[Processing] spiral demo using Processing

//@ http://scriptdemo.blogspot.com float myAngle, myScale, myAlpha0, myAlpha; float shiftX, shiftY; int rr,gg,bb; // to control the shape of spiral float minScale, dAngle, coefScale; boolean isLine=false; boolean isColor=true; void setup() {   size(500,500);   shiftX=width/2;   shiftY=height/2;   myAngle=0;   myScale=1.0;   minScale=0.01;   coefScale=0.99;   myAlpha0=8;   dAngle=PI/50;   noStroke();   background(255);   frameRate(30);   smooth(); } void draw() {    while(myScale>minScale)    {       pushMatrix();       myAngle=myAngle+dAngle;       myScale=myScale*coefScale;       translate(shiftX,shiftY);       rotate(myAngle);       scale(myScale);       if (isColor)       {          rr=ceil(255*sin(myAngle));          gg=ceil(255*cos(myAngle));          if (rr<=0) rr=rr+255;          if (gg<=0) gg+=255;          bb=(rr+gg)%256;       } else {         rr=10; gg=10; bb=10;         if (isLine) myAlpha0=max(myAlpha0,20);       }       myAlpha=min(myAlpha0*(ceil(myAngle/TWO_PI)),255);       if (isLine)       {         stroke(rr,gg,bb,myAlpha);         noFill();         line(-1*shiftX,shiftY,shiftX,shiftY);       } else {         noStroke();         fill(bb,gg,rr,myAlpha);         rect(-1*shiftX,shiftY,width,height);       }       popMatrix();    } } void mouseClicked() {   isLine=!isLine;   myAlpha=myAlpha0;   myScale=1;   myAngle=random(-PI,PI);   background(255); } void mouseDragged() {    isColor=!isColor;    myAlpha=myAlpha0;    myScale=1;    myAngle=random(-PI,PI);    background(255); }