// Initialize some variables.

float rippler = 0;
float rotation = 0;

float[][] boxPos = new float[31][31]; 
float[][] boxPosNew = new float[31][31]; 



// Set up the the environment.

void setup ()
{

  size(600, 400);
  framerate(40);
  colorMode(RGB, 1.0);
  
  noStroke();
  
}



// Draw the squares.

void draw ()
{

  background(0.5);
  
  translate(300, 200); // Set the "master" translation for all of the squares.
  rotate(rotation); // And the "master" rotation.
  
  pushMatrix();
  
  for( int i=0; i<31; i++ ) {
    for( int j=0; j<31; j++ ) {
      pushMatrix();
      if( (i==16) & (j==16) ) {
        boxPosNew[i][j] = -sin(rippler)*2; // The square in the middle is the "rippler" -- it generates the movement.
      } else {
        boxPosNew[i][j] = (boxPos[i][abs(j-1)%31]+boxPos[i][(j+1)%31]+boxPos[abs(i-1)%31][j]+boxPos[(i+1)%31][j])/4; // All of the other squares only respond to the movement of those around them.
      }
      rotate(boxPosNew[i][j]*30);
      translate(-155+i*10, -155+j*10);
      float iFloat = i; // Converts the "i" and "j" int variables into floats. Don't know if this is the best way to do it...
      float jFloat = j;
      fill(color(1-sqrt(abs(boxPosNew[i][j])), sqrt(abs(boxPosNew[i][j]))));
      rect(-5-abs(boxPosNew[i][j]*5), -5-abs(boxPosNew[i][j]*5), 5+abs(boxPosNew[i][j]*5), 5+abs(boxPosNew[i][j]*5)); // Draw the squares.
      popMatrix();
    }
  }
  
  for( int i=0; i<31; i++ ) {
    for( int j=0; j<31; j++ ) {
      boxPos[i][j] = boxPosNew[i][j]; // Copy the position data into the "older" array.
    }
  }

  popMatrix();
  
  rotation -= 0.001; // Increment the motion variables.
  rippler += 0.02;

}