HTML5 canvas画布（六）

贝塞尔曲线

 

下面是canvas绘制贝塞尔曲线的代码：

<script> window.onload = function() { drawCanvas1(); drawCanvas2(); } function drawCanvas1() { var canvas=document.getElementById("myCanvas1"); var context=canvas.getContext("2d"); context.beginPath(); context.moveTo(20,20); context.quadraticCurveTo(30,100,200,90); context.stroke(); //标注坐标点 //context.textAlign = "center"; context.fillStyle = "red"; context.fillText("开始点(20,20)",20,20); context.fillText("控制点(30,100)",30,100); context.fillText("结束点(200,90)",200,90); //红色辅助线 context.strokeStyle = "red"; context.beginPath(); context.moveTo(20,20); context.lineTo(30,100); context.lineTo(200,90); context.stroke(); } function drawCanvas2() { var canvas = document.getElementById("myCanvas2"); var context = canvas.getContext("2d"); context.beginPath(); context.moveTo(20,20); context.bezierCurveTo(20,100,200,300,200,20); context.stroke(); //标注坐标点 //context.textAlign = "center"; context.fillStyle = "red"; context.fillText("开始点(20,20)",20,20); context.fillText("控制点1(20,100)",20,100); context.fillText("控制点2(200,300)",200,300); context.fillText("结束点(200,20)",200,20); //红色辅助线 context.strokeStyle = "red"; context.beginPath(); context.moveTo(20,20);//起始点 context.lineTo(20,100);//控制点1 context.lineTo(200,300);//控制点2 context.lineTo(200,20);//结束点 context.stroke(); } </script>您的浏览器不支持canvas 您的浏览器不支持canvas

效果如下：