Processing练习之自动绘制

       案例代码如下：

import processing.pdf.*;
import java.util.Calendar;

boolean savePDF = false;
 
int maxCount = 5000;
int currentCount = 1;
float[] x=new float[maxCount];
float[] y=new float[maxCount];
float[] r=new float[maxCount];

void setup(){
  size(600,600);
  smooth();
  frameRate(10);
  x[0] = width/2;
  y[0] = height/2;
  r[0] = 10;
  }
   void draw(){
     if(savePDF)beginRecord(PDF,timestamp()+".pdf");
     background(255);
     strokeWeight(0.5);
      float newR = random(1,7);
      float newX = random(0+newR,width-newR);
      float newY = random(0+newR,height-newR);
      float closestDist = 100000000;
      int closestIndex =0;
     for(int i=0;i<currentCount;i++){
     float newDist = dist(newX,newY,x[i],y[i]);
     if(newDist <closestDist){
      closestDist =newDist;
      closestIndex=i;
  }
     }
     float angle =atan2(newY-y[closestIndex],newX-x[closestIndex]);
     x[currentCount] =x[closestIndex]+cos(angle)*(r[closestIndex]+newR);
     y[currentCount] =y[closestIndex]+sin(angle)*(r[closestIndex]+newR);
     r[currentCount] = newR;
     currentCount++;
     for(int i=0;i<currentCount;i++){
       fill(50);
       ellipse(x[i],y[i],r[i]*2,r[i]*2);
     }
     if(currentCount++>=maxCount) noLoop();
     if(savePDF){
       savePDF =false;
      endShape();
     }
 }
 
   void keyReleased(){
     if(key=='s'||key=='S') saveFrame(timestamp()+"_##.png");
     if(key=='p'||key=='P') savePDF=true;
   }
 String timestamp(){
  Calendar now=Calendar.getInstance();
  return String.format("%1$ty%1$tm%1$td_%1$tH%1$tM%1$tS",now);
}

         保存并运行如图1

                             图1