PPS系统的javascript中已经有几个解决方案/工作代码示例:
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由用户
北美设计
@吉图布
https://github.com/nagualdesign/Primordial-Particle-System
Google Drive的旧/原始版本:
https://drive.google.com/file/d/1eX_cczNM4qfDue6j83f8T4gG4ecjSV-p
https://drive.google.com/file/d/1KoJf753p3HXPHwP4N2lW9cWLXgusTP72
我只会在这里作为一个片段发布他的旧的更简单的代码版本。
请访问他的Github页面获取最新版本。
// author: user "nagualdesign" @ github
// github repository: https://github.com/nagualdesign/Primordial-Particle-System
// For more information visit: https://www.youtube.com/watch?v=makaJpLvbow
// This video focuses primarily on specific values of alpha, beta, v and r
// It goes on to show the effects of altering the values of alpha and beta
// To replicate the video it is necessary to tune the density of particles
// Density depends on the screen size, as well as particle size and number
// You can also increase/decrease density by zooming in/out and refreshing
// Global variables:
var a=180; // Alpha in degrees
var b=17; // Beta in degrees
var v=0.67; // Speed of particles
var r=5.0; // Radius of neighbourhood
// Convert to radians!
a=(a/180)*Math.PI;
b=(b/180)*Math.PI;
var canvas, context; // HTML canvas
var t=40; // Time interval in milliseconds
var s=5; // Size/scale of particles
var n=1200; // Number of particles
var p=new Array(n); // Particles
function init() {
// Set up canvas:
canvas=document.getElementById("canvas");
canvas.width=window.innerWidth;
canvas.height=window.innerHeight;
context=canvas.getContext("2d");
for (i=0; i<n; i++) { // Randomize position and orientation of particles:
p[i]=new Array(4); // Each particle has 4 variables
p[i][0]=Math.random()*window.innerWidth; // Set random x coordinate
p[i][1]=Math.random()*window.innerHeight; // Set random y coordinate
p[i][2]=Math.random()*2*Math.PI; // Set random orientation
}
}
function draw() {
context.clearRect(0,0,canvas.width,canvas.height); // Clear canvas
for (i=0; i<n; i++) { // For each particle:
// Set fill colour based on number of neighbours:
let fc='#00C200'; // Green
if (p[i][3]>35) fc='#F8E302'; // Yellow
else if (p[i][3]>16) fc='#0064FF'; // Blue
else if (p[i][3]>15) fc='#FF0792'; // Magenta
else if (p[i][3]>12) fc='#A4714B'; // Brown
// Draw particle:
context.beginPath();
context.arc(p[i][0],p[i][1],s,0,2*Math.PI);
context.fillStyle=fc;
context.fill();
}
}
function scope(ang) { // Ensure angles are between 0 and 2*pi radians!
while (ang>(2*Math.PI)) ang=ang-(2*Math.PI);
while (ang<0) ang=ang+(2*Math.PI);
return ang;
}
function loop() {
for (i=0; i<n; i++) { // For each particle:
// Count neighbors within radius r:
let nLeft=0, nRight=0, nTotal=0;
for (j=0; j<n; j++) if (i!=j) { // Compare every other particle:
let sX=p[j][0]-p[i][0]; // X axis separation
let sY=p[j][1]-p[i][1]; // Y axis separation
let sD=Math.sqrt((sX*sX)+(sY*sY)); // Separation distance
if (sD<(r*s*2)) { // Distance is within radius r
nTotal++; // Increase count
let sA=scope(Math.atan2(sY,sX)); // Separation angle
if (scope(sA-p[i][2])<Math.PI) nRight++; // Neighbour on right
else nLeft++; // Neighbour on left
}
}
p[i][3]=nTotal; // Used for colouring particles
// delta_phi = alpha + beta à N à sign(R - L)
let deltaPhi=a+(b*nTotal*Math.sign(nRight-nLeft));
// turn right delta_phi
p[i][2]+=deltaPhi;
p[i][2]=scope(p[i][2]); // Keep angles within scope!
// Move forward v
p[i][0]+=(v*s*2*Math.cos(p[i][2])); // X coordinate
p[i][1]+=(v*s*2*Math.sin(p[i][2])); // Y coordinate
// Wrap screen edges, Pac-Man style!
if (p[i][0]<(s*-1)) p[i][0]=(canvas.width+s);
else if (p[i][0]>(canvas.width+s)) p[i][0]=(s*-1);
if (p[i][1]<(s*-1)) p[i][1]=(canvas.height+s);
else if (p[i][1]>(canvas.height+s)) p[i][1]=(s*-1);
}
draw(); // Update canvas
}
function run() {
init();
run=setInterval(loop,t);
}
<body style="margin:0; background:#000; overflow:hidden;" onLoad="run();">
<canvas id="canvas" onclick="window.clearTimeout(run)"></canvas>
</body>
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由用户
埃尔格姆
@吉图布
https://github.com/elggem/js-primordialparticles
demo
