html5 isPointInPath相关操作 

<body>
    <canvas id="c1" width="400" height="400">
    </canvas>
    <script type="text/javascript">
        var oC = document.getElementById("c1");
        var oGC = oC.getContext("2d");
        var c1 = new Shape(100, 100, 50);
        var c2 = new Shape(200, 200, 50);
        oC.onmousedown = function (ev) {
            var ev = ev || window.event;
            var point = {
                x: ev.clientX - oC.offsetLeft,
                y: ev.clientY - oC.offsetTop
            };
            c1.reDraw(point);
            c2.reDraw(point);
        }
        c1.click = function () {
            alert(123);
        }
        c2.click = function () {
            alert(456);
        }
        function Shape(x, y, r) {
            this.x = x;
            this.y = y;
            this.r = r;
            oGC.beginPath();
            oGC.arc(x, y, r, 0, 360 * Math.PI / 180,false);
            oGC.closePath();
            oGC.fill();
        }
        Shape.prototype.reDraw = function (point) {
            oGC.beginPath();
            oGC.arc(this.x, this.y, this.r, 0, 360 * Math.PI / 180, false);
            oGC.closePath();
            oGC.fill();
            if (oGC.isPointInPath(point.x, point.y)) {
                this.click();
            }
        }
    </script>
</body>

 使用习惯了html中的click等事件，用isPointInPath()这个方法感觉还是很不方便，有没有像jquery那样的方便链式操作，答案是有，有人已经把canvas的事件操作封装成库，这就是jCanvasScript.js。

posted @ 2016-02-21 08:50  lunawzh  阅读(315)  评论(0)    收藏  举报