//Iryna Andryianets
//Assignment 6 'Image Processing'
//Oct 27,2009
//The program changes the color of the pixels of two images
//If the mouse is being dragged the color of pixels will change depending on the mouse position
//If key 'p' is pressed the new image will be displayed, every forth pixel will be change to the gray value

PImage flo,man;
int floDimension,manDimension;
void setup() {
  size(300,300);
  flo=loadImage("flower1.jpg");
  floDimension=flo.height * flo.width;
  man=loadImage("man1.jpg");
  manDimension=man.height*man.width;
  image(flo,0,0);
} 

void draw() {   //Empty draw function keeps the program running continiously
}

void mouseDragged() {
  image(flo,0,0);
  loadPixels();   //Loads the pixel data for the image into its pixels array
 //In the following for loop the program reads red, green, and blue components from each pixel
 //These components are being changed, depending on the mouse position
 //And then they are returned to the pixels array
  for (int i=0;i<floDimension;i++){
    color p=pixels[i];
    float r=red(p);
    float g=green(p);
    float b=blue(p);
    r=constrain(r+mouseX/2,255,0);//Constrains the first vaulue to not exceed a maximum and minimum value
    //I thought that the second value should be min and the third one max
    //But when I switched them it created very nice effect
    //Like a color is being taking out or something like this
    g=constrain(g+mouseY/3,255,0);
    b=constrain(b+mouseY/4,0,255);
    pixels[i]=color(r,g,b);
  }
  updatePixels();   //Updates the display window with the data in the pixels array
}

void keyPressed() {
    if(key=='p'){
    man.loadPixels();
    //In this for loop the color of every forth pixel is being replaced with a certain grey value
    for(int i=0;i<manDimension;i+=4){
    man.pixels[i]=color((man.pixels[i]-150)%2); 
    }
    man.updatePixels();
    image(man,0,0);
 }
 }
 
void keyReleased() {
  flo.updatePixels();
  image(flo,0,0);
}

void mouseReleased() {
  flo.updatePixels();
  image(flo,0,0);
}