Viewport, Platform: Added work area in ImGuiPlatformMonitor. Renamed fields. (#1542)

examples/imgui_impl_glfw.cpp

@@ -521,25 +521,28 @@ static int ImGui_ImplGlfw_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_inst
 #endif // GLFW_HAS_VULKAN
 
 // FIXME-PLATFORM: Update when changed (using glfwSetMonitorCallback?)
+// FIXME-PLATFORM: GLFW doesn't export work area (see https://github.com/glfw/glfw/pull/989)
 static void ImGui_ImplGlfw_UpdateMonitors()
 {
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     int monitors_count = 0;
     GLFWmonitor** glfw_monitors = glfwGetMonitors(&monitors_count);
-    platform_io.Monitors.resize(monitors_count, ImGuiPlatformMonitor());
+    platform_io.Monitors.resize(0);
     for (int n = 0; n < monitors_count; n++)
     {
+        ImGuiPlatformMonitor monitor;
         int x, y;
         glfwGetMonitorPos(glfw_monitors[n], &x, &y);
         const GLFWvidmode* vid_mode = glfwGetVideoMode(glfw_monitors[n]);
-        platform_io.Monitors[n].Pos = ImVec2((float)x, (float)y);
+        monitor.FullMin = monitor.WorkMin = ImVec2((float)x, (float)y);
-        platform_io.Monitors[n].Size = ImVec2((float)vid_mode->width, (float)vid_mode->height);
+        monitor.FullMax = monitor.WorkMax = ImVec2((float)(x + vid_mode->width), (float)(y + 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;
         glfwGetMonitorContentScale(glfw_monitors[n], &x_scale, &y_scale);
-        platform_io.Monitors[n].DpiScale = x_scale;
+        monitor.DpiScale = x_scale;
 #endif
+        platform_io.Monitors.push_back(monitor);
     }
 }
 

examples/imgui_impl_sdl2.cpp

@@ -30,13 +30,15 @@
 #include "imgui_impl_sdl2.h"
 
 // SDL
+// (the multi-viewports feature requires SDL features suppoted from SDL 2.0.5+)
 #include <SDL.h>
 #include <SDL_syswm.h>
-#define SDL_HAS_CAPTURE_MOUSE       SDL_VERSION_ATLEAST(2,0,4)
+#define SDL_HAS_CAPTURE_MOUSE           SDL_VERSION_ATLEAST(2,0,4)
-#define SDL_HAS_WINDOW_OPACITY      SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_WINDOW_OPACITY          SDL_VERSION_ATLEAST(2,0,5)
-#define SDL_HAS_ALWAYS_ON_TOP       SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_ALWAYS_ON_TOP           SDL_VERSION_ATLEAST(2,0,5)
-#define SDL_HAS_PER_MONITOR_DPI     SDL_VERSION_ATLEAST(2,0,4)
+#define SDL_HAS_USABLE_DISPLAY_BOUNDS   SDL_VERSION_ATLEAST(2,0,5)
-#define SDL_HAS_VULKAN              SDL_VERSION_ATLEAST(2,0,6)
+#define SDL_HAS_PER_MONITOR_DPI         SDL_VERSION_ATLEAST(2,0,4)
+#define SDL_HAS_VULKAN                  SDL_VERSION_ATLEAST(2,0,6)
 #if !SDL_HAS_VULKAN
 static const Uint32 SDL_WINDOW_VULKAN = 0x10000000;
 #endif
@@ -446,20 +448,27 @@ static int ImGui_ImplSDL2_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_inst
 static void ImGui_ImplSDL2_UpdateMonitors()
 {
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
     int display_count = SDL_GetNumVideoDisplays();
-    platform_io.Monitors.resize(display_count, ImGuiPlatformMonitor());
     for (int n = 0; n < display_count; n++)
     {
         // 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.
+        ImGuiPlatformMonitor monitor;
         SDL_Rect r;
         SDL_GetDisplayBounds(n, &r);
-        platform_io.Monitors[n].Pos = ImVec2((float)r.x, (float)r.y);
+        monitor.FullMin = monitor.WorkMin = ImVec2((float)(r.x), (float)(r.y));
-        platform_io.Monitors[n].Size = ImVec2((float)r.w, (float)r.h);
+        monitor.FullMax = monitor.WorkMax = ImVec2((float)(r.x + r.w), (float)(r.y + 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));
+#endif
 #if SDL_HAS_PER_MONITOR_DPI
         float dpi = 0.0f;
-        SDL_GetDisplayDPI(n, &dpi, NULL, NULL);
+        if (SDL_GetDisplayDPI(n, &dpi, NULL, NULL))
-        platform_io.Monitors[n].DpiScale = dpi / 96.0f;
+            monitor.DpiScale = dpi / 96.0f;
 #endif
+        platform_io.Monitors.push_back(monitor);
     }
 }
 

examples/imgui_impl_win32.cpp

@@ -550,11 +550,17 @@ static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd,
     return DefWindowProc(hWnd, msg, wParam, lParam);
 }
 
