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authorsanine <sanine.not@pm.me>2022-04-16 11:55:54 -0500
committersanine <sanine.not@pm.me>2022-04-16 11:55:54 -0500
commit8fb7916a0d0cb007a4c3a4e6a31af58765268ca3 (patch)
tree52b5524a94a5b04e17a1fd7f8aca988ab6d0c75f /src/mesh/assimp-master/code/PostProcessing/TriangulateProcess.cpp
parentdb81b925d776103326128bf629cbdda576a223e7 (diff)
delete src/mesh/assimp-master
Diffstat (limited to 'src/mesh/assimp-master/code/PostProcessing/TriangulateProcess.cpp')
-rw-r--r--src/mesh/assimp-master/code/PostProcessing/TriangulateProcess.cpp628
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diff --git a/src/mesh/assimp-master/code/PostProcessing/TriangulateProcess.cpp b/src/mesh/assimp-master/code/PostProcessing/TriangulateProcess.cpp
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--- a/src/mesh/assimp-master/code/PostProcessing/TriangulateProcess.cpp
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@@ -1,628 +0,0 @@
-/*
----------------------------------------------------------------------------
-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 TriangulateProcess.cpp
- * @brief Implementation of the post processing step to split up
- * all faces with more than three indices into triangles.
- *
- *
- * The triangulation algorithm will handle concave or convex polygons.
- * Self-intersecting or non-planar polygons are not rejected, but
- * they're probably not triangulated correctly.
- *
- * DEBUG SWITCHES - do not enable any of them in release builds:
- *
- * AI_BUILD_TRIANGULATE_COLOR_FACE_WINDING
- * - generates vertex colors to represent the face winding order.
- * the first vertex of a polygon becomes red, the last blue.
- * AI_BUILD_TRIANGULATE_DEBUG_POLYS
- * - dump all polygons and their triangulation sequences to
- * a file
- */
-#ifndef ASSIMP_BUILD_NO_TRIANGULATE_PROCESS
-
-#include "PostProcessing/TriangulateProcess.h"
-#include "PostProcessing/ProcessHelper.h"
-#include "Common/PolyTools.h"
-
-#include <memory>
-#include <cstdint>
-
-//#define AI_BUILD_TRIANGULATE_COLOR_FACE_WINDING
-//#define AI_BUILD_TRIANGULATE_DEBUG_POLYS
-
-#define POLY_GRID_Y 40
-#define POLY_GRID_X 70
-#define POLY_GRID_XPAD 20
-#define POLY_OUTPUT_FILE "assimp_polygons_debug.txt"
-
-using namespace Assimp;
-
-namespace {
-
- /**
- * @brief Helper struct used to simplify NGON encoding functions.
- */
- struct NGONEncoder {
- NGONEncoder() : mLastNGONFirstIndex((unsigned int)-1) {}
-
- /**
- * @brief Encode the current triangle, and make sure it is recognized as a triangle.
- *
- * This method will rotate indices in tri if needed in order to avoid tri to be considered
- * part of the previous ngon. This method is to be used whenever you want to emit a real triangle,
- * and make sure it is seen as a triangle.
- *
- * @param tri Triangle to encode.
- */
- void ngonEncodeTriangle(aiFace * tri) {
- ai_assert(tri->mNumIndices == 3);
-
- // Rotate indices in new triangle to avoid ngon encoding false ngons
- // Otherwise, the new triangle would be considered part of the previous NGON.
- if (isConsideredSameAsLastNgon(tri)) {
- std::swap(tri->mIndices[0], tri->mIndices[2]);
- std::swap(tri->mIndices[1], tri->mIndices[2]);
- }
-
- mLastNGONFirstIndex = tri->mIndices[0];
- }
-
- /**
- * @brief Encode a quad (2 triangles) in ngon encoding, and make sure they are seen as a single ngon.
