Viewport: Changed Monitor field to use Pos+Size (more consistent), changed FullMin,FullMax to MainPos,MainSize. Made main viewport accessible in PlatformIO on first frame. Fixed casing of ImGuiViewportFlags_TopMost flag. (#1542)

examples/imgui_impl_glfw.cpp

@@ -364,7 +364,7 @@ static void ImGui_ImplGlfw_CreateWindow(ImGuiViewport* viewport)
     glfwWindowHint(GLFW_FOCUSED, false);
     glfwWindowHint(GLFW_DECORATED, (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? false : true);
 #if GLFW_HAS_WINDOW_TOPMOST
-    glfwWindowHint(GLFW_FLOATING, (viewport->Flags & imGuiViewportFlags_TopMost) ? true : false);
+    glfwWindowHint(GLFW_FLOATING, (viewport->Flags & ImGuiViewportFlags_TopMost) ? true : false);
 #endif
     GLFWwindow* share_window = (g_ClientApi == GlfwClientApi_OpenGL) ? g_Window : NULL;
     data->Window = glfwCreateWindow((int)viewport->Size.x, (int)viewport->Size.y, "No Title Yet", NULL, share_window);
@@ -579,8 +579,8 @@ static void ImGui_ImplGlfw_UpdateMonitors()
         int x, y;
         glfwGetMonitorPos(glfw_monitors[n], &x, &y);
         const GLFWvidmode* vid_mode = glfwGetVideoMode(glfw_monitors[n]);
-        monitor.FullMin = monitor.WorkMin = ImVec2((float)x, (float)y);
-        monitor.FullMax = monitor.WorkMax = ImVec2((float)(x + vid_mode->width), (float)(y + vid_mode->height));
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)x, (float)y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)vid_mode->width, (float)vid_mode->height);
 #if GLFW_HAS_PER_MONITOR_DPI
         // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
         float x_scale, y_scale;

examples/imgui_impl_sdl2.cpp

@@ -317,7 +317,7 @@ static void ImGui_ImplSDL2_CreateWindow(ImGuiViewport* viewport)
     sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
     sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
 #if SDL_HAS_ALWAYS_ON_TOP
-    sdl_flags |= (viewport->Flags & imGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
 #endif
     data->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Pos.x, (int)viewport->Pos.y, (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
     data->WindowOwned = true; 
@@ -463,12 +463,12 @@ static void ImGui_ImplSDL2_UpdateMonitors()
         ImGuiPlatformMonitor monitor;
         SDL_Rect r;
         SDL_GetDisplayBounds(n, &r);
-        monitor.FullMin = monitor.WorkMin = ImVec2((float)(r.x), (float)(r.y));
-        monitor.FullMax = monitor.WorkMax = ImVec2((float)(r.x + r.w), (float)(r.y + r.h));
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
 #if SDL_HAS_USABLE_DISPLAY_BOUNDS
         SDL_GetDisplayUsableBounds(n, &r);
-        monitor.WorkMin = ImVec2((float)(r.x), (float)(r.y));
-        monitor.WorkMax = ImVec2((float)(r.x + r.w), (float)(r.y + r.h));
+        monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
 #endif
 #if SDL_HAS_PER_MONITOR_DPI
         float dpi = 0.0f;

examples/imgui_impl_win32.cpp

@@ -431,7 +431,7 @@ static void ImGui_ImplWin32_CreateWindow(ImGuiViewport* viewport)
         data->DwStyle = WS_OVERLAPPEDWINDOW;
         data->DwExStyle = no_task_bar_icon ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW;
     }
-    if (viewport->Flags & imGuiViewportFlags_TopMost)
+    if (viewport->Flags & ImGuiViewportFlags_TopMost)
         data->DwExStyle |= WS_EX_TOPMOST;
 
