Introduce IMGUI_USE_BGRA_PACKED_COLOR in imconfig.h.

imconfig.h

@@ -26,6 +26,9 @@
 //---- Don't define obsolete functions names
 //#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 
+//---- Pack colors to BGRA instead of RGBA (remove need to post process vertex buffer in back ends)
+//#define IMGUI_USE_BGRA_PACKED_COLOR
+
 //---- Implement STB libraries in a namespace to avoid conflicts
 //#define IMGUI_STB_NAMESPACE     ImGuiStb
 

imgui.cpp

@@ -1195,16 +1195,20 @@ int ImTextCountUtf8BytesFromStr(const ImWchar* in_text, const ImWchar* in_text_e
 ImVec4 ImGui::ColorConvertU32ToFloat4(ImU32 in)
 {
     float s = 1.0f/255.0f;
-    return ImVec4((in & 0xFF) * s, ((in >> 8) & 0xFF) * s, ((in >> 16) & 0xFF) * s, (in >> 24) * s);
+    return ImVec4(
+        ((in >> IM_COL32_R_SHIFT) & 0xFF) * s,
+        ((in >> IM_COL32_G_SHIFT) & 0xFF) * s,
+        ((in >> IM_COL32_B_SHIFT) & 0xFF) * s,
+        ((in >> IM_COL32_A_SHIFT) & 0xFF) * s);
 }
 
 ImU32 ImGui::ColorConvertFloat4ToU32(const ImVec4& in)
 {
     ImU32 out;
-    out  = ((ImU32)IM_F32_TO_INT8_SAT(in.x));
-    out |= ((ImU32)IM_F32_TO_INT8_SAT(in.y)) << 8;
-    out |= ((ImU32)IM_F32_TO_INT8_SAT(in.z)) << 16;
-    out |= ((ImU32)IM_F32_TO_INT8_SAT(in.w)) << 24;
+    out  = ((ImU32)IM_F32_TO_INT8_SAT(in.x)) << IM_COL32_R_SHIFT;
+    out |= ((ImU32)IM_F32_TO_INT8_SAT(in.y)) << IM_COL32_G_SHIFT;
+    out |= ((ImU32)IM_F32_TO_INT8_SAT(in.z)) << IM_COL32_B_SHIFT;
+    out |= ((ImU32)IM_F32_TO_INT8_SAT(in.w)) << IM_COL32_A_SHIFT;
     return out;
 }
 
@@ -8845,7 +8849,7 @@ bool ImGui::BeginMenu(const char* label, bool enabled)
                 tb.y = ta.y + ImMax((tb.y - extra) - ta.y, -100.0f);            // triangle is maximum 200 high to limit the slope and the bias toward large sub-menus // FIXME: Multiply by fb_scale?
                 tc.y = ta.y + ImMin((tc.y + extra) - ta.y, +100.0f);
                 moving_within_opened_triangle = ImIsPointInTriangle(g.IO.MousePos, ta, tb, tc);
-                //window->DrawList->PushClipRectFullScreen(); window->DrawList->AddTriangleFilled(ta, tb, tc, moving_within_opened_triangle ? 0x80008000 : 0x80000080); window->DrawList->PopClipRect(); // Debug
+                //window->DrawList->PushClipRectFullScreen(); window->DrawList->AddTriangleFilled(ta, tb, tc, moving_within_opened_triangle ? IM_COL32(0,128,0,128) : IM_COL32(128,0,0,128)); window->DrawList->PopClipRect(); // Debug
             }
         }
 
@@ -9201,7 +9205,7 @@ void ImGui::EndGroup()
 
     window->DC.GroupStack.pop_back();
 
-    //window->DrawList->AddRect(group_bb.Min, group_bb.Max, 0xFFFF00FF);   // Debug
+    //window->DrawList->AddRect(group_bb.Min, group_bb.Max, IM_COL32(255,0,255,255));   // Debug
 }
 
 // Gets back to previous line and continue with horizontal layout
@@ -9541,10 +9545,10 @@ void ImGui::ValueColor(const char* prefix, ImU32 v)
     SameLine();
 
     ImVec4 col;
-    col.x = (float)((v >> 0) & 0xFF) / 255.0f;
-    col.y = (float)((v >> 8) & 0xFF) / 255.0f;
-    col.z = (float)((v >> 16) & 0xFF) / 255.0f;
-    col.w = (float)((v >> 24) & 0xFF) / 255.0f;
+    col.x = (float)((v >> IM_COL32_R_SHIFT) & 0xFF) / 255.0f;
+    col.y = (float)((v >> IM_COL32_G_SHIFT) & 0xFF) / 255.0f;
+    col.z = (float)((v >> IM_COL32_B_SHIFT) & 0xFF) / 255.0f;
+    col.w = (float)((v >> IM_COL32_A_SHIFT) & 0xFF) / 255.0f;
     ColorButton(col, true);
 }
 

imgui.h

@@ -827,6 +827,23 @@ struct ImGuiIO
 // Helpers
 //-----------------------------------------------------------------------------
 
