LibGfx: Increase bezier splitting tolerance to 0.5

No noticeable difference a bit faster. This is still arbitrary and
should be somehow derived from the curve.

Userland/Libraries/LibGfx/Painter.cpp

@@ -2086,7 +2086,8 @@ void Painter::draw_triangle_wave(IntPoint a_p1, IntPoint a_p2, Color color, int
 
 static bool can_approximate_bezier_curve(FloatPoint p1, FloatPoint p2, FloatPoint control)
 {
-    constexpr float tolerance = 0.015f;
+    // TODO: Somehow calculate the required number of splits based on the curve (and its size).
+    constexpr float tolerance = 0.5f;
 
     auto p1x = 3 * control.x() - 2 * p1.x() - p2.x();
     auto p1y = 3 * control.y() - 2 * p1.y() - p2.y();
@@ -2163,7 +2164,8 @@ void Painter::for_each_line_segment_on_cubic_bezier_curve(FloatPoint control_poi
 
 static bool can_approximate_cubic_bezier_curve(FloatPoint p1, FloatPoint p2, FloatPoint control_0, FloatPoint control_1)
 {
-    constexpr float tolerance = 0.015f;
+    // TODO: Somehow calculate the required number of splits based on the curve (and its size).
+    constexpr float tolerance = 0.5f;
 
     auto ax = 3 * control_0.x() - 2 * p1.x() - p2.x();
     auto ay = 3 * control_0.y() - 2 * p1.y() - p2.y();

Userland/Libraries/LibGfx/Path.cpp

@@ -514,9 +514,10 @@ Path Path::stroke_to_fill(float thickness) const
     }
 
     // Note: This is the same as the tolerance from bezier curve splitting.
-    constexpr auto flatness = 0.015f;
-    auto pen_vertex_count = max(
-        static_cast<int>(ceilf(AK::Pi<float> / acosf(1 - (2 * flatness) / thickness))), 4);
+    constexpr auto flatness = 0.5f;
+    auto pen_vertex_count = (thickness >= 2 * flatness) ? max(
+                                static_cast<int>(ceilf(AK::Pi<float> / acosf(1 - (2 * flatness) / thickness))), 4)
+                                                        : 4;
     if (pen_vertex_count % 2 == 1)
         pen_vertex_count += 1;