Javascript 画布上大约有120000个粒子？

我有大约120000个粒子（每个粒子的大小为1px），我需要找到最好和最重要的：最快的方式来绘制到我的画布上

你会怎么做

现在我基本上把我的像素放到一个数组中，然后我在这些粒子上循环，做一些x和y计算，然后用fillRect把它们画出来。但是现在的帧速率是8-9 fps

有什么想法吗？请举例说明

多谢各位

最新更新（我的代码）

函数init（）{
addEventListener（“mousemove”，onMouseMove）；
设mouseX，mouseY，比值=2；
const canvas=document.getElementById（“textCanvas”）；
const context=canvas.getContext（“2d”）；
canvas.width=window.innerWidth*比率；
canvas.height=window.innerHeight*比率；
canvas.style.width=window.innerWidth+“px”；
canvas.style.height=window.innerHeight+“px”；
context.imageSmoothingEnabled=false；
context.fillStyle=`rgba（255255,1）`；
setTransform（比率，0，0，比率，0，0）；
const width=canvas.width；
const height=canvas.height；
context.font=“正常232px EB Garamond”；
context.fillText（“howdy”，01160）；
var pixels=context.getImageData（0，0，宽度，高度）；
var data32=新的UINT32阵列（像素.缓冲区）；
常量粒子=新数组（）；
对于（变量i=0；i[
Math.round（Math.random（）*（宽度-1）），
Math.round（Math.random（）*（高度-1））
]);*/
移动鼠标的功能（e）{
mouseX=parseInt（（e.clientX-canvas.offsetLeft）*比率）；
mouseY=parseInt（（e.clientY-canvas.offsetTop）*比率）；
}
功能帧（时间戳）{
clearRect（0，0，宽度，高度）；
const imageData=context.getImageData（0，0，宽度，高度）；
常量数据=imageData.data；
for（设i=0；i0）{
var cursorDX=p.ox-mouseX；
var cursorDY=p.oy-mouseY；
变量cursorDistanceSquared=（cursorDX*cursorDX+cursorDY*cursorDY）；
cursorForce=数学最小值（10/cursorDistanceSquared，10）；
cursorAngle=-Math.atan2（cursorDY，cursorDX）；
}否则{
游标力=0；
橙色=0；
}
p、 xVelocity+=0.2*homeDX+cursorForce*Math.cos（cursorAngle）；
p、 yVelocity+=0.2*homeDY+cursorForce*Math.sin（cursorAngle）；
p、 xVelocity*=0.55；
p、 yVelocity*=0.55；
p、 x+=p.x速度；
p、 y+=p.yVelocity；
}
请求动画帧（帧）；
}
请求动画帧（帧）；
}

在

webgl

上下文中计算着色器中的这些粒子将提供最高效的解决方案。见e。G举个例子

如果希望继续使用

2d

上下文，可以通过在屏幕外执行此操作来加快渲染粒子的速度：

通过调用

context.getImageData（）

通过操纵数据数组绘制像素

使用

context.putImageData（）

一个简化的例子：

const output=document.getElementById（“输出”）；
const canvas=document.getElementById（“canvas”）；
const context=canvas.getContext（“2d”）；
const width=canvas.width；
const height=canvas.height；
const particles=Array.from（{length:120000}，（）=>[
Math.round（Math.random（）*（宽度-1）），
Math.round（Math.random（）*（高度-1））
]);
设previous=0；
功能帧（时间戳）{
//每秒打印帧数：
const delta=时间戳-上一个；
先前=时间戳；
output.textContent=`${（1000/delta）.toFixed（1）}fps`；
//绘制粒子：
clearRect（0，0，宽度，高度）；
const imageData=context.getImageData（0，0，宽度，高度）；
常量数据=imageData.data；
for（设i=0；i