+// Helpers macros to generate 32-bits encoded colors
+#ifdef IMGUI_USE_BGRA_PACKED_COLOR
+#define IM_COL32_R_SHIFT    16
+#define IM_COL32_G_SHIFT    8
+#define IM_COL32_B_SHIFT    0
+#define IM_COL32_A_SHIFT    24
+#else
+#define IM_COL32_R_SHIFT    0
+#define IM_COL32_G_SHIFT    8
+#define IM_COL32_B_SHIFT    16
+#define IM_COL32_A_SHIFT    24
+#endif
+#define IM_COL32(R,G,B,A)    (((ImU32)(A)<<IM_COL32_A_SHIFT) | ((ImU32)(B)<<IM_COL32_B_SHIFT) | ((ImU32)(G)<<IM_COL32_G_SHIFT) | ((ImU32)(R)<<IM_COL32_R_SHIFT))
+#define IM_COL32_WHITE       (IM_COL32(255,255,255,255))
+#define IM_COL32_BLACK       (IM_COL32(0,0,0,255))
+#define IM_COL32_BLACK_TRANS (IM_COL32(0,0,0,0))    // Transparent black
+
 // Lightweight std::vector<> like class to avoid dragging dependencies (also: windows implementation of STL with debug enabled is absurdly slow, so let's bypass it so our code runs fast in debug).
 // Our implementation does NOT call c++ constructors because we don't use them in ImGui. Don't use this class as a straight std::vector replacement in your code!
 template<typename T>
@@ -1044,7 +1061,7 @@ struct ImColor
 
     ImColor()                                                       { Value.x = Value.y = Value.z = Value.w = 0.0f; }
     ImColor(int r, int g, int b, int a = 255)                       { float sc = 1.0f/255.0f; Value.x = (float)r * sc; Value.y = (float)g * sc; Value.z = (float)b * sc; Value.w = (float)a * sc; }
-    ImColor(ImU32 rgba)                                             { float sc = 1.0f/255.0f; Value.x = (float)(rgba&0xFF) * sc; Value.y = (float)((rgba>>8)&0xFF) * sc; Value.z = (float)((rgba>>16)&0xFF) * sc; Value.w = (float)(rgba >> 24) * sc; }
+    ImColor(ImU32 rgba)                                             { float sc = 1.0f/255.0f; Value.x = (float)((rgba>>IM_COL32_R_SHIFT)&0xFF) * sc; Value.y = (float)((rgba>>IM_COL32_G_SHIFT)&0xFF) * sc; Value.z = (float)((rgba>>IM_COL32_B_SHIFT)&0xFF) * sc; Value.w = (float)((rgba>>IM_COL32_A_SHIFT)&0xFF) * sc; }
     ImColor(float r, float g, float b, float a = 1.0f)              { Value.x = r; Value.y = g; Value.z = b; Value.w = a; }
     ImColor(const ImVec4& col)                                      { Value = col; }
     inline operator ImU32() const                                   { return ImGui::ColorConvertFloat4ToU32(Value); }
@@ -1090,12 +1107,6 @@ struct ImGuiListClipper
 // Hold a series of drawing commands. The user provides a renderer for ImDrawData which essentially contains an array of ImDrawList.
 //-----------------------------------------------------------------------------
 
-// Helpers macros to generate 32-bits encoded colors
-#define IM_COL32(R,G,B,A)    (((ImU32)(A)<<24) | ((ImU32)(B)<<16) | ((ImU32)(G)<<8) | ((ImU32)(R)))
-#define IM_COL32_WHITE       (0xFFFFFFFF)
-#define IM_COL32_BLACK       (0xFF000000)
-#define IM_COL32_BLACK_TRANS (0x00000000)    // Transparent black
-
 // Draw callbacks for advanced uses.
 // NB- You most likely do NOT need to use draw callbacks just to create your own widget or customized UI rendering (you can poke into the draw list for that)
 // Draw callback may be useful for example, A) Change your GPU render state, B) render a complex 3D scene inside a UI element (without an intermediate texture/render target), etc.

imgui_demo.cpp

@@ -355,18 +355,18 @@ void ImGui::ShowTestWindow(bool* p_open)
 
