NextIFFChunk

Synopsis

chunkSize = NextIFFChunk(data)
D0                       A0

C Prototype

There is no direct C prototype exported for this function. It is called internally from assembly.

Description

Advances the data pointer to the next chunk in an IFF data structure. The function reads the size field of the current chunk (at offset 4 from the chunk header), then moves the pointer forward by 8 bytes (header size) plus the chunk data size, positioning it at the beginning of the next chunk.

Inputs

• data (A0) — Pointer to the current IFF chunk header. On return, A0 is updated to point to the next chunk.

Result

• chunkSize (D0) — The size of the next chunk’s data.
• A0 — Updated to point to the next chunk header.

See Also

• FindAIFFChunk
• TestAIFFChunk

Implementation

The original 68020 assembly implementation:

; Rel.1.0 - Jul 29 1991 --- NextIFFChunk()
_LVONextIFFChunk
        move.l  4(a0),d0
        lea     8(a0,d0.l),a0
        move.l  4(a0),d0
        rts