NAME
        GetBitMapAttr -- Returns information about a bitmap (V39)


   SYNOPSIS
        value=GetBitMapAttr(bitmap,attribute_number);
          d0                     a0       d1

        ULONG GetBitMapAttr(struct bitmap *,ulong);

   FUNCTION
        Determines information about a bitmap. This function should be used
        instead of reading the bitmap structure fields directly. This will
        provide future compatibility.

   INPUTS
        bm  =  A pointer to a bitmap structure.

        attribute_number = A number telling graphics which attribute
                           of the bitmap should be returned:

                        BMA_HEIGHT returns the height in pixels
                        BMA_WIDTH  returns the width in pixels.
                        BMA_DEPTH  returns the depth. This is the number of
                                bits which are required to store the information
                                for one pixel in the bitmap.
                        BMA_FLAGS  returns a longword bitfield describing
                                various attributes which the bitmap may have.
                                Currently defined flags are BMF_DISPLAYABLE,
                                BMF_INTERLEAVED (see AllocBitMap()). The flag
                                BMF_STANDARD returns will be set if the
                                bitmap is represented as planar data in Amiga
                                Chip RAM.

   BUGS

   NOTES

        Unknown attributes are reserved for future use, and return zero.

        BMF_DISPLAYABLE will only be set if the source bitmap meets all of the
        required alignment restrictions. A bitmap which does not meet these
        restrictions may still be displayable at some loss of efficiency.

        Size values returned by this function may not exactly match the values
        which were passed to allocbitmap(), due to alignment restrictions.

   SEE ALSO
        allocbitmap()