- *
- * @param tri1 First quad triangle
- * @param tri2 Second quad triangle
- *
- * @pre Triangles must be properly fanned from the most appropriate vertex.
- */
- void ngonEncodeQuad(aiFace *tri1, aiFace *tri2) {
- ai_assert(tri1->mNumIndices == 3);
- ai_assert(tri2->mNumIndices == 3);
- ai_assert(tri1->mIndices[0] == tri2->mIndices[0]);
-
- // If the selected fanning vertex is the same as the previously
- // emitted ngon, we use the opposite vertex which also happens to work
- // for tri-fanning a concave quad.
- // ref: https://github.com/assimp/assimp/pull/3695#issuecomment-805999760
- if (isConsideredSameAsLastNgon(tri1)) {
- // Right-rotate indices for tri1 (index 2 becomes the new fanning vertex)
- std::swap(tri1->mIndices[0], tri1->mIndices[2]);
- std::swap(tri1->mIndices[1], tri1->mIndices[2]);
-
- // Left-rotate indices for tri2 (index 2 becomes the new fanning vertex)
- std::swap(tri2->mIndices[1], tri2->mIndices[2]);
- std::swap(tri2->mIndices[0], tri2->mIndices[2]);
-
- ai_assert(tri1->mIndices[0] == tri2->mIndices[0]);
- }
-
- mLastNGONFirstIndex = tri1->mIndices[0];
- }
-
- /**
- * @brief Check whether this triangle would be considered part of the lastly emitted ngon or not.
- *
- * @param tri Current triangle.
- * @return true If used as is, this triangle will be part of last ngon.
- * @return false If used as is, this triangle is not considered part of the last ngon.
- */
- bool isConsideredSameAsLastNgon(const aiFace * tri) const {
- ai_assert(tri->mNumIndices == 3);
- return tri->mIndices[0] == mLastNGONFirstIndex;
- }
-
- private:
- unsigned int mLastNGONFirstIndex;
- };
-
-}
-
-
-// ------------------------------------------------------------------------------------------------
-// Constructor to be privately used by Importer
-TriangulateProcess::TriangulateProcess()
-{
- // nothing to do here
-}
-
-// ------------------------------------------------------------------------------------------------
-// Destructor, private as well
-TriangulateProcess::~TriangulateProcess()
-{
- // nothing to do here
-}
-
-// ------------------------------------------------------------------------------------------------
-// Returns whether the processing step is present in the given flag field.
-bool TriangulateProcess::IsActive( unsigned int pFlags) const
-{
- return (pFlags & aiProcess_Triangulate) != 0;
-}
-
-// ------------------------------------------------------------------------------------------------
-// Executes the post processing step on the given imported data.
-void TriangulateProcess::Execute( aiScene* pScene)
-{
- ASSIMP_LOG_DEBUG("TriangulateProcess begin");
-
- bool bHas = false;
- for( unsigned int a = 0; a < pScene->mNumMeshes; a++)
- {
- if (pScene->mMeshes[ a ]) {
- if ( TriangulateMesh( pScene->mMeshes[ a ] ) ) {
- bHas = true;
- }
- }
- }
- if ( bHas ) {
- ASSIMP_LOG_INFO( "TriangulateProcess finished. All polygons have been triangulated." );
- } else {
- ASSIMP_LOG_DEBUG( "TriangulateProcess finished. There was nothing to be done." );
- }
-}
-
-// ------------------------------------------------------------------------------------------------
-// Triangulates the given mesh.
