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Diffstat (limited to 'libs/assimp/code/PostProcessing/FindInstancesProcess.cpp')
| -rw-r--r-- | libs/assimp/code/PostProcessing/FindInstancesProcess.cpp | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/libs/assimp/code/PostProcessing/FindInstancesProcess.cpp b/libs/assimp/code/PostProcessing/FindInstancesProcess.cpp new file mode 100644 index 0000000..7f8c93f --- /dev/null +++ b/libs/assimp/code/PostProcessing/FindInstancesProcess.cpp @@ -0,0 +1,277 @@ +/* +--------------------------------------------------------------------------- +Open Asset Import Library (assimp) +--------------------------------------------------------------------------- + +Copyright (c) 2006-2022, 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 FindInstancesProcess.cpp + * @brief Implementation of the aiProcess_FindInstances postprocessing step +*/ + + +#include "FindInstancesProcess.h" +#include <memory> +#include <stdio.h> + +using namespace Assimp; + +// ------------------------------------------------------------------------------------------------ +// Constructor to be privately used by Importer +FindInstancesProcess::FindInstancesProcess() +: configSpeedFlag (false) +{} + +// ------------------------------------------------------------------------------------------------ +// Destructor, private as well +FindInstancesProcess::~FindInstancesProcess() +{} + +// ------------------------------------------------------------------------------------------------ +// Returns whether the processing step is present in the given flag field. +bool FindInstancesProcess::IsActive( unsigned int pFlags) const +{ + // FindInstances makes absolutely no sense together with PreTransformVertices + // fixme: spawn error message somewhere else? + return 0 != (pFlags & aiProcess_FindInstances) && 0 == (pFlags & aiProcess_PreTransformVertices); +} + +// ------------------------------------------------------------------------------------------------ +// Setup properties for the step +void FindInstancesProcess::SetupProperties(const Importer* pImp) +{ + // AI_CONFIG_FAVOUR_SPEED + configSpeedFlag = (0 != pImp->GetPropertyInteger(AI_CONFIG_FAVOUR_SPEED,0)); +} + +// ------------------------------------------------------------------------------------------------ +// Compare the bones of two meshes +bool CompareBones(const aiMesh* orig, const aiMesh* inst) +{ + for (unsigned int i = 0; i < orig->mNumBones;++i) { + aiBone* aha = orig->mBones[i]; + aiBone* oha = inst->mBones[i]; + + if (aha->mNumWeights != oha->mNumWeights || + aha->mOffsetMatrix != oha->mOffsetMatrix) { + return false; + } + + // compare weight per weight --- + for (unsigned int n = 0; n < aha->mNumWeights;++n) { + if (aha->mWeights[n].mVertexId != oha->mWeights[n].mVertexId || + (aha->mWeights[n].mWeight - oha->mWeights[n].mWeight) < 10e-3f) { + return false; + } + } + } + return true; +} + +// ------------------------------------------------------------------------------------------------ +// Update mesh indices in the node graph +void UpdateMeshIndices(aiNode* node, unsigned int* lookup) +{ + for (unsigned int n = 0; n < node->mNumMeshes;++n) + node->mMeshes[n] = lookup[node->mMeshes[n]]; + + for (unsigned int n = 0; n < node->mNumChildren;++n) + UpdateMeshIndices(node->mChildren[n],lookup); +} + +// ------------------------------------------------------------------------------------------------ +// Executes the post processing step on the given imported data. +void FindInstancesProcess::Execute( aiScene* pScene) +{ + ASSIMP_LOG_DEBUG("FindInstancesProcess begin"); + if (pScene->mNumMeshes) { + + // use a pseudo hash for all meshes in the scene to quickly find + // the ones which are possibly equal. This step is executed early + // in the pipeline, so we could, depending on the file format, + // have several thousand small meshes. That's too much for a brute + // everyone-against-everyone check involving up to 10 comparisons + // each. + std::unique_ptr<uint64_t[]> hashes (new uint64_t[pScene->mNumMeshes]); + std::unique_ptr<unsigned int[]> remapping (new unsigned int[pScene->mNumMeshes]); + + unsigned int numMeshesOut = 0; + for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) { + + aiMesh* inst = pScene->mMeshes[i]; + hashes[i] = GetMeshHash(inst); + + // Find an appropriate epsilon + // to compare position differences against + float epsilon = ComputePositionEpsilon(inst); + epsilon *= epsilon; + + for (int a = i-1; a >= 0; --a) { + if (hashes[i] == hashes[a]) + { + aiMesh* orig = pScene->mMeshes[a]; + if (!orig) + continue; + + // check for hash collision .. we needn't check + // the vertex format, it *must* match due to the + // (brilliant) construction of the hash + if (orig->mNumBones != inst->mNumBones || + orig->mNumFaces != inst->mNumFaces || + orig->mNumVertices != inst->mNumVertices || + orig->mMaterialIndex != inst->mMaterialIndex || + orig->mPrimitiveTypes != inst->mPrimitiveTypes) + continue; + + // up to now the meshes are equal. Now compare vertex positions, normals, + // tangents and bitangents using this epsilon. + if (orig->HasPositions()) { + if(!CompareArrays(orig->mVertices,inst->mVertices,orig->mNumVertices,epsilon)) + continue; + } + if (orig->HasNormals()) { + if(!CompareArrays(orig->mNormals,inst->mNormals,orig->mNumVertices,epsilon)) + continue; + } + if (orig->HasTangentsAndBitangents()) { + if (!CompareArrays(orig->mTangents,inst->mTangents,orig->mNumVertices,epsilon) || + !CompareArrays(orig->mBitangents,inst->mBitangents,orig->mNumVertices,epsilon)) + continue; + } + + // use a constant epsilon for colors and UV coordinates + static const float uvEpsilon = 10e-4f; + { + unsigned int j, end = orig->GetNumUVChannels(); + for(j = 0; j < end; ++j) { + if (!orig->mTextureCoords[j]) { + continue; + } + if(!CompareArrays(orig->mTextureCoords[j],inst->mTextureCoords[j],orig->mNumVertices,uvEpsilon)) { + break; + } + } + if (j != end) { + continue; + } + } + { + unsigned int j, end = orig->GetNumColorChannels(); + for(j = 0; j < end; ++j) { + if (!orig->mColors[j]) { + continue; + } + if(!CompareArrays(orig->mColors[j],inst->mColors[j],orig->mNumVertices,uvEpsilon)) { + break; + } + } + if (j != end) { + continue; + } + } + + // These two checks are actually quite expensive and almost *never* required. + // Almost. That's why they're still here. But there's no reason to do them + // in speed-targeted imports. + if (!configSpeedFlag) { + + // It seems to be strange, but we really need to check whether the + // bones are identical too. Although it's extremely unprobable + // that they're not if control reaches here, we need to deal + // with unprobable cases, too. It could still be that there are + // equal shapes which are deformed differently. + if (!CompareBones(orig,inst)) + continue; + + // For completeness ... compare even the index buffers for equality + // face order & winding order doesn't care. Input data is in verbose format. + std::unique_ptr<unsigned int[]> ftbl_orig(new unsigned int[orig->mNumVertices]); + std::unique_ptr<unsigned int[]> ftbl_inst(new unsigned int[orig->mNumVertices]); + + for (unsigned int tt = 0; tt < orig->mNumFaces;++tt) { + aiFace& f = orig->mFaces[tt]; + for (unsigned int nn = 0; nn < f.mNumIndices;++nn) + ftbl_orig[f.mIndices[nn]] = tt; + + aiFace& f2 = inst->mFaces[tt]; + for (unsigned int nn = 0; nn < f2.mNumIndices;++nn) + ftbl_inst[f2.mIndices[nn]] = tt; + } + if (0 != ::memcmp(ftbl_inst.get(),ftbl_orig.get(),orig->mNumVertices*sizeof(unsigned int))) + continue; + } + + // We're still here. Or in other words: 'inst' is an instance of 'orig'. + // Place a marker in our list that we can easily update mesh indices. + remapping[i] = remapping[a]; + + // Delete the instanced mesh, we don't need it anymore + delete inst; + pScene->mMeshes[i] = nullptr; + break; + } + } + + // If we didn't find a match for the current mesh: keep it + if (pScene->mMeshes[i]) { + remapping[i] = numMeshesOut++; + } + } + ai_assert(0 != numMeshesOut); + if (numMeshesOut != pScene->mNumMeshes) { + + // Collapse the meshes array by removing all nullptr entries + for (unsigned int real = 0, i = 0; real < numMeshesOut; ++i) { + if (pScene->mMeshes[i]) + pScene->mMeshes[real++] = pScene->mMeshes[i]; + } + + // And update the node graph with our nice lookup table + UpdateMeshIndices(pScene->mRootNode,remapping.get()); + + // write to log + if (!DefaultLogger::isNullLogger()) { + ASSIMP_LOG_INFO( "FindInstancesProcess finished. Found ", (pScene->mNumMeshes - numMeshesOut), " instances" ); + } + pScene->mNumMeshes = numMeshesOut; + } else { + ASSIMP_LOG_DEBUG("FindInstancesProcess finished. No instanced meshes found"); + } + } +} |