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Diffstat (limited to 'thirdparty/assimp/code/Subdivision.cpp')
| -rw-r--r-- | thirdparty/assimp/code/Subdivision.cpp | 588 |
1 files changed, 588 insertions, 0 deletions
diff --git a/thirdparty/assimp/code/Subdivision.cpp b/thirdparty/assimp/code/Subdivision.cpp new file mode 100644 index 0000000000..19db223a55 --- /dev/null +++ b/thirdparty/assimp/code/Subdivision.cpp @@ -0,0 +1,588 @@ +/* +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. + +---------------------------------------------------------------------- +*/ + +#include <assimp/Subdivision.h> +#include <assimp/SceneCombiner.h> +#include <assimp/SpatialSort.h> +#include "ProcessHelper.h" +#include <assimp/Vertex.h> +#include <assimp/ai_assert.h> +#include <stdio.h> + +using namespace Assimp; +void mydummy() {} + +// ------------------------------------------------------------------------------------------------ +/** Subdivider stub class to implement the Catmull-Clarke subdivision algorithm. The + * implementation is basing on recursive refinement. Directly evaluating the result is also + * possible and much quicker, but it depends on lengthy matrix lookup tables. */ +// ------------------------------------------------------------------------------------------------ +class CatmullClarkSubdivider : public Subdivider +{ +public: + void Subdivide (aiMesh* mesh, aiMesh*& out, unsigned int num, bool discard_input); + void Subdivide (aiMesh** smesh, size_t nmesh, + aiMesh** out, unsigned int num, bool discard_input); + + // --------------------------------------------------------------------------- + /** Intermediate description of an edge between two corners of a polygon*/ + // --------------------------------------------------------------------------- + struct Edge + { + Edge() + : ref(0) + {} + Vertex edge_point, midpoint; + unsigned int ref; + }; + + typedef std::vector<unsigned int> UIntVector; + typedef std::map<uint64_t,Edge> EdgeMap; + + // --------------------------------------------------------------------------- + // Hashing function to derive an index into an #EdgeMap from two given + // 'unsigned int' vertex coordinates (!!distinct coordinates - same + // vertex position == same index!!). + // NOTE - this leads to rare hash collisions if a) sizeof(unsigned int)>4 + // and (id[0]>2^32-1 or id[0]>2^32-1). + // MAKE_EDGE_HASH() uses temporaries, so INIT_EDGE_HASH() needs to be put + // at the head of every function which is about to use MAKE_EDGE_HASH(). + // Reason is that the hash is that hash construction needs to hold the + // invariant id0<id1 to identify an edge - else two hashes would refer + // to the same edge. + // --------------------------------------------------------------------------- +#define MAKE_EDGE_HASH(id0,id1) (eh_tmp0__=id0,eh_tmp1__=id1,\ + (eh_tmp0__<eh_tmp1__?std::swap(eh_tmp0__,eh_tmp1__):mydummy()),(uint64_t)eh_tmp0__^((uint64_t)eh_tmp1__<<32u)) + + +#define INIT_EDGE_HASH_TEMPORARIES()\ + unsigned int eh_tmp0__, eh_tmp1__; + +private: + void InternSubdivide (const aiMesh* const * smesh, + size_t nmesh,aiMesh** out, unsigned int num); +}; + + +// ------------------------------------------------------------------------------------------------ +// Construct a subdivider of a specific type +Subdivider* Subdivider::Create (Algorithm algo) +{ + switch (algo) + { + case CATMULL_CLARKE: + return new CatmullClarkSubdivider(); + }; + + ai_assert(false); + return NULL; // shouldn't happen +} + +// ------------------------------------------------------------------------------------------------ +// Call the Catmull Clark subdivision algorithm for one mesh +void CatmullClarkSubdivider::Subdivide ( + aiMesh* mesh, + aiMesh*& out, + unsigned int