Merge pull request #4014 from radarhere/arc

Fixed arc drawing bug for a non-whole number of degrees
python-pillow · Sep 5, 2019 · bd2d7cb · bd2d7cb
2 parents 572a93c + 8fff9a2
commit bd2d7cb
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Showing 3 changed files with 13 additions and 1 deletion.
diff --git a/Tests/images/imagedraw_arc_width_non_whole_angle.png b/Tests/images/imagedraw_arc_width_non_whole_angle.png
diff --git a/Tests/test_imagedraw.py b/Tests/test_imagedraw.py
@@ -140,6 +140,18 @@ def test_arc_width_fill(self):
         # Assert
         self.assert_image_similar(im, Image.open(expected), 1)
 
+    def test_arc_width_non_whole_angle(self):
+        # Arrange
+        im = Image.new("RGB", (W, H))
+        draw = ImageDraw.Draw(im)
+        expected = "Tests/images/imagedraw_arc_width_non_whole_angle.png"
+
+        # Act
+        draw.arc(BBOX1, 10, 259.5, width=5)
+
+        # Assert
+        self.assert_image_similar(im, Image.open(expected), 1)
+
     def test_bitmap(self):
         # Arrange
         small = Image.open("Tests/images/pil123rgba.png").resize((50, 50))

diff --git a/src/libImaging/Draw.c b/src/libImaging/Draw.c
@@ -834,7 +834,7 @@ ellipse(Imaging im, int x0, int y0, int x1, int y1,
 
         // Build edge list
         // malloc check UNDONE, FLOAT?
-        maxEdgeCount = end - start;
+        maxEdgeCount = ceil(end - start);
         if (inner) {
             maxEdgeCount *= 2;
         }