assimp/code/PretransformVertices.cpp

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

All rights reserved.

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  following disclaimer.

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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/

/** @file Implementation of the "PretransformVertices" post processing step 
*/
#include "PretransformVertices.h"
#include "../include/DefaultLogger.h"
#include "../include/aiPostProcess.h"
#include "../include/aiMesh.h"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"

#include <list>

using namespace Assimp;

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

// Destructor, private as well
PretransformVertices::~PretransformVertices()
	{
	// nothing to do here
	}

// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool PretransformVertices::IsActive( unsigned int pFlags) const
{
	return	(pFlags & aiProcess_PreTransformVertices) != 0;
}
// ------------------------------------------------------------------------------------------------
// Count the number of nodes
unsigned int CountNodes( aiNode* pcNode )
{
	unsigned int iRet = 1;
	for (unsigned int i = 0;i < pcNode->mNumChildren;++i)
	{
		iRet += CountNodes(pcNode->mChildren[i]);
	}
	return iRet;
}
// ------------------------------------------------------------------------------------------------
// Get a bitwise combination identifying the vertex format of a mesh
unsigned int GetMeshVFormat(aiMesh* pcMesh)
{
	if (0xdeadbeef == pcMesh->mNumUVComponents[0])
		return pcMesh->mNumUVComponents[1];

	unsigned int iRet = 0;

	// normals
	if (pcMesh->HasNormals())iRet |= 0x1;
	// tangents and bitangents
	if (pcMesh->HasTangentsAndBitangents())iRet |= 0x2;

	// texture coordinates
	unsigned int p = 0;
	ai_assert(4 >= AI_MAX_NUMBER_OF_TEXTURECOORDS);
	while (pcMesh->HasTextureCoords(p))
	{
		iRet |= (0x100 << p++);
		if (3 == pcMesh->mNumUVComponents[p])
			iRet |= (0x1000 << p++);
	}
	// vertex colors
	p = 0;
	while (pcMesh->HasVertexColors(p))iRet |= (0x10000 << p++);

	// store the value for later use
	pcMesh->mNumUVComponents[0] = 0xdeadbeef;
	pcMesh->mNumUVComponents[1] = iRet;

	return iRet;
}
// ------------------------------------------------------------------------------------------------
// Count the number of vertices in the whole scene and a given
// material index
void CountVerticesAndFaces( aiScene* pcScene, aiNode* pcNode, unsigned int iMat,
	unsigned int iVFormat, unsigned int* piFaces, unsigned int* piVertices)
{
	for (unsigned int i = 0; i < pcNode->mNumMeshes;++i)
	{
		aiMesh* pcMesh = pcScene->mMeshes[ pcNode->mMeshes[i] ]; 
		if (iMat == pcMesh->mMaterialIndex && iVFormat == GetMeshVFormat(pcMesh))
		{
			*piVertices += pcMesh->mNumVertices;
			*piFaces += pcMesh->mNumFaces;
		}
	}
	for (unsigned int i = 0;i < pcNode->mNumChildren;++i)
	{
		CountVerticesAndFaces(pcScene,pcNode->mChildren[i],iMat,
			iVFormat,piFaces,piVertices);
	}
	return;
}

#define AI_PTVS_VERTEX 0x0
#define AI_PTVS_FACE 0x1

// ------------------------------------------------------------------------------------------------
// Collect vertex/face data
void CollectData( aiScene* pcScene, aiNode* pcNode, unsigned int iMat,
	unsigned int iVFormat, aiMesh* pcMeshOut, 
	unsigned int aiCurrent[2])
{
	for (unsigned int i = 0; i < pcNode->mNumMeshes;++i)
	{
		aiMesh* pcMesh = pcScene->mMeshes[ pcNode->mMeshes[i] ]; 
		if (iMat == pcMesh->mMaterialIndex && iVFormat == GetMeshVFormat(pcMesh))
		{
			// copy positions, transform them to worldspace
			for (unsigned int n = 0; n < pcMesh->mNumVertices;++n)
			{
				pcMeshOut->mVertices[aiCurrent[AI_PTVS_VERTEX]+n] = 
					pcNode->mTransformation * pcMesh->mVertices[n];
			}
			if (iVFormat & 0x1)
			{
				aiMatrix4x4 mWorldIT = pcNode->mTransformation;
				mWorldIT.Inverse().Transpose();

