Merge branch 'master' into docking. Remove Platform_SetImeInputPos. Remove backend-side IME implementation. Rrevert removal of MouseDragMaxDistanceAbs in 206b9ea. (#2589, #3113)

# Conflicts:
#	backends/imgui_impl_glfw.cpp
#	backends/imgui_impl_sdl.cpp
#	backends/imgui_impl_win32.cpp
#	imgui.cpp
#	imgui.h
#	imgui_internal.h
#	imgui_widgets.cpp

backends/imgui_impl_glfw.cpp

@@ -877,31 +877,6 @@ static void ImGui_ImplGlfw_SwapBuffers(ImGuiViewport* viewport, void*)
     }
 }
 
-//--------------------------------------------------------------------------------------------------------
-// IME (Input Method Editor) basic support for e.g. Asian language users
-//--------------------------------------------------------------------------------------------------------
-
-// We provide a Win32 implementation because this is such a common issue for IME users
-#if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)
-#define HAS_WIN32_IME   1
-#include <imm.h>
-#ifdef _MSC_VER
-#pragma comment(lib, "imm32")
-#endif
-static void ImGui_ImplWin32_SetImeInputPos(ImGuiViewport* viewport, ImVec2 pos)
-{
-    COMPOSITIONFORM cf = { CFS_FORCE_POSITION, { (LONG)(pos.x - viewport->Pos.x), (LONG)(pos.y - viewport->Pos.y) }, { 0, 0, 0, 0 } };
-    if (HWND hwnd = (HWND)viewport->PlatformHandleRaw)
-        if (HIMC himc = ::ImmGetContext(hwnd))
-        {
-            ::ImmSetCompositionWindow(himc, &cf);
-            ::ImmReleaseContext(hwnd, himc);
-        }
-}
-#else
-#define HAS_WIN32_IME   0
-#endif
-
 //--------------------------------------------------------------------------------------------------------
 // Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
 //--------------------------------------------------------------------------------------------------------
@@ -956,9 +931,6 @@ static void ImGui_ImplGlfw_InitPlatformInterface()
 #if GLFW_HAS_VULKAN
     platform_io.Platform_CreateVkSurface = ImGui_ImplGlfw_CreateVkSurface;
 #endif
-#if HAS_WIN32_IME
-    platform_io.Platform_SetImeInputPos = ImGui_ImplWin32_SetImeInputPos;
-#endif
 
     // Register main window handle (which is owned by the main application, not by us)
     // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.

backends/imgui_impl_metal.mm

@@ -14,6 +14,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-01-03: Metal: Ignore ImDrawCmd where ElemCount == 0 (very rare but can technically be manufactured by user code).
 //  2021-12-30: Metal: Added Metal C++ support. Enable with '#define IMGUI_IMPL_METAL_CPP' in your imconfig.h file.
 //  2021-08-24: Metal: Fixed a crash when clipping rect larger than framebuffer is submitted. (#4464)
 //  2021-05-19: Metal: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -554,6 +555,8 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
                 if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
                 if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
                     continue;
+                if (pcmd->ElemCount == 0) // drawIndexedPrimitives() validation doesn't accept this
+                    continue;
 
                 // Apply scissor/clipping rectangle
                 MTLScissorRect scissorRect =

backends/imgui_impl_sdl.cpp

@@ -260,6 +260,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
     bd->MouseCursors[ImGuiMouseCursor_Hand] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_HAND);
     bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NO);
 
+    // Set platform dependent data in viewport
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)window;
@@ -267,7 +268,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
     SDL_SysWMinfo info;
     SDL_VERSION(&info.version);
     if (SDL_GetWindowWMInfo(window, &info))
-        main_viewport->PlatformHandleRaw = info.info.win.window;
+        main_viewport->PlatformHandleRaw = (void*)info.info.win.window;
 #endif
 
     // Set SDL hint to receive mouse click events on window focus, otherwise SDL doesn't emit the event.

backends/imgui_impl_win32.cpp

@@ -670,35 +670,6 @@ float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd)
     return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
 }
 
-
-//--------------------------------------------------------------------------------------------------------
-// IME (Input Method Editor) basic support for e.g. Asian language users
-//--------------------------------------------------------------------------------------------------------
-
-#if defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP) // UWP doesn't have Win32 functions
-#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS
-#endif
-
-#if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)
-#define HAS_WIN32_IME   1
-#include <imm.h>
-#ifdef _MSC_VER
-#pragma comment(lib, "imm32")
-#endif
-static void ImGui_ImplWin32_SetImeInputPos(ImGuiViewport* viewport, ImVec2 pos)
-{
-    COMPOSITIONFORM cf = { CFS_FORCE_POSITION,{ (LONG)(pos.x - viewport->Pos.x), (LONG)(pos.y - viewport->Pos.y) },{ 0, 0, 0, 0 } };
-    if (HWND hwnd = (HWND)viewport->PlatformHandle)
-        if (HIMC himc = ::ImmGetContext(hwnd))
-        {
-            ::ImmSetCompositionWindow(himc, &cf);
-            ::ImmReleaseContext(hwnd, himc);
-        }
-}
-#else
-#define HAS_WIN32_IME   0
-#endif
-
 //--------------------------------------------------------------------------------------------------------
 // MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
 // This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
@@ -1001,9 +972,6 @@ static void ImGui_ImplWin32_InitPlatformInterface()
     platform_io.Platform_UpdateWindow = ImGui_ImplWin32_UpdateWindow;
     platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // FIXME-DPI
     platform_io.Platform_OnChangedViewport = ImGui_ImplWin32_OnChangedViewport; // FIXME-DPI
-#if HAS_WIN32_IME
-    platform_io.Platform_SetImeInputPos = ImGui_ImplWin32_SetImeInputPos;
-#endif
 
     // Register main window handle (which is owned by the main application, not by us)
     // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.

docs/CHANGELOG.txt

@@ -67,7 +67,6 @@ Breaking Changes:
    - Likewise io.MousePos and GetMousePos() will use OS coordinates.
      If you query mouse positions to interact with non-imgui coordinates you will need to offset them.
      e.g. subtract GetWindowViewport()->Pos.
-- IO: Moved IME support functions from io.ImeSetInputScreenPosFn, io.ImeWindowHandle to the PlatformIO api.
 - IO: Removed io.DisplayVisibleMin, io.DisplayVisibleMax settings (they were marked obsoleted, used to clip within the (0,0)..(DisplaySize) range).
 
 Other changes:
@@ -111,6 +110,13 @@ Breaking Changes:
   - ImGui::TreeAdvanceToLabelPos()      -> use ImGui::SetCursorPosX(ImGui::GetCursorPosX() + ImGui::GetTreeNodeToLabelSpacing());
   - ImFontAtlas::CustomRect             -> use ImFontAtlasCustomRect
   - ImGuiColorEditFlags_RGB/HSV/HEX     -> use ImGuiColorEditFlags_DisplayRGB/HSV/Hex
+- Removed io.ImeSetInputScreenPosFn() in favor of more flexible io.SetPlatformImeDataFn() for IME support.
+  Because this field was mostly only ever used by Dear ImGui internally, not by backends nor the vast majority
+  of user code, this should only affect a very small fraction for users who are already very IME-aware.
+- Obsoleted 'void* io.ImeWindowHandle' in favor of writing to 'void* ImGuiViewport::PlatformHandleRaw'.
+  This removes an incompatibility between 'master' and 'multi-viewports' backends and toward enabling
+  better support for IME. Updated backends accordingly. Because the old field is set by existing backends,
+  we are keeping it (marked as obsolete).
 
 Other Changes:
 
@@ -118,15 +124,25 @@ Other Changes:
   which would makes the draw operation of some backends assert (e.g. Metal with debugging). (#4857)
 - Tables, ImDrawListSplitter: Fixed erroneously stripping trailing ImDrawList::AddCallback() when submitted in
   last column or last channel and when there are no other drawing operation. (#4843, #4844) [@hoffstadt]
+- Platform IME: changed io.ImeSetInputScreenPosFn() to io.SetPlatformImeDataFn() API,
+  now taking a ImGuiPlatformImeData structure which we can more easily extend in the future.
+- Platform IME: moved io.ImeWindowHandle to GetMainViewport()->PlatformHandleRaw.
+- Platform IME: add ImGuiPlatformImeData::WantVisible, hide IME composition window when not used. (#2589) [@actboy168]
+- Platform IME: add ImGuiPlatformImeData::InputLineHeight. (#3113) [@liuliu]
+- Platform IME: [windows] call ImmSetCandidateWindow() to position candidate window.
 - Backends: OpenGL3: Fixed a buffer overflow in imgui_impl_opengl3_loader.h init (added in 1.86). (#4468, #4830) [@dymk]
   It would generally not have noticeable side-effect at runtime but would be detected by runtime checkers.
 - Backends: Metal: Added Apple Metal C++ API support. (#4824, #4746) [@luigifcruz]
   Enable with '#define IMGUI_IMPL_METAL_CPP' in your imconfig.h file.
+- Backends: Metal: Ignore ImDrawCmd where ElemCount == 0, which are normally not emitted by the library but
+  can theorically be created by user code manipulating a ImDrawList. (#4857)
 
 Docking+Viewports Branch:
 
 - Viewports: Fixed a CTRL+TAB crash with viewports enabled when the window list needs to appears in
   its own viewport (regression from 1.86). (#4023, #787)
+- (Breaking) Removed ImGuiPlatformIO::Platform_SetImeInputPos() in favor of newly standardized
+  io.SetPlatformImeDataFn() function. Should not affect more than default backends.
 
 
 -----------------------------------------------------------------------

docs/FAQ.md

@@ -607,8 +607,8 @@ Text input: it is up to your application to pass the right character code by cal
 The applications in examples/ are doing that.
 Windows: you can use the WM_CHAR or WM_UNICHAR or WM_IME_CHAR message (depending if your app is built using Unicode or MultiByte mode).
 You may also use MultiByteToWideChar() or ToUnicode() to retrieve Unicode codepoints from MultiByte characters or keyboard state.
-Windows: if your language is relying on an Input Method Editor (IME), you copy the HWND of your window to io.ImeWindowHandle in order for
-the default implementation of io.ImeSetInputScreenPosFn() to set your Microsoft IME position correctly.
+Windows: if your language is relying on an Input Method Editor (IME), you can write your HWND to ImGui::GetMainViewport()->PlatformHandleRaw
+in order for the default the default implementation of io.SetPlatformImeDataFn() to set your Microsoft IME position correctly.
 