num, + bool discard_input + ) +{ + ai_assert(mesh != out); + + Subdivide(&mesh,1,&out,num,discard_input); +} + +// ------------------------------------------------------------------------------------------------ +// Call the Catmull Clark subdivision algorithm for multiple meshes +void CatmullClarkSubdivider::Subdivide ( + aiMesh** smesh, + size_t nmesh, + aiMesh** out, + unsigned int num, + bool discard_input + ) +{ + ai_assert( NULL != smesh ); + ai_assert( NULL != out ); + + // course, both regions may not overlap + ai_assert(smesh<out || smesh+nmesh>out+nmesh); + if (!num) { + // No subdivision at all. Need to copy all the meshes .. argh. + if (discard_input) { + for (size_t s = 0; s < nmesh; ++s) { + out[s] = smesh[s]; + smesh[s] = NULL; + } + } + else { + for (size_t s = 0; s < nmesh; ++s) { + SceneCombiner::Copy(out+s,smesh[s]); + } + } + return; + } + + std::vector<aiMesh*> inmeshes; + std::vector<aiMesh*> outmeshes; + std::vector<unsigned int> maptbl; + + inmeshes.reserve(nmesh); + outmeshes.reserve(nmesh); + maptbl.reserve(nmesh); + + // Remove pure line and point meshes from the working set to reduce the + // number of edge cases the subdivider is forced to deal with. Line and + // point meshes are simply passed through. + for (size_t s = 0; s < nmesh; ++s) { + aiMesh* i = smesh[s]; + // FIX - mPrimitiveTypes might not yet be initialized + if (i->mPrimitiveTypes && (i->mPrimitiveTypes & (aiPrimitiveType_LINE|aiPrimitiveType_POINT))==i->mPrimitiveTypes) { + ASSIMP_LOG_DEBUG("Catmull-Clark Subdivider: Skipping pure line/point mesh"); + + if (discard_input) { + out[s] = i; + smesh[s] = NULL; + } + else { + SceneCombiner::Copy(out+s,i); + } + continue; + } + + outmeshes.push_back(NULL);inmeshes.push_back(i); + maptbl.push_back(static_cast<unsigned int>(s)); + } + + // Do the actual subdivision on the preallocated storage. InternSubdivide + // *always* assumes that enough storage is available, it does not bother + // checking any ranges. + ai_assert(inmeshes.size()==outmeshes.size()&&inmeshes.size()==maptbl.size()); + if (inmeshes.empty()) { + ASSIMP_LOG_WARN("Catmull-Clark Subdivider: Pure point/line scene, I can't do anything"); + return; + } + InternSubdivide(&inmeshes.front(),inmeshes.size(),&outmeshes.front(),num); + for (unsigned int i = 0; i < maptbl.size(); ++i) { + ai_assert(nullptr != outmeshes[i]); + out[maptbl[i]] = outmeshes[i]; + } + + if (discard_input) { + for (size_t s = 0; s < nmesh; ++s) { + delete smesh[s]; + } + } +} + +// ------------------------------------------------------------------------------------------------ +// Note - this is an implementation of the standard (recursive) Cm-Cl algorithm without further +// optimizations (except we're using some nice LUTs). A description of the algorithm can be found +// here: http://en.wikipedia.org/wiki/Catmull-Clark_subdivision_surface +// +// The code is mostly O(n), however parts are O(nlogn) which is therefore the algorithm's +// expected total runtime complexity. The implementation is able to work in-place on the same +// mesh arrays. Calling #InternSubdivide() directly is not encouraged. The code can operate +// in-place unless 'smesh' and 'out' are equal (no strange overlaps or reorderings). +// Previous data is replaced/deleted then. +// ------------------------------------------------------------------------------------------------ +void CatmullClarkSubdivider::InternSubdivide ( + const aiMesh* const * smesh, + size_t nmesh, + aiMesh** out, + unsigned int num + ) +{ + ai_assert(NULL != smesh && NULL != out); + INIT_EDGE_HASH_TEMPORARIES(); + + // no subdivision requested or end of recursive refinement + if (!num) { + return; + } + + UIntVector maptbl; + SpatialSort