Rotating Blocks

Still waiting for my book to arrive, but in the mean time I have been busy reading the information on the Processing Web Site.

I was recently discussing this project with a friend, and he suggested I may be interested in some computer generated art he had seen recently on the Krazydad blog and one particular piece by Daniel Piker inspired me to write my first Processing code showing some Rotating Blocks.

/**
 * Rotating Blocks
 * by Nigel Parker
 * 
 * Each column of blocks rotates at a different rate with the centre 
 * column remaining static and the left an right sides rotating in 
 * a different direction
 */
 
int [] r    =  new int[6];
int [] rVal =  new int[6];

void setup() {

  // Set up initial rotation speeds
  rVal[0]=5;
  rVal[1]=4;
  rVal[2]=3;
  rVal[3]=2;
  rVal[4]=1;
  rVal[5]=0;

  // Set the initial screen size etc  
  size(640,640); 
  smooth(); 
  noStroke();
  
}

void draw() 
{

    background(0);
    
    for(int i=0;i<6;i++)
    {
        int xxLeft  = 65  + (50 * i);
        int xxRight = 565 - (50 * i);
        
        // We will be drawing 11 boxes in a line
        for(int j=0;j<11;j++)
        {
          int yy = 65 + (50 * j);
          drawBox(xxLeft,yy,30,30,radians(r[i]));
          
          // Don't need to draw the centre column twice
          if (i < 5) 
          {
            drawBox(xxRight,yy,30,30,radians((-1 * r[i])));
          }
        }  
        r[i] = (r[i] + rVal[i]) % 360;        
    }

}

void drawBox(int x, int y, int w, int h, float rot)
{
  fill(0,148,255);
  
  // Move the origin of the co-ordinate system to be the
  // centre of the box we are going to draw
  translate(x,y); 
  
  // Rotate the co-ordinate system by the required amount
  rotate(rot);
  
  // Draw the rectangle based around the centre co-ordinates
  rectMode(CENTER);
  rect(0,0,w,h);  
  
  // Rotate the co-ordinate system back by the required amount  
  // We have to do this as rotate is cumulative
  rotate((rot * -1));  
  
  // Move the origin of the co-ordinate system back to 
  // its original position
  // We have to do this as translate is cumulative
  translate(-x,-y);  
}