/**
 * Keys:<br/> <br/> 
 * 1: water<br/> 2: land<br/>  3: erase<br/>  4: change color<br/>  5: liquify<br/>  6: make water white<br/>  7: clear
 */


FPS fps = new FPS();
int water[] = new int[10];
int waterCount = 0;
int waterpixels[];
int pixelids[];
boolean sleepers[];
int waterColor = 0xFF0000FF;
int alphaColor = 0xFF000000;
int bgColor = 0x00C8C8FF;
int bgColor2 = 0xFFC8C8FF;
int toolbarColor = 0xFF8080A0;
Random rand;
PImage waterImage;
final int WATER = 0;
final int LAND = 1;
final int ERASE = 2;
int inputMode = WATER;

void setup() {
  Dimension d = getSize();
  size(400,400,P3D);
  loadPixels();
  waterpixels = pixels;
  hint(DISABLE_TEXT_SMOOTH);
  textFont(loadFont("Verdana-9.vlw"));
  //  waterpixels = new int[width*height];
  //  waterImage = new PImage(waterpixels,width,height,RGBA);
  for (int i=0; i<waterpixels.length; i++)
    waterpixels[i]=i<10*width ? toolbarColor : bgColor;
  waterpixels = pixels;
  pixelids = new int[waterpixels.length];
  sleepers = new boolean[waterpixels.length];
  rand = new Random();
  drawColor();
  drawMode();
  drawParticleCount();
}
void drawColor() {
  fill(waterColor);
  stroke(bgColor);
  rect(1,1,7,7);
}
String modeText = "";
void drawMode() {
  textAlign(LEFT); 
  fill(toolbarColor);
  text(modeText,10,9);
  fill(0xFFFFFFFF);
  switch (inputMode) {
  case WATER:
    modeText = "Add Water";
    break;
  case LAND:
    modeText = "Add Land";
    break;
  case ERASE:
    modeText = "Erase";
    break;
  }
  text(modeText,10,9);
}
String particleCount = "";
void drawParticleCount() {
  textAlign(RIGHT); 
  fill(toolbarColor);
  noStroke();
  int w=(particleCount.length())*7;
  rect(width-w-2,1,w,9);
  particleCount = waterCount+"/"+water.length+" - "+asleep+" sleeping - "+fps.fps+"fps";
  fill(0xFFFFFFFF);
  text(particleCount,width-2,9);
}

void keyReleased() {
  switch (key) {
  case '1': 
    inputMode = WATER; 
    drawMode();
    break;
  case '2': 
    inputMode = LAND; 
    drawMode();
    break;
  case '3': 
    inputMode = ERASE; 
    drawMode();
    break;
  case '4': 
    waterColor = alphaColor|rand.nextInt(); 
    drawColor();
    break;
  case '5': 
    for (int i=11*width; i<waterpixels.length; i++) {
      int c = waterpixels[i];
      if ((0xFF000000&c)!=0 && pixelids[i]==0)
        addWater(i,c);
    }
    break;
  case '6':
    int x,y;
    for (int i=waterCount; --i>=0;) {
      waterpixels[water[i]]=0xFFFFFFFF;
    }
    break;
  case '7':
    for (int i=waterpixels.length; --i>=10*width;) {
      waterpixels[i] = bgColor;
      pixelids[i] = 0;
    }
    waterCount = 0;
    break;
  }
}

void draw() {
  //  background(200);
  if (mousePressed) {

    int dx=pmouseX-mouseX;
    int dy=pmouseY-mouseY;
    if (dx==0&&dy==0)
      drawPoint(mouseX,mouseY);
    else {
      double x=mouseX,y=mouseY;
      double units=Math.max(Math.abs(dx),Math.abs(dy));
      double hunit=dx/units;
      double vunit=dy/units;
      for (int ii=(int)units; --ii>=0;) {
        x+=hunit;
        y+=vunit;
        drawPoint((int)x,(int)y);
      }
    }
  }
  moveWater();
  fps.frame();
  drawParticleCount();
  //  image(waterImage,0,0);
}