-static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, HDC, LPRECT rect, LPARAM)
+static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, HDC, LPRECT, LPARAM)
 {
+    MONITORINFO info = { 0 };
+    info.cbSize = sizeof(MONITORINFO);
+    if (!::GetMonitorInfo(monitor, &info))
+        return TRUE;
     ImGuiPlatformMonitor imgui_monitor;
-    imgui_monitor.Pos = ImVec2((float)rect->left, (float)rect->top);
+    imgui_monitor.FullMin = ImVec2((float)info.rcMonitor.left, (float)info.rcMonitor.top);
-    imgui_monitor.Size = ImVec2((float)(rect->right - rect->left), (float)(rect->bottom - rect->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.DpiScale = ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
     ImGui::GetPlatformIO().Monitors.push_back(imgui_monitor);
     return TRUE;

imgui.cpp

@@ -3802,6 +3802,13 @@ void ImGui::NewFrame()
             // Disable feature, our back-ends do not support it
             g.IO.ConfigFlags &= ~ImGuiConfigFlags_ViewportsEnable;
         }
+        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.DpiScale != 0.0f);
+        }
     }
 
     // Load settings on first frame
@@ -5847,8 +5854,8 @@ 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.Pos;
+        r_screen.Min = monitor.WorkMin;
-        r_screen.Max = monitor.Pos + monitor.Size;
+        r_screen.Max = monitor.WorkMax;
     }
     else
     {
@@ -6028,7 +6035,7 @@ static ImVec2 CalcSizeAutoFit(ImGuiWindow* window, const ImVec2& size_contents)
         const int monitor_idx = window->ViewportAllowPlatformMonitorExtend;
         ImVec2 avail_size = window->Viewport->Size;
         if (window->ViewportOwned)
-            avail_size = (monitor_idx >= 0 && monitor_idx < g.PlatformIO.Monitors.Size) ? g.PlatformIO.Monitors[monitor_idx].Size : ImVec2(FLT_MAX, FLT_MAX);
+            avail_size = (monitor_idx >= 0 && monitor_idx < g.PlatformIO.Monitors.Size) ? (g.PlatformIO.Monitors[monitor_idx].WorkMax - g.PlatformIO.Monitors[monitor_idx].WorkMin) : ImVec2(FLT_MAX, FLT_MAX);
         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),
@@ -6099,8 +6106,7 @@ static int FindPlatformMonitorForPos(ImVec2 platform_pos)
     for (int monitor_n = 0; monitor_n < g.PlatformIO.Monitors.Size; monitor_n++)
     {
         const ImGuiPlatformMonitor* monitor = &g.PlatformIO.Monitors[monitor_n];
-        ImRect monitor_rect(monitor->Pos, monitor->Pos + monitor->Size);
+        if (ImRect(monitor->FullMin, monitor->FullMax).Contains(platform_pos))
-        if (monitor_rect.Contains(platform_pos))
             return monitor_n;
     }
     return -1;
@@ -14252,7 +14258,10 @@ 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%%, Min (%.0f,%.0f), Max (%.0f,%.0f), Size (%.0f,%.0f)", i, mon.DpiScale * 100.0f, mon.Pos.x, mon.Pos.y, mon.Pos.x + mon.Size.x, mon.Pos.y + mon.Size.y, mon.Size.x, mon.Size.y);
+                    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)", 
+                        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);
                 }
                 ImGui::TreePop();
             }

imgui.h

@@ -1876,10 +1876,10 @@ 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  Pos;
+    ImVec2  FullMin, FullMax;   // Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
-    ImVec2  Size;
+    ImVec2  WorkMin, WorkMax;   // (Optional) Coordinates without task bars / side bars / menu bars. imgui uses this to avoid positioning popups/tooltips inside this region.
     float   DpiScale;
-    ImGuiPlatformMonitor() { Pos = ImVec2(0,0); Size = ImVec2(0,0); DpiScale = 1.0f; }
+    ImGuiPlatformMonitor() { FullMin = FullMax = WorkMin = WorkMax = ImVec2(0,0); DpiScale = 1.0f; }
 };
 
 // (Optional) Setup required only if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) is enabled