C++ MakeLeftHandedProcess类代码示例

// ------------------------------------------------------------------------------------------------
// Constructs the return data structure out of the imported data.
void XFileImporter::CreateDataRepresentationFromImport( aiScene* pScene, XFile::Scene* pData)
{
    // Read the global materials first so that meshes referring to them can find them later
    ConvertMaterials( pScene, pData->mGlobalMaterials);

    // copy nodes, extracting meshes and materials on the way
    pScene->mRootNode = CreateNodes( pScene, nullptr, pData->mRootNode);

    // extract animations
    CreateAnimations( pScene, pData);

    // read the global meshes that were stored outside of any node
    if( !pData->mGlobalMeshes.empty() )  {
        // create a root node to hold them if there isn't any, yet
        if( pScene->mRootNode == nullptr ) {
            pScene->mRootNode = new aiNode;
            pScene->mRootNode->mName.Set( "$dummy_node");
        }

        // convert all global meshes and store them in the root node.
        // If there was one before, the global meshes now suddenly have its transformation matrix...
        // Don't know what to do there, I don't want to insert another node under the present root node
        // just to avoid this.
        CreateMeshes( pScene, pScene->mRootNode, pData->mGlobalMeshes);
    }

    if (!pScene->mRootNode) {
        throw DeadlyImportError( "No root node" );
    }

    // Convert everything to OpenGL space... it's the same operation as the conversion back, so we can reuse the step directly
    MakeLeftHandedProcess convertProcess;
    convertProcess.Execute( pScene);

    FlipWindingOrderProcess flipper;
    flipper.Execute(pScene);

    // finally: create a dummy material if not material was imported
    if( pScene->mNumMaterials == 0) {
        pScene->mNumMaterials = 1;
        // create the Material
        aiMaterial* mat = new aiMaterial;
        int shadeMode = (int) aiShadingMode_Gouraud;
        mat->AddProperty<int>( &shadeMode, 1, AI_MATKEY_SHADING_MODEL);
        // material colours
        int specExp = 1;

        aiColor3D clr = aiColor3D( 0, 0, 0);
        mat->AddProperty( &clr, 1, AI_MATKEY_COLOR_EMISSIVE);
        mat->AddProperty( &clr, 1, AI_MATKEY_COLOR_SPECULAR);

        clr = aiColor3D( 0.5f, 0.5f, 0.5f);
        mat->AddProperty( &clr, 1, AI_MATKEY_COLOR_DIFFUSE);
        mat->AddProperty( &specExp, 1, AI_MATKEY_SHININESS);

        pScene->mMaterials = new aiMaterial*[1];
        pScene->mMaterials[0] = mat;
    }
}

// ------------------------------------------------------------------------------------------------
aiReturn Exporter :: Export( const aiScene* pScene, const char* pFormatId, const char* pPath, unsigned int pPreprocessing )
{
	ASSIMP_BEGIN_EXCEPTION_REGION();

	pimpl->mError = "";
	for (size_t i = 0; i < pimpl->mExporters.size(); ++i) {
		const Exporter::ExportFormatEntry& exp = pimpl->mExporters[i];
		if (!strcmp(exp.mDescription.id,pFormatId)) {

			try {

				// Always create a full copy of the scene. We might optimize this one day, 
				// but for now it is the most pragmatic way.
				aiScene* scenecopy_tmp;
				SceneCombiner::CopyScene(&scenecopy_tmp,pScene);

				std::auto_ptr<aiScene> scenecopy(scenecopy_tmp);
				const ScenePrivateData* const priv = ScenePriv(pScene);

				// steps that are not idempotent, i.e. we might need to run them again, usually to get back to the
				// original state before the step was applied first. When checking which steps we don't need
				// to run, those are excluded.
				const unsigned int nonIdempotentSteps = aiProcess_FlipWindingOrder | aiProcess_FlipUVs | aiProcess_MakeLeftHanded;

				// Erase all pp steps that were already applied to this scene
				unsigned int pp = (exp.mEnforcePP | pPreprocessing) & ~(priv 
					? (priv->mPPStepsApplied & ~nonIdempotentSteps)
					: 0u);

				// If no extra postprocessing was specified, and we obtained this scene from an
				// Assimp importer, apply the reverse steps automatically.
				if (!pPreprocessing && priv) {
					pp |= (nonIdempotentSteps & priv->mPPStepsApplied);
				}