 ##### [Return to Index](#index)
 

imgui.cpp

@@ -70,6 +70,7 @@ CODE
 // [SECTION] STYLING
 // [SECTION] RENDER HELPERS
 // [SECTION] MAIN CODE (most of the code! lots of stuff, needs tidying up!)
+// [SECTION] INPUTS
 // [SECTION] ERROR CHECKING
 // [SECTION] LAYOUT
 // [SECTION] SCROLLING
@@ -295,6 +296,7 @@ CODE
        // TODO: Setup viewport covering draw_data->DisplayPos to draw_data->DisplayPos + draw_data->DisplaySize
        // TODO: Setup orthographic projection matrix cover draw_data->DisplayPos to draw_data->DisplayPos + draw_data->DisplaySize
        // TODO: Setup shader: vertex { float2 pos, float2 uv, u32 color }, fragment shader sample color from 1 texture, multiply by vertex color.
+       ImVec2 clip_off = draw_data->DisplayPos;
        for (int n = 0; n < draw_data->CmdListsCount; n++)
        {
           const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -309,9 +311,11 @@ CODE
              }
              else
              {
-                 // The texture for the draw call is specified by pcmd->GetTexID().
-                 // The vast majority of draw calls will use the Dear ImGui texture atlas, which value you have set yourself during initialization.
-                 MyEngineBindTexture((MyTexture*)pcmd->GetTexID());
+                 // Project scissor/clipping rectangles into framebuffer space
+                 ImVec2 clip_min(pcmd->ClipRect.x - clip_off.x, pcmd->ClipRect.y - clip_off.y);
+                 ImVec2 clip_max(pcmd->ClipRect.z - clip_off.x, pcmd->ClipRect.w - clip_off.y);
+                 if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
+                     continue;
 
                  // We are using scissoring to clip some objects. All low-level graphics API should support it.
                  // - If your engine doesn't support scissoring yet, you may ignore this at first. You will get some small glitches
@@ -322,14 +326,16 @@ CODE
                  //   - In the interest of supporting multi-viewport applications (see 'docking' branch on github),
                  //     always subtract draw_data->DisplayPos from clipping bounds to convert them to your viewport space.
                  // - Note that pcmd->ClipRect contains Min+Max bounds. Some graphics API may use Min+Max, other may use Min+Size (size being Max-Min)
-                 ImVec2 pos = draw_data->DisplayPos;
-                 MyEngineScissor((int)(pcmd->ClipRect.x - pos.x), (int)(pcmd->ClipRect.y - pos.y), (int)(pcmd->ClipRect.z - pos.x), (int)(pcmd->ClipRect.w - pos.y));
+                 MyEngineSetScissor(clip_min.x, clip_min.y, clip_max.x, clip_max.y);
+
+                 // The texture for the draw call is specified by pcmd->GetTexID().
+                 // The vast majority of draw calls will use the Dear ImGui texture atlas, which value you have set yourself during initialization.
+                 MyEngineBindTexture((MyTexture*)pcmd->GetTexID());
 
                  // Render 'pcmd->ElemCount/3' indexed triangles.
                  // By default the indices ImDrawIdx are 16-bit, you can change them to 32-bit in imconfig.h if your engine doesn't support 16-bit indices.
-                 MyEngineDrawIndexedTriangles(pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer, vtx_buffer);
+                 MyEngineDrawIndexedTriangles(pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer + pcmd->IdxOffset, vtx_buffer, pcmd->VtxOffset);
              }
-             idx_buffer += pcmd->ElemCount;
           }
        }
     }
@@ -387,9 +393,8 @@ CODE
                           you may use GetMainViewport()->Pos to offset hard-coded positions, e.g. SetNextWindowPos(GetMainViewport()->Pos)
                         - likewise io.MousePos and GetMousePos() will use OS coordinates.
                           If you query mouse positions to interact with non-imgui coordinates you will need to offset them, e.g. subtract GetWindowViewport()->Pos.
- - 2021/XX/XX (1.XX) - Moved IME support functions from io.ImeSetInputScreenPosFn, io.ImeWindowHandle to the PlatformIO api.
-
 
+ - 2022/03/05 (1.87) - removed io.ImeSetInputScreenPosFn() in favor of more flexible io.SetPlatformImeDataFn(). Removed 'void* io.ImeWindowHandle' in favor of writing to 'void* ImGuiViewport::PlatformHandleRaw'.
  - 2022/03/01 (1.87) - commented out redirecting functions/enums names that were marked obsolete in 1.69, 1.70, 1.71, 1.72 (March-July 2019)
                         - ImGui::SetNextTreeNodeOpen()        -> use ImGui::SetNextItemOpen()
                         - ImGui::GetContentRegionAvailWidth() -> use ImGui::GetContentRegionAvail().x
@@ -927,6 +932,7 @@ static void             WindowSettingsHandler_WriteAll(ImGuiContext*, ImGuiSetti
 // Platform Dependents default implementation for IO functions
 static const char*      GetClipboardTextFn_DefaultImpl(void* user_data);
 static void             SetClipboardTextFn_DefaultImpl(void* user_data, const char* text);
+static void             SetPlatformImeDataFn_DefaultImpl(ImGuiViewport* viewport, ImGuiPlatformImeData* data);
 
 namespace ImGui
 {
@@ -1167,6 +1173,7 @@ ImGuiIO::ImGuiIO()
     GetClipboardTextFn = GetClipboardTextFn_DefaultImpl;   // Platform dependent default implementations
     SetClipboardTextFn = SetClipboardTextFn_DefaultImpl;
     ClipboardUserData = NULL;
+    SetPlatformImeDataFn = SetPlatformImeDataFn_DefaultImpl;
 
     // Input (NB: we already have memset zero the entire structure!)
     MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
@@ -3879,62 +3886,63 @@ static bool IsWindowActiveAndVisible(ImGuiWindow* window)
 static void ImGui::UpdateMouseInputs()
 {
     ImGuiContext& g = *GImGui;
+    ImGuiIO& io = g.IO;
 
     // Round mouse position to avoid spreading non-rounded position (e.g. UpdateManualResize doesn't support them well)
-    if (IsMousePosValid(&g.IO.MousePos))
-        g.IO.MousePos = g.MouseLastValidPos = ImFloor(g.IO.MousePos);
+    if (IsMousePosValid(&io.MousePos))
+        io.MousePos = g.MouseLastValidPos = ImFloor(io.MousePos);
 
     // If mouse just appeared or disappeared (usually denoted by -FLT_MAX components) we cancel out movement in MouseDelta
-    if (IsMousePosValid(&g.IO.MousePos) && IsMousePosValid(&g.IO.MousePosPrev))
-        g.IO.MouseDelta = g.IO.MousePos - g.IO.MousePosPrev;
+    if (IsMousePosValid(&io.MousePos) && IsMousePosValid(&io.MousePosPrev))
+        io.MouseDelta = io.MousePos - io.MousePosPrev;
     else
-        g.IO.MouseDelta = ImVec2(0.0f, 0.0f);
+        io.MouseDelta = ImVec2(0.0f, 0.0f);
 
     // If mouse moved we re-enable mouse hovering in case it was disabled by gamepad/keyboard. In theory should use a >0.0f threshold but would need to reset in everywhere we set this to true.
-    if (g.IO.MouseDelta.x != 0.0f || g.IO.MouseDelta.y != 0.0f)
+    if (io.MouseDelta.x != 0.0f || io.MouseDelta.y != 0.0f)
         g.NavDisableMouseHover = false;
 
