ImDrawList: changed AddCircle(), AddCircleFilled() default num_segments from 12 to 0.

docs/CHANGELOG.txt

@@ -37,7 +37,7 @@ HOW TO UPDATE?
 
 Other Changes:
 
-- Nav: Fixed clicking on void from not clearing focused window.
+- Nav: Fixed clicking on void (behind any windows) from not clearing the focused window.
   This would be problematic e.g. in situation where the application relies on io.WantCaptureKeyboard
   flag being cleared accordingly. (bug introduced in 1.77 WIP on 2020/06/16) (#3344, #2880)
 - InputText, ImDrawList: Fixed assert triggering when drawing single line of text with more
@@ -51,6 +51,9 @@ Other Changes:
   - Requires an extra bit of texture space (~64x64 by default), relies on GPU bilinear filtering.
   - Clear io.AntiAliasedLinesUseTex = false; to disable rendering using this method.
   - Clear ImFontAtlasFlags_NoBakedLines in ImFontAtlas::Flags to disable baking data in texture.
+- ImDrawList: changed AddCircle(), AddCircleFilled() default num_segments from 12 to 0, effectively
+  enabling auto-tessellation by default. Tweak tessellation in Style Editor->Rendering section, or
+  by modifying the 'style.CircleSegmentMaxError' value. [@ShironekoBen]
 - ImDrawList: Fixed minor bug introduced in 1.75 where AddCircle() with 12 segments would generate
   an extra vertex. (This bug was mistakenly marked as fixed in earlier 1.77 release). [@ShironekoBen]
 - Demo: Tweak "Child Windows" section.

imgui.h

@@ -2052,6 +2052,7 @@ struct ImDrawList
     // Primitives
     // - For rectangular primitives, "p_min" and "p_max" represent the upper-left and lower-right corners.
     // - For circle primitives, use "num_segments == 0" to automatically calculate tessellation (preferred).
+    //   In older versions (until Dear ImGui 1.77) the AddCircle functions defaulted to num_segments == 12.
     //   In future versions we will use textures to provide cheaper and higher-quality circles.
     //   Use AddNgon() and AddNgonFilled() functions if you need to guaranteed a specific number of sides.
     IMGUI_API void  AddLine(const ImVec2& p1, const ImVec2& p2, ImU32 col, float thickness = 1.0f);
@@ -2062,8 +2063,8 @@ struct ImDrawList
     IMGUI_API void  AddQuadFilled(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, ImU32 col);
     IMGUI_API void  AddTriangle(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, ImU32 col, float thickness = 1.0f);
     IMGUI_API void  AddTriangleFilled(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, ImU32 col);
-    IMGUI_API void  AddCircle(const ImVec2& center, float radius, ImU32 col, int num_segments = 12, float thickness = 1.0f);
+    IMGUI_API void  AddCircle(const ImVec2& center, float radius, ImU32 col, int num_segments = 0, float thickness = 1.0f);
-    IMGUI_API void  AddCircleFilled(const ImVec2& center, float radius, ImU32 col, int num_segments = 12);
+    IMGUI_API void  AddCircleFilled(const ImVec2& center, float radius, ImU32 col, int num_segments = 0);
     IMGUI_API void  AddNgon(const ImVec2& center, float radius, ImU32 col, int num_segments, float thickness = 1.0f);
     IMGUI_API void  AddNgonFilled(const ImVec2& center, float radius, ImU32 col, int num_segments);
     IMGUI_API void  AddText(const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end = NULL);