vertex | Other vertices stay fixed";
     else if(part==MarkPart::Start || part==MarkPart::End) text=L"Drag handle to resize | Endpoints can snap to objects and other arrows";
     else if(c.selected>=0) {
         const auto &m=c.marks[c.selected];
@@ -255,9 +267,11 @@ void updateStatus(Capture &c)
     else if(c.pointer) text=L"Pointer (V): select and edit objects | Drag handles = geometry or thickness | Empty space clears selection";
     else if(c.textTool) text=L"Text (T): click the image to type | Double-click existing text to edit";
     else if(c.highlight) text=L"Highlight (H): drag to paint | Ctrl+drag = paint over an object | V = pointer";
-    else if(c.freehand) text=L"Freehand (F): Shift = 45-degree steps; move >50 px off line to turn | Ctrl = draw over objects";
+    else if(c.freehand) text=L"Freehand (F): auto-smooth / shapes; Ctrl+Z restores original | Shift = 45-degree steps | Ctrl = draw over objects";
     else if(c.arrow) text=L"Drag to draw | Ctrl+drag over objects = linked connector | V = pointer";
     else text=L"Number (N): click to add | V = select and edit | Ctrl+C = copy screenshot";
+    text=L"Zoom: "+std::to_wstring(int(std::lround(100.0*(c.view.right-c.view.left)/c.image->width)))+
+         L"% (Ctrl +/- / wheel; Ctrl+0: fit; middle drag: pan) | "+text;
     if(text!=c.statusText) {
         c.statusText=std::move(text);
         SendMessageW(status,SB_SETTEXTW,0,(LPARAM)c.statusText.c_str());
@@ -297,6 +311,12 @@ void positionInlineText(Capture &c)
     int width=std::min(std::max(120,MulDiv(bounds.right-bounds.left,viewWidth,c.image->width)+24),std::max(32,int(client.right)-x));
     int height=std::min(std::max(40,MulDiv(bounds.bottom-bounds.top,viewWidth,c.image->width)+24),std::max(32,int(client.bottom)-c.statusHeight-y));
     SetWindowPos(c.inlineText,nullptr,x-2,y-2,width,height,SWP_NOZORDER|SWP_NOACTIVATE);
+    RECT editorBounds{x-2,y-2,x-2+width,y-2+height},visible{};
+    IntersectRect(&visible,&editorBounds,&c.canvas);
+    auto clip=IsRectEmpty(&visible)?CreateRectRgn(0,0,0,0):
+        CreateRectRgn(visible.left-editorBounds.left,visible.top-editorBounds.top,
+                      visible.right-editorBounds.left,visible.bottom-editorBounds.top);
+    if(!SetWindowRgn(c.inlineText,clip,TRUE)) DeleteObject(clip);
 }
 Mark textStyleDefaults(const Mark &source)
 {
@@ -337,6 +357,14 @@ void finishInlineText(HWND w,Capture &c,bool commit)
 }
 LRESULT CALLBACK inlineTextProc(HWND w,UINT msg,WPARAM wp,LPARAM lp,UINT_PTR,DWORD_PTR)
 {
+    if(msg==WM_KEYDOWN && (GetKeyState(VK_CONTROL)&0x8000) &&
+       (wp==VK_OEM_PLUS || wp==VK_ADD || wp==VK_OEM_MINUS || wp==VK_SUBTRACT || wp=='0' || wp==VK_NUMPAD0)) {
+        SendMessageW(GetParent(w),msg,wp,lp); return 0;
+    }
+    if(msg==WM_KEYDOWN && wp=='S' && (GetKeyState(VK_CONTROL)&0x8000)) {
+        PostMessageW(GetParent(w),WM_COMMAND,(GetKeyState(VK_SHIFT)&0x8000)?29:28,0); return 0;
+    }
+    if(msg==WM_CHAR && wp==19) return 0; // Ctrl+S is handled by the editor.
     if(msg==WM_KEYDOWN && (wp==VK_ESCAPE || (wp==VK_RETURN && (GetKeyState(VK_CONTROL)&0x8000)))) {
         PostMessageW(GetParent(w),FinishTextMessage,wp==VK_ESCAPE?2:1,(LPARAM)w); return 0;
     }
@@ -366,9 +394,47 @@ void beginMarkText(HWND w,Capture &c,int index)
         beginInlineText(w,c,label,index); c.editingLabel=true;
     }
 }
+POINT rotateShapePoint(const Mark &m,POINT p,double direction=1)
+{
+    if(m.shape==ScreenshotShape::None || m.rotation==0) return p;
+    double cx=(m.from.x+m.to.x)/2.0,cy=(m.from.y+m.to.y)/2.0;
+    double a=direction*m.rotation*3.141592653589793/180,cs=std::cos(a),sn=std::sin(a);
+    return {LONG(std::lround(cx+(p.x-cx)*cs-(p.y-cy)*sn)),
+            LONG(std::lround(cy+(p.x-cx)*sn+(p.y-cy)*cs))};
+}
+std::vector<POINT> shapeOutline(const Mark &m)
+{
+    auto points=m.points;
+    if(points.empty()) {
+        auto r=region(m.from,m.to);
+        if(m.shape==ScreenshotShape::Rectangle)
+            points={{r.left,r.top},{r.right,r.top},{r.right,r.bottom},{r.left,r.bottom},{r.left,r.top}};
+        else if(m.shape==ScreenshotShape::Triangle)
+            points={{(r.left+r.right)/2,r.top},{r.right,r.bottom},{r.left,r.bottom},{(r.left+r.right)/2,r.top}};
+        else if(m.shape==ScreenshotShape::Trapezoid)
+            points={{r.left+(r.right-r.left)/4,r.top},{r.right-(r.right-r.left)/4,r.top},
+                    {r.right,r.bottom},{r.left,r.bottom},{r.left+(r.right-r.left)/4,r.top}};
+        else {
+            for(int i=0;i<180;++i) {
+                double a=i*2*3.141592653589793/180;
+                points.push_back({LONG(std::lround((r.left+r.right)/2.0+(r.right-r.left)/2.0*std::cos(a))),
+                                  LONG(std::lround((r.top+r.bottom)/2.0+(r.bottom-r.top)/2.0*std::sin(a)))});
+            }
+            points.push_back(points.front());
+        }
+    }
+    for(auto &p:points) p=rotateShapePoint(m,p);
+    return points;
+}
 RECT markBounds(const Mark &m)
 {
     if(m.isText()) return screenshotTextBounds(m);
+    if(m.shape!=ScreenshotShape::None && m.rotation!=0) {
+        auto points=shapeOutline(m); RECT r{points[0].x,points[0].y,points[0].x,points[0].y};
+        for(auto p:points) { r.left=std::min(r.left,p.x); r.right=std::max(r.right,p.x);
+                            r.top=std::min(r.top,p.y); r.bottom=std::max(r.bottom,p.y); }
+        return r;
+    }
     RECT r=region(m.from,m.to);
     for(auto p:m.points) {
         r.left=std::min(r.left,p.x); r.top=std::min(r.top,p.y);
@@ -380,7 +446,7 @@ std::pair<POINT,POINT> thicknessSegment(const Mark &m)
 {
     if(m.shape!=ScreenshotShape::None) {
         auto r=region(m.from,m.to);
-        return {{r.right,r.top},{r.left,r.top}};
+        return {rotateShapePoint(m,{r.right,r.top}),rotateShapePoint(m,{r.left,r.top})};
     }
     if(m.freehand && m.points.size()>1) {
         size_t index=(m.points.size()-1)/2;
@@ -484,7 +550,10 @@ void drawMarks(HDC dc, const std::vector<Mark> &marks, const Mark *preview = nul
             if(m.shape!=ScreenshotShape::None) {
                 auto hollow=SelectObject(dc,GetStockObject(HOLLOW_BRUSH));
                 auto r=region(m.from,m.to);
-                if(m.shape==ScreenshotShape::Rectangle) Rectangle(dc,r.left,r.top,r.right+1,r.bottom+1);
+                if(!m.points.empty() || m.rotation!=0 || m.shape==ScreenshotShape::Triangle || m.shape==ScreenshotShape::Trapezoid) {
+                    auto points=shapeOutline(m); Polyline(dc,points.data(),int(points.size()));
+                }
+                else if(m.shape==ScreenshotShape::Rectangle) Rectangle(dc,r.left,r.top,r.right+1,r.bottom+1);
                 else Ellipse(dc,r.left,r.top,r.right+1,r.bottom+1);
                 SelectObject(dc,hollow);
                 SelectObject(dc,previousPen); DeleteObject(arrowPen);
@@ -599,7 +668,7 @@ void layout(HWND w, Capture &c)
     RECT statusRect{}; GetWindowRect(status,&statusRect);
     c.statusHeight=statusRect.bottom-statusRect.top;
     r.bottom-=c.statusHeight;
-    const int positions[]{8,44,80,116,152,188,224,260,296,332,368,416,452,500};
+    const int positions[]{8,44,80,116,152,188,224,260,296,332,368,404,440,488,524,572};
     static_assert(std::size(positions)==std::size(ToolIds));
     for (size_t i = 0; i < std::size(ToolIds); ++i)
     {
@@ -607,6 +676,9 @@ void layout(HWND w, Capture &c)
         MoveWindow(GetDlgItem(w,ToolIds[i]),MulDiv(positions[i],dpi,96),MulDiv(6,dpi,96),
                    MulDiv(32,dpi,96),MulDiv(32,dpi,96),TRUE);
     }
+    SendDlgItemMessageW(w,28,WM_SETFONT,(WPARAM)c.font,TRUE);
+    MoveWindow(GetDlgItem(w,28),MulDiv(612,dpi,96),MulDiv(6,dpi,96),
+               MulDiv(78,dpi,96),MulDiv(32,dpi,96),TRUE);
     c.panelHeight=c.unit+MulDiv(40,dpi,96);
     for(int id:{30,31,32,33,34,35}) SendDlgItemMessageW(w,id,WM_SETFONT,(WPARAM)c.font,TRUE);
     MoveWindow(GetDlgItem(w,32),MulDiv(12,dpi,96),c.unit+MulDiv(6,dpi,96),MulDiv(64,dpi,96),MulDiv(24,dpi,96),TRUE);
@@ -616,13 +688,35 @@ void layout(HWND w, Capture &c)
     MoveWindow(GetDlgItem(w,34),MulDiv(480,dpi,96),c.unit+MulDiv(2,dpi,96),MulDiv(28,dpi,96),MulDiv(28,dpi,96),TRUE);
     MoveWindow(GetDlgItem(w,35),MulDiv(516,dpi,96),c.unit+MulDiv(2,dpi,96),MulDiv(28,dpi,96),MulDiv(28,dpi,96),TRUE);
     syncLineOptions(w,c);
-    double ratio = std::min({1.0, double(std::max(1L,r.right-16))/c.image->width,
+    c.canvas={0,c.panelHeight,r.right,std::max(LONG(c.panelHeight+1),r.bottom)};
+    double ratio = c.zoom*std::min({1.0, double(std::max(1L,r.right-16))/c.image->width,
                                   double(std::max(1L,r.bottom-c.panelHeight-16))/c.image->height});
-    int width = int(c.image->width*ratio), height = int(c.image->height*ratio);
+    int width = std::max(1,int(std::lround(c.image->width*ratio))), height = std::max(1,int(std::lround(c.image->height*ratio)));
-    c.view = {(r.right-width)/2, c.panelHeight+(r.bottom-c.panelHeight-height)/2,
+    double maxX=std::max(0.0,(width-double(c.canvas.right-c.canvas.left))/2);
-              (r.right+width)/2, c.panelHeight+(r.bottom-c.panelHeight+height)/2};
+    double maxY=std::max(0.0,(height-double(c.canvas.bottom-c.canvas.top))/2);
+    c.panX=std::clamp(c.panX,-maxX,maxX); c.panY=std::clamp(c.panY,-maxY,maxY);
+    LONG x=LONG(std::lround((r.right-width)/2.0+c.panX));
+    LONG y=LONG(std::lround(c.panelHeight+(r.bottom-c.panelHeight-height)/2.0+c.panY));
+    c.view = {x,y,x+width,y+height};
     InvalidateRect(w, nullptr, FALSE);
 }
+void zoomCanvas(HWND w,Capture &c,double factor,POINT anchor,bool reset=false)
+{
+    if(!c.editing || c.dragging || c.panning) return;
+    double u=double(anchor.x-c.view.left)/std::max(1L,c.view.right-c.view.left);
+    double v=double(anchor.y-c.view.top)/std::max(1L,c.view.bottom-c.view.top);
+    double next=reset?1.0:std::clamp(c.zoom*factor,.1,16.0);
+    if(next==c.zoom && !reset) return;
+    c.zoom=next;
+    if(reset) c.panX=c.panY=0;
+    layout(w,c);
+    if(!reset) {
+        c.panX+=anchor.x-(c.view.left+u*(c.view.right-c.view.left));
+        c.panY+=anchor.y-(c.view.top+v*(c.view.bottom-c.view.top));
+        layout(w,c);
+    }
+    positionInlineText(c); updateStatus(c); InvalidateRect(w,nullptr,FALSE);
+}
 POINT imagePoint(Capture &c, POINT p, bool clamp = true)
 {
     POINT result{MulDiv(p.x-c.view.left,c.image->width,std::max(1L,c.view.right-c.view.left)),
@@ -650,6 +744,10 @@ std::pair<int,MarkPart> markAt(Capture &c, POINT p)
     if(c.selected>=0)
     {
         const auto &m=c.marks[c.selected];
+        if(m.shape!=ScreenshotShape::None) {
+            auto grip=screenshotShapeRotationHandle(m,double(c.unit)*c.image->width/std::max(1L,c.view.right-c.view.left));
+            if(std::hypot(double(p.x-grip.x),double(p.y-grip.y))<=tolerance) return {c.selected,MarkPart::Rotation};
+        }
         if(m.isText() || (m.isLine() && !m.label.empty())) {
             auto text=m.isText()?m:screenshotArrowLabel(m);
             auto grip=screenshotTextRotationHandle(text,double(c.unit*0.6)*c.image->width/std::max(1L,c.view.right-c.view.left));
@@ -673,7 +771,7 @@ HCURSOR toolCursor(const Capture &c)
     if(c.pointer) return LoadCursorW(nullptr,IDC_ARROW);
     if(c.textTool) return LoadCursorW(nullptr,IDC_IBEAM);
     if(c.freehand && c.pencilCursor) return c.pencilCursor;
-    int tool=c.highlight?19:c.straight?22:c.shape!=ScreenshotShape::None?22+int(c.shape):c.arrow?11:10;
+    int tool=c.highlight?19:c.straight?22:c.shape==ScreenshotShape::Trapezoid?37:c.shape==ScreenshotShape::Triangle?36:c.shape!=ScreenshotShape::None?22+int(c.shape):c.arrow?11:10;
     for(size_t i=0;i<std::size(CursorTools);++i)
         if(CursorTools[i]==tool && c.drawingCursors[i]) return c.drawingCursors[i];
     return LoadCursorW(nullptr,IDC_CROSS);
@@ -684,6 +782,7 @@ HCURSOR actionCursor(const Capture &c,std::pair<int,MarkPart> hit,bool inside)
     LPCWSTR cursor=nullptr;
     if(hit.second==MarkPart::Body || hit.second==MarkPart::Label) cursor=IDC_SIZEALL;
     else if(hit.second==MarkPart::Rotation) cursor=IDC_HAND;
+    else if(hit.second>=MarkPart::Vertex0 && hit.second<=MarkPart::Vertex2) cursor=IDC_SIZEALL;
     else if(hit.second==MarkPart::Radius) cursor=IDC_SIZEWE;
     else if(hit.second==MarkPart::Start || hit.second==MarkPart::End || hit.second==MarkPart::Thickness) {
         const auto &mark=c.marks[hit.first];