-    g.IO.MousePosPrev = g.IO.MousePos;
-    for (int i = 0; i < IM_ARRAYSIZE(g.IO.MouseDown); i++)
+    io.MousePosPrev = io.MousePos;
+    for (int i = 0; i < IM_ARRAYSIZE(io.MouseDown); i++)
     {
-        g.IO.MouseClicked[i] = g.IO.MouseDown[i] && g.IO.MouseDownDuration[i] < 0.0f;
-        g.IO.MouseClickedCount[i] = 0; // Will be filled below
-        g.IO.MouseReleased[i] = !g.IO.MouseDown[i] && g.IO.MouseDownDuration[i] >= 0.0f;
-        g.IO.MouseDownDurationPrev[i] = g.IO.MouseDownDuration[i];
-        g.IO.MouseDownDuration[i] = g.IO.MouseDown[i] ? (g.IO.MouseDownDuration[i] < 0.0f ? 0.0f : g.IO.MouseDownDuration[i] + g.IO.DeltaTime) : -1.0f;
-        if (g.IO.MouseClicked[i])
+        io.MouseClicked[i] = io.MouseDown[i] && io.MouseDownDuration[i] < 0.0f;
+        io.MouseClickedCount[i] = 0; // Will be filled below
+        io.MouseReleased[i] = !io.MouseDown[i] && io.MouseDownDuration[i] >= 0.0f;
+        io.MouseDownDurationPrev[i] = io.MouseDownDuration[i];
+        io.MouseDownDuration[i] = io.MouseDown[i] ? (io.MouseDownDuration[i] < 0.0f ? 0.0f : io.MouseDownDuration[i] + io.DeltaTime) : -1.0f;
+        if (io.MouseClicked[i])
         {
             bool is_repeated_click = false;
-            if ((float)(g.Time - g.IO.MouseClickedTime[i]) < g.IO.MouseDoubleClickTime)
+            if ((float)(g.Time - io.MouseClickedTime[i]) < io.MouseDoubleClickTime)
             {
-                ImVec2 delta_from_click_pos = IsMousePosValid(&g.IO.MousePos) ? (g.IO.MousePos - g.IO.MouseClickedPos[i]) : ImVec2(0.0f, 0.0f);
-                if (ImLengthSqr(delta_from_click_pos) < g.IO.MouseDoubleClickMaxDist * g.IO.MouseDoubleClickMaxDist)
+                ImVec2 delta_from_click_pos = IsMousePosValid(&io.MousePos) ? (io.MousePos - io.MouseClickedPos[i]) : ImVec2(0.0f, 0.0f);
+                if (ImLengthSqr(delta_from_click_pos) < io.MouseDoubleClickMaxDist * io.MouseDoubleClickMaxDist)
                     is_repeated_click = true;
             }
             if (is_repeated_click)
-                g.IO.MouseClickedLastCount[i]++;
+                io.MouseClickedLastCount[i]++;
             else
-                g.IO.MouseClickedLastCount[i] = 1;
-            g.IO.MouseClickedTime[i] = g.Time;
-            g.IO.MouseClickedPos[i] = g.IO.MousePos;
-            g.IO.MouseClickedCount[i] = g.IO.MouseClickedLastCount[i];
-            g.IO.MouseDragMaxDistanceAbs[i] = ImVec2(0.0f, 0.0f);
-            g.IO.MouseDragMaxDistanceSqr[i] = 0.0f;
+                io.MouseClickedLastCount[i] = 1;
+            io.MouseClickedTime[i] = g.Time;
+            io.MouseClickedPos[i] = io.MousePos;
+            io.MouseClickedCount[i] = io.MouseClickedLastCount[i];
+            io.MouseDragMaxDistanceAbs[i] = ImVec2(0.0f, 0.0f);
+            io.MouseDragMaxDistanceSqr[i] = 0.0f;
         }
-        else if (g.IO.MouseDown[i])
+        else if (io.MouseDown[i])
         {
             // Maintain the maximum distance we reaching from the initial click position, which is used with dragging threshold
-            ImVec2 delta_from_click_pos = IsMousePosValid(&g.IO.MousePos) ? (g.IO.MousePos - g.IO.MouseClickedPos[i]) : ImVec2(0.0f, 0.0f);
-            g.IO.MouseDragMaxDistanceSqr[i] = ImMax(g.IO.MouseDragMaxDistanceSqr[i], ImLengthSqr(delta_from_click_pos));
-            g.IO.MouseDragMaxDistanceAbs[i].x = ImMax(g.IO.MouseDragMaxDistanceAbs[i].x, delta_from_click_pos.x < 0.0f ? -delta_from_click_pos.x : delta_from_click_pos.x);
-            g.IO.MouseDragMaxDistanceAbs[i].y = ImMax(g.IO.MouseDragMaxDistanceAbs[i].y, delta_from_click_pos.y < 0.0f ? -delta_from_click_pos.y : delta_from_click_pos.y);
+            ImVec2 delta_from_click_pos = IsMousePosValid(&io.MousePos) ? (io.MousePos - io.MouseClickedPos[i]) : ImVec2(0.0f, 0.0f);
+            io.MouseDragMaxDistanceSqr[i] = ImMax(io.MouseDragMaxDistanceSqr[i], ImLengthSqr(delta_from_click_pos));
+            io.MouseDragMaxDistanceAbs[i].x = ImMax(io.MouseDragMaxDistanceAbs[i].x, delta_from_click_pos.x < 0.0f ? -delta_from_click_pos.x : delta_from_click_pos.x);
+            io.MouseDragMaxDistanceAbs[i].y = ImMax(io.MouseDragMaxDistanceAbs[i].y, delta_from_click_pos.y < 0.0f ? -delta_from_click_pos.y : delta_from_click_pos.y);
         }
 
         // We provide io.MouseDoubleClicked[] as a legacy service
-        g.IO.MouseDoubleClicked[i] = (g.IO.MouseClickedCount[i] == 2);
+        io.MouseDoubleClicked[i] = (io.MouseClickedCount[i] == 2);
 
         // Clicking any mouse button reactivate mouse hovering which may have been deactivated by gamepad/keyboard navigation
-        if (g.IO.MouseClicked[i])
+        if (io.MouseClicked[i])
             g.NavDisableMouseHover = false;
     }
 }
@@ -4283,8 +4291,10 @@ void ImGui::NewFrame()
 
     g.MouseCursor = ImGuiMouseCursor_Arrow;
     g.WantCaptureMouseNextFrame = g.WantCaptureKeyboardNextFrame = g.WantTextInputNextFrame = -1;
-    g.PlatformImePos = ImVec2(1.0f, 1.0f); // OS Input Method Editor showing on top-left of our window by default
-    g.PlatformImePosViewport = NULL;
+
+    // Platform IME data: reset for the frame
+    g.PlatformImeDataPrev = g.PlatformImeData;
+    g.PlatformImeData.WantVisible = false;
 
     // Mouse wheel scrolling, scale
     UpdateMouseWheel();
@@ -4759,14 +4769,12 @@ void ImGui::EndFrame()
 
     ErrorCheckEndFrameSanityChecks();
 
-    // Notify OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
-    if (g.PlatformIO.Platform_SetImeInputPos && (g.PlatformImeLastPos.x == FLT_MAX || ImLengthSqr(g.PlatformImePos - g.PlatformImeLastPos) > 0.0001f))
-        if (g.PlatformImePosViewport && g.PlatformImePosViewport->PlatformWindowCreated)
-        {
-            g.PlatformIO.Platform_SetImeInputPos(g.PlatformImePosViewport, g.PlatformImePos);
-            g.PlatformImeLastPos = g.PlatformImePos;
-            g.PlatformImePosViewport = NULL;
-        }
+    // Notify Platform/OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
+    if (g.IO.SetPlatformImeDataFn && memcmp(&g.PlatformImeData, &g.PlatformImeDataPrev, sizeof(ImGuiPlatformImeData)) != 0)
+    {
+        ImGuiViewport* viewport = FindViewportByID(g.PlatformImeViewport);
+        g.IO.SetPlatformImeDataFn(viewport ? viewport : GetMainViewport(), &g.PlatformImeData);
+    }
 
     // Hide implicit/fallback "Debug" window if it hasn't been used
     g.WithinFrameScopeWithImplicitWindow = false;
@@ -5010,240 +5018,6 @@ static void FindHoveredWindow()
         g.MovingWindow->Viewport = moving_window_viewport;
 }
 
