import processing.opengl.*;

PImage[] images;
float[] xpos;
float[] ypos;
float[] xvel;
float[] yvel;
float[] rotvel;
float[] rotpos;
int[] textureIndex;
int objectCount = 150;
java.util.Map sortedIndexes = new java.util.TreeMap();
int boxWidth = 200;
int boxhalfwidth = 50;

void setup () 
{
 
  size(800, 800, OPENGL);      // needs to be P3D / OPENGL since we use texture()
  frameRate(60);
  smooth();
  images = new PImage[10];
  textureIndex = new int[objectCount];
  xpos = new float[objectCount];
  ypos = new float[objectCount];
  xvel = new float[objectCount];
  yvel = new float[objectCount];
  rotpos = new float[objectCount];
  rotvel = new float[objectCount];

  for ( int i = 0; i < 10; i++)
  {
//    images[i] = loadImage("tex" + i + ".png");
    images[i] = loadImage("tex12.png");
  }

  for ( int j = 0; j < objectCount; j++)
  {
    xpos[j] = random(width);
    ypos[j] = random(height);
    rotpos[j] = random(PI);
    rotvel[j] = (random(200) - 100)  / 60000;
    textureIndex[j] = (int)random(10);
      xvel[j] = (random(200) - 100) / 300;
      sortedIndexes.put(new Float(-xvel[j]),new Integer(j));
  }
  noStroke();

}

void draw() {
  // see: http://processing.org/reference/vertex_.html
  background(2);
//  for (int i = 0; i < objectCount; i++)
  int i;
  Iterator iter = sortedIndexes.values().iterator();
  while(iter.hasNext())
  {
    Integer index = (Integer)iter.next();
    i = index.intValue();
    if (i == objectCount-1)
    {
      return;
    }
    float zpos = (-xvel[i]) * 50;
    pushMatrix();
    translate(xpos[i],ypos[i],zpos);
    rotateZ(rotpos[i]);
    drawShape(images[textureIndex[i]]);
    popMatrix();
    moveShape(i);
  }
}

void drawShape(PImage z)
{
  noStroke();
  beginShape();
  texture(z);
  vertex( -boxhalfwidth, -boxhalfwidth,   -boxhalfwidth,   -boxhalfwidth);
  vertex( boxhalfwidth, -boxhalfwidth,    boxhalfwidth, -boxhalfwidth);
  vertex( boxhalfwidth, boxhalfwidth,   boxhalfwidth, boxhalfwidth);
  vertex( -boxhalfwidth, boxhalfwidth,   -boxhalfwidth,   boxhalfwidth);
  endShape();
}

void moveShape(int i)
{
  rotpos[i] += rotvel[i];
  xpos[i] += xvel[i];
  ypos[i] += yvel[i];
  if (xpos[i] < -boxWidth)
  {
    xpos[i] = width + boxWidth;
  }
  
  if (xpos[i] > width + boxWidth)
  {
    xpos[i] = -boxWidth;
  }
  
  
}