Fix arcs with very large width/height.

QuLogic · QuLogic · commit 0f69fd9ddd96 · 2017-11-01T21:35:40.000-04:00
Large width/height triggers a different code path that didn't correctly draw limited arcs instead of the whole ellipse. Fixes #9659.
diff --git a/lib/matplotlib/patches.py b/lib/matplotlib/patches.py
@@ -1737,7 +1737,7 @@ def iter_circle_intersect_on_line_seg(x0, y0, x1, y1):
         path_original = self._path
         for theta in thetas:
             if inside:
-                Path.arc(last_theta, theta, 8)
+                self._path = Path.arc(last_theta, theta, 8)
                 Patch.draw(self, renderer)
                 inside = False
             else:
diff --git a/lib/matplotlib/tests/baseline_images/test_axes/arc_angles.png b/lib/matplotlib/tests/baseline_images/test_axes/arc_angles.png
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -1206,22 +1206,32 @@ def test_arc_angles():
     w = 2
     h = 1
     centre = (0.2, 0.5)
+    scale = 2
 
     fig, axs = plt.subplots(3, 3)
     for i, ax in enumerate(axs.flat):
         theta2 = i * 360 / 9
         theta1 = theta2 - 45
+
         ax.add_patch(patches.Ellipse(centre, w, h, alpha=0.3))
         ax.add_patch(patches.Arc(centre, w, h, theta1=theta1, theta2=theta2))
         # Straight lines intersecting start and end of arc
-        ax.plot([2 * np.cos(np.deg2rad(theta1)) + centre[0],
+        ax.plot([scale * np.cos(np.deg2rad(theta1)) + centre[0],
                  centre[0],
-                 2 * np.cos(np.deg2rad(theta2)) + centre[0]],
-                [2 * np.sin(np.deg2rad(theta1)) + centre[1],
+                 scale * np.cos(np.deg2rad(theta2)) + centre[0]],
+                [scale * np.sin(np.deg2rad(theta1)) + centre[1],
                  centre[1],
-                 2 * np.sin(np.deg2rad(theta2)) + centre[1]])
-        ax.set_xlim(-2, 2)
-        ax.set_ylim(-2, 2)
+                 scale * np.sin(np.deg2rad(theta2)) + centre[1]])
+
+        ax.set_xlim(-scale, scale)
+        ax.set_ylim(-scale, scale)
+
+        # This looks the same, but it triggers a different code path when it
+        # gets large enough.
+        w *= 10
+        h *= 10
+        centre = (centre[0] * 10, centre[1] * 10)
+        scale *= 10
 
 
 @image_comparison(baseline_images=['arc_ellipse'],