-// Test if mouse cursor is hovering given rectangle
-// NB- Rectangle is clipped by our current clip setting
-// NB- Expand the rectangle to be generous on imprecise inputs systems (g.Style.TouchExtraPadding)
-bool ImGui::IsMouseHoveringRect(const ImVec2& r_min, const ImVec2& r_max, bool clip)
-{
-    ImGuiContext& g = *GImGui;
-
-    // Clip
-    ImRect rect_clipped(r_min, r_max);
-    if (clip)
-        rect_clipped.ClipWith(g.CurrentWindow->ClipRect);
-
-    // Expand for touch input
-    const ImRect rect_for_touch(rect_clipped.Min - g.Style.TouchExtraPadding, rect_clipped.Max + g.Style.TouchExtraPadding);
-    if (!rect_for_touch.Contains(g.IO.MousePos))
-        return false;
-    if (!g.MouseViewport->GetMainRect().Overlaps(rect_clipped))
-        return false;
-    return true;
-}
-
-int ImGui::GetKeyIndex(ImGuiKey imgui_key)
-{
-    IM_ASSERT(imgui_key >= 0 && imgui_key < ImGuiKey_COUNT);
-    ImGuiContext& g = *GImGui;
-    return g.IO.KeyMap[imgui_key];
-}
-
-// Note that dear imgui doesn't know the semantic of each entry of io.KeysDown[]!
-// Use your own indices/enums according to how your backend/engine stored them into io.KeysDown[]!
-bool ImGui::IsKeyDown(int user_key_index)
-{
-    if (user_key_index < 0)
-        return false;
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
-    return g.IO.KeysDown[user_key_index];
-}
-
-// t0 = previous time (e.g.: g.Time - g.IO.DeltaTime)
-// t1 = current time (e.g.: g.Time)
-// An event is triggered at:
-//  t = 0.0f     t = repeat_delay,    t = repeat_delay + repeat_rate*N
-int ImGui::CalcTypematicRepeatAmount(float t0, float t1, float repeat_delay, float repeat_rate)
-{
-    if (t1 == 0.0f)
-        return 1;
-    if (t0 >= t1)
-        return 0;
-    if (repeat_rate <= 0.0f)
-        return (t0 < repeat_delay) && (t1 >= repeat_delay);
-    const int count_t0 = (t0 < repeat_delay) ? -1 : (int)((t0 - repeat_delay) / repeat_rate);
-    const int count_t1 = (t1 < repeat_delay) ? -1 : (int)((t1 - repeat_delay) / repeat_rate);
-    const int count = count_t1 - count_t0;
-    return count;
-}
-
-int ImGui::GetKeyPressedAmount(int key_index, float repeat_delay, float repeat_rate)
-{
-    ImGuiContext& g = *GImGui;
-    if (key_index < 0)
-        return 0;
-    IM_ASSERT(key_index >= 0 && key_index < IM_ARRAYSIZE(g.IO.KeysDown));
-    const float t = g.IO.KeysDownDuration[key_index];
-    return CalcTypematicRepeatAmount(t - g.IO.DeltaTime, t, repeat_delay, repeat_rate);
-}
-
-bool ImGui::IsKeyPressed(int user_key_index, bool repeat)
-{
-    ImGuiContext& g = *GImGui;
-    if (user_key_index < 0)
-        return false;
-    IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
-    const float t = g.IO.KeysDownDuration[user_key_index];
-    if (t == 0.0f)
-        return true;
-    if (repeat && t > g.IO.KeyRepeatDelay)
-        return GetKeyPressedAmount(user_key_index, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate) > 0;
-    return false;
-}
-
-bool ImGui::IsKeyReleased(int user_key_index)
-{
-    ImGuiContext& g = *GImGui;
-    if (user_key_index < 0) return false;
-    IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
-    return g.IO.KeysDownDurationPrev[user_key_index] >= 0.0f && !g.IO.KeysDown[user_key_index];
-}
-
-bool ImGui::IsMouseDown(ImGuiMouseButton button)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    return g.IO.MouseDown[button];
-}
-
-bool ImGui::IsMouseClicked(ImGuiMouseButton button, bool repeat)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    const float t = g.IO.MouseDownDuration[button];
-    if (t == 0.0f)
-        return true;
-
-    if (repeat && t > g.IO.KeyRepeatDelay)
-    {
-        // FIXME: 2019/05/03: Our old repeat code was wrong here and led to doubling the repeat rate, which made it an ok rate for repeat on mouse hold.
-        int amount = CalcTypematicRepeatAmount(t - g.IO.DeltaTime, t, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate * 0.50f);
-        if (amount > 0)
-            return true;
-    }
-    return false;
-}
-
-bool ImGui::IsMouseReleased(ImGuiMouseButton button)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    return g.IO.MouseReleased[button];
-}
-
-bool ImGui::IsMouseDoubleClicked(ImGuiMouseButton button)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    return g.IO.MouseClickedCount[button] == 2;
-}
-
-int ImGui::GetMouseClickedCount(ImGuiMouseButton button)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    return g.IO.MouseClickedCount[button];
-}
-
-// Return if a mouse click/drag went past the given threshold. Valid to call during the MouseReleased frame.
-// [Internal] This doesn't test if the button is pressed
-bool ImGui::IsMouseDragPastThreshold(ImGuiMouseButton button, float lock_threshold)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    if (lock_threshold < 0.0f)
-        lock_threshold = g.IO.MouseDragThreshold;
-    return g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold;
-}
-
-bool ImGui::IsMouseDragging(ImGuiMouseButton button, float lock_threshold)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    if (!g.IO.MouseDown[button])
-        return false;
-    return IsMouseDragPastThreshold(button, lock_threshold);
-}
-
-ImVec2 ImGui::GetMousePos()
-{
-    ImGuiContext& g = *GImGui;
-    return g.IO.MousePos;
-}
-
-// NB: prefer to call right after BeginPopup(). At the time Selectable/MenuItem is activated, the popup is already closed!
-ImVec2 ImGui::GetMousePosOnOpeningCurrentPopup()
-{
-    ImGuiContext& g = *GImGui;
-    if (g.BeginPopupStack.Size > 0)
-        return g.OpenPopupStack[g.BeginPopupStack.Size - 1].OpenMousePos;
-    return g.IO.MousePos;
-}
-
-// We typically use ImVec2(-FLT_MAX,-FLT_MAX) to denote an invalid mouse position.
-bool ImGui::IsMousePosValid(const ImVec2* mouse_pos)
-{
-    // The assert is only to silence a false-positive in XCode Static Analysis.
-    // Because GImGui is not dereferenced in every code path, the static analyzer assume that it may be NULL (which it doesn't for other functions).
-    IM_ASSERT(GImGui != NULL);
-    const float MOUSE_INVALID = -256000.0f;
-    ImVec2 p = mouse_pos ? *mouse_pos : GImGui->IO.MousePos;
-    return p.x >= MOUSE_INVALID && p.y >= MOUSE_INVALID;
-}
-
-bool ImGui::IsAnyMouseDown()
-{
-    ImGuiContext& g = *GImGui;
-    for (int n = 0; n < IM_ARRAYSIZE(g.IO.MouseDown); n++)
-        if (g.IO.MouseDown[n])
-            return true;
-    return false;
-}
-
-// Return the delta from the initial clicking position while the mouse button is clicked or was just released.
-// This is locked and return 0.0f until the mouse moves past a distance threshold at least once.
-// NB: This is only valid if IsMousePosValid(). backends in theory should always keep mouse position valid when dragging even outside the client window.
-ImVec2 ImGui::GetMouseDragDelta(ImGuiMouseButton button, float lock_threshold)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    if (lock_threshold < 0.0f)
-        lock_threshold = g.IO.MouseDragThreshold;
-    if (g.IO.MouseDown[button] || g.IO.MouseReleased[button])
-        if (g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold)
-            if (IsMousePosValid(&g.IO.MousePos) && IsMousePosValid(&g.IO.MouseClickedPos[button]))
-                return g.IO.MousePos - g.IO.MouseClickedPos[button];
-    return ImVec2(0.0f, 0.0f);
-}
-
-void ImGui::ResetMouseDragDelta(ImGuiMouseButton button)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
-    // NB: We don't need to reset g.IO.MouseDragMaxDistanceSqr
-    g.IO.MouseClickedPos[button] = g.IO.MousePos;
-}
-
-ImGuiMouseCursor ImGui::GetMouseCursor()
-{
-    return GImGui->MouseCursor;
-}
-
-void ImGui::SetMouseCursor(ImGuiMouseCursor cursor_type)
-{
-    GImGui->MouseCursor = cursor_type;
-}
-
-void ImGui::CaptureKeyboardFromApp(bool capture)
-{
-    GImGui->WantCaptureKeyboardNextFrame = capture ? 1 : 0;
-}
-
-void ImGui::CaptureMouseFromApp(bool capture)
-{
-    GImGui->WantCaptureMouseNextFrame = capture ? 1 : 0;
-}
-
 bool ImGui::IsItemActive()
 {
     ImGuiContext& g = *GImGui;
@@ -8043,6 +7817,249 @@ bool ImGui::IsRectVisible(const ImVec2& rect_min, const ImVec2& rect_max)
 }
 
 
+//-----------------------------------------------------------------------------
+// [SECTION] INPUTS
+//-----------------------------------------------------------------------------
+
+// Test if mouse cursor is hovering given rectangle
+// NB- Rectangle is clipped by our current clip setting
+// NB- Expand the rectangle to be generous on imprecise inputs systems (g.Style.TouchExtraPadding)
+bool ImGui::IsMouseHoveringRect(const ImVec2& r_min, const ImVec2& r_max, bool clip)
+{
+    ImGuiContext& g = *GImGui;
+
+    // Clip
+    ImRect rect_clipped(r_min, r_max);
+    if (clip)
+        rect_clipped.ClipWith(g.CurrentWindow->ClipRect);
+
+    // Expand for touch input
+    const ImRect rect_for_touch(rect_clipped.Min - g.Style.TouchExtraPadding, rect_clipped.Max + g.Style.TouchExtraPadding);
+    if (!rect_for_touch.Contains(g.IO.MousePos))
+        return false;
+    if (!g.MouseViewport->GetMainRect().Overlaps(rect_clipped))
+        return false;
+    return true;
+}
+
+int ImGui::GetKeyIndex(ImGuiKey imgui_key)
+{
+    IM_ASSERT(imgui_key >= 0 && imgui_key < ImGuiKey_COUNT);
+    ImGuiContext& g = *GImGui;
+    return g.IO.KeyMap[imgui_key];
+}
+
+// Note that dear imgui doesn't know the semantic of each entry of io.KeysDown[]!
+// Use your own indices/enums according to how your backend/engine stored them into io.KeysDown[]!
+bool ImGui::IsKeyDown(int user_key_index)
+{
+    if (user_key_index < 0)
+        return false;
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
+    return g.IO.KeysDown[user_key_index];
+}
+
+// t0 = previous time (e.g.: g.Time - g.IO.DeltaTime)
+// t1 = current time (e.g.: g.Time)
+// An event is triggered at:
+//  t = 0.0f     t = repeat_delay,    t = repeat_delay + repeat_rate*N
+int ImGui::CalcTypematicRepeatAmount(float t0, float t1, float repeat_delay, float repeat_rate)
+{
+    if (t1 == 0.0f)
+        return 1;
+    if (t0 >= t1)
+        return 0;
+    if (repeat_rate <= 0.0f)
+        return (t0 < repeat_delay) && (t1 >= repeat_delay);
+    const int count_t0 = (t0 < repeat_delay) ? -1 : (int)((t0 - repeat_delay) / repeat_rate);
+    const int count_t1 = (t1 < repeat_delay) ? -1 : (int)((t1 - repeat_delay) / repeat_rate);
+    const int count = count_t1 - count_t0;
+    return count;
+}
+
+int ImGui::GetKeyPressedAmount(int key_index, float repeat_delay, float repeat_rate)
+{
+    ImGuiContext& g = *GImGui;
+    if (key_index < 0)
+        return 0;
+    IM_ASSERT(key_index >= 0 && key_index < IM_ARRAYSIZE(g.IO.KeysDown));
+    const float t = g.IO.KeysDownDuration[key_index];
+    return CalcTypematicRepeatAmount(t - g.IO.DeltaTime, t, repeat_delay, repeat_rate);
+}
+
+bool ImGui::IsKeyPressed(int user_key_index, bool repeat)
+{
+    ImGuiContext& g = *GImGui;
+    if (user_key_index < 0)
+        return false;
+    IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
+    const float t = g.IO.KeysDownDuration[user_key_index];
+    if (t == 0.0f)
+        return true;
+    if (repeat && t > g.IO.KeyRepeatDelay)
+        return GetKeyPressedAmount(user_key_index, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate) > 0;
+    return false;
+}
+
+bool ImGui::IsKeyReleased(int user_key_index)
+{
+    ImGuiContext& g = *GImGui;
+    if (user_key_index < 0) return false;
+    IM_ASSERT(user_key_index >= 0 && user_key_index < IM_ARRAYSIZE(g.IO.KeysDown));
+    return g.IO.KeysDownDurationPrev[user_key_index] >= 0.0f && !g.IO.KeysDown[user_key_index];
+}
+
+bool ImGui::IsMouseDown(ImGuiMouseButton button)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    return g.IO.MouseDown[button];
+}
+
+bool ImGui::IsMouseClicked(ImGuiMouseButton button, bool repeat)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    const float t = g.IO.MouseDownDuration[button];
+    if (t == 0.0f)
+        return true;
+
+    if (repeat && t > g.IO.KeyRepeatDelay)
+    {
+        // FIXME: 2019/05/03: Our old repeat code was wrong here and led to doubling the repeat rate, which made it an ok rate for repeat on mouse hold.
+        int amount = CalcTypematicRepeatAmount(t - g.IO.DeltaTime, t, g.IO.KeyRepeatDelay, g.IO.KeyRepeatRate * 0.50f);
+        if (amount > 0)
+            return true;
+    }
+    return false;
+}
+
+bool ImGui::IsMouseReleased(ImGuiMouseButton button)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    return g.IO.MouseReleased[button];
+}
+
+bool ImGui::IsMouseDoubleClicked(ImGuiMouseButton button)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    return g.IO.MouseClickedCount[button] == 2;
+}
+
+int ImGui::GetMouseClickedCount(ImGuiMouseButton button)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    return g.IO.MouseClickedCount[button];
+}
+
+// Return if a mouse click/drag went past the given threshold. Valid to call during the MouseReleased frame.
+// [Internal] This doesn't test if the button is pressed
+bool ImGui::IsMouseDragPastThreshold(ImGuiMouseButton button, float lock_threshold)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    if (lock_threshold < 0.0f)
+        lock_threshold = g.IO.MouseDragThreshold;
+    return g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold;
+}
+
+bool ImGui::IsMouseDragging(ImGuiMouseButton button, float lock_threshold)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    if (!g.IO.MouseDown[button])
+        return false;
+    return IsMouseDragPastThreshold(button, lock_threshold);
+}
+
+ImVec2 ImGui::GetMousePos()
+{
+    ImGuiContext& g = *GImGui;
+    return g.IO.MousePos;
+}
+
+// NB: prefer to call right after BeginPopup(). At the time Selectable/MenuItem is activated, the popup is already closed!
+ImVec2 ImGui::GetMousePosOnOpeningCurrentPopup()
+{
+    ImGuiContext& g = *GImGui;
+    if (g.BeginPopupStack.Size > 0)
+        return g.OpenPopupStack[g.BeginPopupStack.Size - 1].OpenMousePos;
+    return g.IO.MousePos;
+}
+
+// We typically use ImVec2(-FLT_MAX,-FLT_MAX) to denote an invalid mouse position.
+bool ImGui::IsMousePosValid(const ImVec2* mouse_pos)
+{
+    // The assert is only to silence a false-positive in XCode Static Analysis.
+    // Because GImGui is not dereferenced in every code path, the static analyzer assume that it may be NULL (which it doesn't for other functions).
+    IM_ASSERT(GImGui != NULL);
+    const float MOUSE_INVALID = -256000.0f;
+    ImVec2 p = mouse_pos ? *mouse_pos : GImGui->IO.MousePos;
+    return p.x >= MOUSE_INVALID && p.y >= MOUSE_INVALID;
+}
+
+bool ImGui::IsAnyMouseDown()
+{
+    ImGuiContext& g = *GImGui;
+    for (int n = 0; n < IM_ARRAYSIZE(g.IO.MouseDown); n++)
+        if (g.IO.MouseDown[n])
+            return true;
+    return false;
+}
+
+// Return the delta from the initial clicking position while the mouse button is clicked or was just released.
+// This is locked and return 0.0f until the mouse moves past a distance threshold at least once.
+// NB: This is only valid if IsMousePosValid(). backends in theory should always keep mouse position valid when dragging even outside the client window.
+ImVec2 ImGui::GetMouseDragDelta(ImGuiMouseButton button, float lock_threshold)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    if (lock_threshold < 0.0f)
+        lock_threshold = g.IO.MouseDragThreshold;
+    if (g.IO.MouseDown[button] || g.IO.MouseReleased[button])
+        if (g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold)
+            if (IsMousePosValid(&g.IO.MousePos) && IsMousePosValid(&g.IO.MouseClickedPos[button]))
+                return g.IO.MousePos - g.IO.MouseClickedPos[button];
+    return ImVec2(0.0f, 0.0f);
+}
+
+void ImGui::ResetMouseDragDelta(ImGuiMouseButton button)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
+    // NB: We don't need to reset g.IO.MouseDragMaxDistanceSqr
+    g.IO.MouseClickedPos[button] = g.IO.MousePos;
+}
+
+ImGuiMouseCursor ImGui::GetMouseCursor()
+{
+    ImGuiContext& g = *GImGui;
+    return g.MouseCursor;
+}
+
+void ImGui::SetMouseCursor(ImGuiMouseCursor cursor_type)
+{
+    ImGuiContext& g = *GImGui;
+    g.MouseCursor = cursor_type;
+}
+
+void ImGui::CaptureKeyboardFromApp(bool capture)
+{
+    ImGuiContext& g = *GImGui;
+    g.WantCaptureKeyboardNextFrame = capture ? 1 : 0;
+}
+
+void ImGui::CaptureMouseFromApp(bool capture)
+{
+    ImGuiContext& g = *GImGui;
+    g.WantCaptureMouseNextFrame = capture ? 1 : 0;
+}
+
+
 //-----------------------------------------------------------------------------
 // [SECTION] ERROR CHECKING
 //-----------------------------------------------------------------------------
@@ -16905,6 +16922,49 @@ static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 
 #endif
 
