class Ball{
 
   Tuple3f pos;
   Tuple3f vel;
   
   
   
   Vector history = new Vector();
   
   Ball(float x, float y, float z, float dx, float dy, float dz){
     pos = new Tuple3f(x,y,z);
     vel = new Tuple3f(dx,dy,dz);
   }
   
   void draw(Raytracer tracer){
    
     //check if we ran into anything
     Ray isect = new Ray(pos,vel);
 
     
     //are we going to collide in the next timeStep?
     float mag = vel.getLength();
     isect.maxDist = 100;
     
     
     tracer.accelerator.findNearest(isect);
     if (isect.occluder != null){
       isect.maxDist = isect.distance;
       /*
       lightRay.draw(g,isect.maxDist);
       pushMatrix();
       fill(200,0,0);
       noStroke();
       translate(pos.x + isect.distance*vel.x,pos.y + isect.distance*vel.y,pos.z + isect.distance*vel.z);
       sphere(1);
       popMatrix();
       */
     }
     if (isect.distance < 50 && isect.occluder != null){
              
       vel = vel.reflect(((Triangle)isect.occluder).gNormal);       
       
       vel.normalize();
       
       vel.timesEquals((1.f-damping.getVal())*mag);
     }     
          
 
      if (paused == 0){
        pos.plusEquals(vel);
        vel.y += 2;    
      }
 
    pushMatrix();
    fill(255,255,255);
    noStroke();
    translate(pos.x,pos.y,pos.z);
    sphere(20);
    popMatrix();
   
   if (time%2 == 0){
     history.insertElementAt(pos.getCopy(),0);
     if (history.size() > 8) history.removeElementAt(8);
   }
   
   if (showTrails.getVal()){
   stroke(250,250,250,50);
   noFill();
   beginShape();
   Tuple3f pt;
   for (int i =0; i < history.size(); i++){
      pt = (Tuple3f)history.elementAt(i);
     vertex(pt.x,pt.y,pt.z);
   }    
   endShape();
   }
   }
   
}

//created=14 Oct 07
//description=Collision detection using a KD-Tree and an arbitrary mesh.
//title=Collision
//publish=true
//titlebar=Collision Detection Using a KD Tree
//tags=kdtree
 
import SGGUI.*;
import SGCamera.*;
import Raytracing.*;
import Tuple.*;
 
SGCamera cam; 
Raytracer tracer;
 
Accelerator accel;
 
SGGUI controller;
VerticalLayout settings;
 
SGSlider damping, rate,energy;
SGCheckBox showOctree, showTrails;
SGLabel numHit;
PFont fnt; 
 
Lamp light;
Ray isect;
 
Vector balls = new Vector();
 
 
int paused = 0;    
 
int time = 0;
    
void setup(){
 
  size(550,550,P3D);
  fnt = loadFont("writing.vlw");
  textFont(fnt);
  textMode(SCREEN);
 
  controller = new SGGUI(this,fnt);
  controller.GUI_HIGHLIGHT = color(200,220,200);
  settings = new VerticalLayout(controller,10,10,150);
  settings.title = "Settings";
  damping = new SGSlider( "Damping",.2,.05,0,.5);
  rate = new SGSlider( "Rate",.4,.05,0,1);
  energy = new SGSlider( "Energy",.5,.05,0,2);
  showOctree = new SGCheckBox("Show KD-tree",0);
  showTrails = new SGCheckBox("Show Trails",1);
 
  settings.add(showOctree);
  settings.add(showTrails);
  settings.add(rate);
  settings.add(damping);
  settings.add(energy);
  
  controller.add(settings);
      
  cam = new SGCamera(this,100,-50,100,0,0,0);
  cam.setMouseMode(LEFT,SGCamera.ORBIT);
  cam.setMouseMode(RIGHT,SGCamera.DOLLY);
 
  tracer = new Raytracer(this);
  tracer.openFile("terrain.mra",cam);  
  sphereDetail(3);    
  frameRate(30);
 
 
  accel = tracer.accelerator;
  cam.lookAt(0,0,0);
 
}
 
 
 
public void draw(){
 
  time++;
  if (random(0,1)< rate.getVal())  balls.add(new Ball(0, random(-300,-100),random(-400,400),0,-energy.getVal(),energy.getVal()*random(-10,10)));
 
 
  accel.showTree = showOctree.getVal(); 
        
 
  background(64);
  cam.feed();
  tracer.draw();
  lights();
  
  Ball b;
  for (int i=balls.size()-1; i >= 0; i--){
    b = (Ball)balls.elementAt(i);
    b.draw(tracer);
    if (b.pos.y > 2500) balls.removeElementAt(i);
  }
 
}