void setup() {
  size(600, 600);
  background(100);
  frameRate(15);
}

float paintDripChance = 0.12;
int paintDripNum = 0;
int paintDripMaxNum = 40;
float[] paintDripsX = new float[paintDripMaxNum];  // The location of the drips
float[] paintDripsY = new float[paintDripMaxNum];
float[] paintDripsVel = new float[paintDripMaxNum];  // The velocity of the drips

void mouseDragged() {

  // Draw the main stroke
  stroke(255);
  strokeWeight(15);
//  strokeCap(PROJECT);
  line (pmouseX, pmouseY, mouseX, mouseY);

  // Paint drip generation
  if (random(1) < paintDripChance) { 
  paintDripNum = int(random(paintDripMaxNum));
  paintDripsX[paintDripNum] = mouseX;
  paintDripsY[paintDripNum] = mouseY;
  paintDripsVel[paintDripNum] = 1.5;    // Initial velocity for drip
//  ellipse (paintDripsX[paintDripNum], paintDripsY[paintDripNum], 30, 30);
  }
}


void mouseReleased() {
  //paintDripsX[2] = 2.0;
  //println(paintDripsX);
  //println(paintDripsY);
}


void draw() {

  // Fade out the old paint
  noStroke();
  fill(0, 1);
  rect(0, 0, width, height);

  //Paint drip travel
  for(int i = paintDripMaxNum -1; i > 0; i--) {
  noStroke();
  fill(255);
  ellipse(paintDripsX[i], paintDripsY[i], constrain(-paintDripsVel[i] * 0.8 + 8, 0, 10), paintDripsVel[i]+10);
  paintDripsY[i] = paintDripsY[i] + paintDripsVel[i];  // Move the drip down
  paintDripsVel[i] = constrain(paintDripsVel[i] * random(0.6, 1.4), 0, 10);  // Modify the velocity of drip
  if(paintDripsVel[i] < 0.2) {  // Check if the drip can be stopped
    paintDripsY[i] = -30;
    paintDripsX[i] = 0;
  }
  if(paintDripsY[i] > height) {  // Check if drip reaches the bottom of the screen
  paintDripsY[i] = 0;
  }
  if(paintDripsX[i] == 0) {  // Check for drips on the edge of screen
  paintDripsX[i] = -20;
  }
}
}