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Diffstat (limited to 'thirdparty/assimp/code/FindDegenerates.cpp')
| -rw-r--r-- | thirdparty/assimp/code/FindDegenerates.cpp | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/thirdparty/assimp/code/FindDegenerates.cpp b/thirdparty/assimp/code/FindDegenerates.cpp new file mode 100644 index 0000000000..365f5d7447 --- /dev/null +++ b/thirdparty/assimp/code/FindDegenerates.cpp @@ -0,0 +1,300 @@ +/* +--------------------------------------------------------------------------- +Open Asset Import Library (assimp) +--------------------------------------------------------------------------- + +Copyright (c) 2006-2019, 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 FindDegenerates.cpp + * @brief Implementation of the FindDegenerates post-process step. +*/ + + + +// internal headers +#include "ProcessHelper.h" +#include "FindDegenerates.h" +#include <assimp/Exceptional.h> + +using namespace Assimp; + +//remove mesh at position 'index' from the scene +static void removeMesh(aiScene* pScene, unsigned const index); +//correct node indices to meshes and remove references to deleted mesh +static void updateSceneGraph(aiNode* pNode, unsigned const index); + +// ------------------------------------------------------------------------------------------------ +// Constructor to be privately used by Importer +FindDegeneratesProcess::FindDegeneratesProcess() +: mConfigRemoveDegenerates( false ) +, mConfigCheckAreaOfTriangle( false ){ + // empty +} + +// ------------------------------------------------------------------------------------------------ +// Destructor, private as well +FindDegeneratesProcess::~FindDegeneratesProcess() { + // nothing to do here +} + +// ------------------------------------------------------------------------------------------------ +// Returns whether the processing step is present in the given flag field. +bool FindDegeneratesProcess::IsActive( unsigned int pFlags) const { + return 0 != (pFlags & aiProcess_FindDegenerates); +} + +// ------------------------------------------------------------------------------------------------ +// Setup import configuration +void FindDegeneratesProcess::SetupProperties(const Importer* pImp) { + // Get the current value of AI_CONFIG_PP_FD_REMOVE + mConfigRemoveDegenerates = (0 != pImp->GetPropertyInteger(AI_CONFIG_PP_FD_REMOVE,0)); + mConfigCheckAreaOfTriangle = ( 0 != pImp->GetPropertyInteger(AI_CONFIG_PP_FD_CHECKAREA) ); +} + +// ------------------------------------------------------------------------------------------------ +// Executes the post processing step on the given imported data. +void FindDegeneratesProcess::Execute( aiScene* pScene) { + ASSIMP_LOG_DEBUG("FindDegeneratesProcess begin"); + for (unsigned int i = 0; i < pScene->mNumMeshes;++i) + { + //Do not process point cloud, ExecuteOnMesh works only with faces data + if ((pScene->mMeshes[i]->mPrimitiveTypes != aiPrimitiveType::aiPrimitiveType_POINT) && ExecuteOnMesh(pScene->mMeshes[i])) { + removeMesh(pScene, i); + --i; //the current i is removed, do not skip the next one + } + } + ASSIMP_LOG_DEBUG("FindDegeneratesProcess finished"); +} + +static void removeMesh(aiScene* pScene, unsigned const index) { + //we start at index and copy the pointers one position forward + //save the mesh pointer to delete it later + auto delete_me = pScene->mMeshes[index]; + for (unsigned i = index; i < pScene->mNumMeshes - 1; ++i) { + pScene->mMeshes[i] = pScene->mMeshes[i+1]; + } + pScene->mMeshes[pScene->mNumMeshes - 1] = nullptr; + --(pScene->mNumMeshes); + delete delete_me; + + //removing a mesh also requires updating all references to it in the scene graph + updateSceneGraph(pScene->mRootNode, index); +} + +static void updateSceneGraph(aiNode* pNode, unsigned const index) { + for (unsigned i = 0; i < pNode->mNumMeshes; ++i) { + if (pNode->mMeshes[i] > index) { + --(pNode->mMeshes[i]); + continue; + } + if (pNode->mMeshes[i] == index) { + for (unsigned j = i; j < pNode->mNumMeshes -1; ++j) { + pNode->mMeshes[j] = pNode->mMeshes[j+1]; + } + --(pNode->mNumMeshes); + --i; + continue; + } + } + //recurse to all children + for (unsigned i = 0; i < pNode->mNumChildren; ++i) { + updateSceneGraph(pNode->mChildren[i], index); + } +} + +static ai_real heron( ai_real a, ai_real b, ai_real c ) { + ai_real s = (a + b + c) / 2; + ai_real area = pow((s * ( s - a ) * ( s - b ) * ( s - c ) ), (ai_real)0.5 ); + return area; +} + +static ai_real distance3D( const aiVector3D &vA, aiVector3D &vB ) { + const ai_real lx = ( vB.x - vA.x ); + const ai_real ly = ( vB.y - vA.y ); + const ai_real lz = ( vB.z - vA.z ); + ai_real a = lx*lx + ly*ly + lz*lz; + ai_real d = pow( a, (ai_real)0.5 ); + + return d; +} + +static ai_real calculateAreaOfTriangle( const aiFace& face, aiMesh* mesh ) { + ai_real area = 0; + + aiVector3D vA( mesh->mVertices[ face.mIndices[ 0 ] ] ); + aiVector3D vB( mesh->mVertices[ face.mIndices[ 1 ] ] ); + aiVector3D vC( mesh->mVertices[ face.mIndices[ 2 ] ] ); + + ai_real a( distance3D( vA, vB ) ); + ai_real b( distance3D( vB, vC ) ); + ai_real c( distance3D( vC, vA ) ); + area = heron( a, b, c ); + + return area; +} + +// ------------------------------------------------------------------------------------------------ +// Executes the post processing step on the given imported mesh +bool FindDegeneratesProcess::ExecuteOnMesh( aiMesh* mesh) { + mesh->mPrimitiveTypes = 0; + + std::vector<bool> remove_me; + if (mConfigRemoveDegenerates) { + remove_me.resize( mesh->mNumFaces, false ); + } + + unsigned int deg = 0, limit; + for ( unsigned int a = 0; a < mesh->mNumFaces; ++a ) { + aiFace& face = mesh->mFaces[a]; + bool first = true; + + // check whether the face contains degenerated entries + for (unsigned int i = 0; i < face.mNumIndices; ++i) { + // Polygons with more than 4 points are allowed to have double points, that is + // simulating polygons with holes just with concave polygons. However, + // double points may not come directly after another. + limit = face.mNumIndices; + if (face.mNumIndices > 4) { + limit = std::min( limit, i+2 ); + } + + for (unsigned int t = i+1; t < limit; ++t) { + if (mesh->mVertices[face.mIndices[ i ] ] == mesh->mVertices[ face.mIndices[ t ] ]) { + // we have found a matching vertex position + // remove the corresponding index from the array + --face.mNumIndices; + --limit; + for (unsigned int m = t; m < face.mNumIndices; ++m) { + face.mIndices[ m ] = face.mIndices[ m+1 ]; + } + --t; + + // NOTE: we set the removed vertex index to an unique value + // to make sure the developer gets notified when his + // application attempts to access this data. + face.mIndices[ face.mNumIndices ] = 0xdeadbeef; + + if(first) { + ++deg; + first = false; + } + + if ( mConfigRemoveDegenerates ) { + remove_me[ a ] = true; + goto evil_jump_outside; // hrhrhrh ... yeah, this rocks baby! + } + } + } + + if ( mConfigCheckAreaOfTriangle ) { + if ( face.mNumIndices == 3 ) { + ai_real area = calculateAreaOfTriangle( face, mesh ); + if ( area < 1e-6 ) { + if ( mConfigRemoveDegenerates ) { + remove_me[ a ] = true; + goto evil_jump_outside; + } + + // todo: check for index which is corrupt. + } + } + } + } + + // We need to update the primitive flags array of the mesh. + switch (face.mNumIndices) + { + case 1u: + mesh->mPrimitiveTypes |= aiPrimitiveType_POINT; + break; + case 2u: + mesh->mPrimitiveTypes |= aiPrimitiveType_LINE; + break; + case 3u: + mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE; + break; + default: + mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON; + break; + }; +evil_jump_outside: + continue; + } + + // If AI_CONFIG_PP_FD_REMOVE is true, remove degenerated faces from the import + if (mConfigRemoveDegenerates && deg) { + unsigned int n = 0; + for (unsigned int a = 0; a < mesh->mNumFaces; ++a) + { + aiFace& face_src = mesh->mFaces[a]; + if (!remove_me[a]) { + aiFace& face_dest = mesh->mFaces[n++]; + + // Do a manual copy, keep the index array + face_dest.mNumIndices = face_src.mNumIndices; + face_dest.mIndices = face_src.mIndices; + + if (&face_src != &face_dest) { + // clear source + face_src.mNumIndices = 0; + face_src.mIndices = nullptr; + } + } + else { + // Otherwise delete it if we don't need this face + delete[] face_src.mIndices; + face_src.mIndices = nullptr; + face_src.mNumIndices = 0; + } + } + // Just leave the rest of the array unreferenced, we don't care for now + mesh->mNumFaces = n; + if (!mesh->mNumFaces) { + //The whole mesh consists of degenerated faces + //signal upward, that this mesh should be deleted. + ASSIMP_LOG_DEBUG("FindDegeneratesProcess removed a mesh full of degenerated primitives"); + return true; + } + } + + if (deg && !DefaultLogger::isNullLogger()) { + ASSIMP_LOG_WARN_F( "Found ", deg, " degenerated primitives"); + } + return false; +} |