import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.IOException;

/** 2nd flag program.  Let's create the flag of Poland.
 *  White on top, red on bottom.
 */

public class Flag2
{
  public static void main(String [] args)
  {
    // First, create an image object.
    // The parameters to the constructor are: 
    //   width, height, and image type (we use 1)
    BufferedImage image = new BufferedImage (300,200,1);

    // Second, write pixel values into the image.
    // I think it's easier to think in terms of x/y, not row/column!
    // For each x value (and there are 300 of those):
    //   0 <= y < 100 are white, and 100 <= y < 200 are red.
    for (int x = 0; x < 300; ++x)
    {
      int blueNumber  =   0*65536 +   0*256 + 255;
      int whiteNumber = 255*65536 + 255*256 + 255;
      int redNumber   = 255*65536 +   0*256 +   0;

      // white
      for (int y = 0; y < 100; ++y)
        image.setRGB(x, y, whiteNumber);

      // red
      for (int y = 100; y < 200; ++y)
        image.setRGB(x, y, redNumber);
    }

    // Third, write the image to a file.  
    // May automatically throw "IOException"
    try
    {
      ImageIO.write(image, "png", new File ("poland.png"));
    }
    catch (IOException e)
    {
      System.out.printf("Encountered problem trying to write to file\n");
    }
  }
}