// Project 3 for CS1050 
// by Jarek Rossignac
/*Student should:
 - add the code for the other operations 
 - modify these statements to avoid redundant recursions
 - manually edit the CSG tree and primitive lists to produce a Mikey Mouse face
 - Key action to change selected CSG node (initially 0, root)
   * P means go to parent (or stay if root)
   * L means go toleft child (or stay if leaf)
   * R means go to righ child (or stay if leaf)
 - Key actions to edit the operator at the selected CSG node
 - Key action to change the ID of the primitive at a leaf node

Extra credit if develop data-structure and code to support:
 - Keys to expand primitive nodes to boolean nodes (press key for desired operator): +5%
 - Keys to collapse boolean nodes to primitive: +5%
*/


int nn=10;                                             // number of nodes
int np=3;                                             // number of primitivces
color red = color(155,0,0), green = color(50,255,50);
color blue = color(0,0,155), yellow = color(255,55,50);
Disk[] P = new Disk[np];                              // array of primitives
char o[] = new char[nn];   // operator union '+'. intersection '*', difference '-', xor '#'
int L[]=new int[nn];       // integer index to left child      
int R[]=new int[nn];      // integer index to right child      
int pp=0;                // currently selected primitive for moving it

void setup() {  size(400, 400);   background(255);  noFill(); 
  P[0]=new Disk(150,150,100);         // make primitives with Cx, Cy, radius 
  P[1]=new Disk(250,150,100);
  P[2]=new Disk(200,250,100);
  // make tree specifying the operator or primitive and the opernds
  o[0]='-';  L[0]=1;    R[0]=2;    // node 0 is a difference of node 1 and node 2 
  o[1]='p';  L[1]=0;               // node 1 is the primitive with ID=0
  o[2]='-';  L[2]=3;    R[2]=4;    // node 2 is a difference of node 3 and 4
  o[3]='p';  L[3]=1;               // node 3 is theprimitive with ID=1
  o[4]='p';  L[4]=2;               // node 4 is theprimitive with ID=2
  } 
 
void draw() {                   // paints pixel (i,j) based on its classification
 if (!keyPressed) {            // render CSG
    for(int j=0; j<height; j++) {   //  j defines the row and goes DOWN the screen
      for (int i=0; i<width; i++) { // i defies the pixel in the row goes right
        if (pmc(0,i,j)) { set(i,j,green);} else set(i,j,red);};};   // set color depending on pmc  
  } else {
    for(int j=0; j<height; j++) {  
      for (int i=0; i<width; i++) { 
        if (P[pp].in(i,j)) { set(i,j,yellow);} else set(i,j,blue);};};     
    } ;
 for(int k=0; k<np; k++) {P[k].show();};   // draws primitives as circles for references
}
        
boolean pmc (int n, int pi, int pj) {  // Point-Membership Classification returns true if pixel (pi,pj) is in region of node n
  boolean res=false;
  switch(o[n]) {
   case 'p':  res=P[L[n]].in(pi,pj); break;    // if n is a primitive, call its "in" method
   case '-':  res= pmc(L[n],pi,pj) && !pmc(R[n],pi,pj); break;  // if difference, combine result of recursive call
   // *** add here the lines for union , intersection, xor
   // *** edit to improve performance by avoiding redundant recursive calls
   };
  return(res);    
  };

class Disk {        // class for disk primitive
  int x, y, r;
  Disk (int px, int py, int pr) {x=px; y=py; r=pr;};
  void move (int px, int py) {x=px; y=py;};
  boolean in (int pi, int pj) {boolean isIn=false; if  (sq(pi-x)+sq(pj-y)<sq(r)) {isIn=true;}; return(isIn);};
  void write () {println("x="+x+", y="+y+", r="+r);};
  void show () {ellipse(x,y,2*r,2*r);;};
  };

void keyPressed() {
  switch(key) {
   case 'n':  for(int k=0; k<nn; k++) {println("o["+k+"]="+o[k]+", L["+k+"]="+L[k]+", "+"R["+k+"]="+R[k]);}; break;
   case 'p':  for(int k=0; k<np; k++) {print("P["+k+"] : "); P[k].write();}; break;
   case '.':  pp=(pp+1) % np; break;    // select next primitive
   case ',':  pp=(pp-1) % np; break;
   case '>':  P[pp].r += 10; break;    // incrase the radius of selected primitive
   case '<':  P[pp].r -= 10; break;
      };
 };
 
 void mousePressed() {P[pp].move(mouseX,mouseY);}; // move center of selected primitive