ImGui: fixed framebuffer scaling issues on MacOS

DiligentGraphics · Jun 10, 2023 · 7a820e0 · 7a820e0
1 parent e2b3d90
commit 7a820e0
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Showing 4 changed files with 31 additions and 35 deletions.
diff --git a/Imgui/interface/ImGuiImplMacOS.hpp b/Imgui/interface/ImGuiImplMacOS.hpp
@@ -39,9 +39,9 @@ namespace Diligent
 class ImGuiImplMacOS final : public ImGuiImplDiligent
 {
 public:
-    static std::unique_ptr<ImGuiImplMacOS> Create(const ImGuiDiligentCreateInfo& CI);
+    static std::unique_ptr<ImGuiImplMacOS> Create(const ImGuiDiligentCreateInfo& CI, void* _Nullable view);
 
-    ImGuiImplMacOS(const ImGuiDiligentCreateInfo& CI);
+    ImGuiImplMacOS(const ImGuiDiligentCreateInfo& CI, void* _Nullable view);
     ~ImGuiImplMacOS();
 
     // clang-format off

diff --git a/Imgui/src/ImGuiDiligentRenderer.cpp b/Imgui/src/ImGuiDiligentRenderer.cpp
@@ -783,7 +783,7 @@ float4 ImGuiDiligentRenderer::TransformClipRect(const ImVec2& DisplaySize, const
 void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDrawData)
 {
     // Avoid rendering when minimized
-    if (pDrawData->DisplaySize.x <= 0.0f || pDrawData->DisplaySize.y <= 0.0f)
+    if (pDrawData->DisplaySize.x <= 0.0f || pDrawData->DisplaySize.y <= 0.0f || pDrawData->CmdListsCount == 0)
         return;
 
     // Create and grow vertex/index buffers if needed
@@ -907,15 +907,13 @@ void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDr
         pCtx->SetBlendFactors(blend_factor);
 
         Viewport vp;
-        vp.Width    = static_cast<float>(m_RenderSurfaceWidth) * pDrawData->FramebufferScale.x;
-        vp.Height   = static_cast<float>(m_RenderSurfaceHeight) * pDrawData->FramebufferScale.y;
+        vp.TopLeftX = 0;
+        vp.TopLeftY = 0;
+        vp.Width    = static_cast<float>(m_RenderSurfaceWidth);
+        vp.Height   = static_cast<float>(m_RenderSurfaceHeight);
         vp.MinDepth = 0.0f;
         vp.MaxDepth = 1.0f;
-        vp.TopLeftX = vp.TopLeftY = 0;
-        pCtx->SetViewports(1,
-                           &vp,
-                           static_cast<Uint32>(m_RenderSurfaceWidth * pDrawData->FramebufferScale.x),
-                           static_cast<Uint32>(m_RenderSurfaceHeight * pDrawData->FramebufferScale.y));
+        pCtx->SetViewports(1, &vp, m_RenderSurfaceWidth, m_RenderSurfaceHeight);
     };
 
     SetupRenderState();
@@ -943,6 +941,9 @@ void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDr
             }
             else
             {
+                if (pCmd->ElemCount == 0)
+                    continue;
+
                 // Apply scissor/clipping rectangle
                 float4 ClipRect //
                     {
@@ -961,10 +962,13 @@ void ImGuiDiligentRenderer::RenderDrawData(IDeviceContext* pCtx, ImDrawData* pDr
                         static_cast<Int32>(ClipRect.z),
                         static_cast<Int32>(ClipRect.w) //
                     };
-                pCtx->SetScissorRects(1,
-                                      &Scissor,
-                                      static_cast<Uint32>(m_RenderSurfaceWidth * pDrawData->FramebufferScale.x),
-                                      static_cast<Uint32>(m_RenderSurfaceHeight * pDrawData->FramebufferScale.y));
+                Scissor.left   = std::max(Scissor.left, 0);
+                Scissor.top    = std::max(Scissor.top, 0);
+                Scissor.right  = std::min(Scissor.right, static_cast<Int32>(m_RenderSurfaceWidth));
+                Scissor.bottom = std::min(Scissor.bottom, static_cast<Int32>(m_RenderSurfaceHeight));
+                if (!Scissor.IsValid())
+                    continue;
+                pCtx->SetScissorRects(1, &Scissor, m_RenderSurfaceWidth, m_RenderSurfaceHeight);
 
                 // Bind texture
                 auto* pTextureView = reinterpret_cast<ITextureView*>(pCmd->TextureId);

diff --git a/Imgui/src/ImGuiImplMacOS.mm b/Imgui/src/ImGuiImplMacOS.mm
@@ -29,18 +29,20 @@
 namespace Diligent
 {
 
