p5.js实现动态图形临摹：旋转矩形与螺旋运动详解

function setup() 
{ 
 createCanvas(402,402); 
}
function draw()
{
 background(0); 
 var dx=0; 
 dx+=PI/180;
 var t=(millis()/5)*sin(dx);//返回自程序开始的毫秒数
 if(dx==PI) 
 { 
  dx=0;
 } 
 
 for(var i=0;i<6;i++)//每行每列六个圆形
 {  
  for(var j=0;j<6;j++)
  { 
   fill(255); 
   ellipse(i*66+36, j*66+36, 60, 60);//绘制半径30的圆形，间隔6
   fill(0); 
   translate(i*66+36, j*66+36);//矩形的移动，共四种运动状态
   if(i%2==0&&j%2==0) 
   {  
    rotate(-t); //逆时针旋转
    rect(0,0,30,30);//旋转的边长30黑色矩形
   }  
   else if(i%2==1&&j%2==0)
   { 
    rotate(t);//顺时针旋转
    rect(-30,0,30,30); 
   }  
   else if(i%2==1&&j%2==1) 
   {  
    rotate(-t); 
    rect(-30,-30,30,30); 
   }  
   else if(i%2==0&&j%2==1)
   {  
    rotate(t);
    rect(0,-30,30,30); 
   }  
   resetMatrix(); 
  } 
 }
}

function setup()
{
 createCanvas(500, 500);
 noStroke(); 
}
function draw() {
 background(0); 
 for (var i =1;i <3000; i++)
 {
  drawcircle(255-0.1*i,255-0.1*i,255-0.1*i, i); 
  i++;
 }
}
function drawcircle( r, g, b, interval){
 fill(r, g, b);
 var x = 250; 
 var y = 250; 
 var t = millis() /3+ interval *0.5;
 var xi;
 var yi;i
 var radius = interval *15;
 xi = 0.01*radius * Math.cos(t * Math.PI/180);
 yi = 0.01*radius * Math.sin(t * Math.PI/180); 
 x += xi;
 y += yi;
 ellipse(x, y, 20,20);
}