assimp/code/MD2Loader.cpp

/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

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  following disclaimer.

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  written permission of the ASSIMP Development Team.

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*/

/** @file Implementation of the MD2 importer class */
#include "MD2Loader.h"
#include "MaterialSystem.h"
#include "ByteSwap.h"
#include "MD2NormalTable.h" // shouldn't be included by other units

// public ASSIMP headers
#include "../include/assimp.hpp"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"
#include "../include/IOStream.h"
#include "../include/IOSystem.h"
#include "../include/DefaultLogger.h"

// boost headers
#include <boost/scoped_ptr.hpp>

using namespace Assimp;
using namespace Assimp::MD2;


// helper macro to determine the size of an array
#if (!defined ARRAYSIZE)
#	define ARRAYSIZE(_array) (int(sizeof(_array) / sizeof(_array[0])))
#endif 

// ------------------------------------------------------------------------------------------------
// Helper function to lookup a normal in Quake 2's precalculated table
void MD2::LookupNormalIndex(uint8_t iNormalIndex,aiVector3D& vOut)
{
	// make sure the normal index has a valid value
	if (iNormalIndex >= ARRAYSIZE(g_avNormals))
	{
		DefaultLogger::get()->warn("Index overflow in Quake II normal vector list (the "
			" LUT has only 162 entries). ");

		iNormalIndex = ARRAYSIZE(g_avNormals) - 1;
	}
	vOut = *((const aiVector3D*)(&g_avNormals[iNormalIndex]));
}


// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
MD2Importer::MD2Importer()
{
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well 
MD2Importer::~MD2Importer()
{
}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool MD2Importer::CanRead( const std::string& pFile, IOSystem* pIOHandler) const
{
	// simple check of file extension is enough for the moment
	std::string::size_type pos = pFile.find_last_of('.');
	// no file extension - can't read
	if( pos == std::string::npos)
		return false;
	std::string extension = pFile.substr( pos);

	if (extension.length() < 4)return false;
	if (extension[0] != '.')return false;
	if (extension[1] != 'm' && extension[1] != 'M')return false;
	if (extension[2] != 'd' && extension[2] != 'D')return false;
	if (extension[3] != '2')return false;

	return true;
}
// ------------------------------------------------------------------------------------------------
// Setup configuration properties
void MD2Importer::SetupProperties(const Importer* pImp)
{
	// The AI_CONFIG_IMPORT_MD2_KEYFRAME option overrides the
	// AI_CONFIG_IMPORT_GLOBAL_KEYFRAME option.
	if(0xffffffff == (this->configFrameID = pImp->GetPropertyInteger(
		AI_CONFIG_IMPORT_MD2_KEYFRAME,0xffffffff)))
	{
		this->configFrameID = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_GLOBAL_KEYFRAME,0);
	}
}
// ------------------------------------------------------------------------------------------------
// Validate the file header
void MD2Importer::ValidateHeader( )
{
	// check magic number
	if (this->m_pcHeader->magic != AI_MD2_MAGIC_NUMBER_BE &&
		this->m_pcHeader->magic != AI_MD2_MAGIC_NUMBER_LE)
	{
		char szBuffer[5];
		szBuffer[0] = ((char*)&this->m_pcHeader->magic)[0];
		szBuffer[1] = ((char*)&this->m_pcHeader->magic)[1];
		szBuffer[2] = ((char*)&this->m_pcHeader->magic)[2];
		szBuffer[3] = ((char*)&this->m_pcHeader->magic)[3];
		szBuffer[4] = '\0';

		throw new ImportErrorException("Invalid MD2 magic word: should be IDP2, the "
			"magic word found is " + std::string(szBuffer));
	}

	// check file format version
	if (this->m_pcHeader->version != 8)
		DefaultLogger::get()->warn( "Unsupported md2 file version. Continuing happily ...");

