一位客户要求我将a similar water ripple effect 应用到他们网站上的背景图片（并且仅适用于背景图片）。
考虑到这是使用画布，这似乎是不可能的。有人知道我可以将这种效果应用于页面上的背景图像吗？
【问题讨论】：
标签： javascript css html graphics
不确定您是否还在寻找，但这有一个关于效果的很好的演示/教程： http://code.almeros.com/water-ripple-canvas-and-javascript#.Ukpfe2QY2ok
演示在这里： http://code.almeros.com/code-examples/water-effect-canvas/#.UkpiQmQY2ol
【讨论】：
尝试使用我发布的脚本，只需将其复制并粘贴到您的代码中即可。我已经用代码中的cmets解释了
(function(){
var canvas = document.getElementById('c'),
/** @type {CanvasRenderingContext2D} */
ctx = canvas.getContext('2d'),
width = 500,
height = 200,
half_width = width >> 1,
half_height = height >> 1,
size = width * (height + 2) * 2,
delay = 30,
oldind = width,
newind = width * (height + 3),
riprad = 3,
ripplemap = [],
last_map = [],
ripple,
texture,
line_width = 20,
step = line_width * 2,
count = height / line_width;
canvas.width = width;
canvas.height = height;
/*
* Water ripple demo can work with any bitmap image
*/
with (ctx) {
fillStyle = '#a2ddf8';
fillRect(0, 0, width, height);
fillStyle = '#07b';
save();
rotate(-0.785);
for (var i = 0; i < count; i++) {
fillRect(-width, i * step, width * 3, line_width);
}
restore();
}
texture = ctx.getImageData(0, 0, width, height);
ripple = ctx.getImageData(0, 0, width, height);
for (var i = 0; i < size; i++) {
last_map[i] = ripplemap[i] = 0;
}
/**
* Main loop
*/
function run() {
newframe();
ctx.putImageData(ripple, 0, 0);
}
/**
* Disturb water at specified point
*/
function disturb(dx, dy) {
dx <<= 0;
dy <<= 0;
for (var j = dy - riprad; j < dy + riprad; j++) {
for (var k = dx - riprad; k < dx + riprad; k++) {
ripplemap[oldind + (j * width) + k] += 128;
}
}
}
/**
* Generates new ripples
*/
function newframe() {
var a, b, data, cur_pixel, new_pixel, old_data;
var t = oldind; oldind = newind; newind = t;
var i = 0;
// create local copies of variables to decrease
// scope lookup time in Firefox
var _width = width,
_height = height,
_ripplemap = ripplemap,
_last_map = last_map,
_rd = ripple.data,
_td = texture.data,
_half_width = half_width,
_half_height = half_height;
for (var y = 0; y < _height; y++) {
for (var x = 0; x < _width; x++) {
var _newind = newind + i, _mapind = oldind + i;
data = (
_ripplemap[_mapind - _width] +
_ripplemap[_mapind + _width] +
_ripplemap[_mapind - 1] +
_ripplemap[_mapind + 1]) >> 1;
data -= _ripplemap[_newind];
data -= data >> 5;
_ripplemap[_newind] = data;
//where data=0 then still, where data>0 then wave
data = 1024 - data;
old_data = _last_map[i];
_last_map[i] = data;
if (old_data != data) {
//offsets
a = (((x - _half_width) * data / 1024) << 0) + _half_width;
b = (((y - _half_height) * data / 1024) << 0) + _half_height;
//bounds check
if (a >= _width) a = _width - 1;
if (a < 0) a = 0;
if (b >= _height) b = _height - 1;
if (b < 0) b = 0;
new_pixel = (a + (b * _width)) * 4;
cur_pixel = i * 4;
_rd[cur_pixel] = _td[new_pixel];
_rd[cur_pixel + 1] = _td[new_pixel + 1];
_rd[cur_pixel + 2] = _td[new_pixel + 2];
}
++i;
}
}
}
canvas.onmousemove = function(/* Event */ evt) {
disturb(evt.offsetX || evt.layerX, evt.offsetY || evt.layerY);
};
setInterval(run, delay);
// generate random ripples
var rnd = Math.random;
setInterval(function() {
disturb(rnd() * width, rnd() * height);
}, 700);
})();<canvas id="c"></canvas>【讨论】：
.paperButton {
display: block;
text-align: center;
text-decoration: none;
position: relative;
overflow: hidden;
-webkit-transition: all 0.2s ease;
-moz-transition: all 0.2s ease;
-o-transition: all 0.2s ease;
transition: all 0.2s ease;
z-index: 0;
cursor:pointer;
}
.animate {
-webkit-animation: ripple 0.65s linear;
-moz-animation: ripple 0.65s linear;
-ms-animation: ripple 0.65s linear;
-o-animation: ripple 0.65s linear;
animation: ripple 0.65s linear;
}
@-webkit-keyframes
ripple { 100% {
opacity: 0;
-webkit-transform: scale(2.5);
}
}
@-moz-keyframes
ripple { 100% {
opacity: 0;
-moz-transform: scale(2.5);
}
}
@-o-keyframes
ripple { 100% {
opacity: 0;
-o-transform: scale(2.5);
}
}
@keyframes
ripple { 100% {
opacity: 0;
transform: scale(2.5);
}
}
$(function(){
var ink, i, j, k;
$(".paperButton").mousedown(function(e){
if($(this).find(".ink").length === 0){
$(this).prepend("<span class='ink'></span>");
}
ink = $(this).find(".ink");
ink.removeClass("animate");
if(!ink.height() && !ink.width()){
i = Math.max($(this).outerWidth(), $(this).outerHeight());
ink.css({height: i, width: i});
}
j = e.pageX - $(this).offset().left - ink.width()/2;
k = e.pageY - $(this).offset().top - ink.height()/2;
ink.css({top: k+'px', left: j+'px'}).addClass("animate");
});
});
【讨论】：
如果您将照片上传到https://imgur.com/，我找到了解决方案 然后上传完成后按右键单击图像然后复制图像地址并将其放入您的代码中，如下所示： 背景图片：网址（https://i.imgur.com/yourphotolink.jpg） 注意：复制链接后，请检查您的链接是否以 .jpg 或 .png 结尾 如果它以 .jpg?1 结尾，请删除 ?1 所以你的链接以 .jpg 结尾
我不知道为什么 jquery 波纹效果不支持普通照片，但这些步骤将解决您的问题
【讨论】：