servo: Merge #5770 - Canvas: implement rectangle drawing (from mmatyas:canvas_rect); r=jdm

A simple little patch.

Source-Repo: https://github.com/servo/servo
Source-Revision: 1d66b090a2b25203f751455d9f0f4985a77ccd64

servo/components/canvas/canvas_msg.rs

@@ -33,6 +33,7 @@ pub enum Canvas2dMsg {
     MoveTo(Point2D<f32>),
     PutImageData(Vec<u8>, Rect<f64>, Option<Rect<f64>>),
     QuadraticCurveTo(Point2D<f32>, Point2D<f32>),
+    Rect(Rect<f32>),
     RestoreContext,
     SaveContext,
     StrokeRect(Rect<f32>),

servo/components/canvas/canvas_paint_task.rs

@@ -220,6 +220,7 @@ impl<'a> CanvasPaintTask<'a> {
                             }
                             Canvas2dMsg::MoveTo(ref point) => painter.move_to(point),
                             Canvas2dMsg::LineTo(ref point) => painter.line_to(point),
+                            Canvas2dMsg::Rect(ref rect) => painter.rect(rect),
                             Canvas2dMsg::QuadraticCurveTo(ref cp, ref pt) => {
                                 painter.quadratic_curve_to(cp, pt)
                             }
@@ -351,6 +352,15 @@ impl<'a> CanvasPaintTask<'a> {
         self.path_builder.line_to(*point)
     }
 
+    fn rect(&self, rect: &Rect<f32>) {
+        self.path_builder.move_to(Point2D(rect.origin.x, rect.origin.y));
+        self.path_builder.line_to(Point2D(rect.origin.x + rect.size.width, rect.origin.y));
+        self.path_builder.line_to(Point2D(rect.origin.x + rect.size.width,
+                                          rect.origin.y + rect.size.height));
+        self.path_builder.line_to(Point2D(rect.origin.x, rect.origin.y + rect.size.height));
+        self.path_builder.close();
+    }
+
     fn quadratic_curve_to(&self,
                           cp: &Point2D<AzFloat>,
                           endpoint: &Point2D<AzFloat>) {

servo/components/script/dom/canvasrenderingcontext2d.rs

@@ -640,6 +640,15 @@ impl<'a> CanvasRenderingContext2DMethods for JSRef<'a, CanvasRenderingContext2D>
         self.renderer.send(CanvasMsg::Canvas2d(Canvas2dMsg::LineTo(Point2D(x as f32, y as f32)))).unwrap();
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-rect
+    fn Rect(self, x: f64, y: f64, width: f64, height: f64) {
+        if [x, y, width, height].iter().all(|val| val.is_finite()) {
+            let rect = Rect(Point2D(x as f32, y as f32),
+                            Size2D(width as f32, height as f32));
+            self.renderer.send(CanvasMsg::Canvas2d(Canvas2dMsg::Rect(rect))).unwrap();
+        }
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-quadraticcurveto
     fn QuadraticCurveTo(self, cpx: f64, cpy: f64, x: f64, y: f64) {
         if !(cpx.is_finite() && cpy.is_finite() &&

servo/components/script/dom/webidls/CanvasRenderingContext2D.webidl

@@ -171,7 +171,7 @@ interface CanvasPathMethods {
              unrestricted double radius);
 // NOT IMPLEMENTED  [LenientFloat] void arcTo(double x1, double y1, double x2, double y2, double radiusX, double radiusY, double rotation);
 
-  //void rect(double x, double y, double w, double h);
+  void rect(unrestricted double x, unrestricted double y, unrestricted double w, unrestricted double h);
 
   [Throws]
   void arc(double x, double y, double radius, double startAngle, double endAngle, optional boolean anticlockwise = false);