/*
 * File: Pyramid.java
 * ------------------
 * This program draws a brick pyramid.
 * The size of the brick and number of bricks on the base
 * are defined as constants.
 */

import acm.graphics.*;
import acm.program.*;

public class Pyramid extends GraphicsProgram {

   public void run() {
      /* y-coordinate of the top layer */
      int initY = (getHeight() - BRICKS_IN_BASE*BRICK_HEIGHT) / 2;
      
      /* draw layers, top down */
      for (int i = 0; i < BRICKS_IN_BASE; i++) {
         /* y-coordinate of layer i */
         int y = initY + i*BRICK_HEIGHT;
         /* starting x-coordinate of layer i */
         int initX = (getWidth() - (i + 1)*BRICK_WIDTH) / 2;
         /* draw bricks in layer i */
         for (int j = 0; j <= i; j++) {
            /* x-coordinate of brick j in layer i */
            int x = initX + j*BRICK_WIDTH;
            /* draw brick j in layer i */
            GRect brick = new GRect(x, y, BRICK_WIDTH, BRICK_HEIGHT);
            add(brick);
         } /* for j */
      } /* for i */
   }

/* private constants */
   private static final int BRICK_WIDTH = 32;
   private static final int BRICK_HEIGHT = 15;
   private static final int BRICKS_IN_BASE = 12;
}