backend_cairo: Clip drawn paths to context.clip_extents()

MathieuDuponchelle · MathieuDuponchelle · commit a5d6753c309c · 2015-03-06T15:53:14.000+01:00
+ Fixes #4054
diff --git a/lib/matplotlib/backends/backend_cairo.py b/lib/matplotlib/backends/backend_cairo.py
@@ -133,8 +133,8 @@ def _fill_and_stroke (self, ctx, fill_c, alpha, alpha_overrides):
         ctx.stroke()
 
     @staticmethod
-    def convert_path(ctx, path, transform):
-        for points, code in path.iter_segments(transform):
+    def convert_path(ctx, path, transform, clip=None):
+        for points, code in path.iter_segments(transform, clip=clip):
             if code == Path.MOVETO:
                 ctx.move_to(*points)
             elif code == Path.CLOSEPOLY:
@@ -152,11 +152,18 @@ def convert_path(ctx, path, transform):
     def draw_path(self, gc, path, transform, rgbFace=None):
         ctx = gc.ctx
 
+        # We'll clip the path to the actual rendering extents
+        # if the path isn't filled.
+        if rgbFace is None and gc.get_hatch() is None:
+            clip = ctx.clip_extents()
+        else:
+            clip = None
+
         transform = transform + \
             Affine2D().scale(1.0, -1.0).translate(0, self.height)
 
         ctx.new_path()
-        self.convert_path(ctx, path, transform)
+        self.convert_path(ctx, path, transform, clip)
 
         self._fill_and_stroke(ctx, rgbFace, gc.get_alpha(), gc.get_forced_alpha())
 