@@ -699,7 +798,7 @@ HCURSOR actionCursor(const Capture &c,std::pair<int,MarkPart> hit,bool inside)
 void captureCursor(HWND w, Capture &c)
 {
     POINT p; GetCursorPos(&p); ScreenToClient(w,&p);
-    bool inside=PtInRect(&c.view,p)!=FALSE;
+    bool inside=PtInRect(&c.view,p) && PtInRect(&c.canvas,p);
     auto hit=c.editing?(c.dragging?std::pair{c.selected,c.part}:markAt(c,imagePoint(c,p,false))):std::pair{-1,MarkPart::None};
     if(!c.dragging && !inside && hit.second!=MarkPart::Thickness && hit.second!=MarkPart::Rotation) hit={-1,MarkPart::None};
     SetCursor(actionCursor(c,hit,inside || c.dragging));
@@ -755,7 +854,18 @@ void drawHandles(HDC dc, const Capture &c)
         handle({m.from.x+m.radius,m.from.y});
     }
     else {
-        handle(m.from); handle(m.to);
+        if(m.shape==ScreenshotShape::Triangle) {
+            auto vertices=shapeOutline(m);
+            for(size_t i=0;i<3;++i) handle(vertices[i]);
+        } else { handle(rotateShapePoint(m,m.from)); handle(rotateShapePoint(m,m.to)); }
+        if(m.shape!=ScreenshotShape::None) {
+            auto r=region(m.from,m.to);
+            auto top=point(rotateShapePoint(m,{(r.left+r.right)/2,r.top}));
+            auto grip=screenshotShapeRotationHandle(m,double(c.unit)*c.image->width/std::max(1L,c.view.right-c.view.left));
+            auto end=point(grip); MoveToEx(dc,top.x,top.y,nullptr); LineTo(dc,end.x,end.y);
+            int radius=std::max(4,c.unit/8);
+            Ellipse(dc,end.x-radius,end.y-radius,end.x+radius+1,end.y+radius+1);
+        }
         auto [from,to]=thicknessSegment(m);
         auto mid=point({(from.x+to.x)/2,(from.y+to.y)/2});
         auto grip=thicknessHandle(c,m),end=point(grip);
@@ -771,7 +881,8 @@ void drawTool(const DRAWITEMSTRUCT &item, const Capture &c)
     RECT r=item.rcItem;
     bool active=(item.CtlID==27 && c.pointer)||(item.CtlID==10 && !c.pointer && !c.arrow && !c.highlight && !c.freehand && !c.textTool)||(item.CtlID==11 && c.arrow && !c.straight && c.shape==ScreenshotShape::None)||
                 (item.CtlID==19 && c.highlight)||(item.CtlID==21 && c.freehand)||
-                (item.CtlID==22 && c.straight)||(item.CtlID>=23 && item.CtlID<=25 && int(c.shape)==int(item.CtlID)-22)||(item.CtlID==26 && c.textTool);
+                (item.CtlID==22 && c.straight)||(item.CtlID>=23 && item.CtlID<=25 && int(c.shape)==int(item.CtlID)-22)||(item.CtlID==26 && c.textTool)||
+                (item.CtlID==36 && c.shape==ScreenshotShape::Triangle)||(item.CtlID==37 && c.shape==ScreenshotShape::Trapezoid);
     bool disabled=item.itemState&ODS_DISABLED;
     POINT mouse; GetCursorPos(&mouse); ScreenToClient(item.hwndItem,&mouse);
     bool hover=PtInRect(&r,mouse) && !disabled;
@@ -785,7 +896,16 @@ void drawTool(const DRAWITEMSTRUCT &item, const Capture &c)
     RoundRect(dc,r.left,r.top,r.right,r.bottom,corner,corner);
     SelectObject(dc,oldPen); SelectObject(dc,oldBrush); DeleteObject(pen); DeleteObject(brush);
     int iconIndex=item.CtlID==35?13:item.CtlID==34?14:item.CtlID>=22?int(item.CtlID)-13:item.CtlID==18?5:item.CtlID==19?6:item.CtlID==20?7:item.CtlID==21?8:item.CtlID-10;
-    auto icon=item.CtlID==27?(HICON)LoadCursorW(nullptr,IDC_ARROW):c.toolIcons[disabled?2:active?1:0][iconIndex];
+    auto icon=(item.CtlID==36 || item.CtlID==37)?nullptr:item.CtlID==27?(HICON)LoadCursorW(nullptr,IDC_ARROW):c.toolIcons[disabled?2:active?1:0][iconIndex];
+    if(item.CtlID==36 || item.CtlID==37) {
+        int cx=(r.left+r.right)/2,cy=(r.top+r.bottom)/2,s=c.iconSize/2;
+        auto trianglePen=CreatePen(PS_SOLID,std::max(1,MulDiv(2,GetDpiForWindow(item.hwndItem),96)),
+                                  disabled?RGB(148,163,184):active?RGB(37,99,235):RGB(51,65,85));
+        auto previous=SelectObject(dc,trianglePen);
+        if(item.CtlID==36) { POINT vertices[]{{cx,cy-s},{cx+s,cy+s},{cx-s,cy+s},{cx,cy-s}}; Polyline(dc,vertices,4); }
+        else { POINT vertices[]{{cx-s/2,cy-s},{cx+s/2,cy-s},{cx+s,cy+s},{cx-s,cy+s},{cx-s/2,cy-s}}; Polyline(dc,vertices,5); }
+        SelectObject(dc,previous); DeleteObject(trianglePen);
+    }
     if(icon) DrawIconEx(dc,(r.right-c.iconSize)/2,(r.bottom-c.iconSize)/2,icon,c.iconSize,c.iconSize,0,nullptr,DI_NORMAL);
     if(item.CtlID==20) {
         auto color=c.selected>=0?c.marks[c.selected].color:c.currentColor;
@@ -821,6 +941,64 @@ void copy(HWND w, Capture &c, DWORD (*publish)(HWND,const Clip &)=writeClipboard
     publish(c.app.window, clip);
     c.copied=true;
 }
+void saveToFile(HWND w, Capture &c, const std::filesystem::path &path)
+{
+    finishInlineText(w,c,true);
+    auto pixels=decodeImage(screenshotClip(c.image->dc,c.image->width,c.image->height,c.marks));
+    // GDI-rendered screenshot pixels are opaque; GDI does not maintain alpha.
+    for(size_t i=3;i<pixels.bgra.size();i+=4) pixels.bgra[i]=255;
+    auto bytes=encodePng(pixels);
+    GUID id{};
+    if(FAILED(CoCreateGuid(&id))) throw std::runtime_error("Cannot prepare screenshot output file");
+    wchar_t unique[40]{}; StringFromGUID2(id,unique,(int)std::size(unique));
+    auto temporary=path.parent_path()/(L".kswitcher-"+std::wstring(unique)+L".png");
+    try {
+        atomicWrite(temporary,bytes);
+        if(!MoveFileExW(temporary.c_str(),path.c_str(),MOVEFILE_REPLACE_EXISTING|MOVEFILE_WRITE_THROUGH))
+            throw std::runtime_error("Cannot save screenshot to the selected file");
+    } catch(...) {
+        std::error_code ignored; std::filesystem::remove(temporary,ignored); throw;
+    }
+    c.savedPath=path;
+    c.copied=true; // Current edits have been exported, either to file or clipboard.
+}
+void save(HWND w, Capture &c, bool saveAs=false,
+          BOOL (WINAPI *chooseFile)(LPOPENFILENAMEW)=GetSaveFileNameW)
+{
+    if(!saveAs && !c.savedPath.empty()) {
+        saveToFile(w,c,c.savedPath);
+        return;
+    }
+    wchar_t filename[32768]{};
+    auto proposed=c.savedPath.wstring();
+    if(proposed.empty()) {
+        SYSTEMTIME time{}; GetLocalTime(&time);
+        wchar_t name[100]{};
+        swprintf_s(name,L"Screenshot-%04u%02u%02u-%02u%02u%02u.png",
+                   time.wYear,time.wMonth,time.wDay,time.wHour,time.wMinute,time.wSecond);
+        proposed=name;
+    }
+    if(proposed.size()>=std::size(filename)) throw std::runtime_error("Screenshot file path is too long");
+    std::copy(proposed.begin(),proposed.end(),filename);
+    OPENFILENAMEW dialog{sizeof(dialog)};
+    dialog.hwndOwner=w;
+    dialog.lpstrTitle=L"Save screenshot";
+    dialog.lpstrFilter=L"PNG image (*.png)\0*.png\0\0";
+    dialog.nFilterIndex=1;
+    dialog.lpstrFile=filename;
+    dialog.nMaxFile=(DWORD)std::size(filename);
+    dialog.lpstrDefExt=L"png";
+    dialog.Flags=OFN_OVERWRITEPROMPT|OFN_PATHMUSTEXIST|OFN_NOCHANGEDIR|OFN_EXPLORER;
+    if(!chooseFile(&dialog)) {
+        if(CommDlgExtendedError()) throw std::runtime_error("Cannot open the screenshot save dialog");
+        return;
+    }
+    if(lower(std::filesystem::path(filename).extension().wstring())!=L".png")
+        throw std::runtime_error("Choose a filename ending in .png for the screenshot");
+    saveToFile(w,c,filename);
+    c.statusText=L"Saved: "+c.savedPath.wstring();
+    SendDlgItemMessageW(w,50,SB_SETTEXTW,0,(LPARAM)c.statusText.c_str());
+}
 void edit(HWND w, Capture &c)
 {
     auto r = region(c.start,c.end);
@@ -841,14 +1019,17 @@ void edit(HWND w, Capture &c)
     SetWindowLongPtrW(w,GWL_EXSTYLE,(GetWindowLongPtrW(w,GWL_EXSTYLE)|WS_EX_APPWINDOW)&~WS_EX_TOOLWINDOW);
     SetWindowLongPtrW(w,GWL_STYLE,WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN);
     auto title=L"KSwitcher — Screenshot #"+std::to_wstring(nextEditorIndex++);
-    SetWindowTextW(w,title.c_str());
+    SetWindowTextW(w,localBuildTitle(title).c_str());
     INITCOMMONCONTROLSEX statusControls{sizeof(statusControls),ICC_BAR_CLASSES};
     InitCommonControlsEx(&statusControls);
     CreateWindowExW(0,STATUSCLASSNAMEW,L"",WS_CHILD|WS_VISIBLE|SBARS_TOOLTIPS,
         0,0,0,0,w,(HMENU)50,c.app.instance,nullptr);
-    const wchar_t *labels[]{L"Pointer (V): select and edit objects", L"Number (N)", L"Arrow (A); Ctrl+drag between objects to link", L"Straight line (L); Ctrl+drag between objects to link", L"Rectangle (R)", L"Circle (O)", L"Ellipse (E)", L"Freehand line (F); Shift for 45-degree steps; move >50 px off line to turn; Ctrl to draw over objects", L"Highlight (H); Ctrl+drag to paint over an object",
+    const wchar_t *labels[]{L"Pointer (V): select and edit objects", L"Number (N)", L"Arrow (A); Ctrl+drag between objects to link", L"Straight line (L); Ctrl+drag between objects to link", L"Rectangle (R)", L"Circle (O)", L"Ellipse (E)", L"Triangle (G): drag to draw; drag each vertex to reshape", L"Trapezoid (B): drag to draw", L"Freehand line (F); Shift for 45-degree steps; move >50 px off line to turn; Ctrl to draw over objects", L"Highlight (H); Ctrl+drag to paint over an object",
         L"Text (T); double-click or F2 to edit", L"Color — selected object and new objects", L"Undo (Ctrl+Z)", L"Redo (Ctrl+Y / Ctrl+Shift+Z)", L"Copy (Ctrl+C)"};
     static_assert(std::size(labels)==std::size(ToolIds));
+    auto saveButton=CreateWindowW(L"BUTTON",L"Save...",WS_CHILD|WS_VISIBLE|WS_TABSTOP|BS_PUSHBUTTON,
+        0,0,0,0,w,(HMENU)28,c.app.instance,nullptr);
+    SetWindowSubclass(saveButton,toolHover,1,0);
     auto tips=CreateWindowExW(WS_EX_TOPMOST,TOOLTIPS_CLASSW,nullptr,WS_POPUP|TTS_ALWAYSTIP|TTS_NOPREFIX,
                              CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,w,nullptr,c.app.instance,nullptr);
     for (size_t i=0;i<std::size(ToolIds);++i)
@@ -938,7 +1119,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             }
             break;
         case WM_DRAWITEM:
-            if((wp>=10 && wp<=13) || (wp>=18 && wp<=27) || wp==34 || wp==35) { drawTool(*reinterpret_cast<DRAWITEMSTRUCT *>(lp),*c); return TRUE; }
+            if((wp>=10 && wp<=13) || (wp>=18 && wp<=27) || wp==34 || wp==35 || wp==36 || wp==37) { drawTool(*reinterpret_cast<DRAWITEMSTRUCT *>(lp),*c); return TRUE; }
             break;
         case WM_CTLCOLORSTATIC:
             SetBkColor((HDC)wp,RGB(255,255,255)); SetTextColor((HDC)wp,RGB(51,65,85));
@@ -1023,19 +1204,22 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 if(next!=value) { c->remember(c->marks); value=next; resolveScreenshotLinks(c->marks); }
             }
             if (LOWORD(wp)==13) { copy(w,*c); return 0; }
+            if (LOWORD(wp)==28 || LOWORD(wp)==29) {
+                save(w,*c,LOWORD(wp)==29); SetFocus(w); return 0;
+            }
             if (LOWORD(wp)==12 || LOWORD(wp)==18)
             {
                 bool changed=LOWORD(wp)==12?c->history.undo(c->marks):c->history.redo(c->marks);
                 if(changed) { c->copied=false; c->selected=-1; c->selectedLabel=false; c->wheelDelta=0; c->wheelTarget=-1; }
                 c->syncHistory();
             }
-            if (LOWORD(wp)==10 || LOWORD(wp)==11 || LOWORD(wp)==19 || (LOWORD(wp)>=21 && LOWORD(wp)<=27))
+            if (LOWORD(wp)==10 || LOWORD(wp)==11 || LOWORD(wp)==19 || LOWORD(wp)==36 || LOWORD(wp)==37 || (LOWORD(wp)>=21 && LOWORD(wp)<=27))
             {
                 c->pointer=LOWORD(wp)==27;
-                c->arrow = LOWORD(wp)==11 || (LOWORD(wp)>=22 && LOWORD(wp)<=25);
+                c->arrow = LOWORD(wp)==11 || LOWORD(wp)==36 || LOWORD(wp)==37 || (LOWORD(wp)>=22 && LOWORD(wp)<=25);
                 c->straight=LOWORD(wp)==22;
                 c->textTool=LOWORD(wp)==26;
-                c->shape=LOWORD(wp)>=23 && LOWORD(wp)<=25?ScreenshotShape(LOWORD(wp)-22):ScreenshotShape::None;
+                c->shape=LOWORD(wp)==37?ScreenshotShape::Trapezoid:LOWORD(wp)==36?ScreenshotShape::Triangle:LOWORD(wp)>=23 && LOWORD(wp)<=25?ScreenshotShape(LOWORD(wp)-22):ScreenshotShape::None;
                 c->selected=-1; c->selectedLabel=false;
                 c->highlight=LOWORD(wp)==19;
                 c->freehand=LOWORD(wp)==21;
@@ -1046,12 +1230,15 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 InvalidateRect(GetDlgItem(w,19),nullptr,FALSE);
                 InvalidateRect(GetDlgItem(w,21),nullptr,FALSE);
                 for(int id=22;id<=27;++id) InvalidateRect(GetDlgItem(w,id),nullptr,FALSE);
+                InvalidateRect(GetDlgItem(w,36),nullptr,FALSE);
+                InvalidateRect(GetDlgItem(w,37),nullptr,FALSE);
             }
 
