Proposals / #1473

Mac SFILE_FindChunk: uint32_t __fastcc (D2MPQFileStrc* pMPQFile ECX, int32_t nChunkId EDX, int* pChunkSize)

checked · by KierTaylor · submitted 2026-11-08

ECX -> ESI = the file (passed as [ESP] to SFileReadFile 0x00012ac1 for each 8-byte chunk header, and to SFileSetFilePointer 0x000129bc to skip). EDX -> EDI = the chunk id compared with each header's id (0x000130d0). [EBP+8] = the out block: [0] = chunk size, [4] = the current position. It returns EBX (SETNZ pos != -1, else 0). Same roles as Windows twin 0x0041b210 uint32_t (nChunkId, pMPQFile, int* pnChunkSize). pn is refused, so it is named pChunkSize.

Changes 1, applied together

1. Set prototype mac 0x00013080

   signatureundefined SFILE_FindChunk(void)→uint32_t SFILE_FindChunk(D2MPQFileStrc* pMPQFile, int32_t nChunkId, int* pChunkSize)
   conventionunknown→__fastcc