	// check some values whether they are valid
	if (0 == this->m_pcHeader->numFrames)
		throw new ImportErrorException( "Invalid md2 file: NUM_FRAMES is 0");

	if (this->m_pcHeader->offsetEnd > (int32_t)fileSize)
		throw new ImportErrorException( "Invalid md2 file: File is too small");

	if (this->m_pcHeader->offsetSkins		+ this->m_pcHeader->numSkins * sizeof (MD2::Skin)			>= this->fileSize ||
		this->m_pcHeader->offsetTexCoords	+ this->m_pcHeader->numTexCoords * sizeof (MD2::TexCoord)	>= this->fileSize ||
		this->m_pcHeader->offsetTriangles	+ this->m_pcHeader->numTriangles * sizeof (MD2::Triangle)	>= this->fileSize ||
		this->m_pcHeader->offsetFrames		+ this->m_pcHeader->numFrames * sizeof (MD2::Frame)			>= this->fileSize ||
		this->m_pcHeader->offsetEnd			> this->fileSize)
	{
		throw new ImportErrorException("Invalid MD2 header: some offsets are outside the file");
	}

	if (this->m_pcHeader->numSkins > AI_MD2_MAX_SKINS)
		DefaultLogger::get()->warn("The model contains more skins than Quake 2 supports");
	if ( this->m_pcHeader->numFrames > AI_MD2_MAX_FRAMES)
		DefaultLogger::get()->warn("The model contains more frames than Quake 2 supports");
	if (this->m_pcHeader->numVertices > AI_MD2_MAX_VERTS)
		DefaultLogger::get()->warn("The model contains more vertices than Quake 2 supports");

	if (this->m_pcHeader->numFrames <= this->configFrameID )
		throw new ImportErrorException("The requested frame is not existing the file");

}
// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void MD2Importer::InternReadFile( const std::string& pFile, 
	aiScene* pScene, IOSystem* pIOHandler)
{
	boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile));

	// Check whether we can read from the file
	if( file.get() == NULL)
		throw new ImportErrorException( "Failed to open MD2 file " + pFile + "");

	// check whether the md3 file is large enough to contain
	// at least the file header
	fileSize = (unsigned int)file->FileSize();
	if( fileSize < sizeof(MD2::Header))
		throw new ImportErrorException( "MD2 File is too small");

	std::vector<unsigned char> mBuffer2(fileSize);
	file->Read(&mBuffer2[0], 1, fileSize);
	this->mBuffer = &mBuffer2[0];


	this->m_pcHeader = (const MD2::Header*)this->mBuffer;

#ifdef AI_BUILD_BIG_ENDIAN

	ByteSwap::Swap4(&m_pcHeader->frameSize);
	ByteSwap::Swap4(&m_pcHeader->magic);
	ByteSwap::Swap4(&m_pcHeader->numFrames);
	ByteSwap::Swap4(&m_pcHeader->numGlCommands);
	ByteSwap::Swap4(&m_pcHeader->numSkins);
	ByteSwap::Swap4(&m_pcHeader->numTexCoords);
	ByteSwap::Swap4(&m_pcHeader->numTriangles);
	ByteSwap::Swap4(&m_pcHeader->numVertices);
	ByteSwap::Swap4(&m_pcHeader->offsetEnd);
	ByteSwap::Swap4(&m_pcHeader->offsetFrames);
	ByteSwap::Swap4(&m_pcHeader->offsetGlCommands);
	ByteSwap::Swap4(&m_pcHeader->offsetSkins);
	ByteSwap::Swap4(&m_pcHeader->offsetTexCoords);
	ByteSwap::Swap4(&m_pcHeader->offsetTriangles);
	ByteSwap::Swap4(&m_pcHeader->skinHeight);
	ByteSwap::Swap4(&m_pcHeader->skinWidth);
	ByteSwap::Swap4(&m_pcHeader->version);

#endif

	this->ValidateHeader();

	// there won't be more than one mesh inside the file
	pScene->mNumMaterials = 1;
	pScene->mRootNode = new aiNode();
	pScene->mRootNode->mNumMeshes = 1;
	pScene->mRootNode->mMeshes = new unsigned int[1];
	pScene->mRootNode->mMeshes[0] = 0;
	pScene->mMaterials = new aiMaterial*[1];
	pScene->mMaterials[0] = new MaterialHelper();
	pScene->mNumMeshes = 1;
	pScene->mMeshes = new aiMesh*[1];
	aiMesh* pcMesh = pScene->mMeshes[0] = new aiMesh();

