/* --------------------------------------------------------------------------- Open Asset Import Library (assimp) --------------------------------------------------------------------------- Copyright (c) 2006-2020, assimp team All rights reserved. Redistribution and use of this software in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the assimp team, nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission of the assimp team. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. --------------------------------------------------------------------------- */ /** @file OptimizeMeshes.cpp * @brief Implementation of the aiProcess_OptimizeMeshes step */ #ifndef ASSIMP_BUILD_NO_OPTIMIZEMESHES_PROCESS #include "OptimizeMeshes.h" #include "ProcessHelper.h" #include #include using namespace Assimp; static const unsigned int NotSet = 0xffffffff; static const unsigned int DeadBeef = 0xdeadbeef; // ------------------------------------------------------------------------------------------------ // Constructor to be privately used by Importer OptimizeMeshesProcess::OptimizeMeshesProcess() : mScene() , pts(false) , max_verts( NotSet ) , max_faces( NotSet ) { // empty } // ------------------------------------------------------------------------------------------------ // Destructor, private as well OptimizeMeshesProcess::~OptimizeMeshesProcess() { // empty } // ------------------------------------------------------------------------------------------------ // Returns whether the processing step is present in the given flag field. bool OptimizeMeshesProcess::IsActive( unsigned int pFlags) const { // Our behaviour needs to be different if the SortByPType or SplitLargeMeshes // steps are active. Thus we need to query their flags here and store the // information, although we're breaking const-correctness. // That's a serious design flaw, consider redesign. if( 0 != (pFlags & aiProcess_OptimizeMeshes) ) { pts = (0 != (pFlags & aiProcess_SortByPType)); max_verts = ( 0 != ( pFlags & aiProcess_SplitLargeMeshes ) ) ? DeadBeef : max_verts; return true; } return false; } // ------------------------------------------------------------------------------------------------ // Setup properties for the post-processing step void OptimizeMeshesProcess::SetupProperties(const Importer* pImp) { if( max_verts == DeadBeef /* magic hack */ ) { max_faces = pImp->GetPropertyInteger(AI_CONFIG_PP_SLM_TRIANGLE_LIMIT,AI_SLM_DEFAULT_MAX_TRIANGLES); max_verts = pImp->GetPropertyInteger(AI_CONFIG_PP_SLM_VERTEX_LIMIT,AI_SLM_DEFAULT_MAX_VERTICES); } } // ------------------------------------------------------------------------------------------------ // Execute step void OptimizeMeshesProcess::Execute( aiScene* pScene) { const unsigned int num_old = pScene->mNumMeshes; if (num_old <= 1) { ASSIMP_LOG_DEBUG("Skipping OptimizeMeshesProcess"); return; } ASSIMP_LOG_DEBUG("OptimizeMeshesProcess begin"); mScene = pScene; // need to clear persistent members from previous runs merge_list.resize( 0 ); output.resize( 0 ); // ensure we have the right sizes merge_list.reserve(pScene->mNumMeshes); output.reserve(pScene->mNumMeshes); // Prepare lookup tables meshes.resize(pScene->mNumMeshes); FindInstancedMeshes(pScene->mRootNode); if( max_verts == DeadBeef ) /* undo the magic hack */ max_verts = NotSet; // ... instanced meshes are immediately processed and added to the output list for (unsigned int i = 0, n = 0; i < pScene->mNumMeshes;++i) { meshes[i].vertex_format = GetMeshVFormatUnique(pScene->mMeshes[i]); if (meshes[i].instance_cnt > 1 && meshes[i].output_id == NotSet ) { meshes[i].output_id = n++; output.push_back(mScene->mMeshes[i]); } } // and process all nodes in the scenegraph recursively ProcessNode(pScene->mRootNode); if (output.empty()) { throw DeadlyImportError("OptimizeMeshes: No meshes remaining; there's definitely something wrong"); } meshes.resize( 0 ); ai_assert(output.size() <= num_old); mScene->mNumMeshes = static_cast(output.size()); std::copy(output.begin(),output.end(),mScene->mMeshes); if (output.size() != num_old) { ASSIMP_LOG_DEBUG_F("OptimizeMeshesProcess finished. Input meshes: ", num_old, ", Output meshes: ", pScene->mNumMeshes); } else { ASSIMP_LOG_DEBUG( "OptimizeMeshesProcess finished" ); } } // ------------------------------------------------------------------------------------------------ // Process meshes for a single node void OptimizeMeshesProcess::ProcessNode( aiNode* pNode) { for (unsigned int i = 0; i < pNode->mNumMeshes;++i) { unsigned int& im = pNode->mMeshes[i]; if (meshes[im].instance_cnt > 1) { im = meshes[im].output_id; } else { merge_list.resize( 0 ); unsigned int verts = 0, faces = 0; // Find meshes to merge with us for (unsigned int a = i+1; a < pNode->mNumMeshes;++a) { unsigned int am = pNode->mMeshes[a]; if (meshes[am].instance_cnt == 1 && CanJoin(im,am,verts,faces)) { merge_list.push_back(mScene->mMeshes[am]); verts += mScene->mMeshes[am]->mNumVertices; faces += mScene->mMeshes[am]->mNumFaces; pNode->mMeshes[a] = pNode->mMeshes[pNode->mNumMeshes - 1]; --pNode->mNumMeshes; --a; } } // and merge all meshes which we found, replace the old ones if (!merge_list.empty()) { merge_list.push_back(mScene->mMeshes[im]); aiMesh* out; SceneCombiner::MergeMeshes(&out,0,merge_list.begin(),merge_list.end()); output.push_back(out); } else { output.push_back(mScene->mMeshes[im]); } im = static_cast(output.size()-1); } } for( unsigned int i = 0; i < pNode->mNumChildren; ++i ) { ProcessNode( pNode->mChildren[ i ] ); } } // ------------------------------------------------------------------------------------------------ // Check whether two meshes can be joined bool OptimizeMeshesProcess::CanJoin ( unsigned int a, unsigned int b, unsigned int verts, unsigned int faces ) { if (meshes[a].vertex_format != meshes[b].vertex_format) return false; aiMesh* ma = mScene->mMeshes[a], *mb = mScene->mMeshes[b]; if ((NotSet != max_verts && verts+mb->mNumVertices > max_verts) || (NotSet != max_faces && faces+mb->mNumFaces > max_faces)) { return false; } // Never merge unskinned meshes with skinned meshes if (ma->mMaterialIndex != mb->mMaterialIndex || ma->HasBones() != mb->HasBones()) return false; // Never merge meshes with different kinds of primitives if SortByPType did already // do its work. We would destroy everything again ... if (pts && ma->mPrimitiveTypes != mb->mPrimitiveTypes) return false; // If both meshes are skinned, check whether we have many bones defined in both meshes. // If yes, we can join them. if (ma->HasBones()) { // TODO return false; } return true; } // ------------------------------------------------------------------------------------------------ // Build a LUT of all instanced meshes void OptimizeMeshesProcess::FindInstancedMeshes (aiNode* pNode) { for( unsigned int i = 0; i < pNode->mNumMeshes; ++i ) { ++meshes[ pNode->mMeshes[ i ] ].instance_cnt; } for( unsigned int i = 0; i < pNode->mNumChildren; ++i ) { FindInstancedMeshes( pNode->mChildren[ i ] ); } } // ------------------------------------------------------------------------------------------------ #endif // !! ASSIMP_BUILD_NO_OPTIMIZEMESHES_PROCESS