+// Win32 API IME support (for Asian languages, etc.)
+#if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS)
+
+#include <imm.h>
+#ifdef _MSC_VER
+#pragma comment(lib, "imm32")
+#endif
+
+static void SetPlatformImeDataFn_DefaultImpl(ImGuiViewport* viewport, ImGuiPlatformImeData* data)
+{
+    // Notify OS Input Method Editor of text input position
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    if (hwnd == 0)
+        hwnd = (HWND)ImGui::GetIO().ImeWindowHandle;
+#endif
+    if (hwnd == 0)
+        return;
+
+    ::ImmAssociateContextEx(hwnd, NULL, data->WantVisible ? IACE_DEFAULT : 0);
+
+    if (HIMC himc = ::ImmGetContext(hwnd))
+    {
+        COMPOSITIONFORM composition_form = {};
+        composition_form.ptCurrentPos.x = (LONG)(data->InputPos.x - viewport->Pos.x);
+        composition_form.ptCurrentPos.y = (LONG)(data->InputPos.y - viewport->Pos.y);
+        composition_form.dwStyle = CFS_FORCE_POSITION;
+        ::ImmSetCompositionWindow(himc, &composition_form);
+        CANDIDATEFORM candidate_form = {};
+        candidate_form.dwStyle = CFS_CANDIDATEPOS;
+        candidate_form.ptCurrentPos.x = (LONG)(data->InputPos.x - viewport->Pos.x);
+        candidate_form.ptCurrentPos.y = (LONG)(data->InputPos.y - viewport->Pos.y);
+        ::ImmSetCandidateWindow(himc, &candidate_form);
+        ::ImmReleaseContext(hwnd, himc);
+    }
+}
+
+#else
+
+static void SetPlatformImeDataFn_DefaultImpl(ImGuiViewport*, ImGuiPlatformImeData*) {}
+
+#endif
+
 //-----------------------------------------------------------------------------
 // [SECTION] METRICS/DEBUGGER WINDOW
 //-----------------------------------------------------------------------------

imgui.h

@@ -35,7 +35,7 @@ Index of this file:
 // [SECTION] Drawing API (ImDrawCallback, ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListSplitter, ImDrawFlags, ImDrawListFlags, ImDrawList, ImDrawData)
 // [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFont)
 // [SECTION] Viewports (ImGuiViewportFlags, ImGuiViewport)
-// [SECTION] Platform interface for multi-viewport support (ImGuiPlatformIO, ImGuiPlatformMonitor)
+// [SECTION] Platform Dependent Interfaces (ImGuiPlatformIO, ImGuiPlatformMonitor, ImGuiPlatformImeData)
 // [SECTION] Obsolete functions and types
 
 */
@@ -65,7 +65,7 @@ Index of this file:
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.87 WIP"
-#define IMGUI_VERSION_NUM           18602
+#define IMGUI_VERSION_NUM           18603
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 #define IMGUI_HAS_VIEWPORT          // Viewport WIP branch
@@ -159,6 +159,7 @@ struct ImGuiOnceUponAFrame;         // Helper for running a block of code not mo
 struct ImGuiPayload;                // User data payload for drag and drop operations
 struct ImGuiPlatformIO;             // Multi-viewport support: interface for Platform/Renderer backends + viewports to render
 struct ImGuiPlatformMonitor;        // Multi-viewport support: user-provided bounds for each connected monitor/display. Used when positioning popups and tooltips to avoid them straddling monitors
+struct ImGuiPlatformImeData;        // Platform IME data for io.SetPlatformImeDataFn() function.
 struct ImGuiSizeCallbackData;       // Callback data when using SetNextWindowSizeConstraints() (rare/advanced use)
 struct ImGuiStorage;                // Helper for key->value storage
 struct ImGuiStyle;                  // Runtime data for styling/colors
@@ -534,7 +535,8 @@ namespace ImGui
 
     // Widgets: Drag Sliders
     // - CTRL+Click on any drag box to turn them into an input box. Manually input values aren't clamped by default and can go off-bounds. Use ImGuiSliderFlags_AlwaysClamp to always clamp.
-    // - For all the Float2/Float3/Float4/Int2/Int3/Int4 versions of every functions, note that a 'float v[X]' function argument is the same as 'float* v', the array syntax is just a way to document the number of elements that are expected to be accessible. You can pass address of your first element out of a contiguous set, e.g. &myvector.x
+    // - For all the Float2/Float3/Float4/Int2/Int3/Int4 versions of every functions, note that a 'float v[X]' function argument is the same as 'float* v',
+    //   the array syntax is just a way to document the number of elements that are expected to be accessible. You can pass address of your first element out of a contiguous set, e.g. &myvector.x
     // - Adjust format string to decorate the value with a prefix, a suffix, or adapt the editing and display precision e.g. "%.3f" -> 1.234; "%5.2f secs" -> 01.23 secs; "Biscuit: %.0f" -> Biscuit: 1; etc.
     // - Format string may also be set to NULL or use the default format ("%f" or "%d").
     // - Speed are per-pixel of mouse movement (v_speed=0.2f: mouse needs to move by 5 pixels to increase value by 1). For gamepad/keyboard navigation, minimum speed is Max(v_speed, minimum_step_at_given_precision).
@@ -721,7 +723,6 @@ namespace ImGui
     IMGUI_API bool          IsPopupOpen(const char* str_id, ImGuiPopupFlags flags = 0);                         // return true if the popup is open.
 
