INTERFACE Bitmap;

TYPE UByte = BITS 8 FOR [0 .. 16_FF];
     Pixel = RECORD R, G, B: UByte; END;
     Point = RECORD x, y: UByte; END;
     T = REF ARRAY OF ARRAY OF Pixel;

CONST
  Black = Pixel{0, 0, 0};
  White = Pixel{255, 255, 255};
  Red = Pixel{255, 0, 0};
  Green = Pixel{0, 255, 0};
  Blue = Pixel{0, 0, 255};
  Yellow = Pixel{255, 255, 0};

EXCEPTION BadImage;
          BadColor;

PROCEDURE NewImage(height, width: UByte): T RAISES {BadImage};
PROCEDURE Fill(VAR pic: T; color: Pixel);
PROCEDURE GetPixel(VAR pic: T; point: Point): Pixel RAISES {BadColor};
PROCEDURE SetPixel(VAR pic: T; point: Point; color: Pixel);

END Bitmap.