//import processing.opengl.*;
//import net.java.games.jogl.*;

float a;
//GL gl;
void setup()
{
  size(400,400,P3D);
//  gl=((PGraphicsGL)g).gl;
  perspective(PI/3.0,1, 1,1000);
  noCursor();
  noStroke();
  a=0;
  sphereDetail(7);
}

void draw()
{
  a+=0.01;
  background(0);
  lights();
  camera(0,-50,50,0,0,0,0,0,-1);
  fill(128,200,128);
  beginShape(QUADS);
  {
    vertex(-50,-50,0);
    vertex(50,-50,0);
    vertex(50,50,0);
    vertex(-50,50,0);
  }
  endShape();
  
  Vector camPos=new Vector(0,-50,50);
  Vector camDir=new Vector(0,1,-1);
  fill(255,0,0);  
  
  Vector left=cross(new Vector(0,0,1),camDir);
  Vector up=cross(camDir,left);
  
//  printVector("camDir",camDir);
//  printVector("left",left);
//  printVector("up",up);
  
  Vector tmp=rotate(camDir,up,-PI/6.0);
//  printVector("tmp",tmp);
  
  Vector tmp2=rotate(camDir,left,-PI/6.0);
//  printVector("tmp2",tmp2);
  
/*  pushMatrix();
  translate(0,-50,50); // vectors from camera, not world-coords
  pushMatrix();
  translate(50*camDir.x,50*camDir.y,50*camDir.z);
  fill(255,0,0);
  sphere(3);
  popMatrix();
  pushMatrix();
  translate(50*tmp.x,50*tmp.y,50*tmp.z);
  fill(0,255,0);
  sphere(3);
  popMatrix();
  pushMatrix();
  translate(50*tmp2.x,50*tmp2.y,50*tmp2.z);
  fill(0,0,255);
  sphere(3);
  popMatrix();
  popMatrix();*/
  
  Vector[] camPlane=new Vector[3];
  camPlane[0]=add(new Vector(0,0,0),add(mul(left,1000),mul(up,1000)));
  camPlane[1]=add(new Vector(0,0,0),add(mul(left,1000),mul(up,-1000)));  
  camPlane[2]=add(new Vector(0,0,0),mul(left,-1000));  
  
  Vector mid=intersectPoint(camPlane[0],camPlane[1],camPlane[2],camPos,add(camPos,mul(camDir,300)));
  Vector leftEdge=intersectPoint(camPlane[0],camPlane[1],camPlane[2],camPos,add(camPos,mul(tmp,300)));
  Vector topEdge=intersectPoint(camPlane[0],camPlane[1],camPlane[2],camPos,add(camPos,mul(tmp2,300)));

//  printVector("mid",mid);
//  printVector("leftEdge",leftEdge);
//  printVector("topEdge",topEdge);

  Vector deltaX=div(dir(mid,leftEdge),(float)width/2.0);
//  printVector("deltaX",deltaX);
  Vector deltaY=div(dir(mid,topEdge),(float)height/2.0);
//  printVector("deltaY",deltaY);  
  Vector mouseVectorX=add(leftEdge,mul(deltaX,constrain(mouseX,0,width-1)));
  Vector mouseVectorY=add(topEdge,mul(deltaY,constrain(mouseY,0,height-1)));  

  Vector mousePlaneVector=add(mouseVectorX,mouseVectorY);
  
  Vector mouseCameraVector=mul(dir(camPos,mousePlaneVector),100);
  
  Vector ip=intersectPoint(new Vector(-1000,-1000,0),new Vector(0,1000,0),new Vector(1000,-1000,0),camPos,add(camPos,mouseCameraVector));


//  translate(0,-50,50);
  pushMatrix();
  translate(mid.x,mid.y,mid.z);
  fill(255,0,0);
  sphere(3);
  popMatrix();
  pushMatrix();
  translate(leftEdge.x,leftEdge.y,leftEdge.z);
  fill(0,255,0);
  sphere(3);
  popMatrix();
  pushMatrix();
  translate(topEdge.x,topEdge.y,topEdge.z);
  fill(0,0,255);
  sphere(3);
  popMatrix();
/*  pushMatrix();
  translate(mousePlaneVector.x,mousePlaneVector.y,mousePlaneVector.z);
  fill(255,0,255);
  sphere(3);
  popMatrix();*/
  pushMatrix();
  translate(ip.x,ip.y,ip.z);
  fill(255,255,0);
  box(3);
  popMatrix();
  
    
//  println("Dot:"+Dot(new Vector(0.806,0.806,0),new Vector(0,100,0)));
/*  a+=0.01;
  background(0);
  Vector axis=new Vector(0,-100,0);
  Vector thing=new Vector(-100,100,0);
  Vector res=rotate(thing,axis,a);
  translate(width/2,height/2,0);
  rotateY(mouseX/(float)width);
  
  beginShape(LINES);
  {
    stroke(255,0,0);
    vertex(0,0,0);
    vertex(axis.x,axis.y,axis.z);
    stroke(0,255,0);
    vertex(0,0,0);
    vertex(thing.x,thing.y,thing.z);
    stroke(0,0,255);
    vertex(0,0,0);
    vertex(res.x,res.y,res.z);
  }
  endShape();  */
}