Fixed imgui font pixel center.

3rdparty/ocornut-imgui/imgui.cpp

@@ -658,6 +658,7 @@ ImGuiIO::ImGuiIO()
     DisplaySize = ImVec2(-1.0f, -1.0f);
     DeltaTime = 1.0f/60.0f;
     IniSavingRate = 5.0f;
+    PixelCenterOffset = 0.5f;
     IniFilename = "imgui.ini";
     LogFilename = "imgui_log.txt";
     Fonts = &GDefaultFontAtlas;
@@ -9180,6 +9181,9 @@ bool    ImFontAtlas::Build()
     ImGui::MemFree(buf_rects);
     buf_rects = NULL;
 
+    ImGuiIO& io = ImGui::GetIO();
+    const float PixelCenterOffset = io.PixelCenterOffset;
+
     // Third pass: setup ImFont and glyphs for runtime
     for (size_t input_i = 0; input_i < InputData.size(); input_i++)
     {
@@ -9213,10 +9217,10 @@ bool    ImFontAtlas::Build()
                 glyph.XOffset = (signed short)(pc.xoff);
                 glyph.YOffset = (signed short)(pc.yoff + (int)(font_ascent * font_scale));
                 glyph.XAdvance = (signed short)(pc.xadvance + character_spacing_x);  // Bake spacing into XAdvance
-                glyph.U0 = ((float)pc.x0 - 0.5f) * uv_scale_x;
-                glyph.V0 = ((float)pc.y0 - 0.5f) * uv_scale_y;
-                glyph.U1 = ((float)pc.x0 - 0.5f + glyph.Width) * uv_scale_x;
-                glyph.V1 = ((float)pc.y0 - 0.5f + glyph.Height) * uv_scale_y;
+                glyph.U0 = ((float)pc.x0 - PixelCenterOffset) * uv_scale_x;
+                glyph.V0 = ((float)pc.y0 - PixelCenterOffset) * uv_scale_y;
+                glyph.U1 = ((float)pc.x0 - PixelCenterOffset + glyph.Width) * uv_scale_x;
+                glyph.V1 = ((float)pc.y0 - PixelCenterOffset + glyph.Height) * uv_scale_y;
             }
         }
 

3rdparty/ocornut-imgui/imgui.h

@@ -609,6 +609,7 @@ struct ImGuiIO
     ImVec2        DisplaySize;              // <unset>              // Display size, in pixels. For clamping windows positions.
     float         DeltaTime;                // = 1.0f/60.0f         // Time elapsed since last frame, in seconds.
     float         IniSavingRate;            // = 5.0f               // Maximum time between saving positions/sizes to .ini file, in seconds.
+    float         PixelCenterOffset;        // = 0.5f;              // Pixel center offset for font texture.
     const char*   IniFilename;              // = "imgui.ini"        // Path to .ini file. NULL to disable .ini saving.
     const char*   LogFilename;              // = "imgui_log.txt"    // Path to .log file (default parameter to ImGui::LogToFile when no file is specified).
     float         MouseDoubleClickTime;     // = 0.30f              // Time for a double-click, in seconds.

examples/common/imgui/ocornut_imgui.cpp

@@ -108,7 +108,7 @@ struct OcornutImguiContext
 		io.DisplaySize = ImVec2(1280.0f, 720.0f);
 		io.DeltaTime = 1.0f / 60.0f;
 		io.IniFilename = NULL;
-//		io.PixelCenterOffset = bgfx::RendererType::Direct3D9 == bgfx::getRendererType() ? -0.5f : 0.0f;
+		io.PixelCenterOffset = bgfx::RendererType::Direct3D9 == bgfx::getRendererType() ? 0.0f : 0.5f;
 
 		for (uint32_t ii = 0; ii < ImGuiKey_COUNT; ++ii)
 		{