Bresenham circle algorithm

Circle.java

public class Circle {
  public static void main(String[] args) {
    // Preparation
    int radius = Integer.parseInt(args[0]);
    int rasterSize = radius * 2 + 1;
    boolean[][] raster = new boolean[rasterSize][rasterSize];

    // Bresenham algorithm
    int y = radius;
    int err = radius;
    for (int x = 0; x <= y; x++) {
      raster[radius+x][radius+y] = true; raster[radius+y][radius+x] = true;
      raster[radius+x][radius-y] = true; raster[radius+y][radius-x] = true;
      raster[radius-x][radius+y] = true; raster[radius-y][radius+x] = true;
      raster[radius-x][radius-y] = true; raster[radius-y][radius-x] = true;
      err -= 2 * x + 1;
      if (err < 0) {
        err += 2 * y - 1;
        y--;
      }
    }

    // Output
    for (int i = 0; i < rasterSize; i++) {
      for (int j = 0; j < rasterSize; j++) {
        System.out.print(raster[i][j] ? "**" : "  ");
      }
      System.out.println();
    }
  }
}