3.绘制曲线图形
在canvas中曲线图形通常分为两种,曲线和弧线,弧线就是圆周上的一部分,曲线上每一点都有相同的曲率,曲线则不一定,曲线的范围更大,曲线包含率弧线
3.1.使用点来画曲线
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
#cvs{
border: 1px solid #ddd;
}
</style>
</head>
<body>
<canvas width="600" height="300" id="cvs"></canvas>
<script>
var oCanvas = document.getElementById('cvs')
var ctx = oCanvas.getContext('2d')
ctx.moveTo(10, 100)
for(var i = 10; i < 600; i++){
var x = i;
var y = 10 * Math.cos(x/10) + 100
ctx.lineTo(x, y)
}
ctx.strokeStyle = "orangered"
ctx.s