				// copy normals, transform them to worldspace
				for (unsigned int n = 0; n < pcMesh->mNumVertices;++n)
				{
					pcMeshOut->mNormals[aiCurrent[AI_PTVS_VERTEX]+n] = 
						mWorldIT * pcMesh->mNormals[n];
				}
			}
			if (iVFormat & 0x2)
			{
				// copy tangents
				memcpy(pcMeshOut->mTangents + aiCurrent[AI_PTVS_VERTEX],
					pcMesh->mTangents,
					pcMesh->mNumVertices * sizeof(aiVector3D));
				// copy bitangents
				memcpy(pcMeshOut->mBitangents + aiCurrent[AI_PTVS_VERTEX],
					pcMesh->mBitangents,
					pcMesh->mNumVertices * sizeof(aiVector3D));
			}
			unsigned int p = 0;
			while (iVFormat & (0x100 << p))
			{
				// copy texture coordinates
				memcpy(pcMeshOut->mTextureCoords[p] + aiCurrent[AI_PTVS_VERTEX],
					pcMesh->mTextureCoords[p],
					pcMesh->mNumVertices * sizeof(aiVector3D));
				++p;
			}
			p = 0;
			while (iVFormat & (0x10000 << p))
			{
				// copy vertex colors
				memcpy(pcMeshOut->mColors[p] + aiCurrent[AI_PTVS_VERTEX],
					pcMesh->mColors[p],
					pcMesh->mNumVertices * sizeof(aiColor4D));
				++p;
			}
			// now we need to copy all faces
			// since we will delete the source mesh afterwards,
			// we don't need to reallocate the array of indices
			for (unsigned int planck = 0;planck<pcMesh->mNumFaces;++planck)
			{
				pcMeshOut->mFaces[aiCurrent[AI_PTVS_FACE]+planck].mNumIndices =
					pcMesh->mFaces[planck].mNumIndices; 

				unsigned int* pi = pcMeshOut->mFaces[aiCurrent[AI_PTVS_FACE]+planck].
					mIndices = pcMesh->mFaces[planck].mIndices; 

				// offset all vrtex indices
				for (unsigned int hahn = 0; hahn < pcMesh->mFaces[planck].mNumIndices;++hahn)
				{
					pi[hahn] += aiCurrent[AI_PTVS_VERTEX];
				}

				// just make sure the array won't be deleted by the
				// aiFace destructor ...
				pcMesh->mFaces[planck].mIndices = NULL;
			}
			aiCurrent[AI_PTVS_VERTEX] += pcMesh->mNumVertices;
			aiCurrent[AI_PTVS_FACE] += pcMesh->mNumFaces;
		}
	}
	for (unsigned int i = 0;i < pcNode->mNumChildren;++i)
	{
		CollectData(pcScene,pcNode->mChildren[i],iMat,
			iVFormat,pcMeshOut,aiCurrent);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
// Get a list of all vertex formats that occur for a given material index
// The output list contains duplicate elements
void GetVFormatList( aiScene* pcScene, aiNode* pcNode, unsigned int iMat,
					std::list<unsigned int>& aiOut)
{
	for (unsigned int i = 0; i < pcNode->mNumMeshes;++i)
	{
		aiMesh* pcMesh = pcScene->mMeshes[ pcNode->mMeshes[i] ]; 
		if (iMat == pcMesh->mMaterialIndex)
		{
			aiOut.push_back(GetMeshVFormat(pcMesh));
		}
	}
	for (unsigned int i = 0;i < pcNode->mNumChildren;++i)
	{
		GetVFormatList(pcScene,pcNode->mChildren[i],iMat,aiOut);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
// Compute the absolute transformation matrices of each node
void ComputeAbsoluteTransform( aiNode* pcNode )
{
	if (pcNode->mParent)
	{
		pcNode->mTransformation =  pcNode->mTransformation*pcNode->mParent->mTransformation;
	}

	for (unsigned int i = 0;i < pcNode->mNumChildren;++i)
	{
		ComputeAbsoluteTransform(pcNode->mChildren[i]);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void PretransformVertices::Execute( aiScene* pScene)
{
	DefaultLogger::get()->debug("PretransformVerticesProcess begin");

	// first compute absolute transformation matrices for all nodes
	ComputeAbsoluteTransform(pScene->mRootNode);

