NewAllocRaster

Synopsis

planeptr = NewAllocRaster(width, height)
D0                        D0     D1

C Prototype

PLANEPTR NewAllocRaster(ULONG width, ULONG height);

Description

A simpler way to allocate a pre-cleared bitplane. This function is faster than graphics.library/AllocRaster(), and additionally allocates a plane that is already cleared. It also simplifies deallocation, as the result can be sent directly to exec.library/FreeVec().

(V41.1) — For future compatibility reasons, the use of this function is discouraged. Always use AddBitPlanes() and RemoveBitPlanes() when possible. The same recommendation applies to graphics.library/AllocRaster() and FreeRaster().

Inputs

• width — Desired width of the plane in pixels.
• height — Desired height of the plane in pixels.

Result

• planeptr — If NULL, an error occurred. Otherwise, it is a pointer to the allocated bitplane, already cleared.

Notes

Planes created with this function must be freed manually. You CANNOT use RemoveBitPlanes() to free them.

See Also

• AddBitPlanes
• exec.library/FreeVec()

Implementation

The original 68020 assembly implementation:

; (06-10-1994) --- planeptr = NewAllocRaster(width, height) (d0,d1)
_LVONewAllocRaster
        movem.l d2/a6,-(sp)
        add.w   #$F,d0
        asr.w   #3,d0
        bclr    #0,d0
        mulu.w  d1,d0
        addq.w  #4,d0
        move.l  d0,d2
        lea     MEMF_CHIP|MEMF_CLEAR,a0
        move.l  a0,d1
        move.l  ab_ExecBase(a6),a6
        jsr     _LVOAllocMem(a6)
        move.l  d0,a0
        move.l  d2,(a0)+
        move.l  a0,d0
        movem.l (sp)+,d2/a6
        rts