             SetFocus(w); captureCursor(w,*c); InvalidateRect(w,nullptr,FALSE); return 0;
         case WM_KEYDOWN:
             if(wp==VK_SHIFT && c->editing && c->dragging && c->freehand && c->part==MarkPart::None && !c->strokeConstrained) {
                 c->strokeConstrained=true;
+                c->strokeUsedConstraint=true;
                 c->strokeAnchor=c->stroke.points.size()-1;
                 c->strokeAxis=0;
                 c->strokeAxisSettled=false;
@@ -1063,6 +1250,12 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             }
             if (c->editing && !c->dragging)
             {
+                if((GetKeyState(VK_CONTROL)&0x8000) &&
+                   (wp==VK_OEM_PLUS || wp==VK_ADD || wp==VK_OEM_MINUS || wp==VK_SUBTRACT || wp=='0' || wp==VK_NUMPAD0)) {
+                    POINT center{(c->canvas.left+c->canvas.right)/2,(c->canvas.top+c->canvas.bottom)/2};
+                    zoomCanvas(w,*c,wp==VK_OEM_MINUS || wp==VK_SUBTRACT?1/1.25:1.25,center,wp=='0' || wp==VK_NUMPAD0);
+                    return 0;
+                }
                 if(wp>=VK_LEFT && wp<=VK_DOWN && c->selected>=0 && !c->inlineText) {
                     POINT delta{wp==VK_LEFT?-1L:wp==VK_RIGHT?1L:0L,wp==VK_UP?-1L:wp==VK_DOWN?1L:0L};
                     const auto &original=c->marks[c->selected];
@@ -1079,6 +1272,9 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     beginMarkText(w,*c,c->selected); return 0;
                 }
                 if ((GetKeyState(VK_CONTROL)&0x8000) && wp=='C') { copy(w,*c); return 0; }
+                if ((GetKeyState(VK_CONTROL)&0x8000) && wp=='S') {
+                    save(w,*c,(GetKeyState(VK_SHIFT)&0x8000)!=0); SetFocus(w); return 0;
+                }
                 if ((GetKeyState(VK_CONTROL)&0x8000) && (wp=='Z' || wp=='Y'))
                     SendMessageW(w,WM_COMMAND,wp=='Y'||(GetKeyState(VK_SHIFT)&0x8000)?18:12,0);
                 if ((GetKeyState(VK_CONTROL)&0x8000) && wp=='D' && c->selected>=0)
@@ -1094,6 +1290,8 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     if(wp=='R') SendMessageW(w,WM_COMMAND,23,0);
                     if(wp=='O') SendMessageW(w,WM_COMMAND,24,0);
                     if(wp=='E') SendMessageW(w,WM_COMMAND,25,0);
+                    if(wp=='G') SendMessageW(w,WM_COMMAND,36,0);
+                    if(wp=='B') SendMessageW(w,WM_COMMAND,37,0);
                 }
                 if (wp=='N' || wp=='A') SendMessageW(w,WM_COMMAND,wp=='N'?10:11,0);
                 if(wp=='H') SendMessageW(w,WM_COMMAND,19,0);
@@ -1118,7 +1316,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
         case WM_LBUTTONDBLCLK:
             if(c->editing && !c->dragging) {
                 POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
-                if(PtInRect(&c->view,p)) {
+                if(PtInRect(&c->view,p) && PtInRect(&c->canvas,p)) {
                     auto [index,part]=markAt(*c,imagePoint(*c,p));
                     if(index>=0 && (c->marks[index].isText() || c->marks[index].isLine())) {
                         c->selected=index; beginMarkText(w,*c,index);
@@ -1128,8 +1326,10 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             return 0;
         case WM_LBUTTONDOWN:
         {
+            if(c->panning) return 0;
             finishInlineText(w,*c,true);
             POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
+            if(c->editing && !PtInRect(&c->canvas,p)) return 0;
             auto hitPart=c->editing?markAt(*c,imagePoint(*c,p,false)).second:MarkPart::None;
             bool thickness=hitPart==MarkPart::Thickness || hitPart==MarkPart::Rotation;
             if (c->editing && !PtInRect(&c->view,p) && !thickness)
@@ -1172,6 +1372,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     c->stroke.freehand=c->freehand; c->stroke.style=c->lineStyle; c->stroke.ends=c->freehandEnds;
                     c->stroke.points.push_back(p);
                     c->strokeConstrained=false;
+                    c->strokeUsedConstraint=(wp&MK_SHIFT)!=0;
                 }
                 c->dragging=true; SetCapture(w);
             }
@@ -1179,8 +1380,17 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
         }
         case WM_MOUSEWHEEL:
         {
-            if(!c->editing || c->dragging) return 0;
+            if(!c->editing || c->dragging || c->panning) return 0;
             POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)}; ScreenToClient(w,&p);
+            if(!PtInRect(&c->canvas,p)) return 0;
+            if(GET_KEYSTATE_WPARAM(wp)&MK_CONTROL) {
+                c->wheelDelta=0; c->wheelTarget=-1;
+                c->zoomWheelDelta+=GET_WHEEL_DELTA_WPARAM(wp);
+                int steps=c->zoomWheelDelta/WHEEL_DELTA; c->zoomWheelDelta%=WHEEL_DELTA;
+                if(steps) zoomCanvas(w,*c,std::pow(1.25,steps),p);
+                return 0;
+            }
+            c->zoomWheelDelta=0;
             if(!PtInRect(&c->view,p)) return 0;
             auto [index,part]=markAt(*c,imagePoint(*c,p));
             if(index<0) { c->wheelDelta=0; c->wheelTarget=-1; return 0; }
@@ -1200,8 +1410,27 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             }
             return 0;
         }
+        case WM_MBUTTONDOWN:
+        {
+            POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
+            if(c->editing && !c->dragging && PtInRect(&c->canvas,p)) {
+                c->panning=true; c->panOrigin=p; SetCapture(w); SetCursor(LoadCursorW(nullptr,IDC_SIZEALL));
+            }
+            return 0;
+        }
+        case WM_MBUTTONUP:
+            if(c->panning) { c->panning=false; ReleaseCapture(); captureCursor(w,*c); }
+            return 0;
         case WM_MOUSEMOVE:
         case WM_LBUTTONUP:
+            if(c->panning) {
+                if(msg==WM_MOUSEMOVE) {
+                    POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
+                    c->panX+=p.x-c->panOrigin.x; c->panY+=p.y-c->panOrigin.y; c->panOrigin=p;
+                    layout(w,*c); positionInlineText(*c); SetCursor(LoadCursorW(nullptr,IDC_SIZEALL));
+                }
+                return 0;
+            }
             if (c->dragging)
             {
                 POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
@@ -1210,6 +1439,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     c->end=constrainScreenshotShape(c->shape,c->start,c->end,c->image->width,c->image->height);
                 if(c->editing && (c->highlight || c->freehand) && c->part==MarkPart::None) {
                     bool constrained=c->freehand && ((wp&MK_SHIFT) || (GetKeyState(VK_SHIFT)&0x8000));
+                    c->strokeUsedConstraint=c->strokeUsedConstraint || constrained;
                     if(constrained) {
                         if(!c->strokeConstrained) {
                             c->strokeAnchor=c->stroke.points.size()-1;
@@ -1303,6 +1533,23 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                             linkScreenshotEndpoint(mark,false,c->end,c->marks,6);
                             resolveScreenshotLinks(c->marks);
                         }
+                        if(c->freehand && !c->strokeUsedConstraint &&
+                           !c->marks.back().fromNumber && !c->marks.back().toNumber &&
+                           !c->marks.back().fromLink.target && !c->marks.back().toLink.target) {
+                            ScreenshotShape recognized{};
+                            auto improved=improveScreenshotStroke(c->marks.back().points,&recognized);
+                            if(!improved.empty()) {
+                                c->remember(c->marks);
+                                auto &mark=c->marks.back();
+                                mark.points=std::move(improved);
+                                mark.from=mark.points.front(); mark.to=mark.points.back();
+                                if(recognized!=ScreenshotShape::None) {
+                                    mark.shape=recognized; mark.freehand=false; mark.ends=LineEnds::None;
+                                    auto bounds=markBounds(mark);
+                                    mark.from={bounds.left,bounds.top}; mark.to={bounds.right,bounds.bottom};
+                                }
+                            }
+                        }
                         c->selected=int(c->marks.size())-1; c->selectedLabel=false;
                     }
                     else if (std::hypot(double(c->end.x-c->start.x),double(c->end.y-c->start.y))>=4)
@@ -1313,6 +1560,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                         c->marks.back().style=c->lineStyle; c->marks.back().ends=c->straight || c->shape!=ScreenshotShape::None?LineEnds::None:c->arrowEnds;
                         c->marks.back().shape=c->shape;
                         auto &mark=c->marks.back();
+                        if(mark.shape==ScreenshotShape::Triangle || mark.shape==ScreenshotShape::Trapezoid) mark.points=shapeOutline(mark);
                         linkScreenshotEndpoint(mark,true,c->start,c->marks,6);
                         linkScreenshotEndpoint(mark,false,c->end,c->marks,6);
                         resolveScreenshotLinks(c->marks);
@@ -1325,6 +1573,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             captureCursor(w,*c);
             return 0;
         case WM_CAPTURECHANGED:
+            c->panning=false;
             if(c->dragging && c->part!=MarkPart::None)
             {
                 c->marks=std::move(c->beforeDrag); c->part=MarkPart::None;
@@ -1334,7 +1583,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             if (c->editing)
             {
                 auto limits = reinterpret_cast<MINMAXINFO *>(lp);
-                limits->ptMinTrackSize = {MulDiv(650,GetDpiForWindow(w),96),MulDiv(240,GetDpiForWindow(w),96)};
+                limits->ptMinTrackSize = {MulDiv(730,GetDpiForWindow(w),96),MulDiv(240,GetDpiForWindow(w),96)};
                 return 0;
             }
             break;
@@ -1384,7 +1633,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     auto previous=SelectObject(buffer,divider);
                     MoveToEx(buffer,0,c->panelHeight-1,nullptr); LineTo(buffer,client.right,c->panelHeight-1);
                     int dpi=GetDpiForWindow(w);
-                    for(int x:{368,452}) {
+                    for(int x:{440,524}) {
                         MoveToEx(buffer,MulDiv(x,dpi,96),MulDiv(13,dpi,96),nullptr);
                         LineTo(buffer,MulDiv(x,dpi,96),MulDiv(31,dpi,96));
                     }
@@ -1402,9 +1651,12 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                     }
                     drawMarks(rendered.dc,visibleMarks,c->dragging && c->part==MarkPart::None?((c->highlight || c->freehand)?&c->stroke:&preview):nullptr);
                     SetStretchBltMode(buffer,HALFTONE); SetBrushOrgEx(buffer,0,0,nullptr);
+                    int savedCanvas=SaveDC(buffer);
+                    IntersectClipRect(buffer,c->canvas.left,c->canvas.top,c->canvas.right,c->canvas.bottom);
                     StretchBlt(buffer,c->view.left,c->view.top,c->view.right-c->view.left,c->view.bottom-c->view.top,
                                rendered.dc,0,0,rendered.width,rendered.height,SRCCOPY);
                     drawHandles(buffer,*c);
+                    RestoreDC(buffer,savedCanvas);
                     BitBlt(dc,0,0,width,height,buffer,0,0,SRCCOPY);
                 }
             }
@@ -1449,6 +1701,11 @@ POINT screenshotTextRotationHandle(const ScreenshotMark &m,double clearance)
     auto r=plainTextBounds(m);
     return rotateTextPoint(m,{(r.left+r.right)/2,r.top-LONG(std::lround(clearance))});
 }
+POINT screenshotShapeRotationHandle(const ScreenshotMark &m,double clearance)
+{
+    auto r=region(m.from,m.to);
+    return rotateShapePoint(m,{(r.left+r.right)/2,r.top-LONG(std::lround(clearance))});
+}
 ScreenshotMark screenshotArrowLabel(const ScreenshotMark &m)
 {
     ScreenshotMark label{{0,0},{0,0},0};
@@ -1528,23 +1785,23 @@ void assignMarkIds(std::vector<ScreenshotMark> &marks)
 }
 POINT objectAnchor(const ScreenshotMark &m,const ScreenshotLink &link)
 {
-    if(m.isText() || m.shape!=ScreenshotShape::None) {
+    if(m.isText() || (m.shape!=ScreenshotShape::None && m.points.empty())) {
         auto r=m.isText()?plainTextBounds(m):region(m.from,m.to);
         POINT p{LONG(std::lround(r.left+(r.right-r.left)*link.u)),LONG(std::lround(r.top+(r.bottom-r.top)*link.v))};
-        return m.isText()?rotateTextPoint(m,p):p;
+        return m.isText()?rotateTextPoint(m,p):rotateShapePoint(m,p);
     }
     size_t segments=m.points.size()>1?m.points.size()-1:1;
     double along=std::clamp(link.u,0.0,1.0)*segments;
     size_t i=std::min(size_t(along),segments-1); double t=along-i;
     POINT a=m.points.size()>1?m.points[i]:m.from,b=m.points.size()>1?m.points[i+1]:m.to;
-    return {LONG(std::lround(a.x+(b.x-a.x)*t)),LONG(std::lround(a.y+(b.y-a.y)*t))};
+    return rotateShapePoint(m,{LONG(std::lround(a.x+(b.x-a.x)*t)),LONG(std::lround(a.y+(b.y-a.y)*t))});
 }
 bool findObjectAnchor(const ScreenshotMark &m,POINT drop,double tolerance,ScreenshotLink &link)
 {
     link={m.id,0,0};
-    if(m.isText() || m.shape!=ScreenshotShape::None) {
+    if(m.isText() || (m.shape!=ScreenshotShape::None && m.points.empty())) {
         auto r=m.isText()?plainTextBounds(m):region(m.from,m.to);
-        POINT p=m.isText()?rotateTextPoint(m,drop,-1):drop;
+        POINT p=m.isText()?rotateTextPoint(m,drop,-1):rotateShapePoint(m,drop,-1);
         double w=std::max(1L,r.right-r.left),h=std::max(1L,r.bottom-r.top);
         double x=(p.x-r.left)/w,y=(p.y-r.top)/h;
         bool inside=x>=0 && x<=1 && y>=0 && y<=1;
@@ -1564,6 +1821,7 @@ bool findObjectAnchor(const ScreenshotMark &m,POINT drop,double tolerance,Screen
         auto anchor=objectAnchor(m,link);
         return inside || std::hypot(double(drop.x-anchor.x),double(drop.y-anchor.y))<=tolerance;
     }
+    drop=rotateShapePoint(m,drop,-1);
     double best=1e100;
     size_t segments=m.points.size()>1?m.points.size()-1:1;
     for(size_t i=0;i<segments;++i) {
@@ -1648,6 +1906,13 @@ void resolveScreenshotLinks(std::vector<ScreenshotMark> &marks)
 }
 MarkPart hitScreenshotMark(const ScreenshotMark &m, POINT p, double tolerance)
 {
+    if(m.shape==ScreenshotShape::Triangle) {
+        auto vertices=shapeOutline(m);
+        for(int i=0;i<3;++i)
+            if(std::hypot(double(p.x-vertices[i].x),double(p.y-vertices[i].y))<=tolerance)
+                return MarkPart(int(MarkPart::Vertex0)+i);
+    }
+    p=rotateShapePoint(m,p,-1);
     if(m.isText()) {
         auto r=plainTextBounds(m);
         auto local=rotateTextPoint(m,p,-1);
@@ -1658,8 +1923,10 @@ MarkPart hitScreenshotMark(const ScreenshotMark &m, POINT p, double tolerance)
     auto distance=[](POINT a, POINT b) { return std::hypot(double(a.x-b.x),double(a.y-b.y)); };
     if(!m.points.empty())
     {
-        if(m.freehand && distance(p,m.from)<=tolerance) return MarkPart::Start;
+        if(m.shape!=ScreenshotShape::Triangle) {
-        if(m.freehand && distance(p,m.to)<=tolerance) return MarkPart::End;
+            if((m.freehand || m.shape!=ScreenshotShape::None) && distance(p,m.from)<=tolerance) return MarkPart::Start;
+            if((m.freehand || m.shape!=ScreenshotShape::None) && distance(p,m.to)<=tolerance) return MarkPart::End;
+        }
         double reach=tolerance+std::clamp(m.thickness,m.isHighlight()?4:1,m.isHighlight()?100:30)/2.0;
         POINT from=m.points.front();
         for(auto to:m.points) {
@@ -1713,7 +1980,32 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
 {
     auto m=original;
     if(position.x==origin.x && position.y==origin.y) return m;
-    if(part==MarkPart::Rotation && (m.isText() || (m.isLine() && !m.label.empty()))) {
+    if(part>=MarkPart::Vertex0 && part<=MarkPart::Vertex2 && m.shape==ScreenshotShape::Triangle) {
+        if(m.points.empty()) { auto local=m; local.rotation=0; m.points=shapeOutline(local); }
+        size_t index=size_t(int(part)-int(MarkPart::Vertex0)),fixed=(index+1)%3;
+        auto fixedWorld=rotateShapePoint(m,m.points[fixed]);
+        auto vertexWorld=rotateShapePoint(m,m.points[index]);
+        POINT target{std::clamp(vertexWorld.x+position.x-origin.x,0L,LONG(width-1)),
+                     std::clamp(vertexWorld.y+position.y-origin.y,0L,LONG(height-1))};
+        m.points[index]=rotateShapePoint(m,target,-1); m.points[3]=m.points[0];
+        RECT bounds{m.points[0].x,m.points[0].y,m.points[0].x,m.points[0].y};
+        for(size_t i=1;i<3;++i) {auto p=m.points[i]; bounds.left=std::min(bounds.left,p.x); bounds.right=std::max(bounds.right,p.x);
+            bounds.top=std::min(bounds.top,p.y); bounds.bottom=std::max(bounds.bottom,p.y);}
+        m.from={bounds.left,bounds.top}; m.to={bounds.right,bounds.bottom};
+        auto shifted=rotateShapePoint(m,m.points[fixed]);
+        LONG dx=fixedWorld.x-shifted.x,dy=fixedWorld.y-shifted.y;
+        m.from.x+=dx; m.to.x+=dx; m.from.y+=dy; m.to.y+=dy;
+        for(auto &p:m.points) {p.x+=dx;p.y+=dy;}
+    }
+    else if(part==MarkPart::Rotation && m.shape!=ScreenshotShape::None) {
+        double cx=(m.from.x+m.to.x)/2.0,cy=(m.from.y+m.to.y)/2.0;
+        if(std::hypot(position.x-cx,position.y-cy)<1) return m;
+        double a=std::atan2(origin.y-cy,origin.x-cx),b=std::atan2(position.y-cy,position.x-cx);
+        m.rotation+=(b-a)*180/3.141592653589793;
+        if(snapRotation) m.rotation=std::round(m.rotation/15)*15;
+        m.rotation=std::remainder(m.rotation,360);
+    }
+    else if(part==MarkPart::Rotation && (m.isText() || (m.isLine() && !m.label.empty()))) {
         if(position.x==origin.x && position.y==origin.y) return m;
         auto text=m.isText()?m:screenshotArrowLabel(m);
         auto r=plainTextBounds(text);
@@ -1767,13 +2059,34 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
     }
     else if(part==MarkPart::Start || part==MarkPart::End)
     {
+        origin=rotateShapePoint(original,origin,-1);
+        position=rotateShapePoint(original,position,-1);
         (part==MarkPart::Start?m.fromNumber:m.toNumber)=0;
         (part==MarkPart::Start?m.fromLink:m.toLink)={};
         auto &endpoint=part==MarkPart::Start?m.from:m.to;
         endpoint.x=std::clamp(endpoint.x+position.x-origin.x,0L,LONG(width-1));
         endpoint.y=std::clamp(endpoint.y+position.y-origin.y,0L,LONG(height-1));
         endpoint=constrainScreenshotShape(m.shape,part==MarkPart::Start?m.to:m.from,endpoint,width,height);
+        if(m.shape!=ScreenshotShape::None && !m.points.empty()) {
+            if(m.from.x==m.to.x || m.from.y==m.to.y) return original;
+            // Resize the entire recognized outline, not just a pencil endpoint.
+            // Keep the opposite corner fixed, including when dragging across it.
+            double oldWidth=original.to.x-original.from.x,oldHeight=original.to.y-original.from.y;
+            for(auto &point:m.points) {
+                double u=oldWidth?(point.x-original.from.x)/oldWidth:0;
+                double v=oldHeight?(point.y-original.from.y)/oldHeight:0;
+                point={LONG(std::lround(m.from.x+u*(m.to.x-m.from.x))),
+                       LONG(std::lround(m.from.y+v*(m.to.y-m.from.y)))};
+            }
+        }
         if(m.freehand && !m.points.empty()) (part==MarkPart::Start?m.points.front():m.points.back())=endpoint;
+        if(m.shape!=ScreenshotShape::None && m.rotation!=0) {
+            auto fixedBefore=rotateShapePoint(original,part==MarkPart::Start?original.to:original.from);
+            auto fixedAfter=rotateShapePoint(m,part==MarkPart::Start?m.to:m.from);
+            LONG dx=fixedBefore.x-fixedAfter.x,dy=fixedBefore.y-fixedAfter.y;
+            m.from.x+=dx; m.to.x+=dx; m.from.y+=dy; m.to.y+=dy;
+            for(auto &p:m.points) {p.x+=dx;p.y+=dy;}
+        }
     }
     return m;
 }

