scummvm/engines/tinsel/scn.cpp
2011-05-12 01:16:22 +02:00

73 lines
2.1 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* A (some would say very) small collection of utility functions.
*/
#include "tinsel/dw.h"
#include "tinsel/film.h"
#include "tinsel/handle.h"
#include "tinsel/multiobj.h"
#include "tinsel/scn.h"
#include "tinsel/tinsel.h" // for _vm
namespace Tinsel {
/**
* Given a scene handle and a chunk id, gets the scene in RAM and
* locates the requested chunk.
* @param handle Scene handle
* @param chunk Chunk Id
*/
byte *FindChunk(SCNHANDLE handle, uint32 chunk) {
byte *bptr = LockMem(handle);
uint32 *lptr = (uint32 *)bptr;
uint32 add;
// Initial adjustmnet for Tinsel 1 chunk types
if ((TinselVersion != TINSEL_V2) && (chunk >= CHUNK_SCENE) &&
(chunk != CHUNK_MBSTRING))
--chunk;
// V0 chunk types can be found by substracting 2 from the
// chunk type. Note that CHUNK_STRING and CHUNK_BITMAP are
// the same in V0 and V1
if (TinselVersion == TINSEL_V0 &&
chunk != CHUNK_STRING && chunk != CHUNK_BITMAP)
chunk -= 0x2L;
while (1) {
if (READ_32(lptr) == chunk)
return (byte *)(lptr + 2);
++lptr;
add = READ_32(lptr);
if (!add)
// End of file reached
return NULL;
// Move to next chunk
lptr = (uint32 *)(bptr + add);
}
}
} // End of namespace Tinsel