float rx=0, ry=0, rz=1;    // view angles
PImage wood;         // texture image
//BALL B = new BALL();
int n = 4;
BALL B[] = new BALL[n];

void setup() {
  size(600, 600, P3D); 
  PFont font = loadFont("Courier-14.vlw"); textFont(font, 14);      // load font
  wood = loadImage("floor.jpg");         // load texture
  textureMode(NORMALIZED);   
  randomSeed(1234);
  for (int i=0; i<n; i++) { B[i] = new BALL(); B[i].reset(); }
  } 
 
void draw() {         // rendering loop to refresh the window
  background(255);  lights();
  directionalLight(256,256,256, 0, 1, 0);
  fill(50); text("Jarek Rossignac",40,40);
  if (keyPressed&&(key=='r')) {rx+=(mouseY-pmouseY)/800.;ry-=(mouseX-pmouseX)/800.;}; // rotate
  if (keyPressed&&(key=='z')) {rz+=(mouseY-pmouseY)/1;rz+=(mouseX-pmouseX)/1;}; // zoom
  translate(width/2,0,rz); rotateY(ry);  translate(-width/2,0,0); 
  rotateX(rx); translate(0,0,-100);
  noStroke(); fill(0); 
  for (int i=0; i<n; i++) B[i].move();
  showFloor(); for (int i=0; i<n; i++) B[i].showShadow(); fill(100,150,50); for (int i=0; i<n; i++) B[i].show();
  stroke(0); for (int i=0; i<n; i++) for (int j=0; j<n; j++) if (i!=j) B[i].C.showLineTo(B[j].C); noStroke(); // draw segments between all pairs of balls
  showWall();
  scale(1,1,-1); translate(0,0,600);
  showFloor(); for (int i=0; i<n; i++) B[i].showShadow();  fill(200,250,150);  noLights(); lights(); directionalLight(256,256,256, 0, -1, 0); for (int i=0; i<n; i++) B[i].show();
 };

void keyPressed() {  
   if (key==' ') {randomSeed(1234); for (int i=0; i<n; i++) B[i].reset();}
   if (key=='X') {String S="bounce"+"-####.tif"; saveFrame(S);};   // makes a picture
   };
   
void showFloor() {  
  beginShape(QUADS);    texture(wood);          // activate texture
  vertex( 600, height+2, 300, 1, 1); vertex(600, height+2, -300, 1, 0); vertex(0,height+2,-300, 0, 0);  vertex( 0, height+2, 300, 0, 1);  
  endShape(); 
  }
  
void showWall() {  
  fill(200,200,20); beginShape();           // activate texture
  vertex( 0, 0, -300); vertex(600, 0, -300); vertex(600,height,-300);  vertex( 0, height, -300);  
  vertex( 0, 100, -300); vertex(100, 100, -300); vertex(100,500,-300);  vertex( 500, 500, -300);  
  vertex( 500, 100, -300); 
  vertex(1, 99, -300);  
  endShape(CLOSE); 
  fill(220,220,250,150); beginShape();           // activate texture
  vertex(100, 100, -300); vertex(100,500,-300);  vertex( 500, 500, -300);  
  vertex( 500, 100, -300); 
  endShape(CLOSE); 
  }


class BALL {
  BALL() {reset();}
  p3 C = new p3(0,0,0);   v3 V = new v3(0,0,0);
  float a, r=40;
  void reset() {C.setTo(random(r,width-r),random(r,height-r),random(-300+r,300-r)); V.setTo(random(-5,5),0,random(-5,5)); a=0.05;}
  void show() {pushMatrix(); translate(C.x,C.y,C.z);   sphere(r);  popMatrix();}
  void showShadow() {pushMatrix(); translate(0,height,0); scale(1,0.001,1);  translate(C.x,0,C.z); fill(30,30,30); sphere(r); popMatrix(); } 
  void move() {C.addVec(V); V.y+=a; if(C.y>height-r) V.y=-V.y; if((C.x>width-r)||(C.x<r)) V.x=-V.x; if((C.z>300-r)||(C.z<-300+r)) V.z=-V.z;}
  }