-std::unique_ptr<ImGuiImplMacOS> ImGuiImplMacOS::Create(const ImGuiDiligentCreateInfo& CI)
+std::unique_ptr<ImGuiImplMacOS> ImGuiImplMacOS::Create(const ImGuiDiligentCreateInfo& CI, void* _Nullable view)
 {
-    return std::make_unique<ImGuiImplMacOS>(CI);
+    return std::make_unique<ImGuiImplMacOS>(CI, view);
 }
 
-ImGuiImplMacOS::ImGuiImplMacOS(const ImGuiDiligentCreateInfo& CI) :
+ImGuiImplMacOS::ImGuiImplMacOS(const ImGuiDiligentCreateInfo& CI, void* _Nullable view) :
     ImGuiImplDiligent{CI}
 {
     ImGui_ImplOSX_Init();
     ImGuiIO& io = ImGui::GetIO();
-    io.FontGlobalScale = 2;
     io.BackendPlatformName = "Diligent-ImGuiImplMacOS";
+
+    const auto framebufferScale = ((NSView*)view).window.screen.backingScaleFactor ?: NSScreen.mainScreen.backingScaleFactor;;
+    io.DisplayFramebufferScale = ImVec2(framebufferScale, framebufferScale);
 }
 
 ImGuiImplMacOS::~ImGuiImplMacOS()
@@ -54,7 +56,7 @@
 {
     std::lock_guard<std::mutex> Lock(m_Mtx);
     ImGuiIO& io = ImGui::GetIO();
-    io.DisplaySize = ImVec2(RenderSurfaceWidth, RenderSurfaceHeight);
+    io.DisplaySize = ImVec2(RenderSurfaceWidth / io.DisplayFramebufferScale.x, RenderSurfaceHeight / io.DisplayFramebufferScale.y);
     ImGui_ImplOSX_NewFrame(nil);
     ImGuiImplDiligent::NewFrame(RenderSurfaceWidth, RenderSurfaceHeight, SurfacePreTransform);
 }
@@ -65,11 +67,10 @@
     ImGuiIO& io = ImGui::GetIO();
     if (event.type == NSEventTypeMouseMoved || event.type == NSEventTypeLeftMouseDragged)
     {
-        NSRect viewRectPoints = [view bounds];
-        NSRect viewRectPixels = [view convertRectToBacking:viewRectPoints];
-        NSPoint curPoint = [view convertPoint:[event locationInWindow] fromView:nil];
-        curPoint = [view convertPointToBacking:curPoint];
-        io.MousePos = ImVec2(curPoint.x, viewRectPixels.size.height-1 - curPoint.y);
+        NSRect  viewRectPoints = [view bounds];
+        NSPoint curPoint       = [view convertPoint:[event locationInWindow] fromView:nil];
+        io.MousePos.x = curPoint.x;
+        io.MousePos.y = viewRectPoints.size.height-1 - curPoint.y;
         return io.WantCaptureMouse;
     }
 

diff --git a/ThirdParty/imgui_v1.85/imgui_impl_osx_v1.85.mm b/ThirdParty/imgui_v1.85/imgui_impl_osx_v1.85.mm
@@ -39,7 +39,6 @@
 @class ImFocusObserver;
 
 // Data
-static double         g_HostClockPeriod = 0.0;
 static double         g_Time = 0.0;
 static NSCursor*      g_MouseCursors[ImGuiMouseCursor_COUNT] = {};
 static bool           g_MouseCursorHidden = false;
@@ -55,16 +54,9 @@ + (id)_windowResizeNorthSouthCursor;
 + (id)_windowResizeEastWestCursor;
 @end
 
-static void InitHostClockPeriod()
+static CFTimeInterval GetMachAbsoluteTimeInSeconds()
 {
-    struct mach_timebase_info info;
-    mach_timebase_info(&info);
-    g_HostClockPeriod = 1e-9 * ((double)info.denom / (double)info.numer); // Period is the reciprocal of frequency.
-}
-
-static double GetMachAbsoluteTimeInSeconds()
-{
-    return (double)mach_absolute_time() * g_HostClockPeriod;
+    return (CFTimeInterval)(double)(clock_gettime_nsec_np(CLOCK_UPTIME_RAW) / 1e9);;
 }
 
 static void resetKeys()
@@ -248,7 +240,6 @@ void ImGui_ImplOSX_NewFrame(NSView* view)
     // Setup time step
     if (g_Time == 0.0)
     {
-        InitHostClockPeriod();
         g_Time = GetMachAbsoluteTimeInSeconds();
     }
     double current_time = GetMachAbsoluteTimeInSeconds();