每秒移动720万个粒子
不使用webGL和着色器，并且您希望每帧的粒子数为120K
每秒60帧您需要每秒720万点的吞吐量。你需要一台速度快的机器

Web workers多核CPU
快速解决方案。在多核机器上，web工作者为每个硬件核心提供线性性能提升。例如在8芯i上
function init(){

    window.addEventListener("mousemove", onMouseMove);

    let mouseX, mouseY, ratio = 2;

    const canvas = document.getElementById("textCanvas");
    const context = canvas.getContext("2d");
    canvas.width = window.innerWidth * ratio;
    canvas.height = window.innerHeight * ratio;

    canvas.style.width = window.innerWidth + "px";
    canvas.style.height = window.innerHeight + "px";

    context.imageSmoothingEnabled = false;
    context.fillStyle = `rgba(255,255,255,1)`;
    context.setTransform(ratio, 0, 0, ratio, 0, 0);

    const width = canvas.width;
    const height = canvas.height;

    context.font = "normal normal normal 232px EB Garamond";
    context.fillText("howdy", 0, 160);

    var pixels = context.getImageData(0, 0, width, height).data;
    var data32 = new Uint32Array(pixels.buffer);

    const particles = new Array();

    for(var i = 0; i < data32.length; i++) {

        if (data32[i] & 0xffff0000) {
            particles.push({
                x: (i % width),
                y: ((i / width)|0),
                ox: (i % width),
                oy: ((i / width)|0),
                xVelocity: 0,
                yVelocity: 0,
                a: pixels[i*4 + 3] / 255
            });
        }
    }

    /*const particles = Array.from({length: 120000}, () => [
        Math.round(Math.random() * (width - 1)),
        Math.round(Math.random() * (height - 1))
    ]);*/

    function onMouseMove(e){
        mouseX = parseInt((e.clientX-canvas.offsetLeft) * ratio);
        mouseY = parseInt((e.clientY-canvas.offsetTop) * ratio);
    }

    function frame(timestamp) {

        context.clearRect(0, 0, width, height);
        const imageData = context.getImageData(0, 0, width, height);
        const data = imageData.data;
        for (let i = 0; i < particles.length; i++) {
            const particle = particles[i];
            const index = 4 * Math.round((particle.x + particle.y * width));

            data[index + 0] = 0;
            data[index + 1] = 0;
            data[index + 2] = 0;
            data[index + 3] = 255;
        }
        context.putImageData(imageData, 0, 0);

        for (let i = 0; i < particles.length; i++) {
            const p = particles[i];

            var homeDX = p.ox - p.x;
            var homeDY = p.oy - p.y;

            var cursorForce = 0;
            var cursorAngle = 0;

            if(mouseX && mouseX > 0){
                var cursorDX = p.ox - mouseX;
                var cursorDY = p.oy - mouseY;
                var cursorDistanceSquared = (cursorDX * cursorDX + cursorDY * cursorDY);
                cursorForce = Math.min(10/cursorDistanceSquared,10);

                cursorAngle = -Math.atan2(cursorDY, cursorDX);
            }else{
                cursorForce = 0;
                cursorAngle = 0;
            }

            p.xVelocity += 0.2 * homeDX + cursorForce * Math.cos(cursorAngle);
            p.yVelocity += 0.2 * homeDY + cursorForce * Math.sin(cursorAngle);

            p.xVelocity *= 0.55;
            p.yVelocity *= 0.55;

            p.x += p.xVelocity;
            p.y += p.yVelocity;
        }
        requestAnimationFrame(frame);
    }

    requestAnimationFrame(frame);
}

// call this just once outside the animation loop.
const imageData = this.context.getImageData(0, 0, this.width * this.ratio, this.height * this.ratio);
// create a 32bit buffer
const data32 = new Uint32Array(imageData.data.buffer);
const pixel = 0xFF000000; // pixel to fill
const width = imageData.width;