src/screenshot.h

@@ -15,7 +15,7 @@ void showScreenshot(ScreenshotHost &);
 void showScreenshotEditor(ScreenshotHost &,const Clip &);
 enum class LineStyle { Solid, Dotted, Dashed, DashDot };
 enum class LineEnds { End, Start, Both, None };
-enum class ScreenshotShape { None, Rectangle, Circle, Ellipse };
+enum class ScreenshotShape { None, Rectangle, Circle, Ellipse, Triangle, Trapezoid };
 struct ScreenshotOffset { double x, y; };
 struct ScreenshotLink {
     unsigned long long target{};
@@ -40,7 +40,7 @@ struct ScreenshotMark {
     unsigned long long id{};
     ScreenshotLink fromLink, toLink;
     bool isText() const { return !text.empty(); }
-    bool isHighlight() const { return !points.empty() && !freehand; }
+    bool isHighlight() const { return !points.empty() && !freehand && shape==ScreenshotShape::None; }
     bool isLine() const { return !number && !isText() && !isHighlight() && shape==ScreenshotShape::None; }
 };
 class ScreenshotHistory {
@@ -55,7 +55,7 @@ class ScreenshotHistory {
 void resolveScreenshotLinks(std::vector<ScreenshotMark> &);
 void linkScreenshotEndpoint(ScreenshotMark &, bool start, POINT drop,
                             std::vector<ScreenshotMark> &, double tolerance);
-enum class MarkPart { None, Body, Start, End, Radius, Thickness, Rotation, Label };
+enum class MarkPart { None, Body, Start, End, Radius, Thickness, Rotation, Label, Vertex0, Vertex1, Vertex2 };
 POINT screenshotThicknessHandle(const ScreenshotMark &, double clearance = 16);
 ScreenshotMark cloneScreenshotMark(const ScreenshotMark &, const std::vector<ScreenshotMark> &, int width, int height);
 int nextScreenshotNumber(const std::vector<ScreenshotMark> &);
@@ -65,6 +65,7 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &, MarkPart, POINT origin
 POINT constrainScreenshotShape(ScreenshotShape, POINT anchor, POINT position, int width, int height);
 RECT screenshotTextBounds(const ScreenshotMark &);
 POINT screenshotTextRotationHandle(const ScreenshotMark &, double clearance=24);
+POINT screenshotShapeRotationHandle(const ScreenshotMark &, double clearance=32);
 ScreenshotMark screenshotArrowLabel(const ScreenshotMark &);
 // Render at source resolution; never reads or writes the system clipboard.
 Clip screenshotClip(HDC source, int width, int height, const std::vector<ScreenshotMark> &marks);

src/screenshot_launcher.cpp

@@ -1,13 +1,15 @@
 #include "app.h"
+#include "screenshot_notifications.h"
 
 namespace ks {
-void launchScreenshot(App &app)
+static void launch(App &app, const Clip *clip)
 {
     auto path=std::filesystem::path(executable()).parent_path()/L"KSwitcher.Screenshot.exe";
     if (!std::filesystem::exists(path))
         throw std::runtime_error("KSwitcher.Screenshot.exe is missing. Extract the complete application package.");
-    auto command=L"\""+path.wstring()+L"\" --auto-open-editor="+
+    auto command=L"\""+path.wstring()+L"\" ";
-        (app.settings.screenshotAutoOpenEditor?L"1":L"0");
+    if(clip) command+=L"--open kswitcher-screenshot:"+cacheScreenshotForEditor(*clip);
+    else command+=std::wstring(L"--auto-open-editor=")+(app.settings.screenshotAutoOpenEditor?L"1":L"0");
     if(app.settings.writeLog) command+=L" --write-log";
     STARTUPINFOW startup{sizeof(startup)};
     PROCESS_INFORMATION process{};
@@ -20,4 +22,6 @@ void launchScreenshot(App &app)
     CloseHandle(process.hThread);
     CloseHandle(process.hProcess);
 }
+void launchScreenshot(App &app) { launch(app,nullptr); }
+void launchScreenshotEditor(App &app,const Clip &clip) { launch(app,&clip); }
 }

src/screenshot_notifications.cpp

@@ -112,6 +112,19 @@ std::wstring escapeXml(const std::wstring &s)
     return result;
 }
 }
+std::wstring cacheScreenshotForEditor(const Clip &clip)
+{
+    // Normalize PNG/DIBV5 and other supported clipboard images at full resolution.
+    auto pixels=decodeImage(clip);
+    if(pixels.bgra.empty() || pixels.bgra.size()>128*1024*1024-sizeof(BITMAPINFOHEADER))
+        throw std::runtime_error("Image is too large for the screenshot editor");
+    auto dib=imageDib(pixels);
+    auto directory=cacheDirectory(); cleanCache(directory);
+    GUID guid{}; check(CoCreateGuid(&guid)); wchar_t value[40]{}; StringFromGUID2(guid,value,40);
+    std::wstring id(value+1,36);
+    atomicWrite(directory/(id+L".capture"),protect(dib.data));
+    return id;
+}
 Clip loadNotifiedScreenshot(const std::wstring &id)
 {
     if(!validScreenshotToken(id)) throw std::runtime_error("Invalid screenshot notification");

src/screenshot_notifications.h

@@ -8,4 +8,5 @@ int runScreenshotToastActivator();
 DWORD startScreenshotActivationListener();
 bool validScreenshotToken(const std::wstring &);
 Clip loadNotifiedScreenshot(const std::wstring &);
+std::wstring cacheScreenshotForEditor(const Clip &);
 }

src/stroke_improvement.h

@@ -0,0 +1,218 @@
+#pragma once
+#include "screenshot.h"
+#include <algorithm>
+#include <cmath>
+#include <vector>
+
+namespace ks::stroke_detail {
+struct Point { double x, y; };
+inline double distance(Point a, Point b) { return std::hypot(a.x-b.x,a.y-b.y); }
+inline double length(const std::vector<Point> &p) {
+    double total=0;
+    for(size_t i=1;i<p.size();++i) total+=distance(p[i-1],p[i]);
+    return total;
+}
+// Arc-length sampling makes fitting independent of mouse speed and bounds its cost.
+inline std::vector<Point> sample(const std::vector<Point> &p, size_t count) {
+    std::vector<Point> out{p.front()};
+    double step=length(p)/(count-1), traversed=0;
+    size_t segment=1;
+    for(size_t i=1;i+1<count;++i) {
+        double target=i*step;
+        while(segment+1<p.size() && traversed+distance(p[segment-1],p[segment])<target) {
+            traversed+=distance(p[segment-1],p[segment]); ++segment;
+        }
+        double span=distance(p[segment-1],p[segment]);
+        double t=span>0?(target-traversed)/span:0;
+        out.push_back({p[segment-1].x+t*(p[segment].x-p[segment-1].x),
+                       p[segment-1].y+t*(p[segment].y-p[segment-1].y)});
+    }
+    out.push_back(p.back()); return out;
+}
+inline double segmentDistance(Point p, Point a, Point b) {
+    double dx=b.x-a.x,dy=b.y-a.y,den=dx*dx+dy*dy;
+    double t=den?std::clamp(((p.x-a.x)*dx+(p.y-a.y)*dy)/den,0.0,1.0):0;
+    return distance(p,{a.x+t*dx,a.y+t*dy});
+}
+inline double cross(Point a, Point b, Point c) { return (b.x-a.x)*(c.y-a.y)-(b.y-a.y)*(c.x-a.x); }
+}
+
+namespace ks {
+// Returns a replacement path; an empty result means no visible improvement.
+// Report recognized geometry separately from a smoothed freehand path.
+inline std::vector<POINT> improveScreenshotStroke(const std::vector<POINT> &input, ScreenshotShape *shape=nullptr) {
+    if(shape) *shape=ScreenshotShape::None;
+    using namespace stroke_detail;
+    if(input.size()<5) return {};
+    std::vector<Point> raw;
+    for(auto p:input) if(raw.empty() || distance(raw.back(),{double(p.x),double(p.y)})>0)
+        raw.push_back({double(p.x),double(p.y)});
+    double total=length(raw);
+    if(raw.size()<5 || total<16) return {};
+    auto points=sample(raw,128);
+    double left=points[0].x,right=left,top=points[0].y,bottom=top;
+    for(auto p:points) { left=std::min(left,p.x); right=std::max(right,p.x); top=std::min(top,p.y); bottom=std::max(bottom,p.y); }
+    double scale=std::min(right-left,bottom-top);
+    std::vector<Point> best;
+    double bestScore=1e30;
+    double gap=distance(raw.front(),raw.back());
+    if(scale>=20 && gap<=scale*.5) {
+        auto consider=[&](std::vector<Point> candidate, ScreenshotShape kind=ScreenshotShape::Rectangle) {
+            bool oval=kind==ScreenshotShape::Circle || kind==ScreenshotShape::Ellipse;
+            if(!oval && gap>scale*.22) return;
+            double perimeter=length(candidate);
+            if(total<perimeter*.82 || total>perimeter*1.25) return;
+            auto probes=sample(candidate,128);
+            double sum=0,maximum=0;
+            auto measure=[&](const std::vector<Point> &a,const std::vector<Point> &b) {
+                for(auto p:a) {
+                    double d=1e30;
+                    for(size_t i=1;i<b.size();++i) d=std::min(d,segmentDistance(p,b[i-1],b[i]));
+                    sum+=d*d; maximum=std::max(maximum,d);
+                }
+            };
+            measure(points,candidate); measure(probes,points);
+            double score=std::sqrt(sum/256);
+            if(maximum<=std::max(3.0,scale*(oval?.22:.12)) && score<=std::max(1.5,scale*(oval?.085:.055)) && score<bestScore) {
+                bestScore=score; best=std::move(candidate);
+                if(shape) *shape=kind;
+            }
+        };
+        // Fit oriented bounding boxes; testing angles also handles tilted ovals.
+        for(int degrees=0;degrees<180;degrees+=5) {
+            double angle=degrees*3.141592653589793/180,cs=std::cos(angle),sn=std::sin(angle);
+            double x0=1e30,y0=x0,x1=-x0,y1=-x0;
+            for(auto p:points) {
+                double x=p.x*cs+p.y*sn,y=-p.x*sn+p.y*cs;
+                x0=std::min(x0,x); x1=std::max(x1,x); y0=std::min(y0,y); y1=std::max(y1,y);
+            }
+            auto world=[&](double x,double y)->Point { return {x*cs-y*sn,x*sn+y*cs}; };
+            consider({world(x0,y0),world(x1,y0),world(x1,y1),world(x0,y1),world(x0,y0)});
+            double rx=(x1-x0)/2,ry=(y1-y0)/2;
+            double cx=(x0+x1)/2,cy=(y0+y1)/2;
+            std::vector<Point> local;
+            for(auto p:points) local.push_back({p.x*cs+p.y*sn,-p.x*sn+p.y*cs});
+            // Fit four sides to their supporting samples. Extremal bounds exaggerate
+            // crooked corners and can unfairly make an oval score better than a box.
+            double sides[]{x0,x1,y0,y1};
+            bool supported=true;
+            for(int iteration=0;iteration<6;++iteration) {
+                double sums[4]{}; int counts[4]{};
+                for(auto p:local) {
+                    double distances[]{std::abs(p.x-sides[0]),std::abs(p.x-sides[1]),
+                                       std::abs(p.y-sides[2]),std::abs(p.y-sides[3])};
+                    auto side=std::min_element(distances,distances+4)-distances;
+                    sums[side]+=side<2?p.x:p.y; ++counts[side];
+                }
+                for(int side=0;side<4;++side) {
+                    if(counts[side]<10) { supported=false; break; }
+                    sides[side]=sums[side]/counts[side];
+                }
+                if(!supported) break;
+            }
+            if(supported && sides[1]-sides[0]>=16 && sides[3]-sides[2]>=16)
+                consider({world(sides[0],sides[2]),world(sides[1],sides[2]),
+                          world(sides[1],sides[3]),world(sides[0],sides[3]),world(sides[0],sides[2])});
+            // Fit the whole gesture instead of letting a single mouse wobble set the bounds.
+            auto error=[&](double x,double y,double a,double b) {
+                if(a<8 || b<8) return 1e30;
+                double sum=0;
+                for(auto p:local) {
+                    double u=(p.x-x)/a,v=(p.y-y)/b,r=std::hypot(u,v);
+                    double normal=std::hypot(u/a,v/b);
+                    double d=normal>1e-9?(r-1)*r/normal:std::min(a,b);
+                    sum+=d*d;
+                }
+                return sum;
+            };
+            double fit=error(cx,cy,rx,ry),step=std::max(rx,ry)*.08;
+            for(int iteration=0;iteration<10;++iteration) {
+                for(int parameter=0;parameter<4;++parameter) for(int sign:{-1,1}) {
+                    double values[]{cx,cy,rx,ry}; values[parameter]+=sign*step;
+                    double next=error(values[0],values[1],values[2],values[3]);
+                    if(next<fit) { fit=next; cx=values[0]; cy=values[1]; rx=values[2]; ry=values[3]; }
+                }
+                step*=.65;
+            }
+            // Require almost one complete turn, with little retracing. This admits a small
+            // closing gap or overshoot but rejects C-shaped arcs, spirals and scribbles.
+            double turn=0,travel=0;
+            for(size_t i=1;i<local.size();++i) {
+                double a=std::atan2((local[i-1].y-cy)/ry,(local[i-1].x-cx)/rx);
+                double b=std::atan2((local[i].y-cy)/ry,(local[i].x-cx)/rx);
+                double delta=std::remainder(b-a,2*3.141592653589793);
+                turn+=delta; travel+=std::abs(delta);
+            }
+            if(std::abs(turn)<5.4 || std::abs(turn)>7.1 || travel-std::abs(turn)>.65) continue;
+            // Near-circular gestures become true circles.
+            bool circle=std::abs(rx-ry)<=std::max(rx,ry)*.12;
+            if(circle) rx=ry=(rx+ry)/2;
+            std::vector<Point> oval;
+            for(int i=0;i<96;++i) {
+                double t=i*2*3.141592653589793/96;
+                oval.push_back(world(cx+rx*std::cos(t),cy+ry*std::sin(t)));
+            }
+            oval.push_back(oval.front()); consider(std::move(oval),circle?ScreenshotShape::Circle:ScreenshotShape::Ellipse);
+        }
+        auto sorted=points;
+        std::sort(sorted.begin(),sorted.end(),[](Point a,Point b){return a.x<b.x || (a.x==b.x && a.y<b.y);});
+        std::vector<Point> hull;
+        for(auto p:sorted) {
+            while(hull.size()>1 && cross(hull[hull.size()-2],hull.back(),p)<=0) hull.pop_back();
+            hull.push_back(p);
+        }
+        size_t lower=hull.size();
+        for(size_t i=sorted.size()-1;i-->0;) {
+            auto p=sorted[i];
+            while(hull.size()>lower && cross(hull[hull.size()-2],hull.back(),p)<=0) hull.pop_back();
+            hull.push_back(p);
+        }
+        hull.pop_back();
+        while(hull.size()>3) {
+            if(hull.size()==4 && bestScore>scale*.035) {
+                // Opposite edges must already be nearly parallel; retain their unequal
+                // lengths and fit a shared direction instead of accepting any quadrilateral.
+                for(size_t i=0;i<2;++i) {
+                    Point a=hull[i],b=hull[i+1],c=hull[(i+2)%4],d=hull[(i+3)%4];
+                    double ab=distance(a,b),cd=distance(c,d);
+                    if(std::min(ab,cd)<16 || std::min(ab,cd)/std::max(ab,cd)>.8) continue;
+                    Point u{(b.x-a.x)/ab,(b.y-a.y)/ab},v{(c.x-d.x)/cd,(c.y-d.y)/cd};
+                    if(u.x*v.x+u.y*v.y<.96) continue;
+                    double norm=std::hypot(u.x+v.x,u.y+v.y);
+                    Point axis{(u.x+v.x)/norm,(u.y+v.y)/norm};
+                    auto along=[&](Point p){return p.x*axis.x+p.y*axis.y;};
+                    auto across=[&](Point p){return -p.x*axis.y+p.y*axis.x;};
+                    double y0=(across(a)+across(b))/2,y1=(across(c)+across(d))/2;
+                    if(std::abs(y1-y0)<20) continue;
+                    auto fit=[&](Point p,double y)->Point {double x=along(p);return {x*axis.x-y*axis.y,x*axis.y+y*axis.x};};
+                    std::vector<Point> candidate{fit(a,y0),fit(b,y0),fit(c,y1),fit(d,y1),fit(a,y0)};
+                    consider(std::move(candidate),ScreenshotShape::Trapezoid);
+                }
+            }
+            size_t remove=0; double area=1e30;
+            for(size_t i=0;i<hull.size();++i) {
+                double a=std::abs(cross(hull[(i+hull.size()-1)%hull.size()],hull[i],hull[(i+1)%hull.size()]));
+                if(a<area) { area=a; remove=i; }
+            }
+            hull.erase(hull.begin()+remove);
+        }
+        if(hull.size()==3) { hull.push_back(hull.front()); consider(hull,ScreenshotShape::Triangle); }
+    }
+    if(best.empty()) {
+        // A small spatial filter suppresses jitter without moving endpoints or flattening broad curves.
+        best=sample(raw,size_t(std::clamp(std::ceil(total/2)+1,5.0,2048.0)));
+        auto original=best;
+        for(size_t i=1;i+1<best.size();++i)
+            best[i]={(original[i-1].x+2*original[i].x+original[i+1].x)/4,
+                     (original[i-1].y+2*original[i].y+original[i+1].y)/4};
+    }
+    std::vector<POINT> result;
+    for(auto p:best) {
+        POINT q{LONG(std::lround(p.x)),LONG(std::lround(p.y))};
+        if(result.empty() || result.back().x!=q.x || result.back().y!=q.y) result.push_back(q);
+    }
+    if(result.size()==input.size() && std::equal(result.begin(),result.end(),input.begin(),
+       [](POINT a,POINT b){return a.x==b.x && a.y==b.y;})) return {};
+    return result;
+}
+}