-bool TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
-{
- // Now we have aiMesh::mPrimitiveTypes, so this is only here for test cases
- if (!pMesh->mPrimitiveTypes) {
- bool bNeed = false;
-
- for( unsigned int a = 0; a < pMesh->mNumFaces; a++) {
- const aiFace& face = pMesh->mFaces[a];
-
- if( face.mNumIndices != 3) {
- bNeed = true;
- }
- }
- if (!bNeed)
- return false;
- }
- else if (!(pMesh->mPrimitiveTypes & aiPrimitiveType_POLYGON)) {
- return false;
- }
-
- // Find out how many output faces we'll get
- uint32_t numOut = 0, max_out = 0;
- bool get_normals = true;
- for( unsigned int a = 0; a < pMesh->mNumFaces; a++) {
- aiFace& face = pMesh->mFaces[a];
- if (face.mNumIndices <= 4) {
- get_normals = false;
- }
- if( face.mNumIndices <= 3) {
- numOut++;
-
- }
- else {
- numOut += face.mNumIndices-2;
- max_out = std::max(max_out,face.mNumIndices);
- }
- }
-
- // Just another check whether aiMesh::mPrimitiveTypes is correct
- ai_assert(numOut != pMesh->mNumFaces);
-
- aiVector3D *nor_out = nullptr;
-
- // if we don't have normals yet, but expect them to be a cheap side
- // product of triangulation anyway, allocate storage for them.
- if (!pMesh->mNormals && get_normals) {
- // XXX need a mechanism to inform the GenVertexNormals process to treat these normals as preprocessed per-face normals
- // nor_out = pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
- }
-
- // the output mesh will contain triangles, but no polys anymore
- pMesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
- pMesh->mPrimitiveTypes &= ~aiPrimitiveType_POLYGON;
-
- // The mesh becomes NGON encoded now, during the triangulation process.
- pMesh->mPrimitiveTypes |= aiPrimitiveType_NGONEncodingFlag;
-
- aiFace* out = new aiFace[numOut](), *curOut = out;
- std::vector<aiVector3D> temp_verts3d(max_out+2); /* temporary storage for vertices */
- std::vector<aiVector2D> temp_verts(max_out+2);
-
- NGONEncoder ngonEncoder;
-
- // Apply vertex colors to represent the face winding?
-#ifdef AI_BUILD_TRIANGULATE_COLOR_FACE_WINDING
- if (!pMesh->mColors[0])
- pMesh->mColors[0] = new aiColor4D[pMesh->mNumVertices];
- else
- new(pMesh->mColors[0]) aiColor4D[pMesh->mNumVertices];
-
- aiColor4D* clr = pMesh->mColors[0];
-#endif
-
-#ifdef AI_BUILD_TRIANGULATE_DEBUG_POLYS
- FILE* fout = fopen(POLY_OUTPUT_FILE,"a");
-#endif
-
- const aiVector3D* verts = pMesh->mVertices;
-
- // use std::unique_ptr to avoid slow std::vector<bool> specialiations
- std::unique_ptr<bool[]> done(new bool[max_out]);
- for( unsigned int a = 0; a < pMesh->mNumFaces; a++) {
- aiFace& face = pMesh->mFaces[a];
-
- unsigned int* idx = face.mIndices;
- int num = (int)face.mNumIndices, ear = 0, tmp, prev = num-1, next = 0, max = num;
-
- // Apply vertex colors to represent the face winding?
-#ifdef AI_BUILD_TRIANGULATE_COLOR_FACE_WINDING
- for (unsigned int i = 0; i < face.mNumIndices; ++i) {
- aiColor4D& c = clr[idx[i]];
- c.r = (i+1) / (float)max;
- c.b = 1.f - c.r;
- }
-#endif
-
- aiFace* const last_face = curOut;
-
- // if it's a simple point,line or triangle: just copy it
- if( face.mNumIndices <= 3)
- {
- aiFace& nface = *curOut++;
- nface.mNumIndices = face.mNumIndices;
- nface.mIndices = face.mIndices;
- face.mIndices = nullptr;
-
- // points and lines don't require ngon encoding (and are not supported either!)
