html5 canvas 详细使用教程
时间：2022-09-24 10:20:45|栏目：JavaScript代码|点击： 次
话不多说，请看代码
<!DOCTYPE html ">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script type="text/javascript">
function draw21(id) {
var canvas = document.getElementById(id)
if (canvas == null)
return false;
var context = canvas.getContext("2d");
//实践表明在不设施fillStyle下的默认fillStyle=black
context.fillRect(0, 0, 100, 100);
//实践表明在不设施strokeStyle下的默认strokeStyle=black
context.strokeRect(120, 0, 100, 100);
//设置纯色
context.fillStyle = "red";
context.strokeStyle = "blue";
context.fillRect(0, 120, 100, 100);
context.strokeRect(120, 120, 100, 100);
//设置透明度实践证明透明度值>0,<1值越低，越透明，值>=1时为纯色，值<=0时为完全透明
context.fillStyle = "rgba(255,0,0,0.2)";
context.strokeStyle = "rgba(255,0,0,0.2)";
context.fillRect(240,0 , 100, 100);
context.strokeRect(240, 120, 100, 100);
}
function draw22(id) {
var canvas = document.getElementById(id)
if (canvas == null)
return false;
var context = canvas.getContext("2d");
//实践表明在不设施fillStyle下的默认fillStyle=black
context.fillRect(0, 0, 100, 100);
//实践表明在不设施strokeStyle下的默认strokeStyle=black
context.strokeRect(120, 0, 100, 100);
//设置纯色
context.fillStyle = "red";
context.strokeStyle = "blue";
context.fillRect(0, 120, 100, 100);
context.strokeRect(120, 120, 100, 100);
//设置透明度实践证明透明度值>0,<1值越低，越透明，值>=1时为纯色，值<=0时为完全透明
context.fillStyle = "rgba(255,0,0,0.2)";
context.strokeStyle = "rgba(255,0,0,0.2)";
context.fillRect(240, 0, 100, 100);
context.strokeRect(240, 120, 100, 100);
context.clearRect(50, 50, 240, 120);
}
function draw23(id) {
var canvas = document.getElementById(id);
if (canvas == null) {
return false;
}
var context = canvas.getContext('2d');
var n = 0;
//左侧1/4圆弧
context.beginPath();
context.arc(100, 150, 50, 0, Math.PI/2 , false);
context.fillStyle = 'rgba(255,0,0,0.25)';
context.fill();
context.strokeStyle = 'rgba(255,0,0,0.25)'
context.closePath();
context.stroke();
//右侧1/4圆弧
context.beginPath();
context.arc(300, 150, 50, 0, Math.PI/2 , false);
context.fillStyle = 'rgba(255,0,0,0.25)';
context.fill();
context.strokeStyle = 'rgba(255,0,0,0.25)';
context.closePath();
context.stroke();
}
function draw0(id) {
var canvas = document.getElementById(id);
if (canvas == null) {
return false;
}
var context = canvas.getContext('2d');
context.beginPath();
context.arc(200, 150, 100, 0, Math.PI * 2, true);
//不关闭路径路径会一直保留下去，当然也可以利用这个特点做出意想不到的效果
context.closePath();
context.fillStyle = 'rgba(0,255,0,0.25)';
context.fill();
}
function draw1(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
var n = 0;
var dx = 150;
var dy = 150;
var s = 100;
context.beginPath();
context.fillStyle = 'rgb(100,255,100)';
context.strokeStyle = 'rgb(0,0,100)';
var x = Math.sin(0);
var y = Math.cos(0);
var dig = Math.PI / 15 * 11;
for (var i = 0; i < 30; i++) {
var x = Math.sin(i * dig);
var y = Math.cos(i * dig);
context.lineTo(dx + x * s, dy + y * s);
}
context.closePath();
context.fill();
context.stroke();
}
function draw2(id) {
var canvas = document.getElementById(id);
if (canvas == null) {
return false;
}
var context = canvas.getContext("2d");
context.fillStyle = "#EEEFF";
context.fillRect(0, 0, 400, 300);
var n = 0;
var dx = 150;
var dy = 150;
var s = 100;
context.beginPath();
context.globalCompositeOperation = 'and';
context.fillStyle = 'rgb(100,255,100)';
var x = Math.sin(0);
var y = Math.cos(0);
var dig = Math.PI / 15 * 11;
context.moveTo(dx, dy);
for (var i = 0; i < 30; i++) {
var x = Math.sin(i * dig);
var y = Math.cos(i * dig);
