Increase objects in sketch

kinesthtiaSonja

Hello,

I am trying to increase the objects in a sketch through duplication by increasing the values in an array, but when I try to use expand(), the sketch doesn't run (NullPointerException). When I take expand() out, it runs fine.

Here is the code:

Pulse[] beat = new Pulse[1];

void setup() {
  size(500,500,P3D);

  //bubbles
  for (int i=0; i < beat.length; i++) {
    beat[i] = new Pulse (random(width), random(height), 50, random(50));
  }
}

void draw() {    
  background(255);
  noCursor();

  for (int i=0; i < beat.length; i++) {
    beat[i].multiply();
    beat[i].quiver();
    beat[i].display();
  } 
}

class Pulse {
  float x;
  float y;
  float r;
  float alp;
  float dx = 5;
  float dy = 5;
  int heart = 0;

  //Constructor
  Pulse(float tempX, float tempY, float tempR, float tempAlp) {
    x = tempX;   
    y = tempY;
    r = tempR;
    alp = tempAlp;
  }

  void display() {

    color c = color(138, 3, 3, alp);
    stroke(0, 25);
    fill(c);
    ellipse(x, y, r*2, r*2);
  }

  void quiver() {
    float tx, ty;

    //Keeps x coordinate within boundaries
    tx = x+round(random(-dx, dx));
    while (tx<0 || tx>width)
      tx=x+round(random(-dx, dx));

    //Keeps y coordinate within boundaries
    ty=y+round(random(-dy, dy));
    while (ty<0 || ty>height)
      ty=y+round(random(-dy, dy));

    x = tx;
    y = ty;
  }
  void multiply() {
      beat = (Pulse[]) expand(beat);
  }
}

kfrajer

The problem is line 65.

What is the function expand()?

You are accessing beat there... but beat contains objects of this class. This is illegal to put it in a softer note unless you explain your intentions here.

If you want to increase the size, try just adding: r=r*1.01 or r=r+1; these are different ways to get your effect.

Kf

kinesthtiaSonja

To clarify — I don't want to increase the size of the circle, but the number of circles in the sketch. That is, start with one, and then have the numbers double.

kfrajer

Replace line 65 with r=r+1...

Kf

GoToLoop

https://forum.Processing.org/two/discussion/21508/i-m-trying-to-create-multiple-projectiles-as-if-a-spaceship-is-shooting-an-enemy

Lord_of_the_Galaxy

Why not just write the code to add new circles? Why rely on "expand"? It doesn't fill the newly created spots with anything.