     // Tables
-    // [BETA API] API may evolve slightly! If you use this, please update to the next version when it comes out!
     // - Full-featured replacement for old Columns API.
     // - See Demo->Tables for demo code.
     // - See top of imgui_tables.cpp for general commentary.
@@ -1163,8 +1164,7 @@ enum ImGuiTabItemFlags_
 };
 
 // Flags for ImGui::BeginTable()
-// [BETA API] API may evolve slightly! If you use this, please update to the next version when it comes out!
-// - Important! Sizing policies have complex and subtle side effects, more so than you would expect.
+// - Important! Sizing policies have complex and subtle side effects, much more so than you would expect.
 //   Read comments/demos carefully + experiment with live demos to get acquainted with them.
 // - The DEFAULT sizing policies are:
 //    - Default to ImGuiTableFlags_SizingFixedFit    if ScrollX is on, or if host window has ImGuiWindowFlags_AlwaysAutoResize.
@@ -1172,8 +1172,8 @@ enum ImGuiTabItemFlags_
 // - When ScrollX is off:
 //    - Table defaults to ImGuiTableFlags_SizingStretchSame -> all Columns defaults to ImGuiTableColumnFlags_WidthStretch with same weight.
 //    - Columns sizing policy allowed: Stretch (default), Fixed/Auto.
-//    - Fixed Columns will generally obtain their requested width (unless the table cannot fit them all).
-//    - Stretch Columns will share the remaining width.
+//    - Fixed Columns (if any) will generally obtain their requested width (unless the table cannot fit them all).
+//    - Stretch Columns will share the remaining width according to their respective weight.
 //    - Mixed Fixed/Stretch columns is possible but has various side-effects on resizing behaviors.
 //      The typical use of mixing sizing policies is: any number of LEADING Fixed columns, followed by one or two TRAILING Stretch columns.
 //      (this is because the visible order of columns have subtle but necessary effects on how they react to manual resizing).
@@ -1287,7 +1287,7 @@ enum ImGuiTableColumnFlags_
 enum ImGuiTableRowFlags_
 {
     ImGuiTableRowFlags_None                         = 0,
-    ImGuiTableRowFlags_Headers                      = 1 << 0    // Identify header row (set default background color + width of its contents accounted different for auto column width)
+    ImGuiTableRowFlags_Headers                      = 1 << 0    // Identify header row (set default background color + width of its contents accounted differently for auto column width)
 };
 
 // Enum for ImGui::TableSetBgColor()
@@ -1446,7 +1446,7 @@ enum ImGuiKeyModFlags_
     ImGuiKeyModFlags_Ctrl       = 1 << 0,
     ImGuiKeyModFlags_Shift      = 1 << 1,
     ImGuiKeyModFlags_Alt        = 1 << 2,
-    ImGuiKeyModFlags_Super      = 1 << 3
+    ImGuiKeyModFlags_Super      = 1 << 3    // Cmd/Super/Windows key
 };
 
 // Gamepad/Keyboard navigation
@@ -1456,29 +1456,29 @@ enum ImGuiKeyModFlags_
 enum ImGuiNavInput_
 {
     // Gamepad Mapping
-    ImGuiNavInput_Activate,      // activate / open / toggle / tweak value       // e.g. Cross  (PS4), A (Xbox), A (Switch), Space (Keyboard)
-    ImGuiNavInput_Cancel,        // cancel / close / exit                        // e.g. Circle (PS4), B (Xbox), B (Switch), Escape (Keyboard)
-    ImGuiNavInput_Input,         // text input / on-screen keyboard              // e.g. Triang.(PS4), Y (Xbox), X (Switch), Return (Keyboard)
-    ImGuiNavInput_Menu,          // tap: toggle menu / hold: focus, move, resize // e.g. Square (PS4), X (Xbox), Y (Switch), Alt (Keyboard)
-    ImGuiNavInput_DpadLeft,      // move / tweak / resize window (w/ PadMenu)    // e.g. D-pad Left/Right/Up/Down (Gamepads), Arrow keys (Keyboard)
+    ImGuiNavInput_Activate,      // Activate / Open / Toggle / Tweak value       // e.g. Cross  (PS4), A (Xbox), A (Switch), Space (Keyboard)
+    ImGuiNavInput_Cancel,        // Cancel / Close / Exit                        // e.g. Circle (PS4), B (Xbox), B (Switch), Escape (Keyboard)
+    ImGuiNavInput_Input,         // Text input / On-Screen keyboard              // e.g. Triang.(PS4), Y (Xbox), X (Switch), Return (Keyboard)
+    ImGuiNavInput_Menu,          // Tap: Toggle menu / Hold: Focus, Move, Resize // e.g. Square (PS4), X (Xbox), Y (Switch), Alt (Keyboard)
+    ImGuiNavInput_DpadLeft,      // Move / Tweak / Resize window (w/ PadMenu)    // e.g. D-pad Left/Right/Up/Down (Gamepads), Arrow keys (Keyboard)
     ImGuiNavInput_DpadRight,     //
     ImGuiNavInput_DpadUp,        //
     ImGuiNavInput_DpadDown,      //
-    ImGuiNavInput_LStickLeft,    // scroll / move window (w/ PadMenu)            // e.g. Left Analog Stick Left/Right/Up/Down
+    ImGuiNavInput_LStickLeft,    // Scroll / Move window (w/ PadMenu)            // e.g. Left Analog Stick Left/Right/Up/Down
     ImGuiNavInput_LStickRight,   //
     ImGuiNavInput_LStickUp,      //
     ImGuiNavInput_LStickDown,    //
-    ImGuiNavInput_FocusPrev,     // next window (w/ PadMenu)                     // e.g. L1 or L2 (PS4), LB or LT (Xbox), L or ZL (Switch)
-    ImGuiNavInput_FocusNext,     // prev window (w/ PadMenu)                     // e.g. R1 or R2 (PS4), RB or RT (Xbox), R or ZL (Switch)
-    ImGuiNavInput_TweakSlow,     // slower tweaks                                // e.g. L1 or L2 (PS4), LB or LT (Xbox), L or ZL (Switch)
-    ImGuiNavInput_TweakFast,     // faster tweaks                                // e.g. R1 or R2 (PS4), RB or RT (Xbox), R or ZL (Switch)
+    ImGuiNavInput_FocusPrev,     // Focus Next window (w/ PadMenu)               // e.g. L1 or L2 (PS4), LB or LT (Xbox), L or ZL (Switch)
+    ImGuiNavInput_FocusNext,     // Focus Prev window (w/ PadMenu)               // e.g. R1 or R2 (PS4), RB or RT (Xbox), R or ZL (Switch)
+    ImGuiNavInput_TweakSlow,     // Slower tweaks                                // e.g. L1 or L2 (PS4), LB or LT (Xbox), L or ZL (Switch)
+    ImGuiNavInput_TweakFast,     // Faster tweaks                                // e.g. R1 or R2 (PS4), RB or RT (Xbox), R or ZL (Switch)
 
     // [Internal] Don't use directly! This is used internally to differentiate keyboard from gamepad inputs for behaviors that require to differentiate them.
     // Keyboard behavior that have no corresponding gamepad mapping (e.g. CTRL+TAB) will be directly reading from io.KeysDown[] instead of io.NavInputs[].
-    ImGuiNavInput_KeyLeft_,      // move left                                    // = Arrow keys
-    ImGuiNavInput_KeyRight_,     // move right
-    ImGuiNavInput_KeyUp_,        // move up
-    ImGuiNavInput_KeyDown_,      // move down
+    ImGuiNavInput_KeyLeft_,      // Move left                                    // = Arrow keys
+    ImGuiNavInput_KeyRight_,     // Move right
+    ImGuiNavInput_KeyUp_,        // Move up
+    ImGuiNavInput_KeyDown_,      // Move down
     ImGuiNavInput_COUNT,
     ImGuiNavInput_InternalStart_ = ImGuiNavInput_KeyLeft_
 };
@@ -1958,6 +1958,15 @@ struct ImGuiIO
     void        (*SetClipboardTextFn)(void* user_data, const char* text);
     void*       ClipboardUserData;
 
+    // Optional: Notify OS Input Method Editor of the screen position of your cursor for text input position (e.g. when using Japanese/Chinese IME on Windows)
+    // (default to use native imm32 api on Windows)
+    void        (*SetPlatformImeDataFn)(ImGuiViewport* viewport, ImGuiPlatformImeData* data);
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    void*       ImeWindowHandle;                // = NULL           // [Obsolete] Set ImGuiViewport::PlatformHandleRaw instead. Set this to your HWND to get automatic IME cursor positioning.
+#else
+    void*       _UnusedPadding;                                     // Unused field to keep data structure the same size.
+#endif
+
     //------------------------------------------------------------------
     // Input - Fill before calling NewFrame()
     //------------------------------------------------------------------
@@ -1967,18 +1976,18 @@ struct ImGuiIO
     float       MouseWheel;                     // Mouse wheel Vertical: 1 unit scrolls about 5 lines text.
     float       MouseWheelH;                    // Mouse wheel Horizontal. Most users don't have a mouse with an horizontal wheel, may not be filled by all backends.
     ImGuiID     MouseHoveredViewport;           // (Optional) When using multiple viewports: viewport the OS mouse cursor is hovering _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag, and _REGARDLESS_ of whether another viewport is focused. Set io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport if you can provide this info. If you don't imgui will infer the value using the rectangles and last focused time of the viewports it knows about (ignoring other OS windows).
-    bool        KeyCtrl;                        // Keyboard modifier pressed: Control
-    bool        KeyShift;                       // Keyboard modifier pressed: Shift
-    bool        KeyAlt;                         // Keyboard modifier pressed: Alt
-    bool        KeySuper;                       // Keyboard modifier pressed: Cmd/Super/Windows
+    bool        KeyCtrl;                        // Keyboard modifier down: Control
+    bool        KeyShift;                       // Keyboard modifier down: Shift
+    bool        KeyAlt;                         // Keyboard modifier down: Alt
+    bool        KeySuper;                       // Keyboard modifier down: Cmd/Super/Windows
     bool        KeysDown[512];                  // Keyboard keys that are pressed (ideally left in the "native" order your engine has access to keyboard keys, so you can use your own defines/enums for keys).
     float       NavInputs[ImGuiNavInput_COUNT]; // Gamepad inputs. Cleared back to zero by EndFrame(). Keyboard keys will be auto-mapped and be written here by NewFrame().
 
