/**
 * Schnee: 
 * Design by Steve Gallay, steve@gallay.li
 * Created 11 Juni 2007
 *
 */



//_________________________________________________________________________________________
//
//                  VARIABLES
//


Schnee[] flocons = new Schnee[20000];

int nelement=0;
float winkel=0;
PImage fond;

//_________________________________________________________________________________________
//
//                  SETUP
//

void setup() {

  //size(screen.width,screen.height);
  size(800,600);
  frameRate(10);
  smooth();

  background(10);
  
  fond = loadImage("Neige1.jpg");
  
  
}


//_________________________________________________________________________________________
//
//                  DRAW
//




void draw() {

  image(fond,0,0,width,height);
  
  
  // neue flocons
  for(int i=0; i<10; i=i+1){
      flocons[nelement] = new Schnee(int(random(width)),0,0,0,random(5),random(100));
      nelement +=1;
  } 
  


  // print
  for(int i=0; i<nelement-1; i=i+1){
    flocons[i].wind(0.5 - sin(winkel),0);
    
    if(flocons[i].Flocon_hoehe() > (2 / 3 * height)){;
    flocons[i].bodenWind(width/4,height);
    }
    
    flocons[i].newton();
    flocons[i].druck();
  }

  winkel += 0.005;
 
}


//_________________________________________________________________________________________
//
//                    Schnee - CLASS
//


class Schnee {  

  int X_ref;
  int Y_ref;
  
  float delta_X;
  float delta_Y;
  
  float radius;
  
  float enfernung;

  Schnee(int X_refInput,int Y_refInput,float delta_XInput,float delta_YInput,float radiusInput, float enfernungInput)
  {
    X_ref = X_refInput;
    Y_ref = Y_refInput;
    delta_X = delta_XInput;
    delta_Y = delta_YInput;
    radius = radiusInput;
    enfernung = enfernungInput; // 0-100
  }

  void druck()
  { 
      noStroke();
      fill(255, 255, 255,(255 - enfernung));
      ellipse(X_ref,Y_ref,radius,radius);  
  }

  void newton()
  {   
    
    if (Y_ref < height){
      Y_ref += int((enfernung/100) * 5) + 5 + delta_Y;
      X_ref += delta_X;
    }
  } 
  
  void wind(float x_wind, float y_wind)
  {   
      delta_Y = y_wind;
      delta_X = x_wind;
  }  
  
  void bodenWind(int x_zentrum, int y_zentrum)
  {   
      float vUnit = sqrt(sq(X_ref - x_zentrum) + sq(Y_ref - x_zentrum));
      delta_X += (X_ref - x_zentrum) / vUnit * 4 ;
      delta_Y += -(Y_ref - x_zentrum) / vUnit * 4;
  }
  
  int Flocon_hoehe(){
    return(Y_ref);
  }
    
  
}