- if (nface.mNumIndices == 3) ngonEncoder.ngonEncodeTriangle(&nface);
-
- continue;
- }
- // optimized code for quadrilaterals
- else if ( face.mNumIndices == 4) {
-
- // quads can have at maximum one concave vertex. Determine
- // this vertex (if it exists) and start tri-fanning from
- // it.
- unsigned int start_vertex = 0;
- for (unsigned int i = 0; i < 4; ++i) {
- const aiVector3D& v0 = verts[face.mIndices[(i+3) % 4]];
- const aiVector3D& v1 = verts[face.mIndices[(i+2) % 4]];
- const aiVector3D& v2 = verts[face.mIndices[(i+1) % 4]];
-
- const aiVector3D& v = verts[face.mIndices[i]];
-
- aiVector3D left = (v0-v);
- aiVector3D diag = (v1-v);
- aiVector3D right = (v2-v);
-
- left.Normalize();
- diag.Normalize();
- right.Normalize();
-
- const float angle = std::acos(left*diag) + std::acos(right*diag);
- if (angle > AI_MATH_PI_F) {
- // this is the concave point
- start_vertex = i;
- break;
- }
- }
-
- const unsigned int temp[] = {face.mIndices[0], face.mIndices[1], face.mIndices[2], face.mIndices[3]};
-
- aiFace& nface = *curOut++;
- nface.mNumIndices = 3;
- nface.mIndices = face.mIndices;
-
- nface.mIndices[0] = temp[start_vertex];
- nface.mIndices[1] = temp[(start_vertex + 1) % 4];
- nface.mIndices[2] = temp[(start_vertex + 2) % 4];
-
- aiFace& sface = *curOut++;
- sface.mNumIndices = 3;
- sface.mIndices = new unsigned int[3];
-
- sface.mIndices[0] = temp[start_vertex];
- sface.mIndices[1] = temp[(start_vertex + 2) % 4];
- sface.mIndices[2] = temp[(start_vertex + 3) % 4];
-
- // prevent double deletion of the indices field
- face.mIndices = nullptr;
-
- ngonEncoder.ngonEncodeQuad(&nface, &sface);
-
- continue;
- }
- else
- {
- // A polygon with more than 3 vertices can be either concave or convex.
- // Usually everything we're getting is convex and we could easily
- // triangulate by tri-fanning. However, LightWave is probably the only
- // modeling suite to make extensive use of highly concave, monster polygons ...
- // so we need to apply the full 'ear cutting' algorithm to get it right.
-
- // REQUIREMENT: polygon is expected to be simple and *nearly* planar.
- // We project it onto a plane to get a 2d triangle.
-
- // Collect all vertices of of the polygon.
- for (tmp = 0; tmp < max; ++tmp) {
- temp_verts3d[tmp] = verts[idx[tmp]];
- }
-
- // Get newell normal of the polygon. Store it for future use if it's a polygon-only mesh
- aiVector3D n;
- NewellNormal<3,3,3>(n,max,&temp_verts3d.front().x,&temp_verts3d.front().y,&temp_verts3d.front().z);
- if (nor_out) {
- for (tmp = 0; tmp < max; ++tmp)
- nor_out[idx[tmp]] = n;
- }
-
- // Select largest normal coordinate to ignore for projection
- const float ax = (n.x>0 ? n.x : -n.x);
- const float ay = (n.y>0 ? n.y : -n.y);
- const float az = (n.z>0 ? n.z : -n.z);
-
- unsigned int ac = 0, bc = 1; /* no z coord. projection to xy */
- float inv = n.z;
- if (ax > ay) {
- if (ax > az) { /* no x coord. projection to yz */
- ac = 1; bc = 2;
- inv = n.x;
- }
- }
- else if (ay > az) { /* no y coord. projection to zy */
- ac = 2; bc = 0;