     // Create window
@@ -618,10 +618,10 @@ static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, H
     if (!::GetMonitorInfo(monitor, &info))
         return TRUE;
     ImGuiPlatformMonitor imgui_monitor;
-    imgui_monitor.FullMin = ImVec2((float)info.rcMonitor.left, (float)info.rcMonitor.top);
-    imgui_monitor.FullMax = ImVec2((float)info.rcMonitor.right, (float)info.rcMonitor.bottom);
-    imgui_monitor.WorkMin = ImVec2((float)info.rcWork.left, (float)info.rcWork.top);
-    imgui_monitor.WorkMax = ImVec2((float)info.rcWork.right, (float)info.rcWork.bottom);
+    imgui_monitor.MainPos = ImVec2((float)info.rcMonitor.left, (float)info.rcMonitor.top);
+    imgui_monitor.MainSize = ImVec2((float)(info.rcMonitor.right - info.rcMonitor.left), (float)(info.rcMonitor.bottom - info.rcMonitor.top));
+    imgui_monitor.WorkPos = ImVec2((float)info.rcWork.left, (float)info.rcWork.top);
+    imgui_monitor.WorkSize = ImVec2((float)(info.rcWork.right - info.rcWork.left), (float)(info.rcWork.bottom - info.rcWork.top));
     imgui_monitor.DpiScale = ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
     ImGuiPlatformIO& io = ImGui::GetPlatformIO();
     if (info.dwFlags & MONITORINFOF_PRIMARY)

imgui.cpp

@@ -3620,7 +3620,7 @@ void ImGui::UpdatePlatformWindows()
         {
             bool topmost = (viewport->Window->Flags & ImGuiWindowFlags_Tooltip) != 0;
             bool no_task_bar_icon = (g.IO.ConfigFlags & ImGuiConfigFlags_ViewportsNoTaskBarIcons) != 0 || (viewport->Window->Flags & (ImGuiWindowFlags_ChildMenu | ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup)) != 0;
-            viewport->Flags = topmost ? (viewport->Flags | imGuiViewportFlags_TopMost) : (viewport->Flags & ~imGuiViewportFlags_TopMost);
+            viewport->Flags = topmost ? (viewport->Flags | ImGuiViewportFlags_TopMost) : (viewport->Flags & ~ImGuiViewportFlags_TopMost);
             viewport->Flags = no_task_bar_icon ? (viewport->Flags | ImGuiViewportFlags_NoTaskBarIcon) : (viewport->Flags & ~ImGuiViewportFlags_NoTaskBarIcon);
         }
 
@@ -3881,8 +3881,8 @@ void ImGui::NewFrame()
         for (int monitor_n = 0; monitor_n < g.PlatformIO.Monitors.Size; monitor_n++)
         {
             ImGuiPlatformMonitor& mon = g.PlatformIO.Monitors[monitor_n];
-            IM_ASSERT(mon.FullMin.x < mon.FullMax.x && mon.FullMin.y < mon.FullMax.y && "Monitor bounds not setup properly.");
-            IM_ASSERT(mon.WorkMin.x < mon.WorkMax.x && mon.WorkMin.y < mon.WorkMax.y && "Monitor bounds not setup properly. If you don't have work area information, just copy Min/Max into them.");
+            IM_ASSERT(mon.MainSize.x > 0.0f && mon.MainSize.y > 0.0f && "Monitor bounds not setup properly.");
+            IM_ASSERT(mon.WorkSize.x > 0.0f && mon.WorkSize.y > 0.0f && "Monitor bounds not setup properly. If you don't have work area information, just copy Min/Max into them.");
             IM_ASSERT(mon.DpiScale != 0.0f);
         }
     }
@@ -4152,6 +4152,8 @@ void ImGui::Initialize(ImGuiContext* context)
     viewport->ID = IMGUI_VIEWPORT_DEFAULT_ID;
     viewport->Idx = 0;
     g.Viewports.push_back(viewport);
+    g.PlatformIO.MainViewport = g.Viewports[0]; // Make it accessible in public-facing GetPlatformIO() immediately (before the first call to EndFrame)
+    g.PlatformIO.Viewports.push_back(g.Viewports[0]);
 
