Add the `ellipse` method to canvas paths

canvas/src/lib.rs

@@ -25,6 +25,7 @@ use pathfinder_renderer::scene::{PathObject, Scene};
 use pathfinder_text::{SceneExt, TextRenderMode};
 use skribo::{FontCollection, FontFamily, Layout, TextStyle};
 use std::default::Default;
+use std::f32::consts::PI;
 use std::mem;
 use std::sync::Arc;
 
@@ -325,6 +326,24 @@ impl Path2D {
         self.current_contour.close();
     }
 
+    pub fn ellipse(&mut self,
+                   center: Point2DF,
+                   axes: Point2DF,
+                   rotation: f32,
+                   start_angle: f32,
+                   end_angle: f32) {
+        self.flush_current_contour();
+
+        let mut transform = Transform2DF::from_rotation(rotation);
+        transform = transform.post_mul(&Transform2DF::from_scale(axes));
+        transform = transform.post_mul(&Transform2DF::from_translation(center));
+        self.current_contour.push_arc(&transform, start_angle, end_angle);
+
+        if end_angle - start_angle >= 2.0 * PI {
+            self.current_contour.close();
+        }
+    }
+
     fn into_outline(mut self) -> Outline {
         self.flush_current_contour();
         self.outline

examples/canvas_moire/src/main.rs

@@ -152,7 +152,7 @@ impl MoireRenderer {
         for index in 0..CIRCLE_COUNT {
             let radius = (index + 1) as f32 * CIRCLE_SPACING * self.device_pixel_ratio;
             let mut path = Path2D::new();
-            path.arc(center, radius, 0.0, PI * 2.0);
+            path.ellipse(center, Point2DF::splat(radius), 0.0, 0.0, PI * 2.0);
             canvas.stroke_path(path);
         }
     }