-    // Functions
+    // Input Functions
+    IMGUI_API void  AddFocusEvent(bool focused);                // Queue an hosting application/platform windows gain or loss of focus
     IMGUI_API void  AddInputCharacter(unsigned int c);          // Queue new character input
     IMGUI_API void  AddInputCharacterUTF16(ImWchar16 c);        // Queue new character input from an UTF-16 character, it can be a surrogate
     IMGUI_API void  AddInputCharactersUTF8(const char* str);    // Queue new characters input from an UTF-8 string
-    IMGUI_API void  AddFocusEvent(bool focused);                // Notifies Dear ImGui when hosting platform windows lose or gain input focus
     IMGUI_API void  ClearInputCharacters();                     // [Internal] Clear the text input buffer manually
     IMGUI_API void  ClearInputKeys();                           // [Internal] Release all keys
 
@@ -1988,50 +1997,51 @@ struct ImGuiIO
     //  generally easier and more correct to use their state BEFORE calling NewFrame(). See FAQ for details!)
     //------------------------------------------------------------------
 
-    bool        WantCaptureMouse;               // Set when Dear ImGui will use mouse inputs, in this case do not dispatch them to your main game/application (either way, always pass on mouse inputs to imgui). (e.g. unclicked mouse is hovering over an imgui window, widget is active, mouse was clicked over an imgui window, etc.).
-    bool        WantCaptureKeyboard;            // Set when Dear ImGui will use keyboard inputs, in this case do not dispatch them to your main game/application (either way, always pass keyboard inputs to imgui). (e.g. InputText active, or an imgui window is focused and navigation is enabled, etc.).
-    bool        WantTextInput;                  // Mobile/console: when set, you may display an on-screen keyboard. This is set by Dear ImGui when it wants textual keyboard input to happen (e.g. when a InputText widget is active).
-    bool        WantSetMousePos;                // MousePos has been altered, backend should reposition mouse on next frame. Rarely used! Set only when ImGuiConfigFlags_NavEnableSetMousePos flag is enabled.
-    bool        WantSaveIniSettings;            // When manual .ini load/save is active (io.IniFilename == NULL), this will be set to notify your application that you can call SaveIniSettingsToMemory() and save yourself. Important: clear io.WantSaveIniSettings yourself after saving!
-    bool        NavActive;                      // Keyboard/Gamepad navigation is currently allowed (will handle ImGuiKey_NavXXX events) = a window is focused and it doesn't use the ImGuiWindowFlags_NoNavInputs flag.
-    bool        NavVisible;                     // Keyboard/Gamepad navigation is visible and allowed (will handle ImGuiKey_NavXXX events).
-    float       Framerate;                      // Rough estimate of application framerate, in frame per second. Solely for convenience. Rolling average estimation based on io.DeltaTime over 120 frames.
-    int         MetricsRenderVertices;          // Vertices output during last call to Render()
-    int         MetricsRenderIndices;           // Indices output during last call to Render() = number of triangles * 3
-    int         MetricsRenderWindows;           // Number of visible windows
-    int         MetricsActiveWindows;           // Number of active windows
-    int         MetricsActiveAllocations;       // Number of active allocations, updated by MemAlloc/MemFree based on current context. May be off if you have multiple imgui contexts.
-    ImVec2      MouseDelta;                     // Mouse delta. Note that this is zero if either current or previous position are invalid (-FLT_MAX,-FLT_MAX), so a disappearing/reappearing mouse won't have a huge delta.
+    bool        WantCaptureMouse;                   // Set when Dear ImGui will use mouse inputs, in this case do not dispatch them to your main game/application (either way, always pass on mouse inputs to imgui). (e.g. unclicked mouse is hovering over an imgui window, widget is active, mouse was clicked over an imgui window, etc.).
+    bool        WantCaptureKeyboard;                // Set when Dear ImGui will use keyboard inputs, in this case do not dispatch them to your main game/application (either way, always pass keyboard inputs to imgui). (e.g. InputText active, or an imgui window is focused and navigation is enabled, etc.).
+    bool        WantTextInput;                      // Mobile/console: when set, you may display an on-screen keyboard. This is set by Dear ImGui when it wants textual keyboard input to happen (e.g. when a InputText widget is active).
+    bool        WantSetMousePos;                    // MousePos has been altered, backend should reposition mouse on next frame. Rarely used! Set only when ImGuiConfigFlags_NavEnableSetMousePos flag is enabled.
+    bool        WantSaveIniSettings;                // When manual .ini load/save is active (io.IniFilename == NULL), this will be set to notify your application that you can call SaveIniSettingsToMemory() and save yourself. Important: clear io.WantSaveIniSettings yourself after saving!
+    bool        NavActive;                          // Keyboard/Gamepad navigation is currently allowed (will handle ImGuiKey_NavXXX events) = a window is focused and it doesn't use the ImGuiWindowFlags_NoNavInputs flag.
+    bool        NavVisible;                         // Keyboard/Gamepad navigation is visible and allowed (will handle ImGuiKey_NavXXX events).
+    float       Framerate;                          // Rough estimate of application framerate, in frame per second. Solely for convenience. Rolling average estimation based on io.DeltaTime over 120 frames.
+    int         MetricsRenderVertices;              // Vertices output during last call to Render()
+    int         MetricsRenderIndices;               // Indices output during last call to Render() = number of triangles * 3
+    int         MetricsRenderWindows;               // Number of visible windows
+    int         MetricsActiveWindows;               // Number of active windows
+    int         MetricsActiveAllocations;           // Number of active allocations, updated by MemAlloc/MemFree based on current context. May be off if you have multiple imgui contexts.
+    ImVec2      MouseDelta;                         // Mouse delta. Note that this is zero if either current or previous position are invalid (-FLT_MAX,-FLT_MAX), so a disappearing/reappearing mouse won't have a huge delta.
 
     //------------------------------------------------------------------
     // [Internal] Dear ImGui will maintain those fields. Forward compatibility not guaranteed!
     //------------------------------------------------------------------
 
-    bool        WantCaptureMouseUnlessPopupClose;// Alternative to WantCaptureMouse: (WantCaptureMouse == true && WantCaptureMouseUnlessPopupClose == false) when a click over void is expected to close a popup.
-    ImGuiKeyModFlags KeyMods;                   // Key mods flags (same as io.KeyCtrl/KeyShift/KeyAlt/KeySuper but merged into flags), updated by NewFrame()
-    ImGuiKeyModFlags KeyModsPrev;               // Previous key mods
-    ImVec2      MousePosPrev;                   // Previous mouse position (note that MouseDelta is not necessary == MousePos-MousePosPrev, in case either position is invalid)
-    ImVec2      MouseClickedPos[5];             // Position at time of clicking
-    double      MouseClickedTime[5];            // Time of last click (used to figure out double-click)
-    bool        MouseClicked[5];                // Mouse button went from !Down to Down (same as MouseClickedCount[x] != 0)
-    bool        MouseDoubleClicked[5];          // Has mouse button been double-clicked? (same as MouseClickedCount[x] == 2)
-    ImU16       MouseClickedCount[5];           // == 0 (not clicked), == 1 (same as MouseClicked[]), == 2 (double-clicked), == 3 (triple-clicked) etc. when going from !Down to Down
-    ImU16       MouseClickedLastCount[5];       // Count successive number of clicks. Stays valid after mouse release. Reset after another click is done.
-    bool        MouseReleased[5];               // Mouse button went from Down to !Down
-    bool        MouseDownOwned[5];              // Track if button was clicked inside a dear imgui window or over void blocked by a popup. We don't request mouse capture from the application if click started outside ImGui bounds.
-    bool        MouseDownOwnedUnlessPopupClose[5];//Track if button was clicked inside a dear imgui window.
-    float       MouseDownDuration[5];           // Duration the mouse button has been down (0.0f == just clicked)
-    float       MouseDownDurationPrev[5];       // Previous time the mouse button has been down
-    ImVec2      MouseDragMaxDistanceAbs[5];     // Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
-    float       MouseDragMaxDistanceSqr[5];     // Squared maximum distance of how much mouse has traveled from the clicking point
-    float       KeysDownDuration[512];          // Duration the keyboard key has been down (0.0f == just pressed)
-    float       KeysDownDurationPrev[512];      // Previous duration the key has been down
+    ImGuiKeyModFlags KeyMods;                       // Key mods flags (same as io.KeyCtrl/KeyShift/KeyAlt/KeySuper but merged into flags), updated by NewFrame()
+    ImGuiKeyModFlags KeyModsPrev;                   // Key mods flags (from previous frame)
+    float       KeysDownDuration[512];              // Duration the key has been down (<0.0f: not pressed, 0.0f: just pressed, >0.0f: time held)
+    float       KeysDownDurationPrev[512];          // Duration the key has been down (from previous frame)
+
+    bool        WantCaptureMouseUnlessPopupClose;   // Alternative to WantCaptureMouse: (WantCaptureMouse == true && WantCaptureMouseUnlessPopupClose == false) when a click over void is expected to close a popup.
+    ImVec2      MousePosPrev;                       // Previous mouse position (note that MouseDelta is not necessary == MousePos-MousePosPrev, in case either position is invalid)
+    ImVec2      MouseClickedPos[5];                 // Position at time of clicking
+    double      MouseClickedTime[5];                // Time of last click (used to figure out double-click)
+    bool        MouseClicked[5];                    // Mouse button went from !Down to Down (same as MouseClickedCount[x] != 0)
+    bool        MouseDoubleClicked[5];              // Has mouse button been double-clicked? (same as MouseClickedCount[x] == 2)
+    ImU16       MouseClickedCount[5];               // == 0 (not clicked), == 1 (same as MouseClicked[]), == 2 (double-clicked), == 3 (triple-clicked) etc. when going from !Down to Down
+    ImU16       MouseClickedLastCount[5];           // Count successive number of clicks. Stays valid after mouse release. Reset after another click is done.
+    bool        MouseReleased[5];                   // Mouse button went from Down to !Down
+    bool        MouseDownOwned[5];                  // Track if button was clicked inside a dear imgui window or over void blocked by a popup. We don't request mouse capture from the application if click started outside ImGui bounds.
+    bool        MouseDownOwnedUnlessPopupClose[5];  //Track if button was clicked inside a dear imgui window.
+    float       MouseDownDuration[5];               // Duration the mouse button has been down (0.0f == just clicked)
+    float       MouseDownDurationPrev[5];           // Previous time the mouse button has been down
+    ImVec2      MouseDragMaxDistanceAbs[5];         // Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
+    float       MouseDragMaxDistanceSqr[5];         // Squared maximum distance of how much mouse has traveled from the clicking point (used for moving thresholds)
     float       NavInputsDownDuration[ImGuiNavInput_COUNT];
     float       NavInputsDownDurationPrev[ImGuiNavInput_COUNT];
-    float       PenPressure;                    // Touch/Pen pressure (0.0f to 1.0f, should be >0.0f only when MouseDown[0] == true). Helper storage currently unused by Dear ImGui.
+    float       PenPressure;                        // Touch/Pen pressure (0.0f to 1.0f, should be >0.0f only when MouseDown[0] == true). Helper storage currently unused by Dear ImGui.
     bool        AppFocusLost;
-    ImWchar16   InputQueueSurrogate;            // For AddInputCharacterUTF16
-    ImVector<ImWchar> InputQueueCharacters;     // Queue of _characters_ input (obtained by platform backend). Fill using AddInputCharacter() helper.
+    ImWchar16   InputQueueSurrogate;                // For AddInputCharacterUTF16()
+    ImVector<ImWchar> InputQueueCharacters;         // Queue of _characters_ input (obtained by platform backend). Fill using AddInputCharacter() helper.
 