     g.Initialized = true;
 }
@@ -5936,8 +5938,8 @@ static ImRect FindAllowedExtentRectForWindow(ImGuiWindow* window)
     {
         // Extent with be in the frame of reference of the given viewport (so Min is likely to be negative here)
         const ImGuiPlatformMonitor& monitor = g.PlatformIO.Monitors[window->ViewportAllowPlatformMonitorExtend];
-        r_screen.Min = monitor.WorkMin;
-        r_screen.Max = monitor.WorkMax;
+        r_screen.Min = monitor.WorkPos;
+        r_screen.Max = monitor.WorkPos + monitor.WorkSize;
     }
     else
     {
@@ -6119,7 +6121,7 @@ static ImVec2 CalcSizeAutoFit(ImGuiWindow* window, const ImVec2& size_contents)
             avail_size = ImVec2(FLT_MAX, FLT_MAX);
         const int monitor_idx = window->ViewportAllowPlatformMonitorExtend;
         if (monitor_idx >= 0 && monitor_idx < g.PlatformIO.Monitors.Size)
-            avail_size = (g.PlatformIO.Monitors[monitor_idx].WorkMax - g.PlatformIO.Monitors[monitor_idx].WorkMin);
+            avail_size = g.PlatformIO.Monitors[monitor_idx].WorkSize;
         ImVec2 size_auto_fit = ImClamp(size_contents, style.WindowMinSize, ImMax(style.WindowMinSize, avail_size - g.Style.DisplaySafeAreaPadding * 2.0f));
 
         // When the window cannot fit all contents (either because of constraints, either because screen is too small),
@@ -6190,7 +6192,7 @@ static int ImGui::FindPlatformMonitorForPos(const ImVec2& pos)
     for (int monitor_n = 0; monitor_n < g.PlatformIO.Monitors.Size; monitor_n++)
     {
         const ImGuiPlatformMonitor& monitor = g.PlatformIO.Monitors[monitor_n];
-        if (ImRect(monitor.FullMin, monitor.FullMax).Contains(pos))
+        if (ImRect(monitor.MainPos, monitor.MainPos + monitor.MainSize).Contains(pos))
             return monitor_n;
     }
     return -1;
@@ -6207,10 +6209,10 @@ static int ImGui::FindPlatformMonitorForRect(const ImRect& rect)
     for (int monitor_n = 0; monitor_n < g.PlatformIO.Monitors.Size && best_monitor_surface < surface_threshold; monitor_n++)
     {
         const ImGuiPlatformMonitor& monitor = g.PlatformIO.Monitors[monitor_n];
-        if (ImRect(monitor.FullMin, monitor.FullMax).Contains(rect))
+        if (ImRect(monitor.MainPos, monitor.MainPos + monitor.MainSize).Contains(rect))
             return monitor_n;
         ImRect overlapping_rect = rect;
-        overlapping_rect.ClipWithFull(ImRect(monitor.FullMin, monitor.FullMax));
+        overlapping_rect.ClipWithFull(ImRect(monitor.MainPos, monitor.MainPos + monitor.MainSize));
         float overlapping_surface = overlapping_rect.GetWidth() * overlapping_rect.GetHeight();
         if (overlapping_surface < best_monitor_surface)
             continue;
@@ -6796,7 +6798,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
                 else
                 {
                     ImGuiPlatformMonitor& monitor = g.PlatformIO.Monitors[window->Viewport->PlatformMonitor];
-                    ClampWindowRect(window, ImRect(monitor.WorkMin, monitor.WorkMax), clamp_padding);
+                    ClampWindowRect(window, ImRect(monitor.WorkPos, monitor.WorkPos + monitor.WorkSize), clamp_padding);
                 }
             }
         }
@@ -14401,10 +14403,10 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 for (int i = 0; i < g.PlatformIO.Monitors.Size; i++)
                 {
                     const ImGuiPlatformMonitor& mon = g.PlatformIO.Monitors[i];
-                    ImGui::BulletText("Monitor #%d: DPI %.0f%%\n FullMin (%.0f,%.0f), FullMax (%.0f,%.0f), FullSize (%.0f,%.0f)\n WorkMin (%.0f,%.0f), WorkMax (%.0f,%.0f), WorkSize (%.0f,%.0f)", 
+                    ImGui::BulletText("Monitor #%d: DPI %.0f%%\n MainMin (%.0f,%.0f), MainMax (%.0f,%.0f), MainSize (%.0f,%.0f)\n WorkMin (%.0f,%.0f), WorkMax (%.0f,%.0f), WorkSize (%.0f,%.0f)", 
                         i, mon.DpiScale * 100.0f, 
-                        mon.FullMin.x, mon.FullMin.y, mon.FullMax.x, mon.FullMax.y, mon.FullMax.x - mon.FullMin.x, mon.FullMax.y - mon.FullMin.y,
-                        mon.WorkMin.x, mon.WorkMin.y, mon.WorkMax.x, mon.WorkMax.y, mon.WorkMax.x - mon.WorkMin.x, mon.WorkMax.y - mon.WorkMin.y);
+                        mon.MainPos.x, mon.MainPos.y, mon.MainPos.x + mon.MainSize.x, mon.MainPos.y + mon.MainSize.y, mon.MainSize.x, mon.MainSize.y,
+                        mon.WorkPos.x, mon.WorkPos.y, mon.WorkPos.x + mon.WorkSize.x, mon.WorkPos.y + mon.WorkSize.y, mon.WorkSize.x, mon.WorkSize.y);
                 }
                 ImGui::TreePop();
             }