             ImGui::Text("Test paragraph 1:");
             ImVec2 pos = ImGui::GetCursorScreenPos();
-            ImGui::GetWindowDrawList()->AddRectFilled(ImVec2(pos.x + wrap_width, pos.y), ImVec2(pos.x + wrap_width + 10, pos.y + ImGui::GetTextLineHeight()), 0xFFFF00FF);
+            ImGui::GetWindowDrawList()->AddRectFilled(ImVec2(pos.x + wrap_width, pos.y), ImVec2(pos.x + wrap_width + 10, pos.y + ImGui::GetTextLineHeight()), IM_COL32(255,0,255,255));
             ImGui::PushTextWrapPos(ImGui::GetCursorPos().x + wrap_width);
             ImGui::Text("lazy dog. This paragraph is made to fit within %.0f pixels. The quick brown fox jumps over the lazy dog.", wrap_width);
-            ImGui::GetWindowDrawList()->AddRect(ImGui::GetItemRectMin(), ImGui::GetItemRectMax(), 0xFF00FFFF);
+            ImGui::GetWindowDrawList()->AddRect(ImGui::GetItemRectMin(), ImGui::GetItemRectMax(), IM_COL32(255,255,0,255));
             ImGui::PopTextWrapPos();
 
             ImGui::Text("Test paragraph 2:");
             pos = ImGui::GetCursorScreenPos();
-            ImGui::GetWindowDrawList()->AddRectFilled(ImVec2(pos.x + wrap_width, pos.y), ImVec2(pos.x + wrap_width + 10, pos.y + ImGui::GetTextLineHeight()), 0xFFFF00FF);
+            ImGui::GetWindowDrawList()->AddRectFilled(ImVec2(pos.x + wrap_width, pos.y), ImVec2(pos.x + wrap_width + 10, pos.y + ImGui::GetTextLineHeight()), IM_COL32(255,0,255,255));
             ImGui::PushTextWrapPos(ImGui::GetCursorPos().x + wrap_width);
             ImGui::Text("aaaaaaaa bbbbbbbb, cccccccc,dddddddd. eeeeeeee   ffffffff. gggggggg!hhhhhhhh");
-            ImGui::GetWindowDrawList()->AddRect(ImGui::GetItemRectMin(), ImGui::GetItemRectMax(), 0xFF00FFFF);
+            ImGui::GetWindowDrawList()->AddRect(ImGui::GetItemRectMin(), ImGui::GetItemRectMax(), IM_COL32(255,255,0,255));
             ImGui::PopTextWrapPos();
 
             ImGui::TreePop();
@@ -2063,7 +2063,7 @@ static void ShowExampleAppCustomRendering(bool* p_open)
         }
         draw_list->PushClipRect(canvas_pos, ImVec2(canvas_pos.x+canvas_size.x, canvas_pos.y+canvas_size.y));      // clip lines within the canvas (if we resize it, etc.)
         for (int i = 0; i < points.Size - 1; i += 2)
-            draw_list->AddLine(ImVec2(canvas_pos.x + points[i].x, canvas_pos.y + points[i].y), ImVec2(canvas_pos.x + points[i+1].x, canvas_pos.y + points[i+1].y), 0xFF00FFFF, 2.0f);
+            draw_list->AddLine(ImVec2(canvas_pos.x + points[i].x, canvas_pos.y + points[i].y), ImVec2(canvas_pos.x + points[i+1].x, canvas_pos.y + points[i+1].y), IM_COL32(255,255,0,255), 2.0f);
         draw_list->PopClipRect();
         if (adding_preview)
             points.pop_back();

imgui_draw.cpp

@@ -429,7 +429,7 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32
     {
         // Anti-aliased stroke
         const float AA_SIZE = 1.0f;
-        const ImU32 col_trans = col & 0x00ffffff;
+        const ImU32 col_trans = col & IM_COL32(255,255,255,0);
 
         const int idx_count = thick_line ? count*18 : count*12;
         const int vtx_count = thick_line ? points_count*4 : points_count*3;
@@ -602,7 +602,7 @@ void ImDrawList::AddConvexPolyFilled(const ImVec2* points, const int points_coun
     {
         // Anti-aliased Fill
         const float AA_SIZE = 1.0f;
-        const ImU32 col_trans = col & 0x00ffffff;
+        const ImU32 col_trans = col & IM_COL32(255, 255, 255, 0);
         const int idx_count = (points_count-2)*3 + points_count*6;
         const int vtx_count = (points_count*2);
         PrimReserve(idx_count, vtx_count);
@@ -1119,7 +1119,7 @@ void    ImFontAtlas::GetTexDataAsRGBA32(unsigned char** out_pixels, int* out_wid
         const unsigned char* src = pixels;
         unsigned int* dst = TexPixelsRGBA32;
         for (int n = TexWidth * TexHeight; n > 0; n--)
-            *dst++ = ((unsigned int)(*src++) << 24) | 0x00FFFFFF;
+            *dst++ = IM_COL32(255, 255, 255, (unsigned int)(*src++));
     }
 
     *out_pixels = (unsigned char*)TexPixelsRGBA32;