updated Path docs

dist/kinetic-core.js

@@ -3,7 +3,7 @@
  * http://www.kineticjs.com/
  * Copyright 2012, Eric Rowell
  * Licensed under the MIT or GPL Version 2 licenses.
- * Date: Jun 03 2012
+ * Date: Jun 06 2012
  *
  * Copyright (C) 2011 - 2012 by Eric Rowell
  *
@@ -4147,9 +4147,8 @@ Kinetic.GlobalObject.extend(Kinetic.Line, Kinetic.Shape);
 //  SVG Path
 ///////////////////////////////////////////////////////////////////////
 /**
- * Path constructor.  This shape was inspired by Jason Follas's
+ * Path constructor. 
- *  SVG Path plugin.  Jason also helped build the parser and the
+ * @author Jason Follas
- *  drawing function.
  * @constructor
  * @augments Kinetic.Shape
  * @param {Object} config
@@ -4178,6 +4177,22 @@ Kinetic.Path = function(config) {
                     break;
                 case 'Q':
                     context.quadraticCurveTo(p[0], p[1], p[2], p[3]);
+                    break;
+                case 'A':
+                    var cx = p[0], cy = p[1], rx = p[2], ry = p[3], theta = p[4], dTheta = p[5], psi = p[6], fs = p[7];
+                    
+                    var r = (rx > ry) ? rx : ry;
+                    var scaleX = (rx > ry) ? 1 : rx / ry;
+                    var scaleY = (rx > ry) ? ry / rx : 1;
+
+                    context.translate(cx, cy);
+                    context.rotate(psi);
+                    context.scale(scaleX, scaleY);
+                    context.arc(0, 0, r, theta, theta + dTheta, 1 - fs);
+                    context.scale(1 / scaleX, 1 / scaleY);
+                    context.rotate(-psi);
+                    context.translate(-cx, -cy);
+                            
                     break;                    
                 case 'z':
                     context.closePath();
@@ -4219,19 +4234,17 @@ Kinetic.Path.prototype = {
         //C (x1 y1 x2 y2 x y)+ Absolute Bezier curve
         //q (x1 y1 x y)+       Relative Quadratic Bezier
         //Q (x1 y1 x y)+       Absolute Quadratic Bezier
-        //t (x y)+	Shorthand/Smooth Relative Quadratic Bezier
+        //t (x y)+    Shorthand/Smooth Relative Quadratic Bezier
-        //T (x y)+	Shorthand/Smooth Absolute Quadratic Bezier
+        //T (x y)+    Shorthand/Smooth Absolute Quadratic Bezier
-        //s (x2 y2 x y)+	   Shorthand/Smooth Relative Bezier curve
+        //s (x2 y2 x y)+       Shorthand/Smooth Relative Bezier curve
-        //S (x2 y2 x y)+	   Shorthand/Smooth Absolute Bezier curve
+        //S (x2 y2 x y)+       Shorthand/Smooth Absolute Bezier curve
-
+        //a (rx ry x-axis-rotation large-arc-flag sweep-flag x y)+     Relative Elliptical Arc
-        // Note: SVG a,A not implemented here
-        //a (rx ry x-axis-rotation large-arc-flag sweep-flag x y)+ 	Relative Elliptical Arc
         //A (rx ry x-axis-rotation large-arc-flag sweep-flag x y)+  Absolute Elliptical Arc
 
         // command string
         var cs = this.attrs.data;
         // command chars
-        var cc = ['m', 'M', 'l', 'L', 'v', 'V', 'h', 'H', 'z', 'Z', 'c', 'C', 'q', 'Q', 't', 'T', 's', 'S'];
+        var cc = ['m', 'M', 'l', 'L', 'v', 'V', 'h', 'H', 'z', 'Z', 'c', 'C', 'q', 'Q', 't', 'T', 's', 'S', 'a', 'A'];
         // convert white spaces to commas
         cs = cs.replace(new RegExp(' ', 'g'), ',');
         // create pipes so that we can split the data
@@ -4398,7 +4411,22 @@ Kinetic.Path.prototype = {
                         cmd = 'Q';
                         points.push(ctlPtx, ctlPty, cpx, cpy);
                         break;
+                    case 'A':
+                        var rx = p.shift(), ry = p.shift(), psi = p.shift(), fa = p.shift(), fs = p.shift();
+                        var x1 = cpx, y1 = cpy;
+                        cpx = p.shift(), cpy = p.shift();
                         