imgui.h

@@ -74,6 +74,7 @@ struct ImGuiListClipper;            // Helper to manually clip large list of ite
 struct ImGuiPayload;                // User data payload for drag and drop operations
 struct ImGuiViewport;               // Viewport (generally ~1 per window to output to at the OS level. Need per-platform support to use multiple viewports)
 struct ImGuiPlatformIO;             // Multi-viewport support: interface for Platform/Renderer back-ends + 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 ImGuiContext;                // ImGui context (opaque)
 
 #ifndef ImTextureID
@@ -1890,10 +1891,10 @@ struct ImFont
 // Dear ImGui only uses this to clamp the position of popups and tooltips so they don't straddle multiple monitors
 struct ImGuiPlatformMonitor
 {
-    ImVec2  FullMin, FullMax;   // Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
-    ImVec2  WorkMin, WorkMax;   // (Optional) Coordinates without task bars / side bars / menu bars. imgui uses this to avoid positioning popups/tooltips inside this region.
+    ImVec2  MainPos, MainSize;  // Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
+    ImVec2  WorkPos, WorkSize;  // (Optional) Coordinates without task bars / side bars / menu bars. imgui uses this to avoid positioning popups/tooltips inside this region.
     float   DpiScale;
-    ImGuiPlatformMonitor() { FullMin = FullMax = WorkMin = WorkMax = ImVec2(0,0); DpiScale = 1.0f; }
+    ImGuiPlatformMonitor() { MainPos = MainSize = WorkPos = WorkSize = ImVec2(0,0); DpiScale = 1.0f; }
 };
 
 // (Optional) Setup required only if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) is enabled
@@ -1956,7 +1957,7 @@ enum ImGuiViewportFlags_
     ImGuiViewportFlags_NoInputs                 = 1 << 2,   // Platform Window: Make mouse pass through so we can drag this window while peaking behind it.
     ImGuiViewportFlags_NoTaskBarIcon            = 1 << 3,   // Platform Window: Disable platform task bar icon (for popups, menus, or all windows if ImGuiConfigFlags_ViewportsNoTaskBarIcons if set)
     ImGuiViewportFlags_NoRendererClear          = 1 << 4,   // Platform Window: Renderer doesn't need to clear the framebuffer ahead.
-    imGuiViewportFlags_TopMost                  = 1 << 5    // Platform Window: Display on top (for tooltips only)
+    ImGuiViewportFlags_TopMost                  = 1 << 5    // Platform Window: Display on top (for tooltips only)
 };
 
 // The viewports created and managed by imgui. The role of the platform back-end is to create the platform/OS windows corresponding to each viewport.