PImage img;
PImage newImg;

int x,y,loc,startPixel;
int locPrevious; //Previous location

//Pixel neighbors
color c, cL, cR, cLdown, cCdown, cRdown, cLup, cCup, cRup;
color r = #FF0000;     
color b = #0000FF;
color ye = #FFFF00; 

int startPixelBrightness = 127;
boolean startPixelFound = false;

void setup() {
  size(30,35);
  img = loadImage("Mississippi River9.png");
  newImg = createImage(30,35,RGB);
}

void draw() {
  smooth();
  newImg.loadPixels();
  img.loadPixels();

  //MLF: FIX THIS: Not scanning last two columns or rows
  for (x=0; x<width; x++) {
    for (y=0; y<height; y++) {
      loc = x + y*width;
      c = img.pixels[loc]; //Grab the color

      if (brightness(c) == startPixelBrightness) {
        newImg.pixels[loc] = c; //Start Pixel
        startPixel = loc;
        c = startPixelBrightness;
        startPixelFound = true;
      }

      //loc = startPixel;
      //c = startPixelBrightness;
    }
  }

  if (startPixelFound) { //Evaluate Neighbors  
    for (x=startPixel; x<width; x++) { 
      //MLF: FIX THIS: "x=startPixel" only works for startPixel in top row
      for (y=0; y<height; y++) {
        loc = x + y*width;
        //c = img.pixels[loc]; //Grab the color


        //      loc = startPixel;
        //      c = startPixelBrightness;

        rightPixelModifier();
        lowerRightPixelModifier();
        lowerCenterPixelModifier();
        lowerLeftPixelModifier();
        // leftPixelModifier();
        // upperLeftPixelModifier();
        // upperCenterPixelModifier();
        // upperRightPixelModifier();
      }
    }
  }


  newImg.updatePixels();
  image(newImg,0,0);
  newImg.save("newImg.png");
  println("I've left the for loop!" + startPixel);
}

void upperRightPixelModifier() {

  cRup = img.pixels[loc - img.width + 1]; //color Right above
  if (brightness(cRup) > startPixelBrightness) {
    loc = loc - img.width + 1;
    incrementBrightness(1);
  }
}

void rightPixelModifier() {
  if ((loc + 1) < img.pixels.length) {
  cR = img.pixels[loc+1]; //color Right
  if (brightness(cR) > startPixelBrightness) {
    loc = loc+1;
    incrementBrightness(2);
  }}
}

void lowerRightPixelModifier() {
if ((loc + img.width + 1) < img.pixels.length) {
  cRdown = img.pixels[loc + img.width + 1]; //color Right below
  if (brightness(cRdown) > startPixelBrightness) {
    loc = loc + img.width + 1;
    incrementBrightness(3);
  }}
}

void lowerCenterPixelModifier() {
  if ((loc + img.width) < img.pixels.length) {
  cCdown = img.pixels[loc + img.width];     //color Center below
  if (brightness(cCdown) > startPixelBrightness) {
    loc = loc + img.width;
    incrementBrightness(4);
    //newImg.pixels[loc] = color(r);
  }}
}

void lowerLeftPixelModifier() {
  if ((loc + img.width - 1) < img.pixels.length) {
  cLdown = img.pixels[loc + img.width - 1]; //color Left below
  if (brightness(cLdown) > startPixelBrightness) {
    loc = loc + img.width - 1;
    incrementBrightness(5);
  }}
}

void leftPixelModifier() {

  cL = img.pixels[loc-1]; //color Left
  if (brightness(cL) > startPixelBrightness) {
    loc = loc-1;
    incrementBrightness(6);
  }
}

void upperLeftPixelModifier() {

  cLup = img.pixels[loc - img.width - 1]; //color Left above
  if (brightness(cLup) > startPixelBrightness) {
    loc = loc - img.width - 1;
    incrementBrightness(7);
  }
}


void upperCenterPixelModifier() {
  locPrevious = loc;
  cCup = img.pixels[loc - img.width];     //color Center above
  if ((cCup != locPrevious) && (brightness(cCup) > startPixelBrightness)) {
    //if (brightness(cCup) > startPixelBrightness) {
    loc = loc - img.width;
    incrementBrightness(8);
    //}
  }
}

void incrementBrightness(int error_) {    
  //c=c+1;
  int error = error_;
  newImg.pixels[loc] = color(brightness(c+1));
  c=c+1;
  println(loc + ": " + error + " (" + brightness(c) + ")");
  //println(loc + ": " + error + " (" + locPrevious + ")");
}