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author | Kari Salminen | 2008-06-30 17:24:23 +0000 |
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committer | Kari Salminen | 2008-06-30 17:24:23 +0000 |
commit | 2ecf8fdbb5a0141ea43a7d2074a2a7356182f12c (patch) | |
tree | 7cebdd43148735696256788e952c5e6d02d5e8b0 /engines/cine | |
parent | 63c0dde2ef48ca7751e888e257e00d822951a01b (diff) | |
download | scummvm-rg350-2ecf8fdbb5a0141ea43a7d2074a2a7356182f12c.tar.gz scummvm-rg350-2ecf8fdbb5a0141ea43a7d2074a2a7356182f12c.tar.bz2 scummvm-rg350-2ecf8fdbb5a0141ea43a7d2074a2a7356182f12c.zip |
Fixed addAni (A test before using resetGfxEntityEntry was incorrect). Also added comments and checked that most 8-bit values used in this function are used as signed integers.
svn-id: r32850
Diffstat (limited to 'engines/cine')
-rw-r--r-- | engines/cine/various.cpp | 43 |
1 files changed, 30 insertions, 13 deletions
diff --git a/engines/cine/various.cpp b/engines/cine/various.cpp index 6bbc907eb0..ea5956be6b 100644 --- a/engines/cine/various.cpp +++ b/engines/cine/various.cpp @@ -1682,33 +1682,49 @@ uint16 computeMove2(SeqListElement &element) { return returnVar; } -uint16 addAni(uint16 param1, uint16 objIdx, const byte *ptr, SeqListElement &element, uint16 param3, int16 *param4) { - const byte *currentPtr = ptr; - const byte *ptrData; - const byte *ptr2; +uint16 addAni(uint16 param1, uint16 objIdx, const byte *ptrByte, SeqListElement &element, uint16 param3, int16 *param4) { + const int8 *ptr = (const int8 *)ptrByte; + const int8 *ptrData; + const int8 *ptr2; int16 di; + // In the original an error string is set and 0 is returned if the following doesn't hold assert(ptr); - assert(param4); - - dummyU16 = READ_BE_UINT16((currentPtr + param1 * 2) + 8); + // We probably could just use a local variable here instead of the dummyU16 but + // haven't checked if this has any side-effects so keeping it this way still. + dummyU16 = READ_BE_UINT16(ptr + param1 * 2 + 8); ptrData = ptr + dummyU16; + // In the original an error string is set and 0 is returned if the following doesn't hold assert(*ptrData); di = (objectTable[objIdx].costume + 1) % (*ptrData); - ptr2 = (ptrData + (di * 8)) + 1; - + ++ptrData; // Jump over the just read byte + // Here ptr2 seems to be indexing a table of structs (8 bytes per struct): + // struct { + // int8 x; // 0 (Used with checkCollision) + // int8 y; // 1 (Used with checkCollision) + // int8 numZones; // 2 (Used with checkCollision) + // int8 var3; // 3 (Not used in this function) + // int8 xAdd; // 4 (Used with an object) + // int8 yAdd; // 5 (Used with an object) + // int8 maskAdd; // 6 (Used with an object) + // int8 frameAdd; // 7 (Used with an object) + // }; + ptr2 = ptrData + di * 8; + + // We might probably safely discard the AND by 1 here because + // at least in the original checkCollision returns always 0 or 1. if ((checkCollision(objIdx, ptr2[0], ptr2[1], ptr2[2], ptr[0]) & 1)) { return 0; } - objectTable[objIdx].x += (int8)ptr2[4]; - objectTable[objIdx].y += (int8)ptr2[5]; - objectTable[objIdx].mask += (int8)ptr2[6]; + objectTable[objIdx].x += ptr2[4]; + objectTable[objIdx].y += ptr2[5]; + objectTable[objIdx].mask += ptr2[6]; - if (objectTable[objIdx].frame) { + if (ptr2[6]) { resetGfxEntityEntry(objIdx); } @@ -1717,6 +1733,7 @@ uint16 addAni(uint16 param1, uint16 objIdx, const byte *ptr, SeqListElement &ele if (param3 || !element.var14) { objectTable[objIdx].costume = di; } else { + assert(param4); *param4 = di; } |