- inv = n.y;
- }
-
- // Swap projection axes to take the negated projection vector into account
- if (inv < 0.f) {
- std::swap(ac,bc);
- }
-
- for (tmp =0; tmp < max; ++tmp) {
- temp_verts[tmp].x = verts[idx[tmp]][ac];
- temp_verts[tmp].y = verts[idx[tmp]][bc];
- done[tmp] = false;
- }
-
-#ifdef AI_BUILD_TRIANGULATE_DEBUG_POLYS
- // plot the plane onto which we mapped the polygon to a 2D ASCII pic
- aiVector2D bmin,bmax;
- ArrayBounds(&temp_verts[0],max,bmin,bmax);
-
- char grid[POLY_GRID_Y][POLY_GRID_X+POLY_GRID_XPAD];
- std::fill_n((char*)grid,POLY_GRID_Y*(POLY_GRID_X+POLY_GRID_XPAD),' ');
-
- for (int i =0; i < max; ++i) {
- const aiVector2D& v = (temp_verts[i] - bmin) / (bmax-bmin);
- const size_t x = static_cast<size_t>(v.x*(POLY_GRID_X-1)), y = static_cast<size_t>(v.y*(POLY_GRID_Y-1));
- char* loc = grid[y]+x;
- if (grid[y][x] != ' ') {
- for(;*loc != ' '; ++loc);
- *loc++ = '_';
- }
- *(loc+::ai_snprintf(loc, POLY_GRID_XPAD,"%i",i)) = ' ';
- }
-
-
- for(size_t y = 0; y < POLY_GRID_Y; ++y) {
- grid[y][POLY_GRID_X+POLY_GRID_XPAD-1] = '\0';
- fprintf(fout,"%s\n",grid[y]);
- }
-
- fprintf(fout,"\ntriangulation sequence: ");
-#endif
-
- //
- // FIXME: currently this is the slow O(kn) variant with a worst case
- // complexity of O(n^2) (I think). Can be done in O(n).
- while (num > 3) {
-
- // Find the next ear of the polygon
- int num_found = 0;
- for (ear = next;;prev = ear,ear = next) {
-
- // break after we looped two times without a positive match
- for (next=ear+1;done[(next>=max?next=0:next)];++next);
- if (next < ear) {
- if (++num_found == 2) {
- break;
- }
- }
- const aiVector2D* pnt1 = &temp_verts[ear],
- *pnt0 = &temp_verts[prev],
- *pnt2 = &temp_verts[next];
-
- // Must be a convex point. Assuming ccw winding, it must be on the right of the line between p-1 and p+1.
- if (OnLeftSideOfLine2D(*pnt0,*pnt2,*pnt1)) {
- continue;
- }
-
- // and no other point may be contained in this triangle
- for ( tmp = 0; tmp < max; ++tmp) {
-
- // We need to compare the actual values because it's possible that multiple indexes in
- // the polygon are referring to the same position. concave_polygon.obj is a sample
- //
- // FIXME: Use 'epsiloned' comparisons instead? Due to numeric inaccuracies in
- // PointInTriangle() I'm guessing that it's actually possible to construct
- // input data that would cause us to end up with no ears. The problem is,
- // which epsilon? If we chose a too large value, we'd get wrong results
- const aiVector2D& vtmp = temp_verts[tmp];
- if ( vtmp != *pnt1 && vtmp != *pnt2 && vtmp != *pnt0 && PointInTriangle2D(*pnt0,*pnt1,*pnt2,vtmp)) {
- break;
- }
- }
- if (tmp != max) {
- continue;
- }
-
- // this vertex is an ear
- break;
- }
- if (num_found == 2) {
-
- // Due to the 'two ear theorem', every simple polygon with more than three points must
- // have 2 'ears'. Here's definitely something wrong ... but we don't give up yet.
- //
-
- // Instead we're continuing with the standard tri-fanning algorithm which we'd
- // use if we had only convex polygons. That's life.
