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authorsanine <sanine.not@pm.me>2022-04-16 11:55:09 -0500
committersanine <sanine.not@pm.me>2022-04-16 11:55:09 -0500
commitdb81b925d776103326128bf629cbdda576a223e7 (patch)
tree58bea8155c686733310009f6bed7363f91fbeb9d /libs/assimp/code/PostProcessing/CalcTangentsProcess.cpp
parent55860037b14fb3893ba21cf2654c83d349cc1082 (diff)
move 3rd-party librarys into libs/ and add built-in honeysuckle
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+/*
+---------------------------------------------------------------------------
+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 Implementation of the post processing step to calculate
+ * tangents and bitangents for all imported meshes
+ */
+
+// internal headers
+#include "CalcTangentsProcess.h"
+#include "ProcessHelper.h"
+#include <assimp/TinyFormatter.h>
+#include <assimp/qnan.h>
+
+using namespace Assimp;
+
+// ------------------------------------------------------------------------------------------------
+// Constructor to be privately used by Importer
+CalcTangentsProcess::CalcTangentsProcess() :
+ configMaxAngle(float(AI_DEG_TO_RAD(45.f))), configSourceUV(0) {
+ // nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Destructor, private as well
+CalcTangentsProcess::~CalcTangentsProcess() {
+ // nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Returns whether the processing step is present in the given flag field.
+bool CalcTangentsProcess::IsActive(unsigned int pFlags) const {
+ return (pFlags & aiProcess_CalcTangentSpace) != 0;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Executes the post processing step on the given imported data.
+void CalcTangentsProcess::SetupProperties(const Importer *pImp) {
+ ai_assert(nullptr != pImp);
+
+ // get the current value of the property
+ configMaxAngle = pImp->GetPropertyFloat(AI_CONFIG_PP_CT_MAX_SMOOTHING_ANGLE, 45.f);
+ configMaxAngle = std::max(std::min(configMaxAngle, 45.0f), 0.0f);
+ configMaxAngle = AI_DEG_TO_RAD(configMaxAngle);
+
+ configSourceUV = pImp->GetPropertyInteger(AI_CONFIG_PP_CT_TEXTURE_CHANNEL_INDEX, 0);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Executes the post processing step on the given imported data.
+void CalcTangentsProcess::Execute(aiScene *pScene) {
+ ai_assert(nullptr != pScene);
+
+ ASSIMP_LOG_DEBUG("CalcTangentsProcess begin");
+
+ bool bHas = false;
+ for (unsigned int a = 0; a < pScene->mNumMeshes; a++) {
+ if (ProcessMesh(pScene->mMeshes[a], a)) bHas = true;
+ }
+
+ if (bHas) {
+ ASSIMP_LOG_INFO("CalcTangentsProcess finished. Tangents have been calculated");
+ } else {
+ ASSIMP_LOG_DEBUG("CalcTangentsProcess finished");
+ }
+}
+
+// ------------------------------------------------------------------------------------------------
+// Calculates tangents and bi-tangents for the given mesh
+bool CalcTangentsProcess::ProcessMesh(aiMesh *pMesh, unsigned int meshIndex) {
+ // we assume that the mesh is still in the verbose vertex format where each face has its own set
+ // of vertices and no vertices are shared between faces. Sadly I don't know any quick test to
+ // assert() it here.
+ // assert( must be verbose, dammit);
+
+ if (pMesh->mTangents) // this implies that mBitangents is also there
+ return false;
+
+ // If the mesh consists of lines and/or points but not of
+ // triangles or higher-order polygons the normal vectors
+ // are undefined.