void drawPoint(int xx, int yy) {
  for (int y=-2;y<=2;y++)
    for (int x=-2;x<=2;x++) {
      switch (inputMode) {
      case WATER:
        addWater(xx+x,yy+y,waterColor);
        break;
      case LAND:
        addLand(xx+x,yy+y,0xFFB77E39);
        break;
      case ERASE:
        erase(xx+x,yy+y);
        break;
      }
    }
}
void moveWater() {
  int x,y,pos,c;
  boolean l,r;
  for (int i=0; i<waterCount; i++) {
    pos = water[i];
    x = pos%width;
    y = pos/width;
    if (pixelids[pos]-1 != i) {
      waterpixels[pos] = 0xFF00FF00;
      println("Error at water ["+x+","+y+"] should be "+i+", but is "+(pixelids[pos]-1));
      continue;
    }
    c = mixColor(x,y);
    // Check for solid below
    if (solid(x,y+1)) {
      // check left and right
      l = solid(x-1,y);
      r = solid(x+1,y);

      // stuck? go to sleep.
      if (l&&r) {
        sleep(x,y);
        continue; // we've lost this particle
      } 
      else if (l) {
        if (rand.nextInt(5)>0) {
          wake(x-1,y);
          wake(x,y-1);
          x++;
        } 
        else continue; // nothing moved
      } 
      else if (r) {
        if (rand.nextInt(5)>0) {
          wake(x+1,y);
          wake(x,y-1);
          x--;
        } 
        else continue; // nothing moved
      } 
      else {
        int dx = rand.nextInt(3)-1;
        if (dx==0) continue; // nothing moved
        x += dx;
        wake(x,y-1);
      }
    } 
    else { /* nothing solid beneath */
      wake(x-1,y);
      wake(x+1,y);
      wake(x,y-1);
      y++;
    }
    // clear old square color and pixel id
    waterpixels[pos] = bgColor;
    //    waterpixels[pos] = 0xFF808000;
    pixelids[pos] = 0;
    // calculate new square
    pos = x+y*width;

    if (sleepers[pos]) {
      println("Trying to overwrite sleeper ["+x+","+y+"]");
      c = 0xFFFF0000;
    }
    if (pixelids[pos]>0) {
      println("Trying to overwrite water ["+x+","+y+"]");
      c = 0xFF000000;
    }

    // update water's position
    water[i] = pos;
    // update color and pixel id
    waterpixels[pos] = c;
    pixelids[pos] = i+1;
  }
}
final private int mix(int c1, int c2) {
  return alphaColor | ((((c1&0xFEFEFF))+((c2&0xFEFEFF)))>>1);
}
final private int mixColor(int x, int y) {
  int c=waterpixels[x+y*width];
  if (true)
    return c;
  if (rand.nextInt(5)>0) return c;
  /*
  switch (rand.nextInt(4)) {
   case 0: if (liquid(x,y-1)) waterpixels[x+(y-1)*width]=c=mix(c,waterpixels[x+(y-1)*width]); break;
   case 1: if (liquid(x,y+1)) waterpixels[x+(y+1)*width]=c=mix(c,waterpixels[x+(y+1)*width]); break;
   case 2: if (liquid(x+1,y)) waterpixels[x+1+y*width]=c=mix(c,waterpixels[x+1+y*width]); break;
   case 3: if (liquid(x-1,y)) waterpixels[x-1+y*width]=c=mix(c,waterpixels[x-1+y*width]); break;
   }
   */
  if (liquid(x,y-1)) waterpixels[x+(y-1)*width]=c=mix(c,waterpixels[x+(y-1)*width]); 
  if (liquid(x,y+1)) waterpixels[x+(y+1)*width]=c=mix(c,waterpixels[x+(y+1)*width]); 
  if (liquid(x+1,y)) waterpixels[x+1+y*width]=c=mix(c,waterpixels[x+1+y*width]); 
  if (liquid(x-1,y)) waterpixels[x-1+y*width]=c=mix(c,waterpixels[x-1+y*width]);
  waterpixels[x+y*width] = c;
  return c;
}

