GetBitMapAttr

Returns information about a bitmap

Declaration

Source position: agraphics.pas line 2458

Description

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

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.

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