+ if (!(pMesh->mPrimitiveTypes & (aiPrimitiveType_TRIANGLE | aiPrimitiveType_POLYGON))) {
+ ASSIMP_LOG_INFO("Tangents are undefined for line and point meshes");
+ return false;
+ }
+
+ // what we can check, though, is if the mesh has normals and texture coordinates. That's a requirement
+ if (pMesh->mNormals == nullptr) {
+ ASSIMP_LOG_ERROR("Failed to compute tangents; need normals");
+ return false;
+ }
+ if (configSourceUV >= AI_MAX_NUMBER_OF_TEXTURECOORDS || !pMesh->mTextureCoords[configSourceUV]) {
+ ASSIMP_LOG_ERROR("Failed to compute tangents; need UV data in channel", configSourceUV);
+ return false;
+ }
+
+ const float angleEpsilon = 0.9999f;
+
+ std::vector<bool> vertexDone(pMesh->mNumVertices, false);
+ const float qnan = get_qnan();
+
+ // create space for the tangents and bitangents
+ pMesh->mTangents = new aiVector3D[pMesh->mNumVertices];
+ pMesh->mBitangents = new aiVector3D[pMesh->mNumVertices];
+
+ const aiVector3D *meshPos = pMesh->mVertices;
+ const aiVector3D *meshNorm = pMesh->mNormals;
+ const aiVector3D *meshTex = pMesh->mTextureCoords[configSourceUV];
+ aiVector3D *meshTang = pMesh->mTangents;
+ aiVector3D *meshBitang = pMesh->mBitangents;
+
+ // calculate the tangent and bitangent for every face
+ for (unsigned int a = 0; a < pMesh->mNumFaces; a++) {
+ const aiFace &face = pMesh->mFaces[a];
+ if (face.mNumIndices < 3) {
+ // There are less than three indices, thus the tangent vector
+ // is not defined. We are finished with these vertices now,
+ // their tangent vectors are set to qnan.
+ for (unsigned int i = 0; i < face.mNumIndices; ++i) {
+ unsigned int idx = face.mIndices[i];
+ vertexDone[idx] = true;
+ meshTang[idx] = aiVector3D(qnan);
+ meshBitang[idx] = aiVector3D(qnan);
+ }
+
+ continue;
+ }
+
+ // triangle or polygon... we always use only the first three indices. A polygon
+ // is supposed to be planar anyways....
+ // FIXME: (thom) create correct calculation for multi-vertex polygons maybe?
+ const unsigned int p0 = face.mIndices[0], p1 = face.mIndices[1], p2 = face.mIndices[2];
+
+ // position differences p1->p2 and p1->p3
+ aiVector3D v = meshPos[p1] - meshPos[p0], w = meshPos[p2] - meshPos[p0];
+
+ // texture offset p1->p2 and p1->p3
+ float sx = meshTex[p1].x - meshTex[p0].x, sy = meshTex[p1].y - meshTex[p0].y;
+ float tx = meshTex[p2].x - meshTex[p0].x, ty = meshTex[p2].y - meshTex[p0].y;
+ float dirCorrection = (tx * sy - ty * sx) < 0.0f ? -1.0f : 1.0f;
+ // when t1, t2, t3 in same position in UV space, just use default UV direction.
+ if (sx * ty == sy * tx) {
+ sx = 0.0;
+ sy = 1.0;
+ tx = 1.0;
+ ty = 0.0;
+ }
+
+ // tangent points in the direction where to positive X axis of the texture coord's would point in model space
+ // bitangent's points along the positive Y axis of the texture coord's, respectively
+ aiVector3D tangent, bitangent;
+ tangent.x = (w.x * sy - v.x * ty) * dirCorrection;
+ tangent.y = (w.y * sy - v.y * ty) * dirCorrection;
+ tangent.z = (w.z * sy - v.z * ty) * dirCorrection;
+ bitangent.x = (- w.x * sx + v.x * tx) * dirCorrection;
+ bitangent.y = (- w.y * sx + v.y * tx) * dirCorrection;
+ bitangent.z = (- w.z * sx + v.z * tx) * dirCorrection;
+
+ // store for every vertex of that face
+ for (unsigned int b = 0; b < face.mNumIndices; ++b) {
+ unsigned int p = face.mIndices[b];
+
+ // project tangent and bitangent into the plane formed by the vertex' normal
+ aiVector3D localTangent = tangent - meshNorm[p] * (tangent * meshNorm[p]);
+ aiVector3D localBitangent = bitangent - meshNorm[p] * (bitangent * meshNorm[p]) - localTangent * (bitangent * localTangent);
+ localTangent.NormalizeSafe();
+ localBitangent.NormalizeSafe();
+
+ // reconstruct tangent/bitangent according to normal and bitangent/tangent when it's infinite or NaN.
