HTML5Canvas实现玫瑰曲线和心形图案的代码实例_html5教程技巧

提示：把代码复制到一个html文件中并保存，直接打开即可看到效果。

实现代码：

代码如下:









Your browser does not support the canvas element.




function draw() {
var ctx = document.getElementById('canvas').getContext('2d');
ctx.save();
ctx.translate(400,300);
ctx.clearRect(-400,-300,800,600);
ctx.strokeStyle = "#cc0000";
var a = 0, b = 1, m = 6, n = 1;
m = document.forms[0].m.value;
n = document.forms[0].n.value;
a = document.forms[0].a.value;
b = document.forms[0].b.value;
drawRose(ctx,a,b,m,n);
ctx.restore();
}
function drawRose(ctx,a,b,m,n){
ctx.beginPath();
var e = 0, c = 120;
var k = 2 * Math.PI / 360;
do {
var r = a/b + Math.sin( m * e / n * k);
r = r * c;
var x = r * Math.cos( e * k );
var y = r * Math.sin( e * k );
e += 0.1;
ctx.lineTo(x,y);
} while ( e <= 4320 );
ctx.stroke();
}
function draw2(){
var ctx = document.getElementById('canvas').getContext('2d');
ctx.save();
ctx.translate(400,300);
ctx.clearRect(-400,-300,800,600);
ctx.strokeStyle = "#cc0000";
ctx.beginPath(); //ctx.moveTo(0,0);
var e = 0, c = 150;
var k = 2 * Math.PI / 360;
do {
x = 150*Math.cos( 5/2 * e*k ) + 50*Math.cos( 15/16 * 5/2 * e*k );
y = 150*Math.sin( 5/2 * e*k ) - 50*Math.sin( 15/16 * 5/2 * e*k );
e += 0.1;
ctx.lineTo(x,y);
} while ( e <= 3600 );
ctx.stroke();
ctx.restore();
}
function draw3(){
var ctx = document.getElementById('canvas').getContext('2d');
ctx.save();
ctx.translate(400,300);
ctx.clearRect(-400,-300,800,600);
ctx.strokeStyle = "#ff0000";
ctx.beginPath();
var x = 1, y;
do {
y = -80*(Math.sqrt(1-x*x) + Math.pow(x*x,1/3));
x -= 0.001;
ctx.lineTo(100*x,y);
} while ( x >= -1 );

do {
y = 80*(Math.sqrt(1-x*x) - Math.pow(x*x,1/3));
x += 0.001;
ctx.lineTo(100*x,y);
} while ( x <= 1 );
ctx.closePath();

var grad = ctx.createRadialGradient(-40,-60,10,-40,-40,200);
grad.addColorStop(0, "#ffcc00");
grad.addColorStop(1, "#ff0000");
ctx.fillStyle = grad;
ctx.fill();
// ctx.stroke();
ctx.restore();
}
window.onload = function (){
draw();
}