//Variablen
int meinRot = 0;
int meinBlau = 0;
int meinGruen = 0;
int c = 0;
int r = 7;

void setup(){
  smooth();
  frameRate(25);
  size(640,480);
  background(0);
  noCursor();
}

void draw(){
  noStroke();
  fill(0,15);
  rectMode(CENTER);
  rect(width/2,height/2,width,height);

  strokeWeight(3);
  for (int i = 0; i <= 640; i = i+40) {
    for (int j = 0; j <= 480; j = j+40) {
      int meinRot = 0;
      int meinBlau = 0;
      int meinGruen = 0;
      c++;
      if(c == r){
        meinRot = (int)(255f * i / width);
        meinGruen = (int)(255f * j / height);
        meinBlau = (255);
        c = 1;
        r = int(random(5,10));
      }
      stroke(meinRot,meinGruen,meinBlau);
      drawHalfWay(i, j);
    }
  }
}

void drawHalfWay(int theX,int theY){
  int myHalfX = getAverage(mouseX, theX);
  int myHalfY = getAverage(mouseY, theY);
  line(myHalfX, myHalfY, theX, theY);
}
int getAverage(int theA, int theB){
  int myHalfWay = ((theA + theB)/2);
  return myHalfWay;
}