src/ui.cpp

@@ -1,5 +1,7 @@
 #include "../resources/resource.h"
 #include "app.h"
+#include "history_preview.h"
+#include "ui_scroll.h"
 #include "configuration.h"
 #include "ocr.h"
 #include "richtext.h"
@@ -238,6 +240,9 @@ HWND control(HWND parent, const wchar_t *cls, const wchar_t *title, DWORD style,
                              scale(parent, width), scale(parent, height), parent, (HMENU)(INT_PTR)id,
                              GetModuleHandleW(nullptr), nullptr);
     SendMessageW(w, WM_SETFONT, (WPARAM)GetPropW(parent, L"Font"), TRUE);
+    if(wcscmp(cls,L"LISTBOX")==0 || wcscmp(cls,WC_LISTVIEWW)==0 ||
+       wcscmp(cls,L"COMBOBOX")==0 || (wcscmp(cls,L"EDIT")==0 && (style&ES_MULTILINE)))
+        enableWheelBatching(w,wcscmp(cls,L"LISTBOX")==0);
     if (auto *layout = windowLayoutState(parent); layout && layout->scrolling)
     {
         layout->controls.push_back({w, {x, y, x + width, y + height}});
@@ -368,11 +373,12 @@ HWND makeWindow(App &app, const wchar_t *cls, const wchar_t *title, WNDPROC proc
     int top = monitor.rcWork.top + std::max(0L, (monitor.rcWork.bottom - monitor.rcWork.top - outerHeight) / 2);
     SetPropW(w, L"WindowLayout", new WindowLayout{width, height, 0, 0, !(extra & WS_THICKFRAME)});
     SetWindowSubclass(w, layoutProc, 2, 0);
+    if(windowLayoutState(w)->scrolling) enableWheelBatching(w);
     RECT initial = fitWindowRect({left, top, left + outerWidth, top + outerHeight}, monitor.rcWork);
     SetWindowPos(w, nullptr, initial.left, initial.top, initial.right - initial.left, initial.bottom - initial.top,
                  SWP_NOACTIVATE | SWP_NOZORDER);
     arrangeWindow(w);
-    SetWindowTextW(w, title);
+    SetWindowTextW(w, localBuildTitle(title).c_str());
     auto smallIcon = (HICON)LoadImageW(app.instance, MAKEINTRESOURCEW(IDI_KSWITCHER), IMAGE_ICON,
                                        GetSystemMetricsForDpi(SM_CXSMICON, dpi),
                                        GetSystemMetricsForDpi(SM_CYSMICON, dpi), LR_SHARED);
@@ -478,7 +484,17 @@ struct HistoryView
     std::map<std::wstring, std::string> richTexts;
     HWND rich{};
     std::set<std::wstring> pending;
+    bool scrolling{};
 };
+bool selectedImage(HWND w, HistoryView *v)
+{
+    int i=(int)SendDlgItemMessageW(w,102,LB_GETCURSEL,0,0);
+    return i>=0 && i<(int)v->items.size() && v->items[i].image;
+}
+void updateHistoryActions(HWND w, HistoryView *v)
+{
+    SetDlgItemTextW(w,114,selectedImage(w,v)?L"Edit image":L"Open item");
+}
 std::wstring selected(HWND w, HistoryView *v)
 {
     int i = (int)SendDlgItemMessageW(w, 102, LB_GETCURSEL, 0, 0);
@@ -507,6 +523,7 @@ void search(HWND w, HistoryView *v)
 }
 void requestPreview(HWND w, HistoryView *v, const Entry &entry)
 {
+    if(v->scrolling) return;
     const auto id = entry.id;
     const bool image = entry.image;
     if (v->thumbnails.contains(id) || v->richTexts.contains(id) || !v->pending.insert(id).second)
@@ -690,6 +707,12 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
     {
         switch (msg)
         {
+        case ScrollActivity:
+            if((HWND)wp==GetDlgItem(w,102)) {
+                v->scrolling=lp!=0;
+                if(!v->scrolling) InvalidateRect((HWND)wp,nullptr,FALSE);
+            }
+            return 0;
         case WM_COMMAND:
         {
             int id = LOWORD(wp);
@@ -702,6 +725,7 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             }
             if (id == 102 && HIWORD(wp) == LBN_SELCHANGE)
             {
+                updateHistoryActions(w,v);
                 return 0;
             }
             if (id == 102 && HIWORD(wp) == LBN_DBLCLK)
@@ -747,10 +771,13 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             if (result->generation != v->generation)
                 return 0;
             auto old = selected(w, v);
+            int top=(int)SendDlgItemMessageW(w,102,LB_GETTOPINDEX,0,0);
+            auto topId=top>=0 && top<(int)v->items.size()?v->items[top].id:L"";
             v->items = std::move(result->items);
             SendDlgItemMessageW(w, 102, WM_SETREDRAW, FALSE, 0);
             SendDlgItemMessageW(w, 102, LB_RESETCONTENT, 0, 0);
             int select = 0;
+            int restoreTop=0;
             for (size_t i = 0; i < v->items.size(); ++i)
             {
                 auto &e = v->items[i];
@@ -758,8 +785,11 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 SendDlgItemMessageW(w, 102, LB_ADDSTRING, 0, (LPARAM)text.c_str());
                 if (e.id == old)
                     select = (int)i;
+                if(e.id==topId) restoreTop=(int)i;
             }
             SendDlgItemMessageW(w, 102, LB_SETCURSEL, select, 0);
+            SendDlgItemMessageW(w,102,LB_SETTOPINDEX,restoreTop,0);
+            updateHistoryActions(w,v);
             SendDlgItemMessageW(w, 102, WM_SETREDRAW, TRUE, 0);
             InvalidateRect(GetDlgItem(w, 102), nullptr, TRUE);
             return 0;
@@ -770,16 +800,25 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             if (result->generation != v->generation || !IsWindowVisible(w))
                 return 0;
             v->pending.erase(result->id);
-            // At most ~3.3 MiB, irrespective of history length or source image size.
+            auto list=GetDlgItem(w,102);
-            if (v->thumbnails.size() >= 32)
+            RECT client{}; GetClientRect(list,&client);
-                v->thumbnails.erase(v->thumbnails.begin());
+            std::set<std::wstring> visible;
-            if (v->richTexts.size() >= 32)
+            RECT changed{}; bool repaint=false;
-                v->richTexts.erase(v->richTexts.begin());
+            int top=(int)SendMessageW(list,LB_GETTOPINDEX,0,0);
+            for(int i=std::max(0,top);i<(int)v->items.size();++i) {
+                RECT row{}, intersection{};
+                if(SendMessageW(list,LB_GETITEMRECT,i,(LPARAM)&row)==LB_ERR || row.top>=client.bottom) break;
+                if(!IntersectRect(&intersection,&row,&client)) continue;
+                visible.insert(v->items[i].id);
+                if(v->items[i].id==result->id) { changed=intersection; repaint=true; }
+            }
             if (!result->rtf.empty())
                 v->richTexts[result->id] = std::move(result->rtf);
             else
                 v->thumbnails[result->id] = std::move(result->pixels);
-            InvalidateRect(GetDlgItem(w, 102), nullptr, FALSE);
+            trimHistoryPreviews(v->thumbnails,visible);
+            trimHistoryPreviews(v->richTexts,visible);
+            if(repaint) InvalidateRect(list,&changed,FALSE);
             return 0;
         }
         case WM_MEASUREITEM:
@@ -798,15 +837,29 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
             break;
         case WM_CONTEXTMENU:
         {
+            auto list=GetDlgItem(w,102);
+            if((HWND)wp!=list) break;
+            POINT p{(short)LOWORD(lp),(short)HIWORD(lp)};
+            if(lp!=-1) {
+                POINT hit=p; ScreenToClient(list,&hit);
+                auto item=SendMessageW(list,LB_ITEMFROMPOINT,0,MAKELPARAM(hit.x,hit.y));
+                if(HIWORD(item)) return 0;
+                SendMessageW(list,LB_SETCURSEL,LOWORD(item),0);
+                updateHistoryActions(w,v);
+            } else {
+                RECT row{};
+                auto index=SendMessageW(list,LB_GETCURSEL,0,0);
+                if(index==LB_ERR) return 0;
+                SendMessageW(list,LB_GETITEMRECT,index,(LPARAM)&row);
+                p={row.left,row.top}; ClientToScreen(list,&p);
+            }
             HMENU menu = CreatePopupMenu();
             AppendMenuW(menu, MF_STRING, 110, L"Paste");
             AppendMenuW(menu, MF_STRING, 111, L"Paste plain text");
             AppendMenuW(menu, MF_STRING, 112, L"Pin / unpin");
             AppendMenuW(menu, MF_STRING, 113, L"Delete");
-            AppendMenuW(menu, MF_STRING, 114, L"Open full item");
+            AppendMenuW(menu, MF_STRING, 114, selectedImage(w,v)?L"Edit image in screenshot editor":L"Open full item");
             AppendMenuW(menu, MF_STRING, 115, L"Copy text from image (OCR)");
-            POINT p;
-            GetCursorPos(&p);
             int cmd = TrackPopupMenu(menu, TPM_RETURNCMD, p.x, p.y, 0, w, nullptr);
             DestroyMenu(menu);
             if (cmd)
@@ -1700,11 +1753,17 @@ void showEntry(App &app, const std::wstring &id)
     try
     {
         auto clip = app.history->load(id);
+        if(std::any_of(clip.formats.begin(),clip.formats.end(),[](const auto &format) {
+            return format.id==CF_DIB || format.id==CF_DIBV5 || format.name==L"PNG";
+        })) {
+            launchScreenshotEditor(app,clip);
+            return;
+        }
         auto text = clip.text();
         if (text.empty())
         {
             MessageBoxW(app.historyWindow,
-                        L"This item contains an image or files. Use the preview or paste it into the "
+                        L"This item contains files. Paste it into the "
                         L"destination application.",
                         L"Clipboard item", MB_OK);
             return;

src/ui_scroll.h

@@ -0,0 +1,83 @@
+#pragma once
+#include "platform.h"
+#include <algorithm>
+#include <commctrl.h>
+#include <windowsx.h>
+
+namespace ks {
+inline constexpr UINT ScrollActivity=WM_APP+42;
+inline constexpr UINT_PTR ScrollFrameTimer=0x4b5301, ScrollIdleTimer=0x4b5302;
+struct WheelBatch {
+    long long vertical{}, horizontal{};
+    WORD keys{};
+    LPARAM point{};
+    bool frame{}, active{}, listBox{};
+    int remainder{};
+};
+inline LRESULT CALLBACK wheelBatchProc(HWND w,UINT msg,WPARAM wp,LPARAM lp,UINT_PTR id,DWORD_PTR data)
+{
+    auto *batch=reinterpret_cast<WheelBatch *>(data);
+    if(msg==WM_MOUSEWHEEL || msg==WM_MOUSEHWHEEL) {
+        (msg==WM_MOUSEWHEEL?batch->vertical:batch->horizontal)+=GET_WHEEL_DELTA_WPARAM(wp);
+        batch->keys=GET_KEYSTATE_WPARAM(wp); batch->point=lp;
+        if(!batch->active) {
+            batch->active=true;
+            SendMessageW(GetParent(w),ScrollActivity,(WPARAM)w,TRUE);
+        }
+        // Do not restart the frame timer: an uninterrupted wheel stream must
+        // keep moving, rather than wait for a debounce interval to expire.
+        if(!batch->frame) batch->frame=SetTimer(w,ScrollFrameTimer,16,nullptr)!=0;
+        SetTimer(w,ScrollIdleTimer,100,nullptr);
+        return 0;
+    }
+    if(msg==WM_TIMER && wp==ScrollFrameTimer) {
+        KillTimer(w,ScrollFrameTimer); batch->frame=false;
+        if(batch->listBox && batch->vertical) {
+            UINT lines=3; SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0,&lines,0);
+            if(lines==WHEEL_PAGESCROLL) {
+                RECT client{}; GetClientRect(w,&client);
+                auto height=SendMessageW(w,LB_GETITEMHEIGHT,0,0);
+                lines=std::max<LRESULT>(1,client.bottom/std::max<LRESULT>(1,height));
+            }
+            auto delta=batch->vertical+batch->remainder;
+            batch->remainder=(int)(delta%WHEEL_DELTA);
+            auto top=SendMessageW(w,LB_GETTOPINDEX,0,0);
+            auto count=SendMessageW(w,LB_GETCOUNT,0,0);
+            auto next=std::clamp<long long>(top-(delta/WHEEL_DELTA)*lines,0,std::max<LRESULT>(0,count-1));
+            if(next!=top) SendMessageW(w,LB_SETTOPINDEX,(WPARAM)next,0);
+            batch->vertical=0;
+        } else if(batch->vertical) {
+            // Native edit/list-view/window handlers retain their own scrolling
+            // semantics, including system settings and partial wheel deltas.
+            auto delta=(short)std::clamp<long long>(batch->vertical,-32760,32760);
+            batch->vertical-=delta;
+            DefSubclassProc(w,WM_MOUSEWHEEL,MAKEWPARAM(batch->keys,(WORD)delta),batch->point);
+        }
+        if(batch->horizontal) {
+            auto delta=(short)std::clamp<long long>(batch->horizontal,-32760,32760);
+            batch->horizontal-=delta;
+            DefSubclassProc(w,WM_MOUSEHWHEEL,MAKEWPARAM(batch->keys,(WORD)delta),batch->point);
+        }
+        if(batch->vertical || batch->horizontal)
+            batch->frame=SetTimer(w,ScrollFrameTimer,16,nullptr)!=0;
+        return 0;
+    }
+    if(msg==WM_TIMER && wp==ScrollIdleTimer) {
+        if(batch->frame) return 0;
+        KillTimer(w,ScrollIdleTimer); batch->active=false;
+        SendMessageW(GetParent(w),ScrollActivity,(WPARAM)w,FALSE);
+        return 0;
+    }
+    if(msg==WM_NCDESTROY) {
+        KillTimer(w,ScrollFrameTimer); KillTimer(w,ScrollIdleTimer);
+        RemoveWindowSubclass(w,wheelBatchProc,id); delete batch;
+    }
+    return DefSubclassProc(w,msg,wp,lp);
+}
+inline void enableWheelBatching(HWND window,bool listBox=false)
+{
+    if(!window) return;
+    auto *batch=new WheelBatch; batch->listBox=listBox;
+    if(!SetWindowSubclass(window,wheelBatchProc,ScrollFrameTimer,(DWORD_PTR)batch)) delete batch;
+}
+}