context.bezierCurveTo(dx + x * s, dy + y * s - 100, dx + x * s + 100, dy + y * s, dx + x * s, dy + y * s);
}
context.closePath();
context.fill();
context.stroke();
}
function draw24(id) {
var canvas = document.getElementById(id);
if (canvas == null) {
return false;
}
var context = canvas.getContext("2d");
context.moveTo(50, 50);
context.bezierCurveTo(50, 50,150, 50, 150, 150);
context.stroke();
context.quadraticCurveTo(150, 250, 250, 250);
context.stroke();
}
function draw25(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
var g1 = context.createLinearGradient(0, 0, 0, 300);
g1.addColorStop(0, 'rgb(255,0,0)'); //红
g1.addColorStop(0.5, 'rgb(0,255,0)');//绿
g1.addColorStop(1, 'rgb(0,0,255)'); //蓝
//可以把lg对象理解成GDI中线性brush
context.fillStyle = g1;
//再用这个brush来画正方形
context.fillRect(0, 0, 400, 300);
}
function draw3(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
var g1 = context.createLinearGradient(0, 0, 0, 300);
g1.addColorStop(0,'rgb(255,255,0)');//浅绿
g1.addColorStop(1,'rgb(0,255,255)');//浅蓝
context.fillStyle = g1;
context.fillRect(0, 0, 400, 300);
var n = 0;
var g2 = context.createLinearGradient(0, 0, 300, 0);
g2.addColorStop(0, 'rgba(0,0,255,0.5)');//蓝色
g2.addColorStop(1, 'rgba(255,0,0,0.5)');//红色
for (var i = 0; i < 10; i++) {
context.beginPath();
context.fillStyle = g2;
context.arc(i * 25, i * 25, i * 10, 0, Math.PI * 2, true);
context.closePath();
context.fill();
}
}
function draw26(id) {
//同一个圆心画球型
/*var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
var g1 = context.createRadialGradient(200, 150, 0, 200, 150, 100);
g1.addColorStop(0.1, 'rgb(255,0,0)');
g1.addColorStop(1, 'rgb(50,0,0)');
context.fillStyle = g1;
context.beginPath();
context.arc(200, 150, 100, 0, Math.PI * 2, true);
context.closePath();
context.fill();*/
//不同圆心看径向渐变模型
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
var g1 = context.createRadialGradient(100, 150, 10, 300, 150, 50);
g1.addColorStop(0.1, 'rgb(255,0,0)');
g1.addColorStop(0.5, 'rgb(0,255,0)');
g1.addColorStop(1, 'rgb(0,0,255)');
context.fillStyle = g1;
context.fillRect(0, 0, 400, 300);
}
function draw27(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
context.shadowOffsetX = 10;
context.shadowOffsetY = 10;
context.shadowColor = 'rgba(100,100,100,0.5)';
context.shadowBlur = 1.5;
context.fillStyle = 'rgba(255,0,0,0.5)';
context.fillRect(100, 100, 200, 100);
}
function draw4(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
var g1 = context.createRadialGradient(400, 0, 0, 400, 0, 400);
g1.addColorStop(0.1, 'rgb(255,255,0)');
g1.addColorStop(0.3, 'rgb(255,0,255)');
g1.addColorStop(1, 'rgb(0,255,255)');
context.fillStyle = g1;
context.fillRect(0, 0, 400, 300);
var n = 0;
// var g2 = context.createRadialGradient(250, 250, 0, 250, 250, 300);
// g2.addColorStop(0.1, 'rgba(255,0,0,0.5)');
// g2.addColorStop(0.7, 'rgba(255,255,0,0.5)');
// g2.addColorStop(1, 'rgba(0,0,255,0.5)');
for (var i = 0; i < 10; i++) {
var g2 = context.createRadialGradient(i * 25, i * 25, 0, i * 25, i * 25, i * 10);
g2.addColorStop(0.1, 'rgba(255,0,0,0.5)');
g2.addColorStop(0.7, 'rgba(255,255,0,0.5)');
g2.addColorStop(1, 'rgba(0,0,255,0.5)');
context.beginPath();
context.fillStyle = g2;
context.arc(i * 25, i * 25, i * 10, 0, Math.PI * 2, true);
context.fill();
}
}
function draw5(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.save(); //保存了当前context的状态
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
context.fillStyle = "rgba(255,0,0,0.1)";
//平移 缩放 旋转 1 2 3