// inside render loop
data32.fill(0); // clear the pixel buffer

// this line may be a problem I have no idea what it does. I would
// hope its only passing a reference and not creating a copy 
var particles = this.particleTexts[0].getParticles();

var cDX,cDY,mx,my,p,cDistSqr,cForce,i;
mx = this.mouseX | 0; // may not need the floor bitwize or 0
my = this.mouseY | 0; // if mouse coords already integers

if(mX > 0){  // do mouse test outside the loop. Need loop duplication
             // But at 60fps thats 7.2million less if statements
    for (let i = 0; i < particles.length; i++) {
        var p = particles[i];
        p.xVelocity += 0.2 * (p.ox - p.x);
        p.yVelocity += 0.2 * (p.oy - p.y);
        p.xVelocity *= 0.55;
        p.yVelocity *= 0.55;
        data32[((p.x += p.xVelocity) | 0) + ((p.y += p.yVelocity) | 0) * width] = pixel;
    }
}else{
    for (let i = 0; i < particles.length; i++) {
        var p = particles[i];
        cDX = p.x - mx;
        cDY = p.y - my;
        cDist = Math.sqrt(cDistSqr = cDX*cDX + cDY*cDY + 1);
        cForce = 1000 / (cDistSqr * cDist)
        p.xVelocity += cForce * cDx +  0.2 * (p.ox - p.x);
        p.yVelocity += cForce * cDY +  0.2 * (p.oy - p.y);
        p.xVelocity *= 0.55;
        p.yVelocity *= 0.55;
        data32[((p.x += p.xVelocity) | 0) + ((p.y += p.yVelocity) | 0) * width] = pixel;

    }
}
// put pixel onto the display.
this.context.putImageData(imageData, 0, 0);

    const interleave = 2; // example only setup for 2 frames
                          // but can be extended to 3 or 4

    // create frameCount outside loop
    frameCount += 1;

    // do half of all particals
    for (let i = frameCount % frameCount  ; i < particles.length; i += interleave ) {
        var p = particles[i];
        cDX = p.x - mx;
        cDY = p.y - my;
        cDist = Math.sqrt(cDistSqr = cDX*cDX + cDY*cDY + 1);
        cForce = 1000 / (cDistSqr * cDist)
        p.xVelocity += cForce * cDx +  0.2 * (p.ox - p.x);
        p.yVelocity += cForce * cDY +  0.2 * (p.oy - p.y);
        p.xVelocity *= 0.55;
        p.yVelocity *= 0.55;

        // add pixel index to particle's property 
        p.pixelIndex = ((p.x += p.xVelocity) | 0) + ((p.y += p.yVelocity) | 0) * width;
        // write this frames pixel
        data32[p.pixelIndex] = pixel;

        // speculate the pixel index position in the next frame. This need to be as simple as possible.
        p.pixelIndex += (p.xVelocity | 0) + (p.yVelocity | 0) * width;

        p.x += p.xVelocity;  // as the next frame this particle is coasting
        p.y += p.yVelocity;  // set its position now
     }

     // do every other particle. Just gets the pixel index and sets it
     // this needs to remain as simple as possible.
     for (let i = (frameCount + 1) % frameCount  ; i < particles.length; i += interleave)
         data32[particles[i].pixelIndex] = pixel;
     }

   // for each particle after updating position
   // get index of pixel

   p.pixelIndex = (p.x | 0 + p.y | 0) * width;
   // add pixel
   data32[p.pixelIndex] = pixel;

   // now you get 8 more pixels for the price of one particle 
   var ind = p.offsetArrayIndex; 
   //  offsetArray is an array of pixel offsets both negative and positive
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   data32[p.pixelIndex + offsetArray[ind++]]  = pixel;
   // offset array arranged as sets of 8, each set of 8 is a frame in 
   // looping pre calculated offset animation
   // offset array length is 65536 or any bit mask able size.
   p.offsetArrayIndex = ind & 0xFFFF ; // ind now points at first pixel of next
                                       // set of eight pixels