/** 
 * ParabolicRaytracer v1.0.1 by cdmb architects (cc) 2008<br />
 * is a simple parabolic calculator based on input variables.<br />
 * <br />
 * Use the scroll bars to adjust the variables.<br />
 * <br />
 * For further information and questions about ParabolicRaytracer please<br />
 * take a look at the documentation, the examples, or the <br />
 * website at http://barlieb.com/index.php?option=com_content&task=view&id=79&Itemid=93<br />
 * <br />
 * key combinations:<br />
 * ALT+h hide and show controllers<br />
 * ALT+k bring the key menu to the front. use the arrow keys.<br />
 * Hold the ALT key and move controllers by dragging them.<br />
 */
import controlP5.*;

ControlP5 controlP5;
//Initial Variables
int x = 252;                                          //X coordinates
int f = 172;                                          //Focal Shift
int m = 139;                                          //Vertical Shift
int r = 8;                                            //Ray Spacing

void setup() {                                        //Scrollbar Settings
  size(500,500); 
  background(255);
  frameRate(25);
  controlP5 = new ControlP5(this);
  controlP5.addSlider("x coordinates",0,800,x,1,35,400,12).setId(1);
  controlP5.addSlider("focal shift",0,1000,f,1,50,400,12).setId(2);
  controlP5.addSlider("vertical shift",0,400,m,1,65,400,12).setId(3);
  controlP5.addSlider("ray spacing",1,41,r,1,80,400,12).setId(4);
  controlP5.setColorBackground(255);
  controlP5.setColorForeground(0);
  controlP5.setColorActive(0xffff0000);
  controlP5.setColorLabel(0);
}
void controlEvent(ControlEvent theEvent) {            //Controls the Scrollbar and Variables
  println("got a control event from controller with id "+theEvent.controller().id());
  switch(theEvent.controller().id()) {
    case(1):
    x = (int)(theEvent.controller().value());
    break;
    case(2):
    f = (int)(theEvent.controller().value());
    break;
    case(3):
    m = (int)(theEvent.controller().value());
    break;
    case(4):
    r = (int)(theEvent.controller().value());
    break;
  }
}
void draw() {
  background(255);
  smooth();
  for (int i = 0; i <= x; i+=r ){                     //For loop
    float y = sq(i)/f;                                //Parabolic equation
    float p = sq(i*2)/(16*y);                         //Focal point
    stroke(225,0,0);                                   
    fill(225,0,0);
    point((height/2)+i,y+m);                          //Draws the parabolic points in the positive direction
    point((height/2)-i,y+m);                          //Draws the parabolic points in the negative direction
    stroke(255,0,0,150);                                   
    strokeWeight(0);
    line((height/2)+i,y+m,(height/2)+i,y+1000);       //Draws the incoming rays in the positive direction
    line((height/2)-i,y+m,(height/2)-i,y+1000);       //Draws the incoming rays in the negative direction
    stroke(0);                                   
    strokeWeight(0);
    point((height/2),p+m);                            //Focal point
    line((height/2),p+m,(height/2)+i,y+m);            //Rays from focal point to parabolic curve in the positive direction
    line((height/2),p+m,(height/2)-i,y+m);            //Rays from focal point to parabolic curve in the negative direction
    stroke(200);                                   
    strokeWeight(0);
    line((height/2)+i,y+m,(height/2)+i,m-p);          //Rays from parabolic curve to directrix in the positive direction
    line((height/2)-i,y+m,(height/2)-i,m-p);          //Rays from parabolic curve to directrix in the negative direction
    stroke(255,120,0,150);                                   
    strokeWeight(0);
    noFill();
    ellipse((height/2)+i,y+m,sqrt(sq(i)+sq(y-p))*2,sqrt(sq(i)+sq(y-p))*2);  //Parabolic Circles Positive
    ellipse((height/2)-i,y+m,sqrt(sq(i)+sq(y-p))*2,sqrt(sq(i)+sq(y-p))*2);  //PArabolic Circles Negative
  }
  PFont font;                                         //Prints all the Info to the window.
  font=loadFont("CourierNewPSMT-12.vlw");
  textFont(font);
  fill(0);
  text("ParabolicRaytracer v1.0.1 ",0,12);
  text("cdmb architects (cc) 2008 ",0,24);  
}