- ASSIMP_LOG_ERROR("Failed to triangulate polygon (no ear found). Probably not a simple polygon?");
-
-#ifdef AI_BUILD_TRIANGULATE_DEBUG_POLYS
- fprintf(fout,"critical error here, no ear found! ");
-#endif
- num = 0;
- break;
-
- /*curOut -= (max-num); // undo all previous work
- for (tmp = 0; tmp < max-2; ++tmp) {
- aiFace& nface = *curOut++;
-
- nface.mNumIndices = 3;
- if (!nface.mIndices)
- nface.mIndices = new unsigned int[3];
-
- nface.mIndices[0] = 0;
- nface.mIndices[1] = tmp+1;
- nface.mIndices[2] = tmp+2;
-
- }
- num = 0;
- break;*/
- }
-
- aiFace& nface = *curOut++;
- nface.mNumIndices = 3;
-
- if (!nface.mIndices) {
- nface.mIndices = new unsigned int[3];
- }
-
- // setup indices for the new triangle ...
- nface.mIndices[0] = prev;
- nface.mIndices[1] = ear;
- nface.mIndices[2] = next;
-
- // exclude the ear from most further processing
- done[ear] = true;
- --num;
- }
- if (num > 0) {
- // We have three indices forming the last 'ear' remaining. Collect them.
- aiFace& nface = *curOut++;
- nface.mNumIndices = 3;
- if (!nface.mIndices) {
- nface.mIndices = new unsigned int[3];
- }
-
- for (tmp = 0; done[tmp]; ++tmp);
- nface.mIndices[0] = tmp;
-
- for (++tmp; done[tmp]; ++tmp);
- nface.mIndices[1] = tmp;
-
- for (++tmp; done[tmp]; ++tmp);
- nface.mIndices[2] = tmp;
-
- }
- }
-
-#ifdef AI_BUILD_TRIANGULATE_DEBUG_POLYS
-
- for(aiFace* f = last_face; f != curOut; ++f) {
- unsigned int* i = f->mIndices;
- fprintf(fout," (%i %i %i)",i[0],i[1],i[2]);
- }
-
- fprintf(fout,"\n*********************************************************************\n");
- fflush(fout);
-
-#endif
-
- for(aiFace* f = last_face; f != curOut; ) {
- unsigned int* i = f->mIndices;
-
- // drop dumb 0-area triangles - deactivated for now:
- //FindDegenerates post processing step can do the same thing
- //if (std::fabs(GetArea2D(temp_verts[i[0]],temp_verts[i[1]],temp_verts[i[2]])) < 1e-5f) {
- // ASSIMP_LOG_VERBOSE_DEBUG("Dropping triangle with area 0");
- // --curOut;
-
- // delete[] f->mIndices;
- // f->mIndices = nullptr;
-
- // for(aiFace* ff = f; ff != curOut; ++ff) {
- // ff->mNumIndices = (ff+1)->mNumIndices;
- // ff->mIndices = (ff+1)->mIndices;
- // (ff+1)->mIndices = nullptr;
- // }
- // continue;
- //}
-
- i[0] = idx[i[0]];
- i[1] = idx[i[1]];
- i[2] = idx[i[2]];
-
- // IMPROVEMENT: Polygons are not supported yet by this ngon encoding + triangulation step.
- // So we encode polygons as regular triangles. No way to reconstruct the original
- // polygon in this case.
- ngonEncoder.ngonEncodeTriangle(f);
- ++f;
- }
-
- delete[] face.mIndices;
- face.mIndices = nullptr;
- }
-
-#ifdef AI_BUILD_TRIANGULATE_DEBUG_POLYS
- fclose(fout);
-#endif
-
- // kill the old faces
- delete [] pMesh->mFaces;
-
- // ... and store the new ones
- pMesh->mFaces = out;
- pMesh->mNumFaces = (unsigned int)(curOut-out); /* not necessarily equal to numOut */
- return true;
-}
-
-#endif // !! ASSIMP_BUILD_NO_TRIANGULATE_PROCESS