import controlP5.*;

PImage img;
ControlP5 debugUI;
int brightness1 = 255;
int saturation1= 255;
int hue1= 255;

void setup()
{
  size(1000, 750);                        //set window size to same resolution as image

  colorMode(HSB, 255, 255, 255);

  img = loadImage( "GracefieldMorning.jpg" );   //loading image into memory (RAM) - no GPU acceleration here

  //setting up our slider and adding the "brightness" so it knows that the variable it controls
  debugUI = new ControlP5(this);

  debugUI.addKnob("brightness1")
         .setRadius(30)
         .setPosition( 10, 10 )
         .setRange( 0 , 510 )
         .setValue(255);

  debugUI.addKnob("saturation1")
         .setRadius(30)
         .setPosition( 80, 10 )
         .setRange( 0, 510 )
         .setValue(255);

  debugUI.addKnob("hue1")
         .setRadius(30)
         .setPosition( 150, 10 )
         .setRange( 0, 20 );
}

void draw()
{
  //MAke a copy so we can keep original intact
  PImage imgcopy = img.get();

  imgcopy.loadPixels();

  float brightRatio = (float)brightness1 / 255.0f;
  float satRatio = (float)saturation1/ 255.0f;
  float hueRatio = (float)hue1;//255.0;

  int numPixels = imgcopy.pixels.length;
  for(int i = 0; i < numPixels; i++)
  {
    color prevCol = imgcopy.pixels[i];
    color newCol = color( hue(prevCol) * hueRatio, saturation(prevCol) * satRatio, brightness(prevCol) * brightRatio);
    imgcopy.pixels[i] = newCol;
  }

  imgcopy.updatePixels();

  image(imgcopy, 0, 0, width, height);
}