				// If the input scene is not in verbose format, but there is at least postprocessing step that relies on it,
				// we need to run the MakeVerboseFormat step first.
				if (scenecopy->mFlags & AI_SCENE_FLAGS_NON_VERBOSE_FORMAT) {
					
					bool verbosify = false;
					for( unsigned int a = 0; a < pimpl->mPostProcessingSteps.size(); a++) {
						BaseProcess* const p = pimpl->mPostProcessingSteps[a];

						if (p->IsActive(pp) && p->RequireVerboseFormat()) {
							verbosify = true;
							break;
						}
					}

					if (verbosify || (exp.mEnforcePP & aiProcess_JoinIdenticalVertices)) {
						DefaultLogger::get()->debug("export: Scene data not in verbose format, applying MakeVerboseFormat step first");

						MakeVerboseFormatProcess proc;
						proc.Execute(scenecopy.get());
					}
				}

				if (pp) {
					// the three 'conversion' steps need to be executed first because all other steps rely on the standard data layout
					{
						FlipWindingOrderProcess step;
						if (step.IsActive(pp)) {
							step.Execute(scenecopy.get());
						}
					}
					
					{
						FlipUVsProcess step;
						if (step.IsActive(pp)) {
							step.Execute(scenecopy.get());
						}
					}

					{
						MakeLeftHandedProcess step;
						if (step.IsActive(pp)) {
							step.Execute(scenecopy.get());
						}
					}

					// dispatch other processes
					for( unsigned int a = 0; a < pimpl->mPostProcessingSteps.size(); a++) {
						BaseProcess* const p = pimpl->mPostProcessingSteps[a];

						if (p->IsActive(pp) 
							&& !dynamic_cast<FlipUVsProcess*>(p) 
							&& !dynamic_cast<FlipWindingOrderProcess*>(p) 
							&& !dynamic_cast<MakeLeftHandedProcess*>(p)) {

							p->Execute(scenecopy.get());
						}
					}
					ScenePrivateData* const privOut = ScenePriv(scenecopy.get());
					ai_assert(privOut);

					privOut->mPPStepsApplied |= pp;
				}

				exp.mExportFunction(pPath,pimpl->mIOSystem.get(),scenecopy.get());
//.........这里部分代码省略.........

//.........这里部分代码省略.........
    if( !_meshes.size() ) Fail( "No meshes" );

    //Fix nodes/meshes/bones
    for(size_t i=0;i<_nodes.size();++i ){
        aiNode *node=_nodes[i];

        for( size_t j=0;j<node->mNumMeshes;++j ){
            aiMesh *mesh=_meshes[node->mMeshes[j]];

            int n_tris=mesh->mNumFaces;
            int n_verts=mesh->mNumVertices=n_tris * 3;

            aiVector3D *mv=mesh->mVertices=new aiVector3D[ n_verts ],*mn=0,*mc=0;
            if( _vflags & 1 ) mn=mesh->mNormals=new aiVector3D[ n_verts ];
            if( _tcsets ) mc=mesh->mTextureCoords[0]=new aiVector3D[ n_verts ];

            aiFace *face=mesh->mFaces;

            vector< vector<aiVertexWeight> > vweights( _nodes.size() );

            for( int i=0;i<n_verts;i+=3 ){
                for( int j=0;j<3;++j ){
                    Vertex &v=_vertices[face->mIndices[j]];

                    *mv++=v.vertex;
                    if( mn ) *mn++=v.normal;
                    if( mc ) *mc++=v.texcoords;

                    face->mIndices[j]=i+j;

                    for( int k=0;k<4;++k ){
                        if( !v.weights[k] ) break;

                        int bone=v.bones[k];
                        float weight=v.weights[k];

                        vweights[bone].push_back( aiVertexWeight(i+j,weight) );
                    }
                }
                ++face;
            }

            vector<aiBone*> bones;
            for(size_t i=0;i<vweights.size();++i ){
                vector<aiVertexWeight> &weights=vweights[i];
                if( !weights.size() ) continue;

                aiBone *bone=new aiBone;
                bones.push_back( bone );

                aiNode *bnode=_nodes[i];

                bone->mName=bnode->mName;
                bone->mNumWeights=weights.size();
                bone->mWeights=to_array( weights );

                aiMatrix4x4 mat=bnode->mTransformation;
                while( bnode->mParent ){
                    bnode=bnode->mParent;
                    mat=bnode->mTransformation * mat;
                }
                bone->mOffsetMatrix=mat.Inverse();
            }
            mesh->mNumBones=bones.size();
            mesh->mBones=to_array( bones );
        }
    }

    //nodes
    scene->mRootNode=_nodes[0];

    //material
    if( !_materials.size() ){
        _materials.push_back( new aiMaterial );
    }
    scene->mNumMaterials=_materials.size();
    scene->mMaterials=to_array( _materials );