spatial; + + // --------------------------------------------------------------------- + // 0. Offset table to index all meshes continuously, generate a spatially + // sorted representation of all vertices in all meshes. + // --------------------------------------------------------------------- + typedef std::pair<unsigned int,unsigned int> IntPair; + std::vector<IntPair> moffsets(nmesh); + unsigned int totfaces = 0, totvert = 0; + for (size_t t = 0; t < nmesh; ++t) { + const aiMesh* mesh = smesh[t]; + + spatial.Append(mesh->mVertices,mesh->mNumVertices,sizeof(aiVector3D),false); + moffsets[t] = IntPair(totfaces,totvert); + + totfaces += mesh->mNumFaces; + totvert += mesh->mNumVertices; + } + + spatial.Finalize(); + const unsigned int num_unique = spatial.GenerateMappingTable(maptbl,ComputePositionEpsilon(smesh,nmesh)); + + +#define FLATTEN_VERTEX_IDX(mesh_idx, vert_idx) (moffsets[mesh_idx].second+vert_idx) +#define FLATTEN_FACE_IDX(mesh_idx, face_idx) (moffsets[mesh_idx].first+face_idx) + + // --------------------------------------------------------------------- + // 1. Compute the centroid point for all faces + // --------------------------------------------------------------------- + std::vector<Vertex> centroids(totfaces); + unsigned int nfacesout = 0; + for (size_t t = 0, n = 0; t < nmesh; ++t) { + const aiMesh* mesh = smesh[t]; + for (unsigned int i = 0; i < mesh->mNumFaces;++i,++n) + { + const aiFace& face = mesh->mFaces[i]; + Vertex& c = centroids[n]; + + for (unsigned int a = 0; a < face.mNumIndices;++a) { + c += Vertex(mesh,face.mIndices[a]); + } + + c /= static_cast<float>(face.mNumIndices); + nfacesout += face.mNumIndices; + } + } + + { + // we want edges to go away before the recursive calls so begin a new scope + EdgeMap edges; + + // --------------------------------------------------------------------- + // 2. Set each edge point to be the average of all neighbouring + // face points and original points. Every edge exists twice + // if there is a neighboring face. + // --------------------------------------------------------------------- + for (size_t t = 0; t < nmesh; ++t) { + const aiMesh* mesh = smesh[t]; + + for (unsigned int i = 0; i < mesh->mNumFaces;++i) { + const aiFace& face = mesh->mFaces[i]; + + for (unsigned int p =0; p< face.mNumIndices; ++p) { + const unsigned int id[] = { + face.mIndices[p], + face.mIndices[p==face.mNumIndices-1?0:p+1] + }; + const unsigned int mp[] = { + maptbl[FLATTEN_VERTEX_IDX(t,id[0])], + maptbl[FLATTEN_VERTEX_IDX(t,id[1])] + }; + + Edge& e = edges[MAKE_EDGE_HASH(mp[0],mp[1])]; + e.ref++; + if (e.ref<=2) { + if (e.ref==1) { // original points (end points) - add only once + e.edge_point = e.midpoint = Vertex(mesh,id[0])+Vertex(mesh,id[1]); + e.midpoint *= 0.5f; + } + e.edge_point += centroids[FLATTEN_FACE_IDX(t,i)]; + } + } + } + } + + // --------------------------------------------------------------------- + // 3. Normalize edge points + // --------------------------------------------------------------------- + {unsigned int bad_cnt = 0; + for (EdgeMap::iterator it = edges.begin(); it != edges.end(); ++it) { + if ((*it).second.ref < 2) { + ai_assert((*it).second.ref); + ++bad_cnt; + } + (*it).second.edge_point *= 1.f/((*it).second.ref+2.f); + } + + if (bad_cnt) { + // Report the number of bad edges. bad edges are referenced by less than two + // faces in the mesh. They occur at outer model boundaries in non-closed + // shapes. + ASSIMP_LOG_DEBUG_F("Catmull-Clark Subdivider: got ", bad_cnt, " bad edges touching only one face (totally ", + static_cast<unsigned int>(edges.size()), " edges). "); + }} + + // --------------------------------------------------------------------- + // 4. Compute a vertex-face adjacency table. We can't reuse the code + // from VertexTriangleAdjacency