diff options
Diffstat (limited to 'src/mesh/assimp-master/code/AssetLib/Assjson/mesh_splitter.cpp')
-rw-r--r-- | src/mesh/assimp-master/code/AssetLib/Assjson/mesh_splitter.cpp | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/src/mesh/assimp-master/code/AssetLib/Assjson/mesh_splitter.cpp b/src/mesh/assimp-master/code/AssetLib/Assjson/mesh_splitter.cpp new file mode 100644 index 0000000..978437c --- /dev/null +++ b/src/mesh/assimp-master/code/AssetLib/Assjson/mesh_splitter.cpp @@ -0,0 +1,319 @@ +/* +Assimp2Json +Copyright (c) 2011, Alexander C. Gessler + +Licensed under a 3-clause BSD license. See the LICENSE file for more information. + +*/ + +#include "mesh_splitter.h" + +#include <assimp/scene.h> + +// ---------------------------------------------------------------------------- +// Note: this is largely based on assimp's SplitLargeMeshes_Vertex process. +// it is refactored and the coding style is slightly improved, though. +// ---------------------------------------------------------------------------- + +// ------------------------------------------------------------------------------------------------ +// Executes the post processing step on the given imported data. +void MeshSplitter::Execute( aiScene* pScene) { + std::vector<std::pair<aiMesh*, unsigned int> > source_mesh_map; + + for( unsigned int a = 0; a < pScene->mNumMeshes; a++) { + SplitMesh(a, pScene->mMeshes[a],source_mesh_map); + } + + const unsigned int size = static_cast<unsigned int>(source_mesh_map.size()); + if (size != pScene->mNumMeshes) { + // it seems something has been split. rebuild the mesh list + delete[] pScene->mMeshes; + pScene->mNumMeshes = size; + pScene->mMeshes = new aiMesh*[size](); + + for (unsigned int i = 0; i < size;++i) { + pScene->mMeshes[i] = source_mesh_map[i].first; + } + + // now we need to update all nodes + UpdateNode(pScene->mRootNode,source_mesh_map); + } +} + + +// ------------------------------------------------------------------------------------------------ +void MeshSplitter::UpdateNode(aiNode* pcNode, const std::vector<std::pair<aiMesh*, unsigned int> >& source_mesh_map) { + // TODO: should better use std::(multi)set for source_mesh_map. + + // for every index in out list build a new entry + std::vector<unsigned int> aiEntries; + aiEntries.reserve(pcNode->mNumMeshes + 1); + for (unsigned int i = 0; i < pcNode->mNumMeshes;++i) { + for (unsigned int a = 0, end = static_cast<unsigned int>(source_mesh_map.size()); a < end;++a) { + if (source_mesh_map[a].second == pcNode->mMeshes[i]) { + aiEntries.push_back(a); + } + } + } + + // now build the new list + delete pcNode->mMeshes; + pcNode->mNumMeshes = static_cast<unsigned int>(aiEntries.size()); + pcNode->mMeshes = new unsigned int[pcNode->mNumMeshes]; + + for (unsigned int b = 0; b < pcNode->mNumMeshes;++b) { + pcNode->mMeshes[b] = aiEntries[b]; + } + + // recursively update children + for (unsigned int i = 0, end = pcNode->mNumChildren; i < end;++i) { + UpdateNode ( pcNode->mChildren[i], source_mesh_map ); + } +} + +static const unsigned int WAS_NOT_COPIED = 0xffffffff; + +using PerVertexWeight = std::pair <unsigned int,float>; +using VertexWeightTable = std::vector <PerVertexWeight>; + +// ------------------------------------------------------------------------------------------------ +VertexWeightTable* ComputeVertexBoneWeightTable(const aiMesh* pMesh) { + if (!pMesh || !pMesh->mNumVertices || !pMesh->mNumBones) { + return nullptr; + } + + VertexWeightTable* const avPerVertexWeights = new VertexWeightTable[pMesh->mNumVertices]; + for (unsigned int i = 0; i < pMesh->mNumBones;++i) { + + aiBone* bone = pMesh->mBones[i]; + for (unsigned int a = 0; a < bone->mNumWeights;++a) { + const aiVertexWeight& weight = bone->mWeights[a]; + avPerVertexWeights[weight.mVertexId].emplace_back(i,weight.mWeight); + } + } + return avPerVertexWeights; +} + +// ------------------------------------------------------------------------------------------------ +void MeshSplitter :: SplitMesh(unsigned int a, aiMesh* in_mesh, std::vector<std::pair<aiMesh*, unsigned int> >& source_mesh_map) { + // TODO: should better use std::(multi)set for source_mesh_map. + + if (in_mesh->mNumVertices <= LIMIT) { + source_mesh_map.emplace_back(in_mesh,a); + return; + } + + // build a per-vertex weight list if necessary + VertexWeightTable* avPerVertexWeights = ComputeVertexBoneWeightTable(in_mesh); + + // we need to split this mesh into sub meshes. Estimate submesh size + const unsigned int sub_meshes = (in_mesh->mNumVertices / LIMIT) + 1; + + // create a std::vector<unsigned int> to remember which vertices have already + // been copied and to which position (i.e. output index) + std::vector<unsigned int> was_copied_to; + was_copied_to.resize(in_mesh->mNumVertices,WAS_NOT_COPIED); + + // Try to find a good estimate for the number of output faces + // per mesh. Add 12.5% as buffer + unsigned int size_estimated = in_mesh->mNumFaces / sub_meshes; + size_estimated += size_estimated / 8; + + // now generate all submeshes + unsigned int base = 0; + while (true) { + const unsigned int out_vertex_index = LIMIT; + + aiMesh* out_mesh = new aiMesh(); + out_mesh->mNumVertices = 0; + out_mesh->mMaterialIndex = in_mesh->mMaterialIndex; + + // the name carries the adjacency information between the meshes + out_mesh->mName = in_mesh->mName; + + typedef std::vector<aiVertexWeight> BoneWeightList; + if (in_mesh->HasBones()) { + out_mesh->mBones = new aiBone*[in_mesh->mNumBones](); + } + + // clear the temporary helper array + if (base) { + std::fill(was_copied_to.begin(), was_copied_to.end(), WAS_NOT_COPIED); + } + + std::vector<aiFace> vFaces; + + // reserve enough storage for most cases + if (in_mesh->HasPositions()) { + out_mesh->mVertices = new aiVector3D[out_vertex_index]; + } + + if (in_mesh->HasNormals()) { + out_mesh->mNormals = new aiVector3D[out_vertex_index]; + } + + if (in_mesh->HasTangentsAndBitangents()) { + out_mesh->mTangents = new aiVector3D[out_vertex_index]; + out_mesh->mBitangents = new aiVector3D[out_vertex_index]; + } + + for (unsigned int c = 0; in_mesh->HasVertexColors(c);++c) { + out_mesh->mColors[c] = new aiColor4D[out_vertex_index]; + } + + for (unsigned int c = 0; in_mesh->HasTextureCoords(c);++c) { + out_mesh->mNumUVComponents[c] = in_mesh->mNumUVComponents[c]; + out_mesh->mTextureCoords[c] = new aiVector3D[out_vertex_index]; + } + vFaces.reserve(size_estimated); + + // (we will also need to copy the array of indices) + while (base < in_mesh->mNumFaces) { + const unsigned int iNumIndices = in_mesh->mFaces[base].mNumIndices; + + // doesn't catch degenerates but is quite fast + unsigned int iNeed = 0; + for (unsigned int v = 0; v < iNumIndices;++v) { + unsigned int index = in_mesh->mFaces[base].mIndices[v]; + + // check whether we do already have this vertex + if (WAS_NOT_COPIED == was_copied_to[index]) { + iNeed++; + } + } + if (out_mesh->mNumVertices + iNeed > out_vertex_index) { + // don't use this face + break; + } + + vFaces.emplace_back(); + aiFace& rFace = vFaces.back(); + + // setup face type and number of indices + rFace.mNumIndices = iNumIndices; + rFace.mIndices = new unsigned int[iNumIndices]; + + // need to update the output primitive types + switch (rFace.mNumIndices) + { + case 1: + out_mesh->mPrimitiveTypes |= aiPrimitiveType_POINT; + break; + case 2: + out_mesh->mPrimitiveTypes |= aiPrimitiveType_LINE; + break; + case 3: + out_mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE; + break; + default: + out_mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON; + } + + // and copy the contents of the old array, offset them by current base + for (unsigned int v = 0; v < iNumIndices;++v) { + const unsigned int index = in_mesh->mFaces[base].mIndices[v]; + + // check whether we do already have this vertex + if (WAS_NOT_COPIED != was_copied_to[index]) { + rFace.mIndices[v] = was_copied_to[index]; + continue; + } + + // copy positions + out_mesh->mVertices[out_mesh->mNumVertices] = (in_mesh->mVertices[index]); + + // copy normals + if (in_mesh->HasNormals()) { + out_mesh->mNormals[out_mesh->mNumVertices] = (in_mesh->mNormals[index]); + } + + // copy tangents/bi-tangents + if (in_mesh->HasTangentsAndBitangents()) { + out_mesh->mTangents[out_mesh->mNumVertices] = (in_mesh->mTangents[index]); + out_mesh->mBitangents[out_mesh->mNumVertices] = (in_mesh->mBitangents[index]); + } + + // texture coordinates + for (unsigned int c = 0; c < AI_MAX_NUMBER_OF_TEXTURECOORDS;++c) { + if (in_mesh->HasTextureCoords( c)) { + out_mesh->mTextureCoords[c][out_mesh->mNumVertices] = in_mesh->mTextureCoords[c][index]; + } + } + // vertex colors + for (unsigned int c = 0; c < AI_MAX_NUMBER_OF_COLOR_SETS;++c) { + if (in_mesh->HasVertexColors( c)) { + out_mesh->mColors[c][out_mesh->mNumVertices] = in_mesh->mColors[c][index]; + } + } + // check whether we have bone weights assigned to this vertex + rFace.mIndices[v] = out_mesh->mNumVertices; + if (avPerVertexWeights) { + VertexWeightTable& table = avPerVertexWeights[ out_mesh->mNumVertices ]; + for (VertexWeightTable::const_iterator iter = table.begin(), end = table.end(); iter != end;++iter) { + // allocate the bone weight array if necessary and store it in the mBones field (HACK!) + BoneWeightList* weight_list = reinterpret_cast<BoneWeightList*>(out_mesh->mBones[(*iter).first]); + if (!weight_list) { + weight_list = new BoneWeightList(); + out_mesh->mBones[(*iter).first] = reinterpret_cast<aiBone*>(weight_list); + } + weight_list->push_back(aiVertexWeight(out_mesh->mNumVertices,(*iter).second)); + } + } + + was_copied_to[index] = out_mesh->mNumVertices; + out_mesh->mNumVertices++; + } + base++; + if(out_mesh->mNumVertices == out_vertex_index) { + // break here. The face is only added if it was complete + break; + } + } + + // check which bones we'll need to create for this submesh + if (in_mesh->HasBones()) { + aiBone** ppCurrent = out_mesh->mBones; + for (unsigned int k = 0; k < in_mesh->mNumBones;++k) { + // check whether the bone exists + BoneWeightList* const weight_list = reinterpret_cast<BoneWeightList*>(out_mesh->mBones[k]); + + if (weight_list) { + const aiBone* const bone_in = in_mesh->mBones[k]; + aiBone* const bone_out = new aiBone(); + *ppCurrent++ = bone_out; + bone_out->mName = aiString(bone_in->mName); + bone_out->mOffsetMatrix =bone_in->mOffsetMatrix; + bone_out->mNumWeights = (unsigned int)weight_list->size(); + bone_out->mWeights = new aiVertexWeight[bone_out->mNumWeights]; + + // copy the vertex weights + ::memcpy(bone_out->mWeights, &(*weight_list)[0],bone_out->mNumWeights * sizeof(aiVertexWeight)); + + delete weight_list; + out_mesh->mNumBones++; + } + } + } + + // copy the face list to the mesh + out_mesh->mFaces = new aiFace[vFaces.size()]; + out_mesh->mNumFaces = (unsigned int)vFaces.size(); + + for (unsigned int p = 0; p < out_mesh->mNumFaces;++p) { + out_mesh->mFaces[p] = vFaces[p]; + } + + // add the newly created mesh to the list + source_mesh_map.push_back(std::make_pair(out_mesh,a)); + + if (base == in_mesh->mNumFaces) { + break; + } + } + + // delete the per-vertex weight list again + delete[] avPerVertexWeights; + + // now delete the old mesh data + delete in_mesh; +} |