    //meshes
    scene->mNumMeshes=_meshes.size();
    scene->mMeshes=to_array( _meshes );

    //animations
    if( _animations.size()==1 && _nodeAnims.size() ){

        aiAnimation *anim=_animations.back();
        anim->mNumChannels=_nodeAnims.size();
        anim->mChannels=to_array( _nodeAnims );

        scene->mNumAnimations=_animations.size();
        scene->mAnimations=to_array( _animations );
    }

    // convert to RH
    MakeLeftHandedProcess makeleft;
    makeleft.Execute( scene );

    FlipWindingOrderProcess flip;
    flip.Execute( scene );
}

//.........这里部分代码省略.........
		else {
			tri.matIndex = static_cast<unsigned int>(nt-materials.begin());
			++nt->numFaces;
		}
	}

	if (!pScene->mNumMeshes) {
		throw DeadlyImportError("UNREAL: Unable to find valid mesh data");
	}

	// allocate meshes and bind them to the node graph
	pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
	pScene->mMaterials = new aiMaterial*[pScene->mNumMaterials = pScene->mNumMeshes];

	nd->mNumMeshes  = pScene->mNumMeshes;
	nd->mMeshes = new unsigned int[nd->mNumMeshes];
	for (unsigned int i = 0; i < pScene->mNumMeshes;++i) {
		aiMesh* m = pScene->mMeshes[i] =  new aiMesh();
		m->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

		const unsigned int num = materials[i].numFaces;
		m->mFaces            = new aiFace     [num];
		m->mVertices         = new aiVector3D [num*3];
		m->mTextureCoords[0] = new aiVector3D [num*3];

		nd->mMeshes[i] = i;

		// create materials, too
		aiMaterial* mat = new aiMaterial();
		pScene->mMaterials[i] = mat;

		// all white by default - texture rulez
		aiColor3D color(1.f,1.f,1.f);

		aiString s;
		::sprintf(s.data,"mat%i_tx%i_",i,materials[i].tex);

		// set the two-sided flag
		if (materials[i].type == Unreal::MF_NORMAL_TS) {
			const int twosided = 1;
			mat->AddProperty(&twosided,1,AI_MATKEY_TWOSIDED);
			::strcat(s.data,"ts_");
		}
		else ::strcat(s.data,"os_");

		// make TRANS faces 90% opaque that RemRedundantMaterials won't catch us
		if (materials[i].type == Unreal::MF_NORMAL_TRANS_TS)	{
			const float opac = 0.9f;
			mat->AddProperty(&opac,1,AI_MATKEY_OPACITY);
			::strcat(s.data,"tran_");
		}
		else ::strcat(s.data,"opaq_");

		// a special name for the weapon attachment point
		if (materials[i].type == Unreal::MF_WEAPON_PLACEHOLDER)	{
			s.length = ::sprintf(s.data,"$WeaponTag$");
			color = aiColor3D(0.f,0.f,0.f);
		}

		// set color and name
		mat->AddProperty(&color,1,AI_MATKEY_COLOR_DIFFUSE);
		s.length = ::strlen(s.data);
		mat->AddProperty(&s,AI_MATKEY_NAME);

		// set texture, if any
		const unsigned int tex = materials[i].tex;
		for (std::vector< std::pair< unsigned int, std::string > >::const_iterator it = textures.begin();it != textures.end();++it)	{
			if ((*it).first == tex)	{
				s.Set((*it).second);
				mat->AddProperty(&s,AI_MATKEY_TEXTURE_DIFFUSE(0));
				break;
			}
		}
	}

	// fill them.
	for (std::vector<Unreal::Triangle>::iterator it = triangles.begin(), end = triangles.end();it != end; ++it)	{
		Unreal::Triangle& tri = *it;
		Unreal::TempMat mat(tri);
		std::vector<Unreal::TempMat>::iterator nt = std::find(materials.begin(),materials.end(),mat);

		aiMesh* mesh = pScene->mMeshes[nt-materials.begin()];
		aiFace& f    = mesh->mFaces[mesh->mNumFaces++];
		f.mIndices   = new unsigned int[f.mNumIndices = 3];
		
		for (unsigned int i = 0; i < 3;++i,mesh->mNumVertices++) {
			f.mIndices[i] = mesh->mNumVertices;

			mesh->mVertices[mesh->mNumVertices] = vertices[ tri.mVertex[i] ];
			mesh->mTextureCoords[0][mesh->mNumVertices] = aiVector3D( tri.mTex[i][0] / 255.f, 1.f - tri.mTex[i][1] / 255.f, 0.f);
		}
	}