because we need the table for multiple + // meshes and out vertex indices need to be mapped to distinct values + // first. + // --------------------------------------------------------------------- + UIntVector faceadjac(nfacesout), cntadjfac(maptbl.size(),0), ofsadjvec(maptbl.size()+1,0); { + for (size_t t = 0; t < nmesh; ++t) { + const aiMesh* const minp = smesh[t]; + for (unsigned int i = 0; i < minp->mNumFaces; ++i) { + + const aiFace& f = minp->mFaces[i]; + for (unsigned int n = 0; n < f.mNumIndices; ++n) { + ++cntadjfac[maptbl[FLATTEN_VERTEX_IDX(t,f.mIndices[n])]]; + } + } + } + unsigned int cur = 0; + for (size_t i = 0; i < cntadjfac.size(); ++i) { + ofsadjvec[i+1] = cur; + cur += cntadjfac[i]; + } + for (size_t t = 0; t < nmesh; ++t) { + const aiMesh* const minp = smesh[t]; + for (unsigned int i = 0; i < minp->mNumFaces; ++i) { + + const aiFace& f = minp->mFaces[i]; + for (unsigned int n = 0; n < f.mNumIndices; ++n) { + faceadjac[ofsadjvec[1+maptbl[FLATTEN_VERTEX_IDX(t,f.mIndices[n])]]++] = FLATTEN_FACE_IDX(t,i); + } + } + } + + // check the other way round for consistency +#ifdef ASSIMP_BUILD_DEBUG + + for (size_t t = 0; t < ofsadjvec.size()-1; ++t) { + for (unsigned int m = 0; m < cntadjfac[t]; ++m) { + const unsigned int fidx = faceadjac[ofsadjvec[t]+m]; + ai_assert(fidx < totfaces); + for (size_t n = 1; n < nmesh; ++n) { + + if (moffsets[n].first > fidx) { + const aiMesh* msh = smesh[--n]; + const aiFace& f = msh->mFaces[fidx-moffsets[n].first]; + + bool haveit = false; + for (unsigned int i = 0; i < f.mNumIndices; ++i) { + if (maptbl[FLATTEN_VERTEX_IDX(n,f.mIndices[i])]==(unsigned int)t) { + haveit = true; + break; + } + } + ai_assert(haveit); + if (!haveit) { + ASSIMP_LOG_DEBUG("Catmull-Clark Subdivider: Index not used"); + } + break; + } + } + } + } + +#endif + } + +#define GET_ADJACENT_FACES_AND_CNT(vidx,fstartout,numout) \ + fstartout = &faceadjac[ofsadjvec[vidx]], numout = cntadjfac[vidx] + + typedef std::pair<bool,Vertex> TouchedOVertex; + std::vector<TouchedOVertex > new_points(num_unique,TouchedOVertex(false,Vertex())); + // --------------------------------------------------------------------- + // 5. Spawn a quad from each face point to the corresponding edge points + // the original points being the fourth quad points. + // --------------------------------------------------------------------- + for (size_t t = 0; t < nmesh; ++t) { + const aiMesh* const minp = smesh[t]; + aiMesh* const mout = out[t] = new aiMesh(); + + for (unsigned int a = 0; a < minp->mNumFaces; ++a) { + mout->mNumFaces += minp->mFaces[a].mNumIndices; + } + + // We need random access to the old face buffer, so reuse is not possible. + mout->mFaces = new aiFace[mout->mNumFaces]; + + mout->mNumVertices = mout->mNumFaces*4; + mout->mVertices = new aiVector3D[mout->mNumVertices]; + + // quads only, keep material index + mout->mPrimitiveTypes = aiPrimitiveType_POLYGON; + mout->mMaterialIndex = minp->mMaterialIndex; + + if (minp->HasNormals()) { + mout->mNormals = new aiVector3D[mout->mNumVertices]; + } + + if (minp->HasTangentsAndBitangents()) { + mout->mTangents = new aiVector3D[mout->mNumVertices]; + mout->mBitangents = new aiVector3D[mout->mNumVertices]; + } + + for(unsigned int i = 0; minp->HasTextureCoords(i); ++i) { + mout->mTextureCoords[i] = new aiVector3D[mout->mNumVertices]; + mout->mNumUVComponents[i] = minp->mNumUVComponents[i]; + } + + for(unsigned int i = 0; minp->HasVertexColors(i); ++i) { + mout->mColors[i] = new aiColor4D[mout->mNumVertices]; + } + + mout->mNumVertices = mout->mNumFaces<<2u; + for (unsigned int i = 0, v = 0, n = 0; i < minp->mNumFaces;++i) { + + const aiFace& face = minp->mFaces[i]; + for (unsigned int a = 0; a < face.mNumIndices;++a) { + + // Get a clean new