import java.io.*;

public abstract class RGBPixmap extends Pixmap {

  private static String MAGIC_PPM = "P6\n";
  private byte[] data;

  public RGBPixmap(int w, int h) {
    super(w, h);
  }

  public RGBPixmap(String fileName) throws IOException {
    super(fileName, MAGIC_PPM);
    data = readBytes(3*size);
  }

  byte[] getChunky(int first) {
    if ( data == null )
      return null;
    byte[] buffer = new byte[size];
    for (int i = first, j = 0; i < data.length; i+=3, j++)
      buffer[j] = data[i];
    return buffer;
  }

  final void closeRGB() {
    close();
    data = null;
  }

  private byte[] makeBytes() {
    byte[] r = getR().getBytes();
    byte[] g = getG().getBytes();
    byte[] b = getB().getBytes();
    byte[] buffer = new byte[3*size];
    for (int i = 0, j = 0; i < r.length; i++) {
      buffer[j++] = r[i];
      buffer[j++] = g[i];
      buffer[j++] = b[i];
    }
    return buffer;
  }

  public void write(String fileName) {
    write(fileName, MAGIC_PPM, makeBytes());
  }

  // conversions
  public abstract Pixmap getR();
  public abstract Pixmap getG();
  public abstract Pixmap getB();

  public byte[] getBytes() {
    return null;
  }
  public short[] getShorts() {
    return null;
  }
  public double[] getDoubles() {
    return null;
  }

}