context.translate(100, 100);
context.scale(0.5, 0.5);
context.rotate(Math.PI / 4);
context.fillRect(0, 0, 100, 100);
context.restore(); //恢复到刚刚保存的状态,保存恢复只能使用一次
context.save(); //保存了当前context的状态
context.fillStyle = "rgba(255,0,0,0.2)";
//平移 旋转 缩放 1 3 2
context.translate(100, 100);
context.rotate(Math.PI / 4);
context.scale(0.5, 0.5);
context.fillRect(0, 0, 100, 100);
context.restore(); //恢复到刚刚保存的状态
context.save(); //保存了当前context的状态
context.fillStyle = "rgba(255,0,0,0.3)";
//缩放 平移 旋转 2 1 3
context.scale(0.5, 0.5);
context.translate(100, 100);
context.rotate(Math.PI / 4);
context.fillRect(0, 0, 100, 100);
context.restore(); //恢复到刚刚保存的状态
context.save(); //保存了当前context的状态
context.fillStyle = "rgba(255,0,0,0.4)";
//缩放 旋转 平移 2 3 1
context.scale(0.5, 0.5);
context.rotate(Math.PI / 4);
context.translate(100, 100);
context.fillRect(0, 0, 100, 100);
context.restore(); //恢复到刚刚保存的状态
context.save(); //保存了当前context的状态
context.fillStyle = "rgba(255,0,0,0.5)";
//旋转 平移 缩放 3 1 2
context.rotate(Math.PI / 4);
context.translate(100, 100);
context.scale(0.5, 0.5);
context.fillRect(0, 0, 100, 100);
context.restore(); //恢复到刚刚保存的状态
context.save(); //保存了当前context的状态
context.fillStyle = "rgba(255,0,0,1)";
//旋转 缩放 平移 3 2 1
context.rotate(Math.PI / 4);
context.scale(0.5, 0.5);
context.translate(100, 100);
context.fillRect(0, 0, 100, 100);
//实验表明应该移动的是坐标轴
//实验表明缩放的是坐标轴比例
//实验表明旋转的是坐标轴
//综合上述，因此平移 缩放 旋转 三者的顺序不同都将画出不同的结果
}
function draw6(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext('2d');
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
//图形绘制
context.translate(200, 50);
context.fillStyle = 'rgba(255,0,0,0.25)';
for (var i = 0; i < 50; i++) {
//实验表明translate、scale、rotate都是在原有的context属性上调整的
context.translate(25, 25);
context.scale(0.95, 0.95);
context.rotate(Math.PI / 10);
context.fillRect(0, 0, 100, 50);
}
}
function draw7(id) {
var canvas = document.getElementById(id);
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
//图形绘制
context.translate(200, 50);
for (var i = 0; i < 50; i++) {
context.translate(25, 25);
context.scale(0.95, 0.95);
context.rotate(Math.PI / 10);
create5Star(context);
context.fill();
}
}
function draw8(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
//context.beginPath();
context.strokeStyle = "rgb(250,0,0)";
context.fillStyle = "rgb(250,0,0)"
//实验证明第一次lineTo的时候和moveTo功能一样
context.lineTo(100, 100);
//之后的lineTo会以上次lineTo的节点为开始
context.lineTo(200, 200);
context.lineTo(200, 100);
context.moveTo(200, 50);
context.lineTo(100,50);
context.stroke();
}
function draw9(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
//定义颜色
var colors = ["red", "orange", "yellow", "green", "blue", "navy", "perple"];
//定义线宽
context.lineWidth = 10;
context.transform(1,0,0,1,100,0)
//循环绘制圆弧
for (var i = 0; i < colors.length; i++) {
//定义每次向下移动10个像素的变换矩阵
context.transform(1, 0, 0, 1, 0, 10);
//设定颜色
context.strokeStyle = colors[i];
context.beginPath();
context.arc(50, 100, 100, 0, Math.PI, true);
context.stroke();
}
}
function draw10(id) {
var canvas = document.getElementById(id);
if (canvas == null) {
return false;
}
var context = canvas.getContext("2d");
var oprtns = new Array(
"source-over",
"destination-over",
"source-in",
"destination-in",
"source-out",
"destination-out",
"source-atop",
"destination-atop",
"lighter",
"xor",
"copy"
);
var i = 0;//组合效果编号
//结合setinterval动态显示组合
var interal = setInterval(function () {
if (i == 10) {
i=0;
}
else {
i++;
}
//每次重绘前清空
context.clearRect(0,0,400,300)