face. + aiFace& faceOut = mout->mFaces[n++]; + faceOut.mIndices = new unsigned int [faceOut.mNumIndices = 4]; + + // Spawn a new quadrilateral (ccw winding) for this original point between: + // a) face centroid + centroids[FLATTEN_FACE_IDX(t,i)].SortBack(mout,faceOut.mIndices[0]=v++); + + // b) adjacent edge on the left, seen from the centroid + const Edge& e0 = edges[MAKE_EDGE_HASH(maptbl[FLATTEN_VERTEX_IDX(t,face.mIndices[a])], + maptbl[FLATTEN_VERTEX_IDX(t,face.mIndices[a==face.mNumIndices-1?0:a+1]) + ])]; // fixme: replace with mod face.mNumIndices? + + // c) adjacent edge on the right, seen from the centroid + const Edge& e1 = edges[MAKE_EDGE_HASH(maptbl[FLATTEN_VERTEX_IDX(t,face.mIndices[a])], + maptbl[FLATTEN_VERTEX_IDX(t,face.mIndices[!a?face.mNumIndices-1:a-1]) + ])]; // fixme: replace with mod face.mNumIndices? + + e0.edge_point.SortBack(mout,faceOut.mIndices[3]=v++); + e1.edge_point.SortBack(mout,faceOut.mIndices[1]=v++); + + // d= original point P with distinct index i + // F := 0 + // R := 0 + // n := 0 + // for each face f containing i + // F := F+ centroid of f + // R := R+ midpoint of edge of f from i to i+1 + // n := n+1 + // + // (F+2R+(n-3)P)/n + const unsigned int org = maptbl[FLATTEN_VERTEX_IDX(t,face.mIndices[a])]; + TouchedOVertex& ov = new_points[org]; + + if (!ov.first) { + ov.first = true; + + const unsigned int* adj; unsigned int cnt; + GET_ADJACENT_FACES_AND_CNT(org,adj,cnt); + + if (cnt < 3) { + ov.second = Vertex(minp,face.mIndices[a]); + } + else { + + Vertex F,R; + for (unsigned int o = 0; o < cnt; ++o) { + ai_assert(adj[o] < totfaces); + F += centroids[adj[o]]; + + // adj[0] is a global face index - search the face in the mesh list + const aiMesh* mp = NULL; + size_t nidx; + + if (adj[o] < moffsets[0].first) { + mp = smesh[nidx=0]; + } + else { + for (nidx = 1; nidx<= nmesh; ++nidx) { + if (nidx == nmesh ||moffsets[nidx].first > adj[o]) { + mp = smesh[--nidx]; + break; + } + } + } + + ai_assert(adj[o]-moffsets[nidx].first < mp->mNumFaces); + const aiFace& f = mp->mFaces[adj[o]-moffsets[nidx].first]; + bool haveit = false; + + // find our original point in the face + for (unsigned int m = 0; m < f.mNumIndices; ++m) { + if (maptbl[FLATTEN_VERTEX_IDX(nidx,f.mIndices[m])] == org) { + + // add *both* edges. this way, we can be sure that we add + // *all* adjacent edges to R. In a closed shape, every + // edge is added twice - so we simply leave out the + // factor 2.f in the amove formula and get the right + // result. + + const Edge& c0 = edges[MAKE_EDGE_HASH(org,maptbl[FLATTEN_VERTEX_IDX( + nidx,f.mIndices[!m?f.mNumIndices-1:m-1])])]; + // fixme: replace with mod face.mNumIndices? + + const Edge& c1 = edges[MAKE_EDGE_HASH(org,maptbl[FLATTEN_VERTEX_IDX( + nidx,f.mIndices[m==f.mNumIndices-1?0:m+1])])]; + // fixme: replace with mod face.mNumIndices? + R += c0.midpoint+c1.midpoint; + + haveit = true; + break; + } + } + + // this invariant *must* hold if the vertex-to-face adjacency table is valid + ai_assert(haveit); + if ( !haveit ) { + ASSIMP_LOG_WARN( "OBJ: no name for material library specified." ); + } + } + + const float div = static_cast<float>(cnt), divsq = 1.f/(div*div); + ov.second = Vertex(minp,face.mIndices[a])*((div-3.f) / div) + R*divsq + F*divsq; + } + } + ov.second.SortBack(mout,faceOut.mIndices[2]=v++); + } + } + } + } // end of scope for edges, freeing its memory + + // --------------------------------------------------------------------- + // 7. Apply the next subdivision step. + // --------------------------------------------------------------------- + if (num != 1) { + std::vector<aiMesh*> tmp(nmesh); + InternSubdivide (out,nmesh,&tmp.front(),num-1); + for (size_t i = 0; i < nmesh; ++i) { + delete out[i]; + out[i] = tmp[i]; + } + } +} |