// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 16-8: Brightness mirror
  
  // Each pixel from the video source is drawn as a
  // rectangle with size based on brightness.
  
  import processing.video.*;
  
  // Size of each cell in the grid
  int videoScale = 10;
  // Number of columns and rows in our system
  int cols, rows;
  // Variable for capture device
  Capture video;
  
  void setup() {
    size(640,480);
    // Initialize columns and rows
    cols = width/videoScale;
    rows = height/videoScale;
    smooth();
    // Construct the Capture object
    video = new Capture(this,cols,rows,15);
  }
  
  void draw() {
    if (video.available()) {
      video.read();
    }
    background(0);
  
    video.loadPixels();
  
    // Begin loop for columns
    for (int i = 0; i < cols; i++) {
      // Begin loop for rows
      for (int j = 0; j < rows; j++) {
  
        // Where are we, pixel-wise?
        int x = i*videoScale;
        int y = j*videoScale;
  
        // Reversing x to mirror the image
        // In order to mirror the image, the column is reversed with the following formula:
        // mirrored column = width - column - 1
        int loc = (video.width - i - 1) + j*video.width;
  
        // Each rect is colored white with a size determined by brightness
        color c = video.pixels[loc];
  
        // A rectangle size is calculated as a function of the pixel's brightness. 
        // A bright pixel is a large rectangle, and a dark pixel is a small one.
        float sz = (brightness(c)/255.0)*videoScale; 
        rectMode(CENTER);
        fill(255);
        noStroke();
        rect(x + videoScale/2,y + videoScale/2,sz,sz);
  
      }
    }
  }