[gtk/path-stroke: 24/27] Special-case circles for strokes

[Matthias Clasen <matthiasc src gnome org>]

commit bd5f4bcea9a22858956aa6a5f6251a3893a977a0
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Dec 13 22:42:09 2020 -0500

    Special-case circles for strokes
    
    The outline of a circle is just two circles.

 gsk/gskcontour.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
---
diff --git a/gsk/gskcontour.c b/gsk/gskcontour.c
index 1dc862e7ff..e0a1df709a 100644
--- a/gsk/gskcontour.c
+++ b/gsk/gskcontour.c
@@ -905,6 +905,23 @@ gsk_circle_contour_add_stroke (const GskContour *contour,
                                GskPathBuilder   *builder,
                                GskStroke        *stroke)
 {
+  const GskCircleContour *self = (const GskCircleContour *) contour;
+
+  if (stroke->dash_length == 0 &&
+      fabs (self->start_angle - self->end_angle) >= 360)
+    {
+      GskContour *c;
+
+      c = gsk_circle_contour_new (&self->center, self->radius + stroke->line_width / 2,
+                                  self->start_angle,
+                                  self->end_angle);
+      gsk_path_builder_add_contour (builder, c);
+
+      c = gsk_circle_contour_new (&self->center, self->radius - stroke->line_width / 2,
+                                  self->end_angle,
+                                  self->start_angle);
+      gsk_path_builder_add_contour (builder, c);
+    }
 }
 
 static const GskContourClass GSK_CIRCLE_CONTOUR_CLASS =