final private boolean liquid(int x, int y) {
  if (x<0||y<10||x>=width||y>=height) return false;
  int pos = x+y*width;
  return pixelids[pos]>0;
}
final private boolean solid(int x, int y) {
  if (x<0||y<10||x>=width||y>=height) return true;
  int pos = x+y*width;
  return ((0xFF000000&waterpixels[pos]) != 0) || pixelids[pos]>0;
}

void addWater(int x, int y, int c) {
  // Don't overwrite land
  if (solid(x,y)) return;
  // If square is already water, just change its color
  int pos = x+y*width;
  if (liquid(x,y)) {
    waterpixels[pos]=c;
    return;
  }
  // otherwise, add it!
  addWater(pos,c);
}
void addWater(int pos, int c) {
  // Make sure there is enough room to add water
  if (waterCount >= water.length) {
    int t[] = water;
    water = new int[t.length*2];
    System.arraycopy(t,0,water,0,t.length);
    t = null;
  }
  // add water at very end and increment counter
  water[waterCount++] = pos;
  // set color
  waterpixels[pos] = c;
  // set pixel id (this is +1 from the actual id, but we already did waterCount++ above)
  pixelids[pos] = waterCount;
  // not asleep
  sleepers[pos] = false;

}
int asleep=0;
void sleep(int x, int y) {
  if (x<0 || y<10 || x>=width || y>=height) return;
  // get position
  int pos = x+y*width;
  // get water id
  int id = pixelids[pos]-1;
  pixelids[pos] = 0;
  // continue if there is no water id
  if (id < 0 || id>=waterCount) return;
  // set water id to zero
  sleepers[pos] = true;
  //waterpixels[pos] = 0xFF000080;
  pixelids[pos] = 0;
  asleep++;
  // decrement water count (this deletes water)
  waterCount--;
  // copy last water and replace the deleted water id with that
  if (id!=waterCount) {
    water[id] = water[waterCount];
    water[waterCount] = 0;
    pixelids[water[id]] = id+1;
  }
}
void wake(int x, int y) {
  if (x<0 || y<10 || x>=width || y>=height) return;
  int pos = x+y*width;
  if (!sleepers[pos]) return;
  if (asleep<=0) {
    println("Trying to wake up more than we've put to sleep!");
    return;
  }
  asleep--;
  sleepers[pos] = false;


  // Make sure there is enough room to add water
  if (waterCount >= water.length) {
    int t[] = water;
    water = new int[t.length*2];
    System.arraycopy(t,0,water,0,t.length);
    t = null;
  }
  water[waterCount++] = pos;
  pixelids[pos] = waterCount;
  //waterpixels[pos] = 0xFF0000FF;
}
void erase(int x, int y) {
  if (x<0 || y<10 || x>=width || y>=height) return;
  // calculate position
  int pos = x+y*width;
  // clear color
  waterpixels[pos] = bgColor;

  // get id and check if the cell has water
  int id = pixelids[pos]-1;

  if (id>=0 && id<waterCount) {
    // delete water
    waterCount--;
    // clear the id
    pixelids[pos] = 0;
    // copy last water to replace deleted
    if (id<waterCount) {
      water[id] = water[waterCount];
      pixelids[water[id]] = id+1;
    }
  }
  if (sleepers[pos]) {
    asleep--;
    sleepers[pos] = false;
  }

  // wake the particles around deleted particle
  wake(x,y-1);
  wake(x-1,y);
  wake(x+1,y);
}
void addLand(int x, int y, int c) {
  if (solid(x,y)) return;
  pixelids[x+y*width] = 0;
  waterpixels[x+y*width] = c;
}