//蓝色矩形
context.fillStyle = "blue";
context.fillRect(10, 10, 60, 60);
//设置组合方式
context.globalCompositeOperation = oprtns[i];
//设置新图形（红色圆形）
context.beginPath();
context.fillStyle = "red";
context.arc(60, 60, 30, 0, Math.PI * 2, false);
context.fill();
}, 1000);
}
function create5Star(context) {
var n = 0;
var dx = 100;
var dy = 0;
var s = 50;
//创建路径
context.beginPath();
context.fillStyle = 'rgba(255,0,0,0.5)';
var x = Math.sin(0);
var y = Math.cos(0);
var dig = Math.PI / 5 * 4;
for (var i = 0; i < 5; i++) {
var x = Math.sin(i * dig);
var y = Math.cos(i * dig);
context.lineTo(dx + x * s, dy + y * s);
}
context.closePath();
}
function draw11(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
context.shadowOffsetX = 10;
context.shadowOffsetY = 10;
context.shadowColor = 'rgba(100,100,100,0.5)';
context.shadowBlur =5;
//图形绘制
context.translate(0, 50);
for (var i = 0; i < 3; i++) {
context.translate(50, 50);
create5Star(context);
context.fill();
}
}
//drawImage(image,x,y)
function draw28(id) {
var image = new Image();
image.src = "http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png";
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
image.onload = function () {
context.drawImage(image,0,0);
}
}
//drawImage(image,x,y,w,h)
function draw12(id) {
var image = new Image();
image.src = "http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png";
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
image.onload = function () {
context.drawImage(image, 50, 50, 300, 200);
}
}
//drawImage(image,sx,sy,sw,sh,dx,dy,dw,dh)
function draw13(id){
var image = new Image();
image.src = "http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png";
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
image.onload = function () {
context.drawImage(image, 100, 100, 200, 150,50,50,300,200);//这里取的是实际尺寸
}
}
function draw14(id) {
//传统的平铺是用for循环来处理的，现在直接调用接口
var image = new Image();
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
var type = ["no-repeat", "repeat-x", "repeat-y", "repeat"];
var i = 0;
image.src = "http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png";
image.onload = function () {
var interval = setInterval(function () {
//每次转换平铺类型清空
context.clearRect(0, 0, 400, 300);
if (i >= 4) {
i = 0;
}
var ptrn = context.createPattern(image, type[i]);
context.fillStyle = ptrn;
context.fillRect(0, 0, 400, 300);
i++;
}, 1000);
};
}
//图像裁剪
function draw15(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "black";
context.fillRect(0, 0, 400, 300);
image = new Image();
image.onload = function () {
drawImg(context,image);
}
image.src = "http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png"
}
function drawImg(context, image) {
//圆形裁剪区
//createCircleClip(context)
//星形裁剪区
create5StarClip(context);
context.drawImage(image,0,0);
}
function createCircleClip(context) {
context.beginPath();
context.arc(200, 150, 100, 0, Math.PI * 2, true);
context.closePath();
context.clip();
}
function create5StarClip(context) {
var n = 0;
var dx = 200;
var dy = 135;
var s = 150;
context.beginPath();
var x = Math.sin(0);
var y = Math.cos(0);
var dig = Math.PI / 5 * 4;
for (var i = 0; i < 5; i++) {
var x = Math.sin(i * dig);
var y = Math.cos(i * dig);
context.lineTo(dx + x * s, dy + y * s);
}
context.closePath();
context.clip();
}
function draw16(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = 'red'
//在右下角画一个正方形
context.fillRect(250,250,150,50);
var image = new Image();