     IMGUI_API   ImGuiIO();
 };
@@ -2387,16 +2397,16 @@ typedef void (*ImDrawCallback)(const ImDrawList* parent_list, const ImDrawCmd* c
 #define ImDrawCallback_ResetRenderState     (ImDrawCallback)(-1)
 
 // Typically, 1 command = 1 GPU draw call (unless command is a callback)
-// - VtxOffset/IdxOffset: When 'io.BackendFlags & ImGuiBackendFlags_RendererHasVtxOffset' is enabled,
-//   those fields allow us to render meshes larger than 64K vertices while keeping 16-bit indices.
-//   Pre-1.71 backends will typically ignore the VtxOffset/IdxOffset fields.
+// - VtxOffset: When 'io.BackendFlags & ImGuiBackendFlags_RendererHasVtxOffset' is enabled,
+//   this fields allow us to render meshes larger than 64K vertices while keeping 16-bit indices.
+//   Backends made for <1.71. will typically ignore the VtxOffset fields.
 // - The ClipRect/TextureId/VtxOffset fields must be contiguous as we memcmp() them together (this is asserted for).
 struct ImDrawCmd
 {
     ImVec4          ClipRect;           // 4*4  // Clipping rectangle (x1, y1, x2, y2). Subtract ImDrawData->DisplayPos to get clipping rectangle in "viewport" coordinates
     ImTextureID     TextureId;          // 4-8  // User-provided texture ID. Set by user in ImfontAtlas::SetTexID() for fonts or passed to Image*() functions. Ignore if never using images or multiple fonts atlas.
     unsigned int    VtxOffset;          // 4    // Start offset in vertex buffer. ImGuiBackendFlags_RendererHasVtxOffset: always 0, otherwise may be >0 to support meshes larger than 64K vertices with 16-bit indices.
-    unsigned int    IdxOffset;          // 4    // Start offset in index buffer. Always equal to sum of ElemCount drawn so far.
+    unsigned int    IdxOffset;          // 4    // Start offset in index buffer.
     unsigned int    ElemCount;          // 4    // Number of indices (multiple of 3) to be rendered as triangles. Vertices are stored in the callee ImDrawList's vtx_buffer[] array, indices in idx_buffer[].
     ImDrawCallback  UserCallback;       // 4-8  // If != NULL, call the function instead of rendering the vertices. clip_rect and texture_id will be set normally.
     void*           UserCallbackData;   // 4-8  // The draw callback code can access this.
@@ -2933,6 +2943,7 @@ struct ImGuiViewport
     ImGuiID             ParentViewportId;       // (Advanced) 0: no parent. Instruct the platform backend to setup a parent/child relationship between platform windows.
     ImDrawData*         DrawData;               // The ImDrawData corresponding to this viewport. Valid after Render() and until the next call to NewFrame().
 
+    // Platform/Backend Dependent Data
     // Our design separate the Renderer and Platform backends to facilitate combining default backends with each others.
     // When our create your own backend for a custom engine, it is possible that both Renderer and Platform will be handled
     // by the same system and you may not need to use all the UserData/Handle fields.
@@ -2940,7 +2951,7 @@ struct ImGuiViewport
     void*               RendererUserData;       // void* to hold custom data structure for the renderer (e.g. swap chain, framebuffers etc.). generally set by your Renderer_CreateWindow function.
     void*               PlatformUserData;       // void* to hold custom data structure for the OS / platform (e.g. windowing info, render context). generally set by your Platform_CreateWindow function.
     void*               PlatformHandle;         // void* for FindViewportByPlatformHandle(). (e.g. suggested to use natural platform handle such as HWND, GLFWWindow*, SDL_Window*)
-    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (e.g. the HWND) when using an abstraction layer like GLFW or SDL (where PlatformHandle would be a SDL_Window*)
+    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (under Win32 this is expected to be a HWND, unused for other platforms), when using an abstraction layer like GLFW or SDL (where PlatformHandle would be a SDL_Window*)
     bool                PlatformRequestMove;    // Platform window requested move (e.g. window was moved by the OS / host window manager, authoritative position will be OS window position)
     bool                PlatformRequestResize;  // Platform window requested resize (e.g. window was resized by the OS / host window manager, authoritative size will be OS window size)
     bool                PlatformRequestClose;   // Platform window requested closure (e.g. window was moved by the OS / host window manager, e.g. pressing ALT-F4)
@@ -2954,7 +2965,7 @@ struct ImGuiViewport
 };
 
 //-----------------------------------------------------------------------------
-// [SECTION] Platform interface for multi-viewport support
+// [SECTION] Platform Dependent Interfaces (for e.g. multi-viewport support)
 //-----------------------------------------------------------------------------
 // [BETA] (Optional) This is completely optional, for advanced users!
 // If you are new to Dear ImGui and trying to integrate it into your engine, you can probably ignore this for now.
@@ -3040,7 +3051,6 @@ struct ImGuiPlatformIO
     void    (*Platform_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers (platform side! This is often unused!). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
     float   (*Platform_GetWindowDpiScale)(ImGuiViewport* vp);               // N . . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Return DPI scale for this viewport. 1.0f = 96 DPI.
     void    (*Platform_OnChangedViewport)(ImGuiViewport* vp);               // . F . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Called during Begin() every time the viewport we are outputting into changes, so backend has a chance to swap fonts to adjust style.
-    void    (*Platform_SetImeInputPos)(ImGuiViewport* vp, ImVec2 pos);      // . F . . .  // (Optional) Set IME (Input Method Editor, e.g. for Asian languages) input position, so text preview appears over the imgui input box. FIXME: The call timing of this is inconsistent because we want to support without multi-viewports.
     int     (*Platform_CreateVkSurface)(ImGuiViewport* vp, ImU64 vk_inst, const void* vk_allocators, ImU64* out_vk_surface); // (Optional) For a Vulkan Renderer to call into Platform code (since the surface creation needs to tie them both).
 
     // (Optional) Renderer functions (e.g. DirectX, OpenGL, Vulkan)
@@ -3075,6 +3085,16 @@ struct ImGuiPlatformMonitor
     ImGuiPlatformMonitor()          { MainPos = MainSize = WorkPos = WorkSize = ImVec2(0, 0); DpiScale = 1.0f; }
 };
 
+// (Optional) Support for IME (Input Method Editor) via the io.SetPlatformImeDataFn() function.
+struct ImGuiPlatformImeData
+{
+    bool    WantVisible;        // A widget wants the IME to be visible
+    ImVec2  InputPos;           // Position of the input cursor
+    float   InputLineHeight;    // Line height
+
+    ImGuiPlatformImeData() { memset(this, 0, sizeof(*this)); }
+};
+
 //-----------------------------------------------------------------------------
 // [SECTION] Obsolete functions and types
 // (Will be removed! Read 'API BREAKING CHANGES' section in imgui.cpp for details)

imgui_internal.h

@@ -1890,9 +1890,9 @@ struct ImGuiContext
     ImVector<ImGuiID>       MenusIdSubmittedThisFrame;          // A list of menu IDs that were rendered at least once
 
     // Platform support
-    ImVec2                  PlatformImePos;                     // Cursor position request & last passed to the OS Input Method Editor
-    ImVec2                  PlatformImeLastPos;
-    ImGuiViewportP*         PlatformImePosViewport;
+    ImGuiPlatformImeData    PlatformImeData;                    // Data updated by current frame
+    ImGuiPlatformImeData    PlatformImeDataPrev;                // Previous frame data (when changing we will call io.SetPlatformImeDataFn
+    ImGuiID                 PlatformImeViewport;
     char                    PlatformLocaleDecimalPoint;         // '.' or *localeconv()->decimal_point
 
     // Extensions
@@ -2068,8 +2068,9 @@ struct ImGuiContext
         TooltipOverrideCount = 0;
         TooltipSlowDelay = 0.50f;
 
-        PlatformImePos = PlatformImeLastPos = ImVec2(FLT_MAX, FLT_MAX);
-        PlatformImePosViewport = 0;
+        PlatformImeData.InputPos = ImVec2(0.0f, 0.0f);
+        PlatformImeDataPrev.InputPos = ImVec2(-1.0f, -1.0f); // Different to ensure initial submission
+        PlatformImeViewport = 0;
         PlatformLocaleDecimalPoint = '.';
 
         SettingsLoaded = false;

imgui_widgets.cpp

@@ -4769,8 +4769,10 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             // Notify OS of text input position for advanced IME (-1 x offset so that Windows IME can cover our cursor. Bit of an extra nicety.)
             if (!is_readonly)
             {
-                g.PlatformImePos = ImVec2(cursor_screen_pos.x - 1, cursor_screen_pos.y - g.FontSize);
-                g.PlatformImePosViewport = window->Viewport;
+                g.PlatformImeData.WantVisible = true;
+                g.PlatformImeData.InputPos = ImVec2(cursor_screen_pos.x - 1.0f, cursor_screen_pos.y - g.FontSize);
+                g.PlatformImeData.InputLineHeight = g.FontSize;
+                g.PlatformImeViewport = window->Viewport->ID;
             }
         }
     }