canvas/api.nas: add square, ellipse and circle to path; update svg.nas accordingly

Nasal/canvas/api.nas

@@ -990,7 +990,42 @@ var Path = {
 
     return me.close();
   },
+  
+  # Add a (rounded) square to the path
+  #
+  # @param x    Position of left border
+  # @param y    Position of top border
+  # @param l    length
+  # @param cfg  Optional settings (eg. {"border-top-radius": 5})
+  square: func(x, y, l, cfg = nil) {
+      return me.rect(x, y, l, l, cfg);
+  },
 
+  # Add an ellipse to the path
+  #
+  # @param rx    radius x
+  # @param ry    radius y
+  # @param cx    (optional) center x coordinate
+  # @param cy    (optional) center y coordinate
+  ellipse: func(rx, ry, cx = nil, cy = nil) {
+    cx = num(cx) or 0;
+    cy = num(cy) or 0;
+    me.moveTo(cx - rx, cy)
+      .arcSmallCW(rx, ry, 0, 2*rx, 0)
+      .arcSmallCW(rx, ry, 0, -2*rx, 0);
+    return me;
+  },
+  
+  
+  # Add a circle to the path
+  #
+  # @param r     radius 
+  # @param cx    (optional) center x coordinate
+  # @param cy    (optional) center y coordinate
+  circle: func(r, cx = nil, cy = nil) {
+    return me.ellipse(r, r, cx, cy);
+  },
+  
   setColor: func me.setStroke(_getColor(arg)),
   getColor: func me.getStroke(),
 

Nasal/canvas/svg.nas

@@ -527,14 +527,14 @@ var parsesvg = func(group, path, options = nil)
         var cx = evalCSSNum(attr['cx']);
         var cy = evalCSSNum(attr['cy']);
         var r = evalCSSNum(attr['r']);
-        stack[-1].moveTo(cx-r,cy).arcSmallCW(r,r,0,2*r,0).arcSmallCW(r,r,0,-2*r,0);
+        stack[-1].circle(r, cx, cy);
       }
       if (name == "ellipse") {
         var cx = evalCSSNum(attr['cx']);
         var cy = evalCSSNum(attr['cy']);
         var rx = evalCSSNum(attr['rx']);
         var ry = evalCSSNum(attr['ry']);
-        stack[-1].moveTo(cx-rx,cy).arcSmallCW(rx,ry,0,2*rx,0).arcSmallCW(rx,ry,0,-2*rx,0);
+        stack[-1].ellipse(rx, ry, cx, cy);
       }
       if (name == "path") {
         parsePath(attr['d']);