image.src = "http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png";
image.onload = function () {
//在左上角画一幅图片
context.drawImage(image, 0, 0,200,200);
//实验证明imagedata取的是canvas所在范围画的图形，不止是图片
//不会取该区域内是空白的canvas的像素
var imagedata = context.getImageData(0, 0, 400, 300);
//修改imagedata
for (var i = 0, n = imagedata.data.length; i < n; i += 4) {
imagedata.data[i + 0] = 255 - imagedata.data[i + 0]; //red;
imagedata.data[i + 1] = 255 - imagedata.data[i + 1]; //green
imagedata.data[i + 2] = 255 - imagedata.data[i + 2]; //blue
//imagedata.data[i + 3] = 255 - imagedata.data[i + 3]; //a
}
context.putImageData(imagedata,0 ,0,100,100,300,200);
}
}
function draw17(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "#EEEEFF";
context.fillRect(0,0,400,300);
context.fillStyle = "#00f";
context.font = "italic 30px sans-serif";
context.textBaseline = 'top';
//填充字符串
var txt="fill示例文字"
context.fillText(txt, 0, 0);
var length=context.measureText(txt);
context.fillText("长" + length.width + "px", 0, 50);
context.font = "bolid 30px sans-serif";
txt = "stroke示例文字";
length = context.measureText(txt);
context.strokeText(txt,0,100);
context.fillText("长" + length.width + "px", 0, 150);
}
function draw18(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "red";
context.save(); //保存了当前context的状态
context.fillStyle = "black";
context.fillRect(0, 0, 100, 100);
context.restore();//恢复到刚刚保存的状态
context.fillRect(0,120,100,100);
}
function draw19(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
context.fillStyle = "rgb(0,0,225)";
context.fillRect(0, 0, canvas.width, canvas.height);
context.fillStyle = "rgb(255,255,0)";
context.fillRect(10, 20, 50, 50);
//把图像保存到新的窗口
var w=window.open(canvas.toDataURL("http://pic002.cnblogs.com/images/2012/407398/2012080410383846.png"),"smallwin","width=400,height=350");
}
function draw20(id) {
var canvas = document.getElementById(id);
if (canvas == null)
return false;
var context = canvas.getContext("2d");
var interal = setInterval(function () {
move(context);
}, 1);
}
var x = 100;//矩形开始坐标
var y = 100;//矩形结束坐标
var mx = 0;//0右1左
var my = 0; //0下1上
var ml = 1;//每次移动长度
var w = 20;//矩形宽度
var h = 20;//矩形高度
var cw = 400;//canvas宽度
var ch = 300; //canvas高度
function move(context) {
context.clearRect(0, 0, 400, 300);
context.fillStyle = "#EEEEFF";
context.fillRect(0, 0, 400, 300);
context.fillStyle = "red";
context.fillRect(x, y, w, h);
if (mx == 0) {
x = x + ml;
if (x >= cw-w) {
mx = 1;
}
}
else {
x = x - ml;
if (x <= 0) {
mx = 0;
}
}
if (my == 0) {
y = y + ml;
if (y >= ch-h) {
my = 1;
}
}
else {
y = y - ml;
if (y <= 0) {
my = 0;
}
}
}
window.onload = function () {
draw21("canvas21");
draw22("canvas22");
draw23("canvas23");
draw24("canvas24");
draw25("canvas25");
draw26("canvas26");
draw27("canvas27");
draw28("canvas28");
draw0("canvas0");
draw1("canvas1");
draw2("canvas2");
draw3("canvas3");
draw4("canvas4");
draw5("canvas5");
draw6("canvas6");
draw8("canvas8");
draw7("canvas7");
draw9("canvas9");
draw10("canvas10");
draw11("canvas11");
draw12("canvas12");
draw13("canvas13");
draw14("canvas14");
draw15("canvas15");
draw16("canvas16");
draw17("canvas17");
draw18("canvas18");
draw19("canvas19");
draw20("canvas20");
}
</script>
</head>
<body>
<section><header><h1>画矩形</h1></header><canvas id="canvas21" width="400" height="300"></canvas></section>
<section><header><h1>清除矩形</h1></header><canvas id="canvas22" width="400" height="300"></canvas></section>
<section><header><h1>绘制路径</h1></header><canvas id="canvas23" width="400" height="300"></canvas></section>
