// (c) 2004 Coolbubble - Nick

int numNodes = 10; // Size of a row or column.
color COL_a, COL_b, COL_c, COL_back;

void setup()
{
  size(400,400);
  COL_a = color(149,208,180);
  COL_b = color(54,120,168);
  COL_c = color(0,0,0);
  COL_back = color(92,48,116);
  ellipseMode(CENTER_DIAMETER);
}

void drawNode(float x, float y, float r, float vx, float vy)
{
  float ox,oy,offset = r*0.1;
  float rad = r*0.6f;

  ox = vx*offset;
  oy = vy*offset;

  noStroke();
  fill(COL_a);
  ellipse(x+ox,y+oy,rad,rad);
  fill(COL_b);
  ellipse(x-ox,y-oy,rad,rad);
  fill(COL_c);
  ellipse(x,y,rad*0.8,rad*0.8);
}


void randomise()
{
  numNodes = (int)random(15)+3;

  COL_a = color(random(255),random(255),random(255));
  COL_b = color(random(255),random(255),random(255));
  COL_c = color(random(255),random(255),random(255));
  COL_back = color(random(255),random(255),random(255));

}

void loop()
{
  background(COL_back);
  float nodeSize = width / (float)numNodes;
  float nodeSize_2 = nodeSize * 0.5f;

  for (int x=0;x<numNodes;x++)
  {
    for (int y=0;y<numNodes;y++)
    {
      float fx = x * nodeSize;
      float fy = y * nodeSize;
      float vx = fx-mouseX+nodeSize_2;
      float vy = fy-mouseY+nodeSize_2;
      float vl = sqrt((vx*vx)+(vy*vy));
      if (vl<1.0) vl=1.0f;
      
      drawNode(fx+nodeSize_2,fy+nodeSize_2,nodeSize+(vl/(float)(width/40)),vx/vl,vy/vl);
    }
  }

  if (mousePressed)
    randomise();
}