+ bool invalid_tangent = is_special_float(localTangent.x) || is_special_float(localTangent.y) || is_special_float(localTangent.z);
+ bool invalid_bitangent = is_special_float(localBitangent.x) || is_special_float(localBitangent.y) || is_special_float(localBitangent.z);
+ if (invalid_tangent != invalid_bitangent) {
+ if (invalid_tangent) {
+ localTangent = meshNorm[p] ^ localBitangent;
+ localTangent.NormalizeSafe();
+ } else {
+ localBitangent = localTangent ^ meshNorm[p];
+ localBitangent.NormalizeSafe();
+ }
+ }
+
+ // and write it into the mesh.
+ meshTang[p] = localTangent;
+ meshBitang[p] = localBitangent;
+ }
+ }
+
+ // create a helper to quickly find locally close vertices among the vertex array
+ // FIX: check whether we can reuse the SpatialSort of a previous step
+ SpatialSort *vertexFinder = nullptr;
+ SpatialSort _vertexFinder;
+ float posEpsilon = 10e-6f;
+ if (shared) {
+ std::vector<std::pair<SpatialSort, float>> *avf;
+ shared->GetProperty(AI_SPP_SPATIAL_SORT, avf);
+ if (avf) {
+ std::pair<SpatialSort, float> &blubb = avf->operator[](meshIndex);
+ vertexFinder = &blubb.first;
+ posEpsilon = blubb.second;
+ ;
+ }
+ }
+ if (!vertexFinder) {
+ _vertexFinder.Fill(pMesh->mVertices, pMesh->mNumVertices, sizeof(aiVector3D));
+ vertexFinder = &_vertexFinder;
+ posEpsilon = ComputePositionEpsilon(pMesh);
+ }
+ std::vector<unsigned int> verticesFound;
+
+ const float fLimit = std::cos(configMaxAngle);
+ std::vector<unsigned int> closeVertices;
+
+ // in the second pass we now smooth out all tangents and bitangents at the same local position
+ // if they are not too far off.
+ for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
+ if (vertexDone[a])
+ continue;
+
+ const aiVector3D &origPos = pMesh->mVertices[a];
+ const aiVector3D &origNorm = pMesh->mNormals[a];
+ const aiVector3D &origTang = pMesh->mTangents[a];
+ const aiVector3D &origBitang = pMesh->mBitangents[a];
+ closeVertices.resize(0);
+
+ // find all vertices close to that position
+ vertexFinder->FindPositions(origPos, posEpsilon, verticesFound);
+
+ closeVertices.reserve(verticesFound.size() + 5);
+ closeVertices.push_back(a);
+
+ // look among them for other vertices sharing the same normal and a close-enough tangent/bitangent
+ for (unsigned int b = 0; b < verticesFound.size(); b++) {
+ unsigned int idx = verticesFound[b];
+ if (vertexDone[idx])
+ continue;
+ if (meshNorm[idx] * origNorm < angleEpsilon)
+ continue;
+ if (meshTang[idx] * origTang < fLimit)
+ continue;
+ if (meshBitang[idx] * origBitang < fLimit)
+ continue;
+
+ // it's similar enough -> add it to the smoothing group
+ closeVertices.push_back(idx);
+ vertexDone[idx] = true;
+ }
+
+ // smooth the tangents and bitangents of all vertices that were found to be close enough
+ aiVector3D smoothTangent(0, 0, 0), smoothBitangent(0, 0, 0);
+ for (unsigned int b = 0; b < closeVertices.size(); ++b) {
+ smoothTangent += meshTang[closeVertices[b]];
+ smoothBitangent += meshBitang[closeVertices[b]];
+ }
+ smoothTangent.Normalize();
+ smoothBitangent.Normalize();
+
+ // and write it back into all affected tangents
+ for (unsigned int b = 0; b < closeVertices.size(); ++b) {
+ meshTang[closeVertices[b]] = smoothTangent;
+ meshBitang[closeVertices[b]] = smoothBitangent;
+ }
+ }
+ return true;
+}