javascript - 多个随机图像让它下雪插件
我一直在和杰森·布朗一起玩，让它下雪插件。 他的代码只适用于单个自定义图像，我一直试图找出如何更改代码，以便在随机范围内容纳多个自定义图像。
!function($){
var defaults = {
speed: 0,
interaction: true,
size: 2,
count: 200,
opacity: 0,
color: "#ffffff",
windPower: 0,
image: false
};
$.fn.let_it_snow = function(options){
var settings = $.extend({}, defaults, options),
el = $(this),
flakes = [],
canvas = el.get(0),
ctx = canvas.getContext("2d"),
flakeCount = settings.count,
mX = -100,
mY = -100;
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
(function() {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
window.requestAnimationFrame = requestAnimationFrame;
})();
function snow() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < flakeCount; i ) {
var flake = flakes[i],
x = mX,
y = mY,
minDist = 100,
x2 = flake.x,
y2 = flake.y;
var dist = Math.sqrt((x2 - x) * (x2 - x) (y2 - y) * (y2 - y)),
dx = x2 - x,
dy = y2 - y;
if (dist < minDist) {
var force = minDist / (dist * dist),
xcomp = (x - x2) / dist,
ycomp = (y - y2) / dist,
deltaV = force / 2;
flake.velX -= deltaV * xcomp;
flake.velY -= deltaV * ycomp;
} else {
flake.velX *= .98;
if (flake.velY <= flake.speed) {
flake.velY = flake.speed
}
switch (settings.windPower) {
case false:
flake.velX = Math.cos(flake.step = .05) * flake.stepSize;
break;
case 0:
flake.velX = Math.cos(flake.step = .05) * flake.stepSize;
break;
default:
flake.velX = 0.01 (settings.windPower/100);
}
}
var s = settings.color;
var patt = /^#([\da-fA-F]{2})([\da-fA-F]{2})([\da-fA-F]{2})$/;
var matches = patt.exec(s);
var rgb = parseInt(matches[1], 16) "," parseInt(matches[2], 16) "," parseInt(matches[3], 16);
flake.y = flake.velY;
flake.x = flake.velX;
if (flake.y >= canvas.height || flake.y <= 0) {
reset(flake);
}
if (flake.x >= canvas.width || flake.x <= 0) {
reset(flake);
}
if (settings.image == false) {
ctx.fillStyle = "rgba(" rgb "," flake.opacity ")"
ctx.beginPath();
ctx.arc(flake.x, flake.y, flake.size, 0, Math.PI * 2);
ctx.fill();
} else {
ctx.drawImage($("img#lis_flake").get(0), flake.x, flake.y, flake.size * 2, flake.size * 2);
}
}
requestAnimationFrame(snow);
};
function reset(flake) {
if (settings.windPower == false || settings.windPower == 0) {
flake.x = Math.floor(Math.random() * canvas.width);
flake.y = 0;
} else {
if (settings.windPower > 0) {
var xarray = Array(Math.floor(Math.random() * canvas.width), 0);
var yarray = Array(0, Math.floor(Math.random() * canvas.height))
var allarray = Array(xarray, yarray)
var selected_array = allarray[Math.floor(Math.random()*allarray.length)];
flake.x = selected_array[0];
flake.y = selected_array[1];
} else {
var xarray = Array(Math.floor(Math.random() * canvas.width),0);
var yarray = Array(canvas.width, Math.floor(Math.random() * canvas.height))
var allarray = Array(xarray, yarray)
var selected_array = allarray[Math.floor(Math.random()*allarray.length)];
flake.x = selected_array[0];
flake.y = selected_array[1];
}
}
flake.size = (Math.random() * 3) settings.size;
flake.speed = (Math.random() * 1) settings.speed;
flake.velY = flake.speed;
flake.velX = 0;
flake.opacity = (Math.random() * 0.5) settings.opacity;
}
function init() {
for (var i = 0; i < flakeCount; i ) {
var x = Math.floor(Math.random() * canvas.width),
y = Math.floor(Math.random() * canvas.height),
size = (Math.random() * 3) settings.size,
speed = (Math.random() * 1) settings.speed,
opacity = (Math.random() * 0.5) settings.opacity;
flakes.push({
speed: speed,
velY: speed,
velX: 0,
x: x,
y: y,
size: size,
stepSize: (Math.random()) / 30,
step: 0,
angle: 180,
opacity: opacity
});
}
snow();
}
if (settings.image != false) {
$("<img src='" settings.image "' style='display: none' id='lis_flake'>").prependTo("body")
}
init();
$(window).resize(function() {
if(this.resizeTO) clearTimeout(this.resizeTO);
this.resizeTO = setTimeout(function() {
el2 = el.clone();
el2.insertAfter(el);
el.remove();
el2.let_it_snow(settings);
}, 200);
});
if (settings.interaction == true) {
canvas.addEventListener("mousemove", function(e) {
mX = e.clientX,
mY = e.clientY
});
}}}(window.jQuery);
在代码的顶部，在默认属性中，是您指向图像的网址的位置。下面是我放入的内容，因此它在image1.jpeg和image2.jpeg之间选择
image: "img/image' Math.floor((Math.random() * 2) 1) '.jpeg";
我希望我的问题很明确，如果您需要更清晰，请告诉我。我是j-script的新手，我们将不胜感激。
最佳答案：
1 个答案:
答案 0 :(得分：0)
插件作者使用
将单个自定义图像加载到隐藏元素中if (settings.image != false) {
$("<img src='" settings.image "' style='display: none' id='lis_flake'>").prependTo("body")
}
并使用此
加载雪花ctx.drawImage($("img#lis_flake").get(0)
此解决方案尚未经过测试，但如果您愿意稍微破解插件，则可能会进行以下更改以使用两个可选图像：
1）在init();函数调用之前添加此项。它添加了settings.image2的另一个隐藏图像。
if (settings.image2) {
$("<img src='" settings.image2 "' style='display: none' id='lis_flake2'>").prependTo("body")
}
2）使用
修改function init()
flakes.push({
// Create a new property called 'imgNum' to hold either "" or "2";
imgNum: (settings.image2 && Math.floor(Math.random() * 2) === 0 ? "2" : ""),
// rest of the code ...
speed: speed,
3）更改
ctx.drawImage($("img#lis_flake").get(0), flake.x, flake.y, flake.size * 2, flake.size * 2);
到
ctx.drawImage($("img#lis_flake" flake.imgNum).get(0), flake.x, flake.y, flake.size * 2, flake.size * 2);
根据flake.imgNum中随机设置的init()选择图片。
4）更改传递给插件的选项，如下所示：
options = {
// other options
image: "img/image1.jpeg",
image2: "img/image2.jpeg",
// other options
}
如果image2未设置，这些更改应该允许插件仍然有效。
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