	// now build a list of output meshes
	std::vector<aiMesh*> apcOutMeshes;
	apcOutMeshes.reserve(pScene->mNumMaterials*2);
	std::list<unsigned int> aiVFormats;
	for (unsigned int i = 0; i < pScene->mNumMaterials;++i)
	{
		// get the list of all vertex formats for this material
		aiVFormats.clear();
		GetVFormatList(pScene,pScene->mRootNode,i,aiVFormats);
		aiVFormats.sort(std::less<unsigned int>());
		aiVFormats.unique();
		for (std::list<unsigned int>::const_iterator
			j =  aiVFormats.begin();
			j != aiVFormats.end();++j)
		{
			unsigned int iVertices = 0;
			unsigned int iFaces = 0; 
			CountVerticesAndFaces(pScene,pScene->mRootNode,i,*j,&iFaces,&iVertices);
			if (iFaces && iVertices)
			{
				apcOutMeshes.push_back(new aiMesh());
				aiMesh* pcMesh = apcOutMeshes.back();
				pcMesh->mNumFaces = iFaces;
				pcMesh->mNumVertices = iVertices;
				pcMesh->mFaces = new aiFace[iFaces];
				pcMesh->mVertices = new aiVector3D[iVertices];
				pcMesh->mMaterialIndex = i;
				if ((*j) & 0x1)pcMesh->mNormals = new aiVector3D[iVertices];
				if ((*j) & 0x2)
				{
					pcMesh->mTangents = new aiVector3D[iVertices];
					pcMesh->mBitangents = new aiVector3D[iVertices];
				}
				iFaces = 0;
				while ((*j) & (0x100 << iFaces))
				{
					pcMesh->mTextureCoords[iFaces] = new aiVector3D[iVertices];
					if ((*j) & (0x1000 << iFaces))pcMesh->mNumUVComponents[iFaces] = 3;
					else pcMesh->mNumUVComponents[iFaces] = 2;
					iFaces++;
				}
				iFaces = 0;
				while ((*j) & (0x10000 << iFaces))
					pcMesh->mColors[iFaces] = new aiColor4D[iVertices];

				// fill the mesh ...
				unsigned int aiTemp[2] = {0,0};
				CollectData(pScene,pScene->mRootNode,i,*j,pcMesh,aiTemp);
			}
		}
	}

	// remove all animations from the scene
	for (unsigned int i = 0; i < pScene->mNumAnimations;++i)
		delete pScene->mAnimations[i];
	pScene->mAnimations = NULL;
	pScene->mNumAnimations = 0;

	// now delete all meshes in the scene and build a new mesh list
	for (unsigned int i = 0; i < pScene->mNumMeshes;++i)
		delete pScene->mMeshes[i];
	if (apcOutMeshes.size() != pScene->mNumMeshes)
	{
		delete[] pScene->mMeshes;
		pScene->mNumMeshes = (unsigned int)apcOutMeshes.size();
		pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
	}
	for (unsigned int i = 0; i < pScene->mNumMeshes;++i)
		pScene->mMeshes[i] = apcOutMeshes[i];

	// now delete all nodes in the scene and build a new
	// flat node graph with a root node and some level 1 children
	delete pScene->mRootNode;
	pScene->mRootNode = new aiNode();
	pScene->mRootNode->mName.Set("<dummy_root>");

	if (1 == pScene->mNumMeshes)
	{
		pScene->mRootNode->mNumMeshes = 1;
		pScene->mRootNode->mMeshes = new unsigned int[1];
		pScene->mRootNode->mMeshes[0] = 0;
	}
	else
	{
		pScene->mRootNode->mNumChildren = pScene->mNumMeshes;
		pScene->mRootNode->mChildren = new aiNode*[pScene->mNumMeshes];
		for (unsigned int i = 0; i < pScene->mNumMeshes;++i)
		{
			aiNode* pcNode = pScene->mRootNode->mChildren[i] = new aiNode();
			pcNode->mName.length = sprintf(pcNode->mName.data,"dummy_%i",i);

			pcNode->mNumMeshes = 1;
			pcNode->mMeshes = new unsigned int[1];
			pcNode->mMeshes[0] = i;
			pcNode->mParent = pScene->mRootNode;
		}
	}

	DefaultLogger::get()->debug("PretransformVerticesProcess finished. All "
		"vertices are in worldspace now");
	return;
}