	// navigate to the begin of the frame data
	const MD2::Frame* pcFrame = (const MD2::Frame*) ((uint8_t*)
		this->m_pcHeader + this->m_pcHeader->offsetFrames);
	pcFrame += this->configFrameID;

	// navigate to the begin of the triangle data
	MD2::Triangle* pcTriangles = (MD2::Triangle*) ((uint8_t*)
		this->m_pcHeader + this->m_pcHeader->offsetTriangles);

	// navigate to the begin of the tex coords data
	const MD2::TexCoord* pcTexCoords = (const MD2::TexCoord*) ((uint8_t*)
		this->m_pcHeader + this->m_pcHeader->offsetTexCoords);

	// navigate to the begin of the vertex data
	const MD2::Vertex* pcVerts = (const MD2::Vertex*) (pcFrame->vertices);

#ifdef AI_BUILD_BIG_ENDIAN
	for (uint32_t i = 0; i< m_pcHeader->numTriangles)
	{
		for (unsigned int p = 0; p < 3;++p)
		{
			ByteSwap::Swap2(& pcTriangles[i].textureIndices[p]);
			ByteSwap::Swap2(& pcTriangles[i].vertexIndices[p]);
		}
	}
	for (uint32_t i = 0; i < m_pcHeader->offsetTexCoords;++i)
	{
		ByteSwap::Swap2(& pcTexCoords[i].s);
		ByteSwap::Swap2(& pcTexCoords[i].t);
	}
	ByteSwap::Swap4( & pcFrame->scale[0] );
	ByteSwap::Swap4( & pcFrame->scale[1] );
	ByteSwap::Swap4( & pcFrame->scale[2] );
	ByteSwap::Swap4( & pcFrame->translate[0] );
	ByteSwap::Swap4( & pcFrame->translate[1] );
	ByteSwap::Swap4( & pcFrame->translate[2] );
#endif

	pcMesh->mNumFaces = this->m_pcHeader->numTriangles;
	pcMesh->mFaces = new aiFace[this->m_pcHeader->numTriangles];

	// allocate output storage
	pcMesh->mNumVertices = (unsigned int)pcMesh->mNumFaces*3;
	pcMesh->mVertices = new aiVector3D[pcMesh->mNumVertices];
	pcMesh->mNormals = new aiVector3D[pcMesh->mNumVertices];

	// not sure whether there are MD2 files without texture coordinates
	// NOTE: texture coordinates can be there without a texture,
	// but a texture can't be there without a valid UV channel
	if (this->m_pcHeader->numTexCoords && this->m_pcHeader->numSkins)
	{
		// navigate to the first texture associated with the mesh
		const MD2::Skin* pcSkins = (const MD2::Skin*) ((unsigned char*)this->m_pcHeader + 
			this->m_pcHeader->offsetSkins);

		const int iMode = (int)aiShadingMode_Gouraud;
		MaterialHelper* pcHelper = (MaterialHelper*)pScene->mMaterials[0];
		pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

		aiColor3D clr;
		clr.b = clr.g = clr.r = 1.0f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_DIFFUSE);
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_SPECULAR);

		clr.b = clr.g = clr.r = 0.05f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

		if (pcSkins->name[0])
		{
			aiString szString;
			const size_t iLen = ::strlen(pcSkins->name);
			::memcpy(szString.data,pcSkins->name,iLen);
			szString.data[iLen] = '\0';
			szString.length = iLen;

			pcHelper->AddProperty(&szString,AI_MATKEY_TEXTURE_DIFFUSE(0));
		}
		else
		{
			DefaultLogger::get()->warn("Texture file name has zero length. It will be skipped.");
		}
	}
	else
	{
		// apply a default material
		const int iMode = (int)aiShadingMode_Gouraud;
		MaterialHelper* pcHelper = (MaterialHelper*)pScene->mMaterials[0];
		pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

		aiColor3D clr;
		clr.b = clr.g = clr.r = 0.6f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_DIFFUSE);
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_SPECULAR);

		clr.b = clr.g = clr.r = 0.05f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

		aiString szName;
		szName.Set(AI_DEFAULT_MATERIAL_NAME);
		pcHelper->AddProperty(&szName,AI_MATKEY_NAME);
	}