+                        cmd = 'A';
+                        points = this._convertEndpointToCenterParameterization(x1, y1, cpx, cpy, fa, fs, rx, ry, psi);
+                        break;
+                    case 'a':
+                        var rx = p.shift(), ry = p.shift(), psi = p.shift(), fa = p.shift(), fs = p.shift();
+                        var x1 = cpx, y1 = cpy;
+                        cpx += p.shift(), cpy += p.shift();
+                        
+                        cmd = 'A';
+                        points = this._convertEndpointToCenterParameterization(x1, y1, cpx, cpy, fa, fs, rx, ry, psi);
+                        break;
                 }
 
                 ca.push({
@@ -4427,12 +4455,57 @@ Kinetic.Path.prototype = {
      * set SVG path data string.  This method
      *  also automatically parses the data string
      *  into a data array.  Currently supported SVG data:
-     *  M, m, L, l, H, h, V, v, Q, q, T, t, C, c, S, s, Z, z
+     *  M, m, L, l, H, h, V, v, Q, q, T, t, C, c, S, s, A, a, Z, z
      * @param {String} SVG path command string
      */
     setData: function(data) {
         this.attrs.data = data;
         this.dataArray = this.getDataArray();
+    },
+    _convertEndpointToCenterParameterization: function(x1, y1, x2, y2, fa, fs, rx, ry, psiDeg) {
+    
+        // Derived from: http://www.w3.org/TR/SVG/implnote.html#ArcImplementationNotes
+        
+        var psi = psiDeg * (Math.PI / 180.0);
+
+        var xp = Math.cos(psi) * (x1 - x2) / 2.0 + Math.sin(psi) * (y1 - y2) / 2.0;
+        var yp = -1 * Math.sin(psi) * (x1 - x2) / 2.0 + Math.cos(psi) * (y1 - y2) / 2.0;
+
+        var lambda = (xp*xp) / (rx*rx) + (yp*yp) / (ry*ry);
+        
+        if (lambda > 1) {
+            rx *= Math.sqrt(lambda);
+            ry *= Math.sqrt(lambda);
+        }
+        
+        var f = Math.sqrt((((rx*rx) * (ry*ry)) - ((rx*rx) * (yp*yp)) - ((ry*ry) * (xp*xp))) / ((rx*rx) * (yp*yp) + (ry*ry) * (xp*xp)));
+        
+        if (fa == fs) f *= -1;
+        if (isNaN(f)) f = 0;
+        
+        var cxp = f * rx * yp / ry;
+        var cyp = f * -ry * xp / rx;
+    
+        var cx = (x1 + x2) / 2.0 + Math.cos(psi) * cxp - Math.sin(psi) * cyp;
+        var cy = (y1 + y2) / 2.0 + Math.sin(psi) * cxp + Math.cos(psi) * cyp;
+        
+        var vMag = function(v) { return Math.sqrt(v[0]*v[0] + v[1]*v[1]); }
+        var vRatio = function(u, v) { return (u[0]*v[0] + u[1]*v[1]) / (vMag(u) * vMag(v)) }
+        var vAngle = function(u, v) { return (u[0]*v[1] < u[1]*v[0] ? -1 : 1) * Math.acos(vRatio(u,v)); }
+        
+        var theta = vAngle([1,0], [(xp - cxp) / rx, (yp - cyp) / ry]);
+
+        var u = [(xp - cxp) / rx, (yp - cyp) / ry];
+        var v = [(-1 * xp - cxp) / rx, (-1 * yp - cyp) / ry];
+        var dTheta = vAngle(u, v);
+        
+        if (vRatio(u,v) <= -1) dTheta = Math.PI;
+        if (vRatio(u,v) >= 1) dTheta = 0;
+
+        if (fs == 0 && dTheta > 0) dTheta = dTheta - 2 * Math.PI;
+        if (fs == 1 && dTheta < 0) dTheta = dTheta + 2 * Math.PI;
+    
+        return [cx, cy, rx, ry, theta, dTheta, psi, fs];       
     }
 };
 

src/shapes/Path.js

@@ -2,9 +2,8 @@
 //  SVG Path
 ///////////////////////////////////////////////////////////////////////
 /**
- * Path constructor.  This shape was inspired by Jason Follas's
+ * Path constructor. 
- *  SVG Path plugin.  Jason also helped build the parser and the
+ * @author Jason Follas
- *  drawing function.
  * @constructor
  * @augments Kinetic.Shape
  * @param {Object} config