	// convert to RH
	MakeLeftHandedProcess hero;
	hero.Execute(pScene);

	FlipWindingOrderProcess flipper;
	flipper.Execute(pScene);
}

// ------------------------------------------------------------------------------------------------
aiReturn Exporter::Export( const aiScene* pScene, const char* pFormatId, const char* pPath,
        unsigned int pPreprocessing, const ExportProperties* pProperties) {
    ASSIMP_BEGIN_EXCEPTION_REGION();

    // when they create scenes from scratch, users will likely create them not in verbose
    // format. They will likely not be aware that there is a flag in the scene to indicate
    // this, however. To avoid surprises and bug reports, we check for duplicates in
    // meshes upfront.
    const bool is_verbose_format = !(pScene->mFlags & AI_SCENE_FLAGS_NON_VERBOSE_FORMAT) || IsVerboseFormat(pScene);

    pimpl->mProgressHandler->UpdateFileWrite(0, 4);

    pimpl->mError = "";
    for (size_t i = 0; i < pimpl->mExporters.size(); ++i) {
        const Exporter::ExportFormatEntry& exp = pimpl->mExporters[i];
        if (!strcmp(exp.mDescription.id,pFormatId)) {
            try {
                // Always create a full copy of the scene. We might optimize this one day,
                // but for now it is the most pragmatic way.
                aiScene* scenecopy_tmp = nullptr;
                SceneCombiner::CopyScene(&scenecopy_tmp,pScene);

                pimpl->mProgressHandler->UpdateFileWrite(1, 4);

                std::unique_ptr<aiScene> scenecopy(scenecopy_tmp);
                const ScenePrivateData* const priv = ScenePriv(pScene);

                // steps that are not idempotent, i.e. we might need to run them again, usually to get back to the
                // original state before the step was applied first. When checking which steps we don't need
                // to run, those are excluded.
                const unsigned int nonIdempotentSteps = aiProcess_FlipWindingOrder | aiProcess_FlipUVs | aiProcess_MakeLeftHanded;

                // Erase all pp steps that were already applied to this scene
                const unsigned int pp = (exp.mEnforcePP | pPreprocessing) & ~(priv && !priv->mIsCopy
                    ? (priv->mPPStepsApplied & ~nonIdempotentSteps)
                    : 0u);

                // If no extra post-processing was specified, and we obtained this scene from an
                // Assimp importer, apply the reverse steps automatically.
                // TODO: either drop this, or document it. Otherwise it is just a bad surprise.
                //if (!pPreprocessing && priv) {
                //  pp |= (nonIdempotentSteps & priv->mPPStepsApplied);
                //}

                // If the input scene is not in verbose format, but there is at least post-processing step that relies on it,
                // we need to run the MakeVerboseFormat step first.
                bool must_join_again = false;
                if (!is_verbose_format) {
                    bool verbosify = false;
                    for( unsigned int a = 0; a < pimpl->mPostProcessingSteps.size(); a++) {
                        BaseProcess* const p = pimpl->mPostProcessingSteps[a];

                        if (p->IsActive(pp) && p->RequireVerboseFormat()) {
                            verbosify = true;
                            break;
                        }
                    }

                    if (verbosify || (exp.mEnforcePP & aiProcess_JoinIdenticalVertices)) {
                        ASSIMP_LOG_DEBUG("export: Scene data not in verbose format, applying MakeVerboseFormat step first");

                        MakeVerboseFormatProcess proc;
                        proc.Execute(scenecopy.get());

                        if(!(exp.mEnforcePP & aiProcess_JoinIdenticalVertices)) {
                            must_join_again = true;
                        }
                    }
                }

                pimpl->mProgressHandler->UpdateFileWrite(2, 4);

                if (pp) {
                    // the three 'conversion' steps need to be executed first because all other steps rely on the standard data layout
                    {
                        FlipWindingOrderProcess step;
                        if (step.IsActive(pp)) {
                            step.Execute(scenecopy.get());
                        }
                    }

                    {
                        FlipUVsProcess step;
                        if (step.IsActive(pp)) {
                            step.Execute(scenecopy.get());
                        }
                    }

                    {
                        MakeLeftHandedProcess step;
                        if (step.IsActive(pp)) {
                            step.Execute(scenecopy.get());
                        }
                    }

                    bool exportPointCloud(false);
                    if (nullptr != pProperties) {
                        exportPointCloud = pProperties->GetPropertyBool(AI_CONFIG_EXPORT_POINT_CLOUDS);
                    }
//.........这里部分代码省略.........