ImDrawList: Revert alteration of normal scaling threshold, for now prioritize preserving property of limiting extents. (#4053, #3366, #2964, #2868, #2518, #2183)

Amend fdda8b8

docs/CHANGELOG.txt

@@ -57,8 +57,7 @@ Other Changes:
 - Popups: Added 'OpenPopup(ImGuiID id)' overload to facilitate calling from nested stacks. (#3993, #331) [@zlash]
 - ImDrawList: Fixed/improved thickness of thick strokes with sharp angles. (#4053, #3366, #2964, #2868, #2518, #2183)
   Effectively introduced a regression in 1.67 (Jan 2019), and a fix in 1.70 (Apr 2019) but the fix wasn't actually on
-  par with original version. Now incorporating the correct fix + tweaked threshold to further mitigate the effect of
-  varying thickness, up to a certain degree. Shapes with very sharp angles and thick strokes will extend a little more.
+  par with original version. Now incorporating the correct revert.
 - ImDrawList: Fixed PathArcTo() regression from 1.82 preventing use of counter-clockwise angles. (#4030, #3491) [@thedmd]
 - Demo: Improved popups demo and comments.
 - Backends: SDL: Rework global mouse pos availability check listing supported platforms explicitly,

imgui_draw.cpp

@@ -689,7 +689,7 @@ void ImDrawList::PrimQuadUV(const ImVec2& a, const ImVec2& b, const ImVec2& c, c
 // On AddPolyline() and AddConvexPolyFilled() we intentionally avoid using ImVec2 and superfluous function calls to optimize debug/non-inlined builds.
 // Those macros expects l-values.
 #define IM_NORMALIZE2F_OVER_ZERO(VX,VY)     do { float d2 = VX*VX + VY*VY; if (d2 > 0.0f) { float inv_len = 1.0f / ImSqrt(d2); VX *= inv_len; VY *= inv_len; } } while (0)
-#define IM_FIXNORMAL2F_MAX_INVLEN2          500.0f
+#define IM_FIXNORMAL2F_MAX_INVLEN2          100.0f // 500.0f (see #4053, #3366)
 #define IM_FIXNORMAL2F(VX,VY)               do { float d2 = VX*VX + VY*VY; if (d2 > 0.000001f) { float inv_len2 = 1.0f / d2; if (inv_len2 > IM_FIXNORMAL2F_MAX_INVLEN2) inv_len2 = IM_FIXNORMAL2F_MAX_INVLEN2; VX *= inv_len2; VY *= inv_len2; } } while (0)
 
 // TODO: Thickness anti-aliased lines cap are missing their AA fringe.