如何使用 HTML5 Canvas 制作水波纹效果

百科常识
鲍翠磊
2023-08-12 08:10:12
1

今天宠物迷的小编给各位宠物饲养爱好者分享canvas 水波效果的宠物知识，其中也会对如何使用 HTML5 Canvas 制作水波纹效果进行专业的解释，如果能碰巧解决你现在面临的宠物相关问题，别忘了关注本站哦，现在我们开始吧！

如何使用 HTML5 Canvas 制作水波纹效果

1、首先：html

Water drops effect

Water drops effect

HTML5 compliant browser required

　

2、然后是css样式
body{background:#eee;margin:0;padding:0}
.example{background:#FFF;width:600px;border:1px #000 solid;margin:20px auto;padding:15px;-moz-border-radius: 3px;-webkit-border-radius: 3px}

#water {
width:500px;
height:400px;
display: block;
margin:0px auto;
cursor:pointer;
}
#switcher {
text-align:center;
overflow:hidden;
margin:15px;
}
#switcher img {
width:160px;
height:120px;
}
3、再然后是js代码
function drop(x, y, damping, shading, refraction, ctx, screenWidth, screenHeight){
this.x = x;
this.y = y;
this.shading = shading;
this.refraction = refraction;
this.bufferSize = this.x * this.y;
this.damping = damping;
this.background = ctx.getImageData(0, 0, screenWidth, screenHeight).data;
this.imageData = ctx.getImageData(0, 0, screenWidth, screenHeight);

this.buffer1 = [];
this.buffer2 = [];
for (var i = 0; i < this.bufferSize; i++){
this.buffer1.push(0);
this.buffer2.push(0);
}

this.update = function(){
for (var i = this.x + 1, x = 1; i < this.bufferSize - this.x; i++, x++){
if ((x < this.x)){
this.buffer2[i] = ((this.buffer1[i - 1] + this.buffer1[i + 1] + this.buffer1[i - this.x] + this.buffer1[i + this.x]) / 2) - this.buffer2[i];
this.buffer2[i] *= this.damping;
} else x = 0;
}

var temp = this.buffer1;
this.buffer1 = this.buffer2;
this.buffer2 = temp;
}

this.draw = function(ctx){
var imageDataArray = this.imageData.data;
for (var i = this.x + 1, index = (this.x + 1) * 4; i < this.bufferSize - (1 + this.x); i++, index += 4){
var xOffset = ~~(this.buffer1[i - 1] - this.buffer1[i + 1]);
var yOffset = ~~(this.buffer1[i - this.x] - this.buffer1[i + this.x]);
var shade = xOffset * this.shading;
var texture = index + (xOffset * this.refraction + yOffset * this.refraction * this.x) * 4;
imageDataArray[index] = this.background[texture] + shade;
imageDataArray[index + 1] = this.background[texture + 1] + shade;
imageDataArray[index + 2] = 50 + this.background[texture + 2] + shade;
}
ctx.putImageData(this.imageData, 0, 0);
}
}

var fps = 0;

var watereff = {
// variables
timeStep : 20,
refractions : 2,
shading : 3,
damping : 0.99,
screenWidth : 500,
screenHeight : 400,
pond : null,
textureImg : null,
interval : null,
backgroundURL : 'data_images/underwater1.jpg',

// initialization
init : function() {
var canvas = document.getElementById('water');
if (canvas.getContext){

// fps countrt
fps = 0;
setInterval(function() {
document.getElementById('fps').innerHTML = fps / 2 + ' FPS';
fps = 0;
}, 2000);

canvas.onmousedown = function(e) {
var mouse = watereff.getMousePosition(e).sub(new vector2d(canvas.offsetLeft, canvas.offsetTop));
watereff.pond.buffer1[mouse.y * watereff.pond.x + mouse.x ] += 200;
}
canvas.onmouseup = function(e) {
canvas.onmousemove = null;
}

canvas.width = this.screenWidth;
canvas.height = this.screenHeight;
this.textureImg = new Image(256, 256);
this.textureImg.src = this.backgroundURL;
canvas.getContext('2d').drawImage(this.textureImg, 0, 0);
this.pond = new drop(
this.screenWidth,
this.screenHeight,
this.damping,
this.shading,
this.refractions,
canvas.getContext('2d'),
this.screenWidth, this.screenHeight
);
if (this.interval != null){
clearInterval(this.interval);
}
this.interval = setInterval(watereff***n, this.timeStep);
}
},

// change image func
changePicture : function(url){
this.backgroundURL = url;
this.init();
},

// get mouse position func
getMousePosition : function(e){
if (!e){
var e = window.event;
}
if (e.pageX || e.pageY){
return new vector2d(e.pageX, e.pageY);
} else if (e.clientX || e.clientY){
return new vector2d(e.clientX, e.clientY);
}
},

// loop drawing
run : function(){
var ctx = document.getElementById('water').getContext('2d');
watereff.pond.update();
watereff.pond.draw(ctx);
fps++;
}
}

window.onload = function(){
watereff.init();
}

看看flash是怎么做的吧。水波波纹效果有好多种做法，实现难度不一样，效果也不一样。
比如这个
http://bbs.9ria***m/forum.php?mod=viewthread&tid=404246&highlight=%E6%B0%B4%E6%B3%A2
可以在论坛搜一搜，有讲原理的，也有直接贴源码的。用遮罩做比较简单，用柏林噪声做比较难。

如何在li里面也实现点下去水波扩散的效果

forName支持数组类型，loadClass不支持数组一般情况下，这两个方法效果一样，都能装载Class。但如果程序依赖于Class是否被初始化，就必须用Class.forName(name)了。例如，在JDBC编程中，常看到这样的用法，Class.forName("com.mysql.jdbc.Driver")

如何使用 HTML5 Canvas 制作水波纹效果

如何给Imageview 设置水波纹效果

水波纹效果：1.标准正余弦水波纹；2.非标准圆形液柱水波纹；虽说都是水波纹，但两者在实现上差异是比较大的，一个通过正余弦函数模拟水波纹效果，另外一个会运用到图像的混合模式（PorterDuffXfermode）；先看效果：自定义View根据实际情况可以...