src/update.h

@@ -2,7 +2,7 @@
 #include "platform.h"
 namespace ks
 {
-inline constexpr wchar_t AppVersion[] = L"0.6.19";
+inline constexpr wchar_t AppVersion[] = L"0.6.24";
 inline constexpr UINT UpdateMessage = WM_APP + 7;
 inline constexpr UINT UpdateCheckIntervalMs = 6 * 60 * 60 * 1000;
 inline constexpr UINT UpdateNotificationRetryMs = 5 * 60 * 1000;

tests/input.cpp

@@ -1,4 +1,5 @@
 #include "app.h"
+#include "ui_scroll.h"
 #include "ui_geometry.h"
 #include "screenshot.h"
 #include <commctrl.h>
@@ -728,16 +729,21 @@ int main(int argc, char **argv) {
             controlMoves=0;
             ValidateRect(settings,nullptr);
             SendMessageW(settings,WM_MOUSEWHEEL,MAKEWPARAM(0,WHEEL_DELTA),0);
+            SendMessageW(settings,WM_TIMER,ks::ScrollFrameTimer,0);
             require(controlMoves==0 && !GetUpdateRect(settings,nullptr,FALSE),"wheel at top does not move controls or erase the window");
             SendMessageW(settings,WM_MOUSEWHEEL,MAKEWPARAM(0,WORD(short(-WHEEL_DELTA/2))),0);
+            SendMessageW(settings,WM_TIMER,ks::ScrollFrameTimer,0);
             require(controlMoves==0,"partial wheel step does not rearrange controls");
             SendMessageW(settings,WM_MOUSEWHEEL,MAKEWPARAM(0,WORD(short(-WHEEL_DELTA/2))),0);
+            require(controlMoves==0,"wheel changes wait for the shared frame timer");
+            SendMessageW(settings,WM_TIMER,ks::ScrollFrameTimer,0);
             require(controlMoves==1,"wheel scroll batches each control movement once");
             SendMessageW(settings,WM_VSCROLL,SB_BOTTOM,0);
             SendMessageW(settings,WM_HSCROLL,SB_RIGHT,0);
             controlMoves=0;
             SendMessageW(settings,WM_MOUSEWHEEL,MAKEWPARAM(0,-WHEEL_DELTA),0);
             SendMessageW(settings,WM_MOUSEHWHEEL,MAKEWPARAM(0,WHEEL_DELTA),0);
+            SendMessageW(settings,WM_TIMER,ks::ScrollFrameTimer,0);
             require(controlMoves==0,"wheel at bottom and right boundaries does not rearrange controls");
             require((GetWindowLongPtrW(settings,GWL_STYLE)&WS_CLIPCHILDREN)!=0,"parent background excludes child controls");
             RemoveWindowSubclass(trackedControl,countControlMoves,99);

tests/integration.cpp

@@ -26,10 +26,17 @@ bool conversionOnly = false;
 int pasteBehavior = 0;
 int enterPresses = 0;
 int copyFailuresRemaining = 0, copyRequests = 0;
+int droppedSelectionKeys = 0;
 bool temporaryClipboardExcluded = true;
 bool clipboardAccessTimedOut = false;
 LRESULT CALLBACK observeEnter(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
 {
+    if (message == WM_KEYDOWN && wp == VK_LEFT && droppedSelectionKeys > 0 &&
+        (GetKeyState(VK_SHIFT) & 0x8000))
+    {
+        --droppedSelectionKeys;
+        return 0;
+    }
     // This bare EDIT control is our test fixture, not a full editor with
     // clipboard retries. Keep clipboard access on its owning UI thread while
     // it handles Ctrl+C/Ctrl+V, so unrelated Windows clipboard listeners cannot
@@ -205,10 +212,12 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 break;
             case 3:
                 require(text() == L"Hello World", "case conversion");
+                droppedSelectionKeys = 5;
                 app->transform(ks::Case);
                 break;
             case 4:
                 require(text() == L"HELLO WORLD", "consecutive command reselects verified previous result");
+                require(droppedSelectionKeys == 0, "partial suffix selection recovered after dropped arrow keys");
                 prepare(L"OLDghbdtn", false);
                 record(L"ghbdtn");
                 app->transform(ks::Direct + ru);
@@ -392,6 +401,32 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                 require(text() == L"привет" && diagnosticLog().size() == diagnosticStart,
                         "disabled diagnostics preserves conversion and writes no records");
                 ks::setLoggingEnabled(true);
+                prepare(L"PuntoSwitcher ", true);
+                app->transform(ks::Direct + ru);
+                break;
+            case 44:
+                app->transform(ks::Direct + en);
+                break;
+            case 45:
+                require(text() == L"PuntoSwitcher ", "previous conversion restores CamelCase and trailing space");
+                droppedSelectionKeys = 5;
+                app->transform(ks::Direct + ru);
+                break;
+            case 46:
+                require(text() == ks::convertTo(L"PuntoSwitcher ", app->layouts, ru, en),
+                        "repeat conversion recovers Switcher suffix and preserves full result");
+                require(droppedSelectionKeys == 0, "CamelCase suffix regression dropped five selection keys");
+                require(ks::readClipboard(app->window).text() == sentinel,
+                        "suffix recovery restores original clipboard");
+                // Derive the actual text from the physical keys, preserving an older prefix.
+                prepare((L"OLD" + ks::convertTo(L"snipping ", app->layouts, ru, en)).c_str(), false);
+                record(L"snipping ");
+                droppedSelectionKeys = 4;
+                app->transform(ks::Direct + en);
+                break;
+            case 47:
+                require(text() == L"OLDsnipping ", "recent Cyrillic suffix recovery preserves older prefix");
+                require(droppedSelectionKeys == 0, "recent suffix regression dropped four selection keys");
                 finish();
                 break;
             case 30:

tests/screenshot_ui.cpp

@@ -2,10 +2,69 @@
 // Including the implementation lets this integration test drive private editor state directly.
 #include "../src/screenshot.cpp"
 #include <iostream>
-int main()
+#include "stroke_improvement.h"
+int main(int argc, char **argv)
 {
     CoInitializeEx(nullptr,COINIT_APARTMENTTHREADED);
     try {
+        testStrokeImprovement();
+        if(argc>1 && std::string(argv[1])=="--save-only") {
+            auto require=[](bool ok,const char *message){if(!ok) throw std::runtime_error(message);};
+            auto root=std::filesystem::temp_directory_path()/(L"KSwitcher-save-"+std::to_wstring(GetCurrentProcessId()));
+            std::filesystem::create_directories(root);
+            struct Cleanup {std::filesystem::path root; ~Cleanup(){std::error_code ec; std::filesystem::remove_all(root,ec);}} cleanup{root};
+            ks::ScreenshotHost app{GetModuleHandleW(nullptr)};
+            ks::Capture c(app);
+            c.image=std::make_unique<ks::Surface>(320,240);
+            PatBlt(c.image->dc,0,0,320,240,WHITENESS);
+            c.marks={ks::Mark{{40,40},{180,140},0}};
+            auto expected=ks::decodeImage(ks::screenshotClip(c.image->dc,320,240,c.marks));
+            for(size_t i=3;i<expected.bgra.size();i+=4) expected.bgra[i]=255;
+            auto path=root/L"Знімок.png";
+            const auto clipboard=GetClipboardSequenceNumber();
+            ks::saveToFile(nullptr,c,path);
+            ks::Clip encoded{{{0,L"PNG",ks::readFile(path,16*1024*1024)}}};
+            auto actual=ks::decodeImage(encoded);
+            require(actual.width==320 && actual.height==240 && actual.bgra==expected.bgra,
+                    "PNG export preserves full resolution, annotations and opaque pixels");
+            require(c.savedPath==path && c.copied,"successful save records destination and exported state");
+            require(GetClipboardSequenceNumber()==clipboard,"saving does not change clipboard");
+            c.remember(c.marks); c.marks.clear();
+            require(!c.copied,"editing after save marks changes unexported");
+            ks::save(nullptr,c);
+            actual=ks::decodeImage(ks::Clip{{{0,L"PNG",ks::readFile(path,16*1024*1024)}}});
+            require(actual.bgra!=expected.bgra && c.copied,"Save overwrites remembered path with current edits without a dialog");
+            c.copied=false;
+            ks::save(nullptr,c,true,[](LPOPENFILENAMEW dialog)->BOOL {
+                if(!(dialog->Flags&OFN_OVERWRITEPROMPT) || std::wstring(dialog->lpstrDefExt)!=L"png" ||
+                   !std::wstring(dialog->lpstrFile).ends_with(L"Знімок.png"))
+                    throw std::runtime_error("Save As dialog must preserve filename, PNG extension and overwrite confirmation");
+                return FALSE;
+            });
+            require(!c.copied && c.savedPath==path,"cancelled Save As preserves dirty state and remembered path");
+            auto another=root/L"Another.png";
+            ks::save(nullptr,c,true,[](LPOPENFILENAMEW dialog)->BOOL {
+                auto destination=std::filesystem::path(dialog->lpstrFile).parent_path()/L"Another.png";
+                wcscpy_s(dialog->lpstrFile,dialog->nMaxFile,destination.c_str());
+                return TRUE;
+            });
+            require(c.savedPath==another && std::filesystem::exists(path),"new destination preserves previous file");
+            c.copied=false;
+            bool failed=false;
+            try {ks::saveToFile(nullptr,c,root/L"missing"/L"fail.png");} catch(const std::exception &){failed=true;}
+            require(failed && !c.copied && c.savedPath==another,"failed save preserves dirty state and previous destination");
+            require(std::distance(std::filesystem::directory_iterator(root),std::filesystem::directory_iterator{})==2,
+                    "saving leaves no temporary files");
+            bool invalid=false;
+            try {ks::save(nullptr,c,true,[](LPOPENFILENAMEW dialog)->BOOL {
+                auto destination=std::filesystem::path(dialog->lpstrFile).parent_path()/L"Wrong.jpg";
+                wcscpy_s(dialog->lpstrFile,dialog->nMaxFile,destination.c_str()); return TRUE;
+            });} catch(const std::exception &){invalid=true;}
+            require(invalid && !std::filesystem::exists(root/L"Wrong.jpg"),"PNG export rejects a misleading file extension");
+            CoUninitialize();
+            std::cout<<"Passed screenshot PNG save regressions without opening windows\n";
+            return 0;
+        }
         INITCOMMONCONTROLSEX controls{sizeof(controls),ICC_STANDARD_CLASSES}; InitCommonControlsEx(&controls);
         ks::ScreenshotHost app{GetModuleHandleW(nullptr)};
         app.window=CreateWindowW(L"STATIC",L"",0,0,0,0,0,HWND_MESSAGE,nullptr,app.instance,nullptr);
@@ -24,6 +83,169 @@ int main()
         require(c.pencilCursor!=nullptr,"pencil drawing cursor loads");
         require(c.freehand && !c.pointer && ks::toolCursor(c)==c.pencilCursor,
                 "new screenshot editor starts with the pencil tool");
+        {
+            require(GetDlgItem(window,36)!=nullptr,"triangle has a dedicated toolbar button");
+            SendMessageW(window,WM_KEYDOWN,'G',0);
+            require(c.shape==ks::ScreenshotShape::Triangle && c.arrow && !c.freehand,"G selects triangle drawing tool");
+            auto mouse=[&](UINT message,POINT p) {
+                int x=c.view.left+MulDiv(p.x,c.view.right-c.view.left,c.image->width);
+                int y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
+                SendMessageW(window,message,message==WM_LBUTTONUP?0:MK_LBUTTON,MAKELPARAM(x,y));
+            };
+            mouse(WM_LBUTTONDOWN,{80,80}); mouse(WM_LBUTTONUP,{220,180});
+            require(c.marks.size()==1 && c.marks[0].shape==ks::ScreenshotShape::Triangle && c.marks[0].points.size()==4,
+                    "triangle tool creates a closed three-vertex shape");
+            auto triangle=c.marks[0];
+            for(double angle:{0.0,37.0,90.0,-125.0}) for(int i=0;i<3;++i) {
+                auto original=triangle; original.rotation=angle;
+                auto vertices=ks::shapeOutline(original);
+                auto part=ks::MarkPart(int(ks::MarkPart::Vertex0)+i);
+                require(ks::hitScreenshotMark(original,vertices[i],4)==part,"each rotated triangle vertex has its own handle");
+                POINT target{vertices[i].x+13,vertices[i].y-9};
+                auto changed=ks::dragScreenshotMark(original,part,vertices[i],target,320,240);
+                auto moved=ks::shapeOutline(changed);
+                for(int j=0;j<3;++j) {
+                    auto expected=j==i?target:vertices[j];
+                    require(std::abs(moved[j].x-expected.x)<=2 && std::abs(moved[j].y-expected.y)<=2,
+                            "dragging one vertex preserves both other world vertices after rotation");
+                }
+                require(changed.points.front().x==changed.points.back().x && changed.points.front().y==changed.points.back().y,
+                        "triangle remains closed after editing any vertex");
+            }
+            auto vertices=ks::shapeOutline(triangle);
+            mouse(WM_LBUTTONDOWN,vertices[0]);
+            require(c.part==ks::MarkPart::Vertex0,"mouse selects apex vertex");
+            mouse(WM_LBUTTONUP,{vertices[0].x+20,vertices[0].y+10});
+            require(c.marks[0].points[0].x==triangle.points[0].x+20 && c.marks[0].points[1].x==triangle.points[1].x,
+                    "mouse vertex drag changes only requested corner");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks[0].points[0].x==triangle.points[0].x,"undo restores triangle vertex");
+            SendMessageW(window,WM_COMMAND,18,0);
+            require(c.marks[0].points[0].x==triangle.points[0].x+20,"redo reapplies triangle vertex edit");
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+            require(GetDlgItem(window,37)!=nullptr,"trapezoid has a dedicated toolbar button");
+            SendMessageW(window,WM_KEYDOWN,'B',0);
+            require(c.shape==ks::ScreenshotShape::Trapezoid && c.arrow && !c.freehand,"B selects trapezoid tool");
+            mouse(WM_LBUTTONDOWN,{60,70}); mouse(WM_LBUTTONUP,{240,180});
+            require(c.marks.size()==1 && c.marks[0].shape==ks::ScreenshotShape::Trapezoid && c.marks[0].points.size()==5 && !c.marks[0].isHighlight(),
+                    "trapezoid tool creates a closed shape with unequal parallel bases");
+            auto trapezoid=c.marks[0];
+            require(trapezoid.points[0].y==trapezoid.points[1].y && trapezoid.points[2].y==trapezoid.points[3].y &&
+                    trapezoid.points[1].x-trapezoid.points[0].x<trapezoid.points[2].x-trapezoid.points[3].x,"toolbar trapezoid has parallel unequal bases");
+            mouse(WM_LBUTTONDOWN,trapezoid.to); mouse(WM_LBUTTONUP,{260,200});
+            require(c.marks[0].to.x==260 && c.marks[0].points[0].y==c.marks[0].points[1].y,"trapezoid resizes as a shape");
+            auto grip=ks::screenshotShapeRotationHandle(c.marks[0]);
+            auto rotated=ks::dragScreenshotMark(c.marks[0],ks::MarkPart::Rotation,grip,{280,135},320,240);
+            require(rotated.rotation!=0 && rotated.shape==ks::ScreenshotShape::Trapezoid,"trapezoid supports shape rotation");
+            SendMessageW(window,WM_COMMAND,12,0); require(c.marks[0].to.x==240,"undo trapezoid resize");
+            SendMessageW(window,WM_COMMAND,12,0); require(c.marks.empty(),"undo trapezoid creation");
+            SendMessageW(window,WM_COMMAND,18,0); require(c.marks[0].shape==ks::ScreenshotShape::Trapezoid,"redo trapezoid creation");
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+            SendMessageW(window,WM_COMMAND,21,0);
+        }
+        {
+            for(auto kind:{ks::ScreenshotShape::Rectangle,ks::ScreenshotShape::Circle,ks::ScreenshotShape::Ellipse,ks::ScreenshotShape::Triangle})
+            for(bool recognized:{false,true}) {
+                if(kind==ks::ScreenshotShape::Triangle && !recognized) continue;
+                ks::Mark shape{{100,90},{200,170},0}; shape.shape=kind; shape.ends=ks::LineEnds::None;
+                if(kind==ks::ScreenshotShape::Circle) shape.to.y=190;
+                if(recognized) shape.points=kind==ks::ScreenshotShape::Triangle?
+                    std::vector<POINT>{{150,90},{200,170},{100,170},{150,90}}:ks::shapeOutline(shape);
+                auto grip=ks::screenshotShapeRotationHandle(shape);
+                POINT center{(shape.from.x+shape.to.x)/2,(shape.from.y+shape.to.y)/2};
+                POINT right{center.x+center.y-grip.y,center.y};
+                auto rotated=ks::dragScreenshotMark(shape,ks::MarkPart::Rotation,grip,right,320,240);
+                require(std::abs(rotated.rotation-90)<.01 && rotated.from.x==shape.from.x && rotated.to.y==shape.to.y,
+                        "all native and recognized shapes rotate around their center");
+                auto corner=ks::rotateShapePoint(rotated,rotated.to);
+                require(ks::hitScreenshotMark(rotated,corner,4)==(kind==ks::ScreenshotShape::Triangle?ks::MarkPart::Vertex1:ks::MarkPart::End),"rotated resize handles remain hittable");
+                auto fixed=ks::rotateShapePoint(rotated,rotated.from);
+                auto resized=ks::dragScreenshotMark(rotated,ks::MarkPart::End,corner,{corner.x-15,corner.y+20},320,240);
+                auto stillFixed=ks::rotateShapePoint(resized,resized.from);
+                require(std::abs(stillFixed.x-fixed.x)<=1 && std::abs(stillFixed.y-fixed.y)<=1 && resized.rotation==90,
+                        "resizing rotated shapes keeps the opposite world corner fixed");
+                auto snapped=ks::dragScreenshotMark(shape,ks::MarkPart::Rotation,grip,{center.x+60,center.y-20},320,240,true);
+                require(std::abs(std::remainder(snapped.rotation,15))<.01,"Shift snaps shape rotation to 15 degrees");
+                auto cloned=ks::cloneScreenshotMark(rotated,{rotated},320,240);
+                require(cloned.rotation==rotated.rotation && cloned.shape==kind,"clone preserves shape rotation");
+                auto boundary=ks::shapeOutline(shape).front();
+                std::vector<ks::Mark> linked{shape,{{20,20},boundary,0}};
+                ks::linkScreenshotEndpoint(linked[1],false,boundary,linked,4);
+                require(linked[1].toLink.target!=0,"connector attaches to shape before rotation");
+                linked[0].rotation=90; ks::resolveScreenshotLinks(linked);
+                auto expected=ks::rotateShapePoint(linked[0],boundary);
+                require(std::abs(linked[1].to.x-expected.x)<=1 && std::abs(linked[1].to.y-expected.y)<=1,
+                        "connector follows rotated shape boundary");
+            }
+            ks::Mark shape{{100,90},{200,170},0}; shape.shape=ks::ScreenshotShape::Rectangle;
+            c.marks={shape}; c.selected=0;
+            auto mouse=[&](UINT message,POINT p) {
+                auto x=c.view.left+MulDiv(p.x,c.view.right-c.view.left,c.image->width);
+                auto y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
+                SendMessageW(window,message,message==WM_LBUTTONUP?0:MK_LBUTTON,MAKELPARAM(x,y));
+            };
+            auto grip=ks::screenshotShapeRotationHandle(shape,double(c.unit)*c.image->width/(c.view.right-c.view.left));
+            require(ks::markAt(c,grip).second==ks::MarkPart::Rotation,"shape rotation grip is distinct from thickness grip");
+            mouse(WM_LBUTTONDOWN,grip); mouse(WM_LBUTTONUP,{150+130-grip.y,130});
+            require(std::abs(c.marks[0].rotation-90)<1,"mouse rotation updates selected shape");
+            SendMessageW(window,WM_COMMAND,12,0); require(c.marks[0].rotation==0,"undo restores original shape orientation");
+            SendMessageW(window,WM_COMMAND,18,0); require(std::abs(c.marks[0].rotation-90)<1,"redo restores shape rotation");
+            c.selected=0;
+            ks::Surface rotatedPixels(320,240); PatBlt(rotatedPixels.dc,0,0,320,240,WHITENESS);
+            auto rendered=ks::decodeImage(ks::screenshotClip(rotatedPixels.dc,320,240,c.marks));
+            auto pixel=(100*320+190)*4;
+            require(rendered.bgra[pixel+2]==GetRValue(shape.color) && rendered.bgra[pixel+1]==GetGValue(shape.color),
+                    "export renders rotated shape at its new boundary");
+            POINT center{(c.canvas.left+c.canvas.right)/2,(c.canvas.top+c.canvas.bottom)/2};
+            ks::zoomCanvas(window,c,2,center);
+            grip=ks::screenshotShapeRotationHandle(c.marks[0],double(c.unit)*c.image->width/(c.view.right-c.view.left));
+            require(ks::markAt(c,grip).second==ks::MarkPart::Rotation,"rotation grip works on zoomed canvas");
+            ks::zoomCanvas(window,c,1,center,true);
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+        }
+        {
+            BYTE savedKeys[256]{},keys[256]{}; GetKeyboardState(savedKeys);
+            std::copy(savedKeys,savedKeys+256,keys); keys[VK_CONTROL]=0x80; SetKeyboardState(keys);
+            auto fit=c.view;
+            SendMessageW(window,WM_KEYDOWN,VK_OEM_PLUS,0);
+            require(c.zoom==1.25 && c.view.right-c.view.left>fit.right-fit.left,"Ctrl+plus zooms canvas");
+            SendMessageW(window,WM_KEYDOWN,VK_SUBTRACT,0);
+            require(std::abs(c.zoom-1)<.001,"Ctrl+numpad minus zooms out");
+            SendMessageW(window,WM_KEYDOWN,VK_ADD,0);
+            SendMessageW(window,WM_KEYDOWN,VK_OEM_MINUS,0);
+            require(std::abs(c.zoom-1)<.001,"both keyboard plus/minus variants work");
+            POINT center{(c.canvas.left+c.canvas.right)/2,(c.canvas.top+c.canvas.bottom)/2};
+            ks::zoomCanvas(window,c,4,center);
+            POINT anchor{center.x+12,center.y+8},screen=anchor; ClientToScreen(window,&screen);
+            auto before=ks::imagePoint(c,anchor,false); double zoom=c.zoom;
+            SendMessageW(window,WM_MOUSEWHEEL,MAKEWPARAM(MK_CONTROL,60),MAKELPARAM(screen.x,screen.y));
+            require(c.zoom==zoom,"partial wheel delta waits for a full step");
+            SendMessageW(window,WM_MOUSEWHEEL,MAKEWPARAM(MK_CONTROL,60),MAKELPARAM(screen.x,screen.y));
+            auto after=ks::imagePoint(c,anchor,false);
+            require(c.zoom>zoom && std::abs(before.x-after.x)<=1 && std::abs(before.y-after.y)<=1,
+                    "Ctrl+wheel zoom keeps image point under cursor");
+            require(!c.history.canUndo(),"zoom does not add image edits to undo history");
+            auto view=c.view;
+            SendMessageW(window,WM_MBUTTONDOWN,MK_MBUTTON,MAKELPARAM(center.x,center.y));
+            SendMessageW(window,WM_MOUSEMOVE,MK_MBUTTON,MAKELPARAM(center.x+15,center.y+10));
+            SendMessageW(window,WM_MBUTTONUP,0,MAKELPARAM(center.x+15,center.y+10));
+            require(c.view.left==view.left+15 && c.view.top==view.top+10 && !c.panning,"middle drag pans enlarged canvas");
+            keys[VK_CONTROL]=0; SetKeyboardState(keys);
+            auto a=ks::imagePoint(c,center),b=ks::imagePoint(c,{center.x+30,center.y+20});
+            SendMessageW(window,WM_LBUTTONDOWN,MK_LBUTTON,MAKELPARAM(center.x,center.y));
+            SendMessageW(window,WM_LBUTTONUP,0,MAKELPARAM(center.x+30,center.y+20));
+            require(c.marks.size()==1 && c.marks[0].from.x==a.x && c.marks[0].to.x==b.x && c.marks[0].to.y==b.y,
+                    "drawing after zoom and pan uses image coordinates");
+            auto original=c.marks[0];
+            keys[VK_CONTROL]=0x80; SetKeyboardState(keys);
+            SendMessageW(window,WM_KEYDOWN,'0',0);
+            require(c.zoom==1 && c.panX==0 && c.panY==0 && c.marks[0].from.x==original.from.x && c.marks[0].to.x==original.to.x,
+                    "Ctrl+0 resets view without transforming annotations");
+            ks::zoomCanvas(window,c,1e6,center); require(c.zoom==16,"zoom has upper bound");
+            ks::zoomCanvas(window,c,1e-6,center); require(c.zoom==.1,"zoom has lower bound");
+            SendMessageW(window,WM_KEYDOWN,'0',0); SetKeyboardState(savedKeys);
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+        }
         {
             BYTE savedKeys[256]{},keys[256]{}; GetKeyboardState(savedKeys);
             std::copy(savedKeys,savedKeys+256,keys); keys[VK_SHIFT]=0; SetKeyboardState(keys);
@@ -32,6 +254,51 @@ int main()
                 int y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
                 SendMessageW(window,message,(message==WM_LBUTTONUP?0:MK_LBUTTON)|(shift?MK_SHIFT:0),MAKELPARAM(x,y));
             };
+            mouse(WM_LBUTTONDOWN,{30,190});
+            for(int x=35;x<=200;x+=5) mouse(WM_MOUSEMOVE,{x,190+(x%10?2:-2)});
+            auto original=c.stroke.points;
+            mouse(WM_LBUTTONUP,c.stroke.to);
+            require(c.marks.size()==1,"improved stroke is one object");
+            auto improved=c.marks.back().points;
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks.size()==1 && c.marks.back().points.size()==original.size() &&
+                    std::equal(original.begin(),original.end(),c.marks.back().points.begin(),
+                        [](POINT a,POINT b){return a.x==b.x && a.y==b.y;}),"first undo restores exact raw stroke");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks.empty(),"second undo removes stroke");
+            SendMessageW(window,WM_COMMAND,18,0); SendMessageW(window,WM_COMMAND,18,0);
+            require(c.marks.size()==1 && c.marks.back().points.size()==improved.size(),"redo restores improvement");
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+            mouse(WM_LBUTTONDOWN,{180,120});
+            for(int i=1;i<=120;++i) {
+                double a=i*2*3.141592653589793/120;
+                mouse(WM_MOUSEMOVE,{LONG(std::lround(130+50*std::cos(a))),LONG(std::lround(120+50*std::sin(a)))});
+            }
+            mouse(WM_LBUTTONUP,c.stroke.to);
+            require(c.marks.size()==1 && c.marks[0].shape==ks::ScreenshotShape::Circle &&
+                    !c.marks[0].freehand && !c.marks[0].isHighlight(),"recognized circle is a shape, not a pencil or highlight");
+            auto circle=c.marks[0];
+            require(ks::hitScreenshotMark(circle,circle.to,6)==ks::MarkPart::End,"recognized shape exposes bounding-box resize handle");
+            mouse(WM_LBUTTONDOWN,circle.to);
+            mouse(WM_MOUSEMOVE,{circle.to.x+30,circle.to.y+20});
+            mouse(WM_LBUTTONUP,{circle.to.x+30,circle.to.y+20});
+            require(c.marks[0].to.x>circle.to.x && c.marks[0].to.x-c.marks[0].from.x==c.marks[0].to.y-c.marks[0].from.y &&
+                    c.marks[0].points[0].x>circle.points[0].x,"dragging recognized circle handle scales the whole circle proportionally");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks[0].shape==ks::ScreenshotShape::Circle && c.marks[0].to.x==circle.to.x,"undo restores shape size");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks[0].freehand && c.marks[0].shape==ks::ScreenshotShape::None,"undo recognition restores editable pencil stroke");
+            SendMessageW(window,WM_COMMAND,18,0);
+            require(c.marks[0].shape==ks::ScreenshotShape::Circle,"redo restores shape type");
+            for(auto kind:{ks::ScreenshotShape::Rectangle,ks::ScreenshotShape::Ellipse,ks::ScreenshotShape::Triangle}) {
+                auto shape=circle; shape.shape=kind;
+                auto resized=ks::dragScreenshotMark(shape,ks::MarkPart::End,shape.to,{shape.to.x+50,shape.to.y+20},320,240);
+                require(resized.points[0].x!=shape.points[0].x && resized.points[24].y!=shape.points[24].y,
+                        "shape resize transforms all outline points in both axes");
+                auto moved=ks::cloneScreenshotMark(resized,{resized},320,240);
+                require(moved.shape==kind && !moved.isHighlight(),"clone preserves recognized shape type");
+            }
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
             mouse(WM_LBUTTONDOWN,{40,40},true);
             mouse(WM_MOUSEMOVE,{100,50},true);
             require(c.stroke.to.x==100 && c.stroke.to.y==40,"Shift constrains pencil horizontally");
@@ -175,7 +442,7 @@ int main()
         }
         c.marks.clear(); SendMessageW(window,WM_COMMAND,27,0);
         wchar_t windowTitle[128]{}; GetWindowTextW(window,windowTitle,128);
-        require(std::wstring(windowTitle)==L"KSwitcher — Screenshot #1","title includes editor index without usage hints");
+        require(std::wstring(windowTitle)==ks::localBuildTitle(L"KSwitcher — Screenshot #1"),"title includes editor index and local build marker without usage hints");
         RECT client{}; GetClientRect(window,&client);
         require(c.view.bottom<=client.bottom-c.statusHeight,"image does not overlap status bar");
         ks::updateStatus(c);

