Method ReadChunkHeader

src/engine/shared/demo.cpp:512–575

}

CDemoPlayer::EReadChunkHeaderResult CDemoPlayer::ReadChunkHeader(int *pType, int *pSize, int *pTick)
{
	*pSize = 0;
	*pType = 0;

	unsigned char Chunk = 0;
	if(io_read(m_File, &Chunk, sizeof(Chunk)) != sizeof(Chunk))
		return CHUNKHEADER_EOF;

	if(Chunk & CHUNKTYPEFLAG_TICKMARKER)
	{
		// decode tick marker
		int TickdeltaLegacy = Chunk & CHUNKMASK_TICK_LEGACY; // compatibility
		*pType = Chunk & (CHUNKTYPEFLAG_TICKMARKER | CHUNKTICKFLAG_KEYFRAME);

		int NewTick;
		if(m_Info.m_Header.m_Version < gs_VersionTickCompression && TickdeltaLegacy != 0)
		{
			if(*pTick < 0) // initial tick not initialized before a tick delta
				return CHUNKHEADER_ERROR;
			NewTick = *pTick + TickdeltaLegacy;
		}
		else if(Chunk & CHUNKTICKFLAG_TICK_COMPRESSED)
		{
			if(*pTick < 0) // initial tick not initialized before a tick delta
				return CHUNKHEADER_ERROR;
			int Tickdelta = Chunk & CHUNKMASK_TICK;
			NewTick = *pTick + Tickdelta;
		}
		else
		{
			unsigned char aTickdata[sizeof(int32_t)];
			if(io_read(m_File, aTickdata, sizeof(aTickdata)) != sizeof(aTickdata))
				return CHUNKHEADER_ERROR;
			NewTick = bytes_be_to_uint(aTickdata);
		}
		if(NewTick < MIN_TICK || NewTick >= MAX_TICK) // invalid tick
			return CHUNKHEADER_ERROR;
		*pTick = NewTick;
	}
	else
	{
		// decode normal chunk
		*pType = (Chunk & CHUNKMASK_TYPE) >> 5;
		*pSize = Chunk & CHUNKMASK_SIZE;

		if(*pSize == 30)
		{
			unsigned char aSizedata[1];
			if(io_read(m_File, aSizedata, sizeof(aSizedata)) != sizeof(aSizedata))
				return CHUNKHEADER_ERROR;
			*pSize = aSizedata[0];
		}
		else if(*pSize == 31)
		{
			unsigned char aSizedata[2];
			if(io_read(m_File, aSizedata, sizeof(aSizedata)) != sizeof(aSizedata))
				return CHUNKHEADER_ERROR;