	// now read all triangles of the first frame, apply scaling and translation
	unsigned int iCurrent = 0;

	float fDivisorU,fDivisorV;
	if (this->m_pcHeader->numTexCoords)
	{
		// allocate storage for texture coordinates, too
		pcMesh->mTextureCoords[0] = new aiVector3D[pcMesh->mNumVertices];
		pcMesh->mNumUVComponents[0] = 2;

		// check whether the skin width or height are zero (this would
		// cause a division through zero)
		if (!this->m_pcHeader->skinWidth)
		{
			DefaultLogger::get()->error("Skin width is zero but there are "
				"valid absolute texture coordinates. Unable to compute "
				"relative texture coordinates ranging from 0 to 1");
			fDivisorU = 1.0f;
		}
		else fDivisorU = (float)this->m_pcHeader->skinWidth;
		if (!this->m_pcHeader->skinHeight)
		{
			DefaultLogger::get()->error("Skin height is zero but there are "
				"valid absolute texture coordinates. Unable to compute "
				"relative texture coordinates ranging from 0 to 1");
			fDivisorV = 1.0f;
		}
		else fDivisorV = (float)this->m_pcHeader->skinHeight;
	}

	for (unsigned int i = 0; i < (unsigned int)this->m_pcHeader->numTriangles;++i)
	{
		// allocate the face
		pScene->mMeshes[0]->mFaces[i].mIndices = new unsigned int[3];
		pScene->mMeshes[0]->mFaces[i].mNumIndices = 3;

		// copy texture coordinates
		// check whether they are different from the previous value at this index.
		// In this case, create a full separate set of vertices/normals/texcoords
		unsigned int iTemp = iCurrent;
		for (unsigned int c = 0; c < 3;++c,++iCurrent)
		{
			// validate vertex indices
			if (pcTriangles[i].vertexIndices[c] >= this->m_pcHeader->numVertices)
			{
				DefaultLogger::get()->error("Vertex index is outside the allowed range");
				pcTriangles[i].vertexIndices[c] = this->m_pcHeader->numVertices-1;
			}

			// copy face indices
			unsigned int iIndex = (unsigned int)pcTriangles[i].vertexIndices[c];

			// read x,y, and z component of the vertex
			aiVector3D& vec = pcMesh->mVertices[iCurrent];

			vec.x = (float)pcVerts[iIndex].vertex[0] * pcFrame->scale[0];
			vec.x += pcFrame->translate[0];

			// (flip z and y component)
			// FIX: no .... invert y instead
			vec.y = (float)pcVerts[iIndex].vertex[1] * pcFrame->scale[1];
			vec.y += pcFrame->translate[1];
			vec.y *= -1.0f;

			vec.z = (float)pcVerts[iIndex].vertex[2] * pcFrame->scale[2];
			vec.z += pcFrame->translate[2];

			// read the normal vector from the precalculated normal table
			aiVector3D& vNormal = pcMesh->mNormals[iCurrent];
			LookupNormalIndex(pcVerts[iIndex].lightNormalIndex,vNormal);
			vNormal.y *= -1.0f;

			if (this->m_pcHeader->numTexCoords)
			{
				// validate texture coordinates
				if (pcTriangles[iIndex].textureIndices[c] >= this->m_pcHeader->numTexCoords)
				{
					DefaultLogger::get()->error("UV index is outside the allowed range");
					pcTriangles[iIndex].textureIndices[c] = this->m_pcHeader->numTexCoords-1;
				}

				aiVector3D& pcOut = pcMesh->mTextureCoords[0][iCurrent];
				float u,v;

				// the texture coordinates are absolute values but we
				// need relative values between 0 and 1
				u = (float)pcTexCoords[pcTriangles[i].textureIndices[c]].s / fDivisorU;
				v = (float)pcTexCoords[pcTriangles[i].textureIndices[c]].t / fDivisorV;
				pcOut.x = u;
				pcOut.y = 1.0f - v; // FIXME: Is this correct for MD2?
			}
		}
		// FIX: flip the face order for use with OpenGL
		pScene->mMeshes[0]->mFaces[i].mIndices[0] = iTemp+2;
		pScene->mMeshes[0]->mFaces[i].mIndices[1] = iTemp+1;
		pScene->mMeshes[0]->mFaces[i].mIndices[2] = iTemp+0;
	}
}