Canvas学习
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Canvas绘图</title>
</head>
<body>
<canvas id="canvas" style="border:1px solid #aaa display:block margin:50px auto;">
当前浏览器不支持Canvas,请更换浏览器后再试。//这句话在浏览器不支持时出现！
</canvas>
<script type="text/javascript">
var tangram=[
{p:[{x:0,y:0},{x:800,y:0},{x:400,y:400}],color:"#caff67"},
{p:[{x:0,y:0},{x:400,y:400},{x:0,y:800}],color:"#67becf"},
{p:[{x:800,y:0},{x:800,y:400},{x:600,y:600},{x:600,y:200}],color:"#ef3d61"},
{p:[{x:600,y:200},{x:600,y:600},{x:400,y:400}],color:"#f9f51a"},
{p:[{x:400,y:400},{x:600,y:600},{x:400,y:800},{x:200,y:600}],color:"#a594c0"},
{p:[{x:200,y:600},{x:400,y:800},{x:0,y:800}],color:"#fa8ecc"},
{p:[{x:800,y:400},{x:800,y:800},{x:400,y:800}],color:"#f6ca29"}
]
window.onload=function(){
var canvas = document.getElementById("canvas");
canvas.width=800;
canvas.height=800;
var context=canvas.getContext("2d");
for(var i=0;i<tangram.length;i++){
draw(tangram[i],context)
}
}
function draw(piece,context){
//beginPath、closePath来标注路径的范围
context.beginPath();
context.moveTo(piece.p[0].x,piece.p[0].y);
for(var i=0;i<piece.p.length;i++){
context.lineTo(piece.p[i].x,piece.p[i].y);
}
context.closePath();
context.fillStyle = piece.color;
context.fill();//为封闭图形填充颜色
context.strokeStyle="black";//设置外边框
context.lineWidth=3;
context.stroke();
}
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>DrawArc</title>
</head>
<body>
<canvas id="canvas" style="border:1px solid #aaa display:block margin:50px auto;">
当前浏览器不支持Canvas,请更换浏览器后再试。//这句话在浏览器不支持时出现！
</canvas>
<script type="text/javascript">
window.onload=function(){
var canvas=document.getElementById("canvas");
canvas.width=1024;
canvas.height=768;
var context = canvas.getContext("2d");
context.lineWidth=5;
context.strokeStyle="#005588";
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,60,40,0,2*Math.PI*(i+1)/10);
context.closePath();
//如果路径没有封闭的话会自动封闭路径（头尾相连
context.stroke();
}
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,180,40,0,2*Math.PI*(i+1)/10);
//context.closePath();
//遇到beginPath知道要重新规划路径
context.stroke();
}
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,300,40,0,2*Math.PI*(i+1)/10,true);
context.closePath();
//遇到beginPath知道要重新规划路径
context.stroke();
}
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,420,40,0,2*Math.PI*(i+1)/10,true);
//context.closePath();
//遇到beginPath知道要重新规划路径
context.stroke();
}
context.fillStyle="#005588"
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,540,40,0,2*Math.PI*(i+1)/10);
context.closePath();
context.fill();
}
for(var i=0;i<10;i++){
context.beginPath();
context.arc(50+i*100,660,40,0,2*Math.PI*(i+1)/10);
context.fill();
//fill填充是自动收尾相连
}
}
/**
window.onload=function(){
var canvas=document.getElementById("canvas");
canvas.width=1024;
canvas.height=768;
var context = canvas.getContext("2d");
context.lineWidth=5;
context.strokeStyle="#005588"
context.arc(300,300,200,0,1.5*Math.PI);
context.stroke();
}*/
</script>
</body>
</html>