Added PushStyleColor(ImGuiCol idx, ImU32 col) overload. (Which _might_ cause an "ambiguous call" compilation error if you are using ImColor() with implicit cast. Cast to ImU32 or ImVec4 explicily to fix.)

imgui.cpp

@@ -204,6 +204,7 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2016/08/20 (1.51) - added PushStyleColor(ImGuiCol idx, ImU32 col) overload, which _might_ cause an "ambiguous call" compilation error if you are using ImColor() with implicit cast. Cast to ImU32 or ImVec4 explicily to fix.
  - 2017/08/15 (1.51) - marked the weird IMGUI_ONCE_UPON_A_FRAME helper macro as obsolete. prefer using the more explicit ImGuiOnceUponAFrame.
  - 2017/08/15 (1.51) - changed parameter order for BeginPopupContextWindow(), note that most uses relied on default parameters completely.
  - 2017/08/13 (1.51) - renamed ImGuiCol_Columns_*** to ImGuiCol_Separator_***
@@ -4712,6 +4713,17 @@ void ImGui::PopTextWrapPos()
     window->DC.TextWrapPos = window->DC.TextWrapPosStack.empty() ? -1.0f : window->DC.TextWrapPosStack.back();
 }
 
+// FIXME: This may incur a round-trip (if the end user got their data from a float4) but eventually we aim to store the in-flight colors as ImU32
+void ImGui::PushStyleColor(ImGuiCol idx, ImU32 col)
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiColMod backup;
+    backup.Col = idx;
+    backup.BackupValue = g.Style.Colors[idx];
+    g.ColorModifiers.push_back(backup);
+    g.Style.Colors[idx] = ColorConvertU32ToFloat4(col);
+}
+
 void ImGui::PushStyleColor(ImGuiCol idx, const ImVec4& col)
 {
     ImGuiContext& g = *GImGui;

imgui.h

@@ -180,6 +180,7 @@ namespace ImGui
     // Parameters stacks (shared)
     IMGUI_API void          PushFont(ImFont* font);                                             // use NULL as a shortcut to push default font
     IMGUI_API void          PopFont();
+    IMGUI_API void          PushStyleColor(ImGuiCol idx, ImU32 col);
     IMGUI_API void          PushStyleColor(ImGuiCol idx, const ImVec4& col);
     IMGUI_API void          PopStyleColor(int count = 1);
     IMGUI_API void          PushStyleVar(ImGuiStyleVar idx, float val);
@@ -1095,8 +1096,8 @@ struct ImGuiSizeConstraintCallbackData
 
 // ImColor() helper to implicity converts colors to either ImU32 (packed 4x1 byte) or ImVec4 (4x1 float)
 // Prefer using IM_COL32() macros if you want a guaranteed compile-time ImU32 for usage with ImDrawList API.
-// **Avoid storing ImColor! Store either u32 of ImVec4. This is not a full-featured color class.
-// **None of the ImGui API are using ImColor directly but you can use it as a convenience to pass colors in either ImU32 or ImVec4 formats.
+// **Avoid storing ImColor! Store either u32 of ImVec4. This is not a full-featured color class. MAY OBSOLETE.
+// **None of the ImGui API are using ImColor directly but you can use it as a convenience to pass colors in either ImU32 or ImVec4 formats. Explicitly cast to ImU32 or ImVec4 if needed.
 struct ImColor
 {
     ImVec4              Value;
@@ -1109,8 +1110,8 @@ struct ImColor
     inline operator ImU32() const                                   { return ImGui::ColorConvertFloat4ToU32(Value); }
     inline operator ImVec4() const                                  { return Value; }
 
