ImFontAtlas: Added TexUvScale (= 1.0f / (float)TexWidth, 1.0f / (float)TexHeight)

imgui.h

@@ -1631,6 +1631,7 @@ struct ImFontAtlas
     unsigned int*               TexPixelsRGBA32;    // 4 component per pixel, each component is unsigned 8-bit. Total size = TexWidth * TexHeight * 4
     int                         TexWidth;           // Texture width calculated during Build().
     int                         TexHeight;          // Texture height calculated during Build().
+    ImVec2                      TexUvScale;         // = (1.0f/TexWidth, 1.0f/TexHeight)
     ImVec2                      TexUvWhitePixel;    // Texture coordinates to a white pixel
     ImVector<ImFont*>           Fonts;              // Hold all the fonts returned by AddFont*. Fonts[0] is the default font upon calling ImGui::NewFrame(), use ImGui::PushFont()/PopFont() to change the current font.
     ImVector<CustomRect>        CustomRects;        // Rectangles for packing custom texture data into the atlas.

imgui_draw.cpp

@@ -1360,7 +1360,8 @@ ImFontAtlas::ImFontAtlas()
     TexPixelsAlpha8 = NULL;
     TexPixelsRGBA32 = NULL;
     TexWidth = TexHeight = 0;
-    TexUvWhitePixel = ImVec2(0, 0);
+    TexUvScale = ImVec2(0.0f, 0.0f);
+    TexUvWhitePixel = ImVec2(0.0f, 0.0f);
     for (int n = 0; n < IM_ARRAYSIZE(CustomRectIds); n++)
         CustomRectIds[n] = -1;
 }
@@ -1604,8 +1605,8 @@ void ImFontAtlas::CalcCustomRectUV(const CustomRect* rect, ImVec2* out_uv_min, I
 {
     IM_ASSERT(TexWidth > 0 && TexHeight > 0);   // Font atlas needs to be built before we can calculate UV coordinates
     IM_ASSERT(rect->IsPacked());                // Make sure the rectangle has been packed
-    *out_uv_min = ImVec2((float)rect->X / TexWidth, (float)rect->Y / TexHeight);
-    *out_uv_max = ImVec2((float)(rect->X + rect->Width) / TexWidth, (float)(rect->Y + rect->Height) / TexHeight);
+    *out_uv_min = ImVec2((float)rect->X * TexUvScale.x, (float)rect->Y * TexUvScale.y);
+    *out_uv_max = ImVec2((float)(rect->X + rect->Width) * TexUvScale.x, (float)(rect->Y + rect->Height) * TexUvScale.y);
 }
 
 bool ImFontAtlas::GetMouseCursorTexData(ImGuiMouseCursor cursor_type, ImVec2* out_offset, ImVec2* out_size, ImVec2 out_uv_border[2], ImVec2 out_uv_fill[2])
@@ -1615,16 +1616,15 @@ bool ImFontAtlas::GetMouseCursorTexData(ImGuiMouseCursor cursor_type, ImVec2* ou
 
     ImFontAtlas::CustomRect& r = CustomRects[CustomRectIds[0]];
     IM_ASSERT(r.ID == FONT_ATLAS_DEFAULT_TEX_DATA_ID);
-    ImVec2 uv_scale(1.0f / TexWidth, 1.0f / TexHeight);
     ImVec2 pos = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][0] + ImVec2((float)r.X, (float)r.Y);
     ImVec2 size = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][1];
     *out_size = size;
     *out_offset = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][2];
-    out_uv_border[0] = (pos) * uv_scale;
-    out_uv_border[1] = (pos + size) * uv_scale;
+    out_uv_border[0] = (pos) * TexUvScale;
+    out_uv_border[1] = (pos + size) * TexUvScale;
     pos.x += FONT_ATLAS_DEFAULT_TEX_DATA_W_HALF + 1;
-    out_uv_fill[0] = (pos) * uv_scale;
-    out_uv_fill[1] = (pos + size) * uv_scale;
+    out_uv_fill[0] = (pos) * TexUvScale;
+    out_uv_fill[1] = (pos + size) * TexUvScale;
     return true;
 }
 
@@ -1658,7 +1658,8 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 
     atlas->TexID = NULL;
     atlas->TexWidth = atlas->TexHeight = 0;
-    atlas->TexUvWhitePixel = ImVec2(0, 0);
+    atlas->TexUvScale = ImVec2(0.0f, 0.0f);
+    atlas->TexUvWhitePixel = ImVec2(0.0f, 0.0f);
     atlas->ClearTexData();
 
     // Count glyphs/ranges
@@ -1767,6 +1768,7 @@ bool    ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 
     // Create texture
     atlas->TexHeight = ImUpperPowerOfTwo(atlas->TexHeight);
+    atlas->TexUvScale = ImVec2(1.0f / atlas->TexWidth, 1.0f / atlas->TexHeight);
     atlas->TexPixelsAlpha8 = (unsigned char*)ImGui::MemAlloc(atlas->TexWidth * atlas->TexHeight);
     memset(atlas->TexPixelsAlpha8, 0, atlas->TexWidth * atlas->TexHeight);
     spc.pixels = atlas->TexPixelsAlpha8;
@@ -1908,8 +1910,7 @@ static void ImFontAtlasBuildRenderDefaultTexData(ImFontAtlas* atlas)
             atlas->TexPixelsAlpha8[offset0] = FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS[n] == '.' ? 0xFF : 0x00;
             atlas->TexPixelsAlpha8[offset1] = FONT_ATLAS_DEFAULT_TEX_DATA_PIXELS[n] == 'X' ? 0xFF : 0x00;
         }
-    const ImVec2 tex_uv_scale(1.0f / atlas->TexWidth, 1.0f / atlas->TexHeight);
-    atlas->TexUvWhitePixel = ImVec2((r.X + 0.5f) * tex_uv_scale.x, (r.Y + 0.5f) * tex_uv_scale.y);
+    atlas->TexUvWhitePixel = ImVec2((r.X + 0.5f) * atlas->TexUvScale.x, (r.Y + 0.5f) * atlas->TexUvScale.y);
 }
 
 void ImFontAtlasBuildFinish(ImFontAtlas* atlas)