tests/scroll.cpp

@@ -0,0 +1,66 @@
+#include "ui_scroll.h"
+#include <iostream>
+
+namespace {
+int forwarded{};
+long long totalDelta{};
+LRESULT CALLBACK observe(HWND w,UINT msg,WPARAM wp,LPARAM lp,UINT_PTR,DWORD_PTR)
+{
+    if(msg==WM_MOUSEWHEEL) { ++forwarded; totalDelta+=GET_WHEEL_DELTA_WPARAM(wp); }
+    return DefSubclassProc(w,msg,wp,lp);
+}
+void require(bool ok,const char *message) { if(!ok) throw std::runtime_error(message); }
+void wheel(HWND w,int delta) { SendMessageW(w,WM_MOUSEWHEEL,MAKEWPARAM(0,(WORD)(short)delta),0); }
+void flush(HWND w) { SendMessageW(w,WM_TIMER,ks::ScrollFrameTimer,0); }
+}
+int main()
+{
+    INITCOMMONCONTROLSEX init{sizeof(init),ICC_STANDARD_CLASSES|ICC_LISTVIEW_CLASSES};
+    InitCommonControlsEx(&init);
+    auto instance=GetModuleHandleW(nullptr);
+    auto parent=CreateWindowW(L"STATIC",L"Scroll regression",WS_OVERLAPPEDWINDOW,0,0,500,400,nullptr,nullptr,instance,nullptr);
+    try {
+        auto list=CreateWindowW(L"LISTBOX",L"",WS_CHILD|WS_VSCROLL,0,0,300,200,parent,nullptr,instance,nullptr);
+        for(int i=0;i<2000;++i) SendMessageW(list,LB_ADDSTRING,0,(LPARAM)L"row");
+        SendMessageW(list,LB_SETCURSEL,5,0);
+        SendMessageW(list,LB_SETTOPINDEX,0,0);
+        ks::enableWheelBatching(list,true);
+        for(int i=0;i<1000;++i) wheel(list,-120);
+        require(SendMessageW(list,LB_GETTOPINDEX,0,0)==0,"burst is deferred to one frame");
+        flush(list);
+        UINT lines{}; SystemParametersInfoW(SPI_GETWHEELSCROLLLINES,0,&lines,0);
+        require(!lines || SendMessageW(list,LB_GETTOPINDEX,0,0)>0,"burst moves list");
+        require(SendMessageW(list,LB_GETCURSEL,0,0)==5,"scroll does not change selection");
+        for(int i=0;i<1000;++i) wheel(list,120);
+        flush(list);
+        require(SendMessageW(list,LB_GETTOPINDEX,0,0)==0,"reverse burst clamps at top");
+        wheel(list,-60); flush(list);
+        require(SendMessageW(list,LB_GETTOPINDEX,0,0)==0,"partial wheel step is retained");
+        wheel(list,-60); flush(list);
+        require(!lines || SendMessageW(list,LB_GETTOPINDEX,0,0)>0,"partial steps combine across frames");
+        DestroyWindow(list);
+        for(auto cls:{L"EDIT",WC_LISTVIEWW,L"COMBOBOX",L"STATIC"}) {
+            auto w=CreateWindowW(cls,L"",WS_CHILD|WS_VSCROLL,0,0,300,200,parent,nullptr,instance,nullptr);
+            require(w!=nullptr,"native scroll control created");
+            SetWindowSubclass(w,observe,1,0); ks::enableWheelBatching(w);
+            forwarded=0; totalDelta=0;
+            for(int i=0;i<100;++i) wheel(w,-120);
+            require(forwarded==0,"native wheel burst is batched");
+            flush(w);
+            require(forwarded==1 && totalDelta==-12000,"one native dispatch preserves burst distance");
+            wheel(w,60); flush(w);
+            require(forwarded==2 && totalDelta==-11940,"native partial steps are preserved");
+            forwarded=0; totalDelta=0;
+            for(int i=0;i<400;++i) wheel(w,-120);
+            flush(w); flush(w);
+            require(forwarded==2 && totalDelta==-48000,"large native burst is not truncated to 16 bits");
+            SendMessageW(w,WM_TIMER,ks::ScrollIdleTimer,0);
+            DestroyWindow(w);
+        }
+        DestroyWindow(parent);
+        std::cout<<"Passed shared wheel batching regressions (list, edit, table, combo, window)\n";
+        return 0;
+    } catch(const std::exception &e) {
+        DestroyWindow(parent); std::cerr<<e.what()<<'\n'; return 1;
+    }
+}

tests/stroke_improvement.h

@@ -0,0 +1,96 @@
+#pragma once
+inline void testStrokeImprovement() {
+    auto require=[](bool ok,const char *message){if(!ok) throw std::runtime_error(message);};
+    auto path=[](std::vector<POINT> corners) {
+        std::vector<POINT> p;
+        for(size_t i=1;i<corners.size();++i) for(int j=0;j<25;++j) {
+            double t=j/25.0;
+            p.push_back({LONG(std::lround(corners[i-1].x*(1-t)+corners[i].x*t)),
+                         LONG(std::lround(corners[i-1].y*(1-t)+corners[i].y*t))});
+        }
+        p.push_back(corners.back()); return p;
+    };
+    for(bool tilted:{false,true}) {
+        auto p=path({{40,40},{240,40},{240,140},{40,140},{40,40}});
+        if(tilted) for(auto &q:p) {double x=q.x,y=q.y;q={LONG(std::lround(x*.866-y*.5+100)),LONG(std::lround(x*.5+y*.866))};}
+        for(size_t i=1;i+1<p.size();++i) p[i].y+=int(i%3)-1;
+        auto result=ks::improveScreenshotStroke(p);
+        require(result.size()==5,"recognize noisy and tilted rectangles");
+        double ax=result[1].x-result[0].x,ay=result[1].y-result[0].y;
+        double bx=result[2].x-result[1].x,by=result[2].y-result[1].y;
+        require(std::abs(ax*bx+ay*by)<300,"rectangle has perpendicular sides");
+    }
+    auto triangle=ks::improveScreenshotStroke(path({{130,30},{240,180},{30,180},{130,30}}));
+    for(auto corners:std::vector<std::vector<POINT>>{
+        {{435,172},{455,135},{481,76},{514,78},{567,78},{605,76},{631,103},{652,135},{681,171},{609,172},{539,174},{435,172}},
+        {{531,311},{553,280},{582,235},{616,236},{672,233},{686,264},{693,287},{710,318},{640,314},{531,311}},
+        {{70,40},{160,40},{220,150},{20,150},{70,40}}})
+    for(double angle:{0.0,.6,2.2}) for(bool reverse:{false,true}) {
+        auto p=path(corners);
+        for(auto &q:p) { double x=q.x,y=q.y; q={LONG(std::lround(x*std::cos(angle)-y*std::sin(angle)+700)),
+            LONG(std::lround(x*std::sin(angle)+y*std::cos(angle)+700))}; }
+        if(reverse) std::reverse(p.begin(),p.end());
+        ks::ScreenshotShape kind{}; auto result=ks::improveScreenshotStroke(p,&kind);
+        require(kind==ks::ScreenshotShape::Trapezoid && result.size()==5,"recognize hand-drawn and tilted trapezoids");
+        double ax=result[1].x-result[0].x,ay=result[1].y-result[0].y;
+        double bx=result[3].x-result[2].x,by=result[3].y-result[2].y;
+        require(std::abs(ax*by-ay*bx)/(std::hypot(ax,ay)*std::hypot(bx,by))<.025,"recognized trapezoid bases are parallel");
+    }
+    // Approximate the reported skewed square, including its small closing gap.
+    auto unevenBox=path({{662,297},{663,213},{659,199},{659,181},{691,181},{718,189},
+                        {753,195},{786,195},{775,217},{771,249},{771,289},{766,313},
+                        {745,311},{716,304},{689,300},{671,300}});
+    for(double factor:{.5,1.0,2.5}) for(bool reverse:{false,true}) {
+        auto p=unevenBox;
+        for(auto &q:p) {q.x=LONG(std::lround((q.x-650)*factor+50));q.y=LONG(std::lround((q.y-170)*factor+50));}
+        if(reverse) std::reverse(p.begin(),p.end());
+        ks::ScreenshotShape kind{};
+        auto result=ks::improveScreenshotStroke(p,&kind);
+        require(kind==ks::ScreenshotShape::Rectangle && result.size()==5,"uneven square must not become a circle");
+    }
+    require(triangle.size()==4,"recognize triangle");
+    for(double ry:{50.0,90.0}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=120;++i) {double a=i*2*3.141592653589793/120;
+            p.push_back({LONG(std::lround(150+90*std::cos(a))),LONG(std::lround(150+ry*std::sin(a)))});}
+        auto result=ks::improveScreenshotStroke(p);
+        require(result.size()==97 && result.front().x==result.back().x && result.front().y==result.back().y,
+                "recognize ellipse and circle as closed outlines");
+    }
+    auto open=path({{20,20},{200,20},{200,150},{60,150}});
+    // Hand-traced approximations of the uneven loops in the reported screenshot.
+    for(auto corners:std::vector<std::vector<POINT>>{
+        {{424,408},{449,407},{474,418},{487,439},{488,461},{475,485},{453,488},{432,479},{412,458},{410,435},{416,418},{431,409}},
+        {{352,474},{373,482},{389,501},{392,518},{378,529},{351,531},{331,519},{324,504},{326,486},{339,477},{352,474}},
+        {{246,236},{221,242},{192,256},{166,271},{151,289},{154,303},{172,316},{195,315},{226,305},{246,291},{250,272},{252,252},{246,236}}}) {
+        auto result=ks::improveScreenshotStroke(path(corners));
+        require(result.size()==97,"recognize uneven hand-drawn loops from screenshot");
+    }
+    for(double size:{35.0,100.0,300.0}) for(double aspect:{.5,1.0}) for(int direction:{-1,1}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=120;++i) {
+            double a=direction*(.3+i*5.85/120),r=1+.07*std::sin(3*a)+.035*std::cos(7*a);
+            double x=size*r*std::cos(a),y=size*aspect*r*std::sin(a);
+            p.push_back({LONG(std::lround(500+x*.866-y*.5)),LONG(std::lround(500+x*.5+y*.866))});
+        }
+        require(ks::improveScreenshotStroke(p).size()==97,"recognize wobbly tilted ovals with closing gaps at different sizes");
+    }
+    for(double turns:{.72,1.8}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=120;++i) {double a=i*turns*2*3.141592653589793/120;
+            p.push_back({LONG(std::lround(150+90*std::cos(a))),LONG(std::lround(150+70*std::sin(a)))});}
+        auto result=ks::improveScreenshotStroke(p);
+        require(result.size()!=97,"do not close broad arcs or repeated loops into ovals");
+    }
+    auto smoothed=ks::improveScreenshotStroke(open);
+    require(smoothed.size()>5 && smoothed.front().x==20 && smoothed.back().x==60,"open outline stays open");
+    auto scribble=path({{20,20},{200,150},{200,20},{20,150},{20,20}});
+    require(ks::improveScreenshotStroke(scribble).size()>97,"crossed scribble is not a shape");
+    require(ks::improveScreenshotStroke({{1,1},{1,1},{1,1},{1,1},{1,1}}).empty(),"stationary stroke unchanged");
+    std::vector<POINT> jitter;
+    for(int i=0;i<=100;++i) jitter.push_back({20+i*2,100+(i%2?2:-2)});
+    auto smooth=ks::improveScreenshotStroke(jitter);
+    double deviation=0; for(auto p:smooth) deviation+=std::abs(p.y-100);
+    require(deviation/smooth.size()<1.5 && smooth.front().y==jitter.front().y && smooth.back().y==jitter.back().y,
+            "smoothing reduces jitter and preserves endpoints");
+}

tests/tests.cpp

@@ -1,4 +1,5 @@
 #include "autocorrect.h"
+#include "history_preview.h"
 #include "ocr.h"
 #include "richtext.h"
 #include "storage.h"
@@ -22,6 +23,20 @@ void rejects(const std::function<void()> &f, const char *name)
     bool thrown = false;
     try
     {
+        {
+            std::map<std::wstring,int> previews;
+            std::set<std::wstring> visible;
+            for(int i=0;i<40;++i) previews[std::to_wstring(i)]=i;
+            for(int i=0;i<8;++i) visible.insert(std::to_wstring(i));
+            ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==32,"preview cache stays bounded");
+            for(const auto &id:visible) require(previews.contains(id),"visible preview survives eviction");
+            for(int i=0;i<40;++i) { auto id=std::to_wstring(i); previews[id]=i; visible.insert(id); }
+            ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==40,"tall viewport does not thrash visible previews");
+            visible.clear(); ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==32,"cache shrinks after leaving tall viewport");
+        }
         f();
     }
     catch (...)
@@ -177,6 +192,26 @@ int main(int argc, char **argv)
         require(ks::convert(L"hello привет", en, ru) == L"руддщ привет", "mixed text preserves target words");
         require(ks::convert(L"htdm.dftim", en, ru) == L"ревьюваешь", "punctuation in words");
         std::vector<ks::Layout> layouts{en, ru, uk};
+        ks::Run suffixRun;
+        suffixRun.keys = L"snipping ";
+        require(suffixRun.matchSuffix(L"зштп ", layouts, en) >= 0,
+                "recent Cyrillic suffix matches physical keys across layouts");
+        require(suffixRun.matchSuffix(L"ping ", layouts, en) == 0,
+                "recent English suffix matches physical keys");
+        require(suffixRun.matchSuffix(L"other", layouts, en) < 0 &&
+                    suffixRun.matchSuffix(L"", layouts, en) < 0 &&
+                    suffixRun.matchSuffix(L"snipping ", layouts, en) < 0,
+                "suffix recovery rejects unrelated, empty and complete ranges");
+        suffixRun.overflow = true;
+        require(suffixRun.matchSuffix(L"зштп ", layouts, en) < 0,
+                "suffix recovery rejects overflowed tracking");
+        suffixRun.overflow = false;
+        suffixRun.keys = L"LinkedIn ";
+        require(suffixRun.matchSuffix(L"лувШт ", layouts, en) >= 0,
+                "ChatGPT partial CamelCase selection matches tracked physical suffix");
+        require(suffixRun.match(L"ДштлувШт ", layouts, en) >= 0 &&
+                    suffixRun.match(L"лувШт ", layouts, en) < 0,
+                "CamelCase conversion still requires the complete tracked text after recovery");
         ks::AutoCorrector corrector;
         ks::Settings autoSettings;
         require(!autoSettings.autoCorrect, "auto-correction defaults off");
@@ -276,6 +311,14 @@ int main(int argc, char **argv)
             options.autoLanguages = {L"en", L"uk", L"ru"};
             options.cycle = {L"en", L"uk", L"ru"};
             supplemental.configure(L"dictionaries", options.autoLanguages);
+            auto current = supplemental.suggest(L"Gjnjxys ", 0, layouts, options);
+            require(current && current->text == L"Поточні " && current->target == 2,
+                    "reported title-case Ukrainian word corrects with all three dictionaries enabled");
+            current = supplemental.suggest(L"Поточны ", 1, layouts, options);
+            require(current && current->text == L"Поточні " && current->target == 2,
+                    "reported Ukrainian word corrects from Russian layout");
+            require(!supplemental.suggest(L"Поточні ", 2, layouts, options),
+                    "correct Ukrainian word remains unchanged");
             for (auto [typed, expected] : {std::pair{L"ntcn ", L"тест "}, std::pair{L"vfkj ", L"мало "}})
             {
                 auto shared = supplemental.suggest(typed, 0, layouts, options);
@@ -292,6 +335,8 @@ int main(int argc, char **argv)
             require(!supplemental.suggest(L"релиз ", 1, layouts, options),
                     "valid Russian release word stays unchanged");
             options.autoMaxRank = 50000;
+            require(!supplemental.suggest(L"Gjnjxys ", 0, layouts, options),
+                    "supplemental current word respects explicit frequency limit");
             require(!supplemental.suggest(L"релыз ", 1, layouts, options),
                     "supplemental vocabulary respects explicit frequency limit");
             options.autoWords[L"uk"] = {L"релізик"};
@@ -322,6 +367,22 @@ int main(int argc, char **argv)
         require(ks::convertTo(L"ghbdtn", layouts, 1, 0) == L"привет", "hint conversion");
         require(ks::convertTo(L"привет", layouts, 1, 1) == L"привет", "same source is unchanged");
         require(ks::convertTo(L"?", layouts, 1, 0) == L",", "punctuation conversion");
+        require(ks::nextConversionLayout(L"рф", layouts, {0, 1, 2}, 1) == 0 &&
+                    ks::convertTo(L"рф", layouts, 0, 1) == L"ha",
+                "cycle skips unchanged Russian to Ukrainian and wraps to English");
+        require(ks::nextConversionLayout(L"шььш", layouts, {0, 2, 1}, 2) == 0 &&
+                    ks::convertTo(L"шььш", layouts, 0, 2) == L"immi",
+                "cycle skips unchanged Ukrainian to Russian");
+        require(ks::nextConversionLayout(L"і", layouts, {0, 2, 1}, 2) == 1,
+                "cycle keeps the next language when text changes");
+        require(ks::nextConversionLayout(L"ha", layouts, {0, 1, 2}, 0) == 1,
+                "cycle preserves configured order for changed text");
+        require(ks::nextConversionLayout(L"рф", layouts, {1, 2}, 1) == 2,
+                "cycle does not use disabled English when all candidates are unchanged");
+        require(ks::nextConversionLayout(L"123 ", layouts, {0, 1, 2}, 0) == 1,
+                "unchanged digits finish after a bounded cycle");
+        require(ks::nextConversionLayout(L"рф", layouts, {2, 0}, 1) == 0,
+                "source outside cycle still skips unchanged candidates");
         require(ks::cycleCase(L"hello world") == L"Hello World", "title case");
         require(ks::cycleCase(L"Hello World") == L"HELLO WORLD", "upper case");
         require(ks::cycleCase(L"ПРИВІТ") == L"привіт", "Unicode lower case");

tools/build-dictionaries.py

@@ -4,7 +4,7 @@ import urllib.request, hashlib, json
 ROOT=Path(__file__).resolve().parents[1]/'dictionaries'
 REV='525f9b560de45753a5ea01069454e72e9aa541c6'
 # Supplemental vocabulary has no corpus frequency: rank after the 50k source list.
-SUPPLEMENTAL={'uk': {'реліз': 50001}}
+SUPPLEMENTAL={'uk': {'реліз': 50001, 'поточні': 50001}}
 ROOT.mkdir(exist_ok=True)
 manifest={}
 for lang in ('en','uk','ru'):