+    // FIXME-OBSOLETE: May need to obsolete/cleanup those helpers.
     inline void    SetHSV(float h, float s, float v, float a = 1.0f){ ImGui::ColorConvertHSVtoRGB(h, s, v, Value.x, Value.y, Value.z); Value.w = a; }
-
     static ImColor HSV(float h, float s, float v, float a = 1.0f)   { float r,g,b; ImGui::ColorConvertHSVtoRGB(h, s, v, r, g, b); return ImColor(r,g,b,a); }
 };
 

imgui_demo.cpp

@@ -285,9 +285,9 @@ void ImGui::ShowTestWindow(bool* p_open)
             {
                 if (i > 0) ImGui::SameLine();
                 ImGui::PushID(i);
-                ImGui::PushStyleColor(ImGuiCol_Button, ImColor::HSV(i/7.0f, 0.6f, 0.6f));
-                ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImColor::HSV(i/7.0f, 0.7f, 0.7f));
-                ImGui::PushStyleColor(ImGuiCol_ButtonActive, ImColor::HSV(i/7.0f, 0.8f, 0.8f));
+                ImGui::PushStyleColor(ImGuiCol_Button, (ImVec4)ImColor::HSV(i/7.0f, 0.6f, 0.6f));
+                ImGui::PushStyleColor(ImGuiCol_ButtonHovered, (ImVec4)ImColor::HSV(i/7.0f, 0.7f, 0.7f));
+                ImGui::PushStyleColor(ImGuiCol_ButtonActive, (ImVec4)ImColor::HSV(i/7.0f, 0.8f, 0.8f));
                 ImGui::Button("Click");
                 ImGui::PopStyleColor(3);
                 ImGui::PopID();
@@ -913,10 +913,10 @@ void ImGui::ShowTestWindow(bool* p_open)
             {
                 if (i > 0) ImGui::SameLine();
                 ImGui::PushID(i);
-                ImGui::PushStyleColor(ImGuiCol_FrameBg, ImColor::HSV(i/7.0f, 0.5f, 0.5f));
-                ImGui::PushStyleColor(ImGuiCol_FrameBgHovered, ImColor::HSV(i/7.0f, 0.6f, 0.5f));
-                ImGui::PushStyleColor(ImGuiCol_FrameBgActive, ImColor::HSV(i/7.0f, 0.7f, 0.5f));
-                ImGui::PushStyleColor(ImGuiCol_SliderGrab, ImColor::HSV(i/7.0f, 0.9f, 0.9f));
+                ImGui::PushStyleColor(ImGuiCol_FrameBg, (ImVec4)ImColor::HSV(i/7.0f, 0.5f, 0.5f));
+                ImGui::PushStyleColor(ImGuiCol_FrameBgHovered, (ImVec4)ImColor::HSV(i/7.0f, 0.6f, 0.5f));
+                ImGui::PushStyleColor(ImGuiCol_FrameBgActive, (ImVec4)ImColor::HSV(i/7.0f, 0.7f, 0.5f));
+                ImGui::PushStyleColor(ImGuiCol_SliderGrab, (ImVec4)ImColor::HSV(i/7.0f, 0.9f, 0.9f));
                 ImGui::VSliderFloat("##v", ImVec2(18,160), &values[i], 0.0f, 1.0f, "");
                 if (ImGui::IsItemActive() || ImGui::IsItemHovered())
                     ImGui::SetTooltip("%.3f", values[i]);
@@ -1271,9 +1271,9 @@ void ImGui::ShowTestWindow(bool* p_open)
                     char num_buf[16];
                     const char* label = (!(n%15)) ? "FizzBuzz" : (!(n%3)) ? "Fizz" : (!(n%5)) ? "Buzz" : (sprintf(num_buf, "%d", n), num_buf);
                     float hue = n*0.05f;
-                    ImGui::PushStyleColor(ImGuiCol_Button, ImColor::HSV(hue, 0.6f, 0.6f));
-                    ImGui::PushStyleColor(ImGuiCol_ButtonHovered, ImColor::HSV(hue, 0.7f, 0.7f));
-                    ImGui::PushStyleColor(ImGuiCol_ButtonActive, ImColor::HSV(hue, 0.8f, 0.8f));
+                    ImGui::PushStyleColor(ImGuiCol_Button, (ImVec4)ImColor::HSV(hue, 0.6f, 0.6f));
+                    ImGui::PushStyleColor(ImGuiCol_ButtonHovered, (ImVec4)ImColor::HSV(hue, 0.7f, 0.7f));
+                    ImGui::PushStyleColor(ImGuiCol_ButtonActive, (ImVec4)ImColor::HSV(hue, 0.8f, 0.8f));
                     ImGui::Button(label, ImVec2(40.0f + sinf((float)(line + n)) * 20.0f, 0.0f));
                     ImGui::PopStyleColor(3);
                     ImGui::PopID();