--- /dev/null
+<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" >
+<head>
+<title>Approximation of an arc with bezier</title>
+<style type="text/css">
+ @import "../../../dojo/resources/dojo.css";
+ @import "../../../dijit/tests/css/dijitTests.css";
+</style>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+<!--
+The next line should include Microsoft's Silverligth.js, if you plan to use the silverlight backend
+<script type="text/javascript" src="Silverlight.js"></script>
+-->
+<script type="text/javascript" src="../../../dojo/dojo.js" djConfig="isDebug: true"></script>
+<script type="text/javascript" src="../_base.js"></script>
+<script type="text/javascript" src="../shape.js"></script>
+<script type="text/javascript" src="../path.js"></script>
+<script type="text/javascript" src="../arc.js"></script>
+<!--<script type="text/javascript" src="../vml.js"></script>-->
+<!--<script type="text/javascript" src="../svg.js"></script>-->
+<!--<script type="text/javascript" src="../canvas.js"></script>-->
+<!--<script type="text/javascript" src="../silverlight.js"></script>-->
+<script type="text/javascript">
+dojo.require("dojox.gfx");
+
+makeShapes = function(){
+ var surface = dojox.gfx.createSurface("test", 500, 300);
+ var g = surface.createGroup();
+
+ // create a reference ellipse
+ var rx = 200;
+ var ry = 100;
+ var startAngle = -30;
+ var arcAngle = -90;
+ var axisAngle = -30;
+ var e = g.createEllipse({rx: rx, ry: ry}).setStroke({});
+
+ // calculate a bezier
+ var alpha = dojox.gfx.matrix._degToRad(arcAngle) / 2; // half of our angle
+ var cosa = Math.cos(alpha);
+ var sina = Math.sin(alpha);
+ // start point
+ var p1 = {x: cosa, y: sina};
+ // 1st control point
+ var p2 = {x: cosa + (4 / 3) * (1 - cosa), y: sina - (4 / 3) * cosa * (1 - cosa) / sina};
+ // 2nd control point (symmetric to the 1st one)
+ var p3 = {x: p2.x, y: -p2.y};
+ // end point (symmetric to the start point)
+ var p4 = {x: p1.x, y: -p1.y};
+
+ // rotate and scale poins as appropriate
+ var s = dojox.gfx.matrix.normalize([dojox.gfx.matrix.scale(e.shape.rx, e.shape.ry), dojox.gfx.matrix.rotateg(startAngle + arcAngle / 2)]);
+ p1 = dojox.gfx.matrix.multiplyPoint(s, p1);
+ p2 = dojox.gfx.matrix.multiplyPoint(s, p2);
+ p3 = dojox.gfx.matrix.multiplyPoint(s, p3);
+ p4 = dojox.gfx.matrix.multiplyPoint(s, p4);
+ // draw control trapezoid
+ var t = g.createPath().setStroke({color: "blue"});
+ t.moveTo(p1.x, p1.y);
+ t.lineTo(p2.x, p2.y);
+ t.lineTo(p3.x, p3.y);
+ t.lineTo(p4.x, p4.y);
+ t.lineTo(p1.x, p1.y);
+ t.moveTo((p1.x + p4.x) / 2, (p1.y + p4.y) / 2);
+ t.lineTo((p2.x + p3.x) / 2, (p2.y + p3.y) / 2);
+ t.moveTo((p1.x + p2.x) / 2, (p1.y + p2.y) / 2);
+ t.lineTo((p3.x + p4.x) / 2, (p3.y + p4.y) / 2);
+ // draw a bezier
+ var b = g.createPath().setStroke({color: "red"});
+ b.moveTo(p1.x, p1.y);
+ b.curveTo(p2.x, p2.y, p3.x, p3.y, p4.x, p4.y);
+ // move everything in a middle
+ g.setTransform([dojox.gfx.matrix.translate(250, 150), dojox.gfx.matrix.rotateg(axisAngle)]);
+};
+
+dojo.addOnLoad(makeShapes);
+
+</script>
+</head>
+<body>
+<h1>Approximation of an arc with bezier</h1>
+<!--<p><button onclick="makeShapes();">Make</button></p>-->
+<div id="test" style="width: 500px; height: 300px;"></div>
+<p>That's all Folks!</p>
+</body>
+</html>
projects / eow / blobdiff