class ColorDrop {
  float initPosX = 0.0, initPosY = 0.0; // initial position of each drop
  float posY = 0.0; // variable to set and get position of painting drop (if initPosY+posY < initPosY+lengthDrop then move the drop down)
  float lengthDrop = random(50, 200); // length of the drop line
  float diameterDrop = random(1.1, 3.0); // diameter of the drop
  float dropSpeed = random(0.1, 5);
  color colorDrop; // color of the drop

    ColorDrop(float initPosX_, float initPosY_, color colorDrop_) { // position & color
    initPosX = initPosX_;
    initPosY = initPosY_;
    colorDrop = colorDrop_;
  }

  ColorDrop(float initPosX_, float initPosY_, color colorDrop_, float lengthDrop_) { // position, color & length
    initPosX = initPosX_;
    initPosY = initPosY_;
    lengthDrop = lengthDrop_;
    colorDrop = colorDrop_;
  }

  ColorDrop(float initPosX_, float initPosY_, color colorDrop_, float lengthDrop_, float diameterDrop_) { // position, color, length & width
    initPosX = initPosX_;
    initPosY = initPosY_;
    lengthDrop = lengthDrop_;
    diameterDrop = diameterDrop_;
    colorDrop = colorDrop_;
  }

  boolean moveDrop() {
    if (posY <= lengthDrop) {
      posY += noise(1) * dropSpeed;
      return true;
    } 
    else {
      return false;
    }
  }

  void drawDrop() {
    noStroke();
    fill(colorDrop, 255 - int(posY / lengthDrop * 250));
    strokeWeight(1);
    ellipseMode(CENTER);
    ellipse(initPosX, initPosY + posY, diameterDrop, diameterDrop * 2);
  }
}

//import fullscreen.*;
//FullScreen fullscreenGraffiti;

ColorDrop[] drops, delDrops;

color pencil = #2E792B; // color of the spray painter
int dropAlpha = 255;
int randomDrop = 10; // percentaged possibility to generate a color drop

// --- setup procedure ---
void setup() {
  size(1024, 768);
  frameRate(60);

  //fullscreenGraffiti = new FullScreen(this);
  //fullscreenGraffiti.enter();

  drops = new ColorDrop[0];
  delDrops = new ColorDrop[0];

  stroke(pencil, dropAlpha);
  strokeWeight(20);
  background(0);
  smooth();
}

// --- draw procedure ---
void draw() {
  for (int i = 0; i < drops.length; i++) {
    if (drops[i].moveDrop())
      drops[i].drawDrop();
  }

  stroke(100);
  strokeWeight(1);
  noFill();
  rect(0, 0, width-1, height-1);
}

void mouseDragged() {
  if (mouseButton == LEFT) {
    // normal spray drawing foo
    stroke(pencil, dropAlpha);
    strokeWeight(20);
    line(pmouseX, pmouseY, mouseX, mouseY);

    // drop generating
    int randomValueForDrop = floor(random(0, 100));
    if (randomValueForDrop <= randomDrop) {
      ColorDrop setDrop = new ColorDrop(mouseX, mouseY, pencil);
      drops = (ColorDrop[]) append(drops, setDrop);
    }
  }

  if (mouseButton == RIGHT) {
    drops = delDrops;
    background(0);
  }
}