NAME
    BltBitMap -- Move a rectangular region of bits in a bitmap.

SYNOPSIS
    planecnt = BltBitMap(SrcBitMap, SrcX, SrcY, DstBitMap,
    D0                   A0         D0:16 D1:16 A1
        DstX, DstY, SizeX, SizeY, Minterm, Mask [, TempA])
        D2:16 D3:16 D4:16  D5:16  D6:8     D7:8   [A2]

    ULONG BltBitMap(struct bitmap *, word, word, struct bitmap *,
        WORD, WORD, WORD, WORD, UBYTE, UBYTE, UWORD *);

FUNCTION
    Perform non-destructive blits to move a rectangle from one
    area in a bitmap to another area, which can be on a different
    bitmap.
    This blit is assumed to be friendly: no error conditions (e.g.
    a rectangle outside the bitmap bounds) are tested or reported.

INPUTS
    SrcBitMap, DstBitMap - the BitMap(s) containing the
          rectangles
        - the planes copied from the source to the destination are
          only those whose plane numbers are identical and less
          than the minimum Depth of either bitmap and whose mask
          bit for that plane is non-zero.
        - as a special case, if a plane pointer in the SrcBitMap
          is zero, it acts as a pointer to a plane of all zeros, and
          if the plane pointer is 0xffffffff, it acts as a pointer
          to a plane of all ones.  (Note: new for V36)
        - SrcBitMap and DstBitMap can be identical if they point
          to actual planes.
    SrcX, SrcY - the x and y coordinates of the upper left corner
        of the source rectangle.  Valid range is positive
        signed integer such that the raster word's offset
        0..(32767-Size)
    DstX, DstY - the x and y coordinates of the upper left
        corner of the destination for the rectangle.  Valid
        range is as for Src.
    SizeX, SizeY - the size of the rectangle to be moved.  Valid
        range is (X: 1..976; Y: 1..1023 such that final raster
        word's offset is 0..32767)
    Minterm - the logic function to apply to the rectangle when
        A is non-zero (i.e. within the rectangle).  B is the
        source rectangle and C, D is the destination for the
        rectangle.
        - $0C0 is a vanilla copy
        - $030 inverts the source before the copy
        - $050 ignores the source and inverts the destination
        - see the hardware reference manual for other combinations
    Mask - the write mask to apply to this operation.  Bits set
        indicate the corresponding planes (if not greater than
        the minimum plane count) are to participate in the
        operation.  Typically this is set to 0xff.
    TempA - If the copy overlaps exactly to the left or right
        (i.e. the scan line addresses overlap), and TempA is
        non-zero, it points to enough chip accessable memory
        to hold a line of A source for the blit (ie CHIP RAM).
        BitBitMap will allocate (and free) the needed TempA if
        none is provided and one is needed.  Blit overlap is
        determined from the relation of the first non-masked
        planes in the source and destination bit maps.

RESULTS
    planecnt - the number of planes actually involved in the blit.

NOTES
    o   This function may use the blitter.

SEE ALSO
    clipblit()  graphics/gfx.h  hardware/blit.h