RwBinaryStream

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Revision as of 03:34, 29 May 2007 by Shrew (talk | contribs)
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Reading Binary Streams

RwStreams are heirarchical streams of sections. Every section consists of:

  • (gauranteed) RwHeader
  • (gauranteed) RwData child section (the contents are specific to the section type, see definitions below.)
  • (optional) Children sections

The RwHeader contains the size (sectionSize member) of all the data and children (and their data and children). This allows you to either skip the entire section and it's children by advancing the stream pointer, or to know when you have parsed all it's children by comparing the stream pointer to the address of the section RwHeader added to the sectionSize.

Simple Pseudo C++ Code to read a Binary Stream

//-----------------------------------------------------------------------
// The RwSection is a base class from which all RwType classes derive

RwSection * ReadSection(FileStream * stream, RwSection * parent)
{
	//-----------------------------------------------------------------------
	// read the header
	
	RwHeader header = ReadRwHeader(stream);
	
	//-----------------------------------------------------------------------
	// create the section - the type returned is based on header.sectionType
	// the reason the parent is passed in is because if the section is an
	// rwDATA what data it reads is dependant on the parent's sectionType and
	// also the number of rwDATA children the parent already has read
	
	RwSection * section = CreateAppropriateSection(stream, header.sectionType, parent);
	
	//-----------------------------------------------------------------------
	// recursively read the children
	
	u8 * endOfSection = stream.GetPosition() + header.sectionSize;
	while(stream.GetPosition() < endOfSection)
	{
		RwSection * childSection = ReadSection(stream, section)
		section->AddChild(childSection);
	}
	
	//-----------------------------------------------------------------------
	// return the newly created section
	
	return section;
}

RwType

enum
{
    rwDATA = 1,
    rwSTRING = 2,
    rwEXTENSION = 3,
    rwTEXTURE = 6,
    rwMATERIAL = 7,
    rwMATERIALLIST = 8,
    rwFRAMELIST = 14,
    rwGEOMETRY = 15,
    rwCLUMP = 16,
    rwLIGHT = 18,
    rwATOMIC = 20,
    rwTEXTURENATIVE = 21,
    rwTEXDICT = 22,
    rwGEOMETRYLIST = 26,
    rwMATERIALSPLIT = 124,
    rwFRAME = 39056126,
    rwPLUGIN_PARTICLES = 0x118,
    rwPLUGIN_MATERIALEFFECTS = 0x120,
    rwPLUGIN_BINMESH = 0x50e,
};

RwHeader

struct RwHeader
{
    s32 sectionType; // RwType
    s32 sectionSize;
    u8 unknown[2];
    s16 versionNumber;
};

Dff Files

Top level section is always a single RwClump.

RwClump section RwData

VersionNumber(s) 0, 2048
  • Gauranteed, first and only data in the RwClump
s32 objectCount = stream->ReadS32();
VersionNumber(s) 3074, 4099, 6147
  • Gauranteed, first data in the RwClump
s32 objectCount = stream->ReadS32();
stream->SkipUnknownU8s(8);
  • Optional, second and subsequent data in the RwClump
stream->SkipUnknownU8s(4);

RwGeometry section RwData

VersionNumber(s) 0, 2048, 3074
  • Gauranteed, first and only data in the RwGeometryList
abc def ghi
jkl mno pqr
stu vwx yz
u16 flags = stream->ReadU16();
stream->SkipUnknownU8s(2);

s32 triangleCount = stream->ReadS32();
s32 vertexCount = stream->ReadS32();
s32 morphTargetCount = stream->ReadS32();

if(versionNumber == 0 || versionNumber == 2048 || versionNumber == 3074)
{
	u32 ambientRgba = stream->ReadU32();
	u32 diffuseRgba = stream->ReadU32();
	u32 specularRgba = stream->ReadU32();
}

if(flags & rwGEOM_COLOR)
	u32 colorsRgba[vertexCount] = stream->readU32(vertexCount);

if(flags & rwGEOM_TEXTURE)
{
	f32 uvs[vertexCount * 2];
	for(int idx = 0; idx < vertexCount; ++idx)
	{
		uvs[idx * 2 + 0] = stream->readF32();
		uvs[idx * 2 + 1] = stream->readF32();
	}
}

Txd Files

Top level section is always a single RwTexdict.