ColorEdit, RadioButton, Windows: Using adaptative tesselation for preview circles.

docs/CHANGELOG.txt

@@ -47,6 +47,8 @@ Other changes:
 - Drag, Sliders: Fixed parsing of text input when '+' or '#' format flags are used
   in the format string. (#6259) [@idbrii]
 - ColorEdit: Fixed shading of S/V triangle in Hue Wheel mode. (#5200, #6254) [@jamesthomasgriffin]
+- Rendering: Using adaptative tesselation for: RadioButton, ColorEdit preview circles,
+  Windows Close and Collapse Buttons.
 - IO: Fixed support for calling io.AddXXXX functions fron inactive context (wrongly
   advertised as supported in 1.89.4). (#6199, #6256, #5856) [@cfillion]
 - Backends: OpenGL3: Fixed GL loader crash when GL_VERSION returns NULL. (#6154, #4445, #3530)

docs/FAQ.md

@@ -480,7 +480,7 @@ ImDrawList* draw_list = ImGui::GetWindowDrawList();
 ImVec2 p = ImGui::GetCursorScreenPos();
 
 // Draw a red circle
-draw_list->AddCircleFilled(ImVec2(p.x + 50, p.y + 50), 30.0f, IM_COL32(255, 0, 0, 255), 16);
+draw_list->AddCircleFilled(ImVec2(p.x + 50, p.y + 50), 30.0f, IM_COL32(255, 0, 0, 255));
 
 // Draw a 3 pixel thick yellow line
 draw_list->AddLine(ImVec2(p.x, p.y), ImVec2(p.x + 100.0f, p.y + 100.0f), IM_COL32(255, 255, 0, 255), 3.0f);

imgui_draw.cpp

@@ -3790,6 +3790,7 @@ void ImGui::RenderArrow(ImDrawList* draw_list, ImVec2 pos, ImU32 col, ImGuiDir d
 
 void ImGui::RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col)
 {
+    // FIXME-OPT: This should be baked in font.
     draw_list->AddCircleFilled(pos, draw_list->_Data->FontSize * 0.20f, col, 8);
 }
 

imgui_widgets.cpp

@@ -827,7 +827,7 @@ bool ImGui::CloseButton(ImGuiID id, const ImVec2& pos)
     ImU32 col = GetColorU32(held ? ImGuiCol_ButtonActive : ImGuiCol_ButtonHovered);
     ImVec2 center = bb.GetCenter();
     if (hovered)
-        window->DrawList->AddCircleFilled(center, ImMax(2.0f, g.FontSize * 0.5f + 1.0f), col, 12);
+        window->DrawList->AddCircleFilled(center, ImMax(2.0f, g.FontSize * 0.5f + 1.0f), col);
 
     float cross_extent = g.FontSize * 0.5f * 0.7071f - 1.0f;
     ImU32 cross_col = GetColorU32(ImGuiCol_Text);
@@ -852,7 +852,7 @@ bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
     ImU32 bg_col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
     ImU32 text_col = GetColorU32(ImGuiCol_Text);
     if (hovered || held)
-        window->DrawList->AddCircleFilled(bb.GetCenter()/*+ ImVec2(0.0f, -0.5f)*/, g.FontSize * 0.5f + 1.0f, bg_col, 12);
+        window->DrawList->AddCircleFilled(bb.GetCenter()/*+ ImVec2(0.0f, -0.5f)*/, g.FontSize * 0.5f + 1.0f, bg_col);
     RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
 
     // Switch to moving the window after mouse is moved beyond the initial drag threshold
@@ -1233,17 +1233,18 @@ bool ImGui::RadioButton(const char* label, bool active)
         MarkItemEdited(id);
 
     RenderNavHighlight(total_bb, id);
-    window->DrawList->AddCircleFilled(center, radius, GetColorU32((held && hovered) ? ImGuiCol_FrameBgActive : hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg), 16);
+    const int num_segment = window->DrawList->_CalcCircleAutoSegmentCount(radius);
+    window->DrawList->AddCircleFilled(center, radius, GetColorU32((held && hovered) ? ImGuiCol_FrameBgActive : hovered ? ImGuiCol_FrameBgHovered : ImGuiCol_FrameBg), num_segment);
     if (active)
     {
         const float pad = ImMax(1.0f, IM_FLOOR(square_sz / 6.0f));
-        window->DrawList->AddCircleFilled(center, radius - pad, GetColorU32(ImGuiCol_CheckMark), 16);
+        window->DrawList->AddCircleFilled(center, radius - pad, GetColorU32(ImGuiCol_CheckMark));
     }
 
     if (style.FrameBorderSize > 0.0f)
     {
-        window->DrawList->AddCircle(center + ImVec2(1, 1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
-        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
+        window->DrawList->AddCircle(center + ImVec2(1, 1), radius, GetColorU32(ImGuiCol_BorderShadow), num_segment, style.FrameBorderSize);
+        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), num_segment, style.FrameBorderSize);
     }
 
     ImVec2 label_pos = ImVec2(check_bb.Max.x + style.ItemInnerSpacing.x, check_bb.Min.y + style.FramePadding.y);
@@ -5614,7 +5615,7 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
         float sin_hue_angle = ImSin(H * 2.0f * IM_PI);
         ImVec2 hue_cursor_pos(wheel_center.x + cos_hue_angle * (wheel_r_inner + wheel_r_outer) * 0.5f, wheel_center.y + sin_hue_angle * (wheel_r_inner + wheel_r_outer) * 0.5f);
         float hue_cursor_rad = value_changed_h ? wheel_thickness * 0.65f : wheel_thickness * 0.55f;
-        int hue_cursor_segments = ImClamp((int)(hue_cursor_rad / 1.4f), 9, 32);
+        int hue_cursor_segments = draw_list->_CalcCircleAutoSegmentCount(hue_cursor_rad); // Lock segment count so the +1 one matches others.
         draw_list->AddCircleFilled(hue_cursor_pos, hue_cursor_rad, hue_color32, hue_cursor_segments);
         draw_list->AddCircle(hue_cursor_pos, hue_cursor_rad + 1, col_midgrey, hue_cursor_segments);
         draw_list->AddCircle(hue_cursor_pos, hue_cursor_rad, col_white, hue_cursor_segments);
@@ -5650,9 +5651,10 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
 
     // Render cursor/preview circle (clamp S/V within 0..1 range because floating points colors may lead HSV values to be out of range)
     float sv_cursor_rad = value_changed_sv ? 10.0f : 6.0f;
-    draw_list->AddCircleFilled(sv_cursor_pos, sv_cursor_rad, user_col32_striped_of_alpha, 12);
-    draw_list->AddCircle(sv_cursor_pos, sv_cursor_rad + 1, col_midgrey, 12);
-    draw_list->AddCircle(sv_cursor_pos, sv_cursor_rad, col_white, 12);
+    int sv_cursor_segments = draw_list->_CalcCircleAutoSegmentCount(sv_cursor_rad); // Lock segment count so the +1 one matches others.
+    draw_list->AddCircleFilled(sv_cursor_pos, sv_cursor_rad, user_col32_striped_of_alpha, sv_cursor_segments);
+    draw_list->AddCircle(sv_cursor_pos, sv_cursor_rad + 1, col_midgrey, sv_cursor_segments);
+    draw_list->AddCircle(sv_cursor_pos, sv_cursor_rad, col_white, sv_cursor_segments);
 
     // Render alpha bar
     if (alpha_bar)