如何使用 HTML5 Canvas 制作水波纹效果

1、css样式
body{background:#eee;margin:0;padding:0}
.example{background:#FFF;width:600px;border:1px #000 solid;margin:20px auto;padding:15px;-moz-border-radius: 3px;-webkit-border-radius: 3px}
#water {
width:500px;
height:400px;
display: block;
margin:0px auto;
cursor:pointer;
}
#switcher {
text-align:center;
overflow:hidden;
margin:15px;
}
#switcher img {
width:160px;
height:120px;
}
3、js代码
function drop(x, y, damping, shading, refraction, ctx, screenWidth, screenHeight){
this.x = x;
this.y = y;
this.shading = shading;
this.refraction = refraction;
this.bufferSize = this.x * this.y;
this.damping = damping;
this.background = ctx.getImageData(0, 0, screenWidth, screenHeight).data;
this.imageData = ctx.getImageData(0, 0, screenWidth, screenHeight);

this.buffer1 = [];
this.buffer2 = [];
for (var i = 0; i < this.bufferSize; i++){
this.buffer1.push(0);
this.buffer2.push(0);
}

this.update = function(){
for (var i = this.x + 1, x = 1; i < this.bufferSize - this.x; i++, x++){
if ((x < this.x)){
this.buffer2[i] = ((this.buffer1[i - 1] + this.buffer1[i + 1] + this.buffer1[i - this.x] + this.buffer1[i + this.x]) / 2) - this.buffer2[i];
this.buffer2[i] *= this.damping;
} else x = 0;
}

var temp = this.buffer1;
this.buffer1 = this.buffer2;
this.buffer2 = temp;
}

this.draw = function(ctx){
var imageDataArray = this.imageData.data;
for (var i = this.x + 1, index = (this.x + 1) * 4; i < this.bufferSize - (1 + this.x); i++, index += 4){
var xOffset = ~~(this.buffer1[i - 1] - this.buffer1[i + 1]);
var yOffset = ~~(this.buffer1[i - this.x] - this.buffer1[i + this.x]);
var shade = xOffset * this.shading;
var texture = index + (xOffset * this.refraction + yOffset * this.refraction * this.x) * 4;
imageDataArray[index] = this.background[texture] + shade;
imageDataArray[index + 1] = this.background[texture + 1] + shade;
imageDataArray[index + 2] = 50 + this.background[texture + 2] + shade;
}
ctx.putImageData(this.imageData, 0, 0);
}
}

var fps = 0;

var watereff = {
// variables
timeStep : 20,
refractions : 2,
shading : 3,
damping : 0.99,
screenWidth : 500,
screenHeight : 400,
pond : null,
textureImg : null,
interval : null,
backgroundURL : 'data_images/underwater1.jpg',

// initialization
init : function() {
var canvas = document.getElementById('water');
if (canvas.getContext){

手机怎么测试html5手机上下滑动翻页特效

使用浏览器可以进行手机效果测试：现在各大浏览器都有这种功能了，谷歌、QQ、360搜狐等；首先打开网页，点击右键列表里会有“审查元素”，再点击手机那个按钮，就可以调整屏幕宽度查看手机效果。

如何用html5的 canvas标签做一个聊天气泡

canvas？要会动？
http://www***anyifeng***m/blog/2010/04/css_speech_bubbles.html
这个大牛你可以关注一下

HTML5用canvas怎么实现动画效果

HTML5用canvas实现动画效果的方法： body { margin: 0px; padding: 0px; } window.requestAnimFrame = (function(callback) { return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(callback) { window.setTimeout(callback, 1000 / 60); }; })(); function drawRectangle(myRectangle, context) { context.beginPath(); context.rect(myRectangle.x, myRectangle.y, myRectangle.width, myRectangle.height); context.fillStyle = '#8ED6FF'; context.fill(); context.lineWidth = myRectangle.borderWidth; context.strokeStyle = 'black'; context.stroke(); } function animate(myRectangle, canvas, context, startTime) { // update var time = (new Date()).getTime() - startTime; var linearSpeed = 100; // pixels / second var newX = linearSpeed * time / 1000; if(newX < canvas.width - myRectangle.width - myRectangle.borderWidth / 2) { myRectangle.x = newX; } // clear context.clearRect(0, 0, canvas.width, canvas.height); drawRectangle(myRectangle, context); // request new frame requestAnimFrame(function() { animate(myRectangle, canvas, context, startTime); }); } var canvas = document.getElementById('myCanvas'); var context = canvas.getContext('2d'); var myRectangle = { x: 0, y: 75, width: 100, height: 50, borderWidth: 5 }; drawRectangle(myRectangle, context); // wait one second before starting animation setTimeout(function() { var startTime = (new Date()).getTime(); animate(myRectangle, canvas, context, startTime); }, 1000); 实现效果：

87％的宠物爱好者还学习了如下宠物知识：

红贵宾的性格及特点

三菱PLC 4AD模块零点调整和增益调整指的是什么意思

本文由宠物迷百科常识栏目发布，非常欢迎各位朋友分享到个人朋友圈，但转载请说明文章出处“如何使用 HTML5 Canvas 制作水波纹效果”