<section><header><h1>画圆()</h1></header><canvas id="canvas0" width="400" height="300"></canvas></section>
<section><header><h1>画线test(lineTo moveTo)</h1></header><canvas id="canvas8" width="400" height="300"></canvas></section>
<section><header><h1>画线demo(lineTo moveTo)</h1></header><canvas id="canvas1" width="400" height="300"></canvas></section>
<section><header><h1>贝塞尔曲线test（bezierCurveTo）</h1></header><canvas id="canvas24" width="400" height="300"></canvas></section>
<section><header><h1>贝塞尔曲线demo（bezierCurveTo）</h1></header><canvas id="canvas2" width="400" height="300"></canvas></section>
<section><header><h1>线性test（createLinearGradient addColorStop）</h1></header><canvas id="canvas25" width="400" height="300"></canvas></section>
<section><header><h1>线性demo（createLinearGradient addColorStop）</h1></header><canvas id="canvas3" width="400" height="300"></canvas></section>
<section><header><h1>发散test（createRadialGradient）</h1></header><canvas id="canvas26" width="400" height="300"></canvas></section>
<section><header><h1>发散demo（createRadialGradient）</h1></header><canvas id="canvas4" width="400" height="300"></canvas></section>
<section><header><h1>平移 test（translate）缩放（scale） 旋转（rotate）</h1></header><canvas id="canvas5" width="400" height="300"></canvas></section>
<section><header><h1>平移 demo（translate）缩放（scale） 旋转（rotate）</h1></header><canvas id="canvas6" width="400" height="300"></canvas></section>
<section><header><h1>坐标与路径的结合使用</h1></header><canvas id="canvas7" width="400" height="300"></canvas></section>
<section><header><h1>矩阵变换</h1></header><canvas id="canvas9" width="400" height="300"></canvas></section>
<section><header><h1>图形组合叠加(globalCompositeOperation)</h1></header><canvas id="canvas10" width="400" height="300"></canvas></section>
<section><header><h1>给图像绘制阴影test shadowOffsetX(阴影的横向位移量) shadowOffsetY(盈盈的纵向位移量) shadowColor（阴影的颜色） shadowBlur（阴影的模糊范围）</h1></header><canvas id="canvas27" width="400" height="300"></canvas></section>
<section><header><h1>给图像绘制阴影demo shadowOffsetX(阴影的横向位移量) shadowOffsetY(盈盈的纵向位移量) shadowColor（阴影的颜色） shadowBlur（阴影的模糊范围）</h1></header><canvas id="canvas11" width="400" height="300"></canvas></section>
<section><header><h1>绘制图像drawImage(image,x,y)</h1></header><canvas id="canvas28" width="400" height="300"></canvas></section>
<section><header><h1>绘制图像drawImage(image,x,y,w,h)</h1></header><canvas id="canvas12" width="400" height="300"></canvas></section>
<section><header><h1>绘制局部图像drawImage(image,sx,sy,sw,sh,dx,dy,dw,dh)</h1></header><canvas id="canvas13" width="400" height="300"></canvas></section>
<section><header><h1>图像平铺</h1></header><canvas id="canvas14" width="400" height="300"></canvas></section>
<section><header><h1>图像裁剪clip</h1></header><canvas id="canvas15" width="400" height="300"></canvas></section>
<section><header><h1>像素处理getImageData</h1></header><canvas id="canvas16" width="400" height="300"></canvas></section>
<section><header><h1>绘制文字fillText strokeText</h1></header><canvas id="canvas17" width="400" height="300"></canvas></section>
<section><header><h1>绘图状态的保存save与恢复restore</h1></header><canvas id="canvas18" width="400" height="300"></canvas></section>
<section><header><h1>保存文件canvas.toDataURL</h1></header><canvas id="canvas19" width="400" height="300"></canvas></section>
<section><header><h1>简单动画</h1></header><canvas id="canvas20" width="400" height="300"></canvas></section>
</body>
</html>
