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Diffstat (limited to 'src/3rdparty/assimp/code/IFCBoolean.cpp')
| -rw-r--r-- | src/3rdparty/assimp/code/IFCBoolean.cpp | 831 |
1 files changed, 0 insertions, 831 deletions
diff --git a/src/3rdparty/assimp/code/IFCBoolean.cpp b/src/3rdparty/assimp/code/IFCBoolean.cpp deleted file mode 100644 index d250fbe36..000000000 --- a/src/3rdparty/assimp/code/IFCBoolean.cpp +++ /dev/null @@ -1,831 +0,0 @@ -/* -Open Asset Import Library (assimp) ----------------------------------------------------------------------- - -Copyright (c) 2006-2010, 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 IFCBoolean.cpp - * @brief Implements a subset of Ifc boolean operations - */ - - -#ifndef ASSIMP_BUILD_NO_IFC_IMPORTER -#include "IFCUtil.h" -#include "PolyTools.h" -#include "ProcessHelper.h" -#include <assimp/Defines.h> - -#include <iterator> -#include <tuple> - - -namespace Assimp { - namespace IFC { - -// ------------------------------------------------------------------------------------------------ -// Calculates intersection between line segment and plane. To catch corner cases, specify which side you prefer. -// The function then generates a hit only if the end is beyond a certain margin in that direction, filtering out -// "very close to plane" ghost hits as long as start and end stay directly on or within the given plane side. -bool IntersectSegmentPlane(const IfcVector3& p,const IfcVector3& n, const IfcVector3& e0, - const IfcVector3& e1, bool assumeStartOnWhiteSide, IfcVector3& out) -{ - const IfcVector3 pdelta = e0 - p, seg = e1 - e0; - const IfcFloat dotOne = n*seg, dotTwo = -(n*pdelta); - - // if segment ends on plane, do not report a hit. We stay on that side until a following segment starting at this - // point leaves the plane through the other side - if( std::abs(dotOne + dotTwo) < 1e-6 ) - return false; - - // if segment starts on the plane, report a hit only if the end lies on the *other* side - if( std::abs(dotTwo) < 1e-6 ) - { - if( (assumeStartOnWhiteSide && dotOne + dotTwo < 1e-6) || (!assumeStartOnWhiteSide && dotOne + dotTwo > -1e-6) ) - { - out = e0; - return true; - } - else - { - return false; - } - } - - // ignore if segment is parallel to plane and far away from it on either side - // Warning: if there's a few thousand of such segments which slowly accumulate beyond the epsilon, no hit would be registered - if( std::abs(dotOne) < 1e-6 ) - return false; - - // t must be in [0..1] if the intersection point is within the given segment - const IfcFloat t = dotTwo / dotOne; - if( t > 1.0 || t < 0.0 ) - return false; - - out = e0 + t*seg; - return true; -} - -// ------------------------------------------------------------------------------------------------ -void FilterPolygon(std::vector<IfcVector3>& resultpoly) -{ - if( resultpoly.size() < 3 ) - { - resultpoly.clear(); - return; - } - - IfcVector3 vmin, vmax; - ArrayBounds(resultpoly.data(), static_cast<unsigned int>(resultpoly.size()), vmin, vmax); - - // filter our IfcFloat points - those may happen if a point lies - // directly on the intersection line or directly on the clipping plane - const IfcFloat epsilon = (vmax - vmin).SquareLength() / 1e6f; - FuzzyVectorCompare fz(epsilon); - std::vector<IfcVector3>::iterator e = std::unique(resultpoly.begin(), resultpoly.end(), fz); - - if( e != resultpoly.end() ) - resultpoly.erase(e, resultpoly.end()); - - if( !resultpoly.empty() && fz(resultpoly.front(), resultpoly.back()) ) - resultpoly.pop_back(); -} - -// ------------------------------------------------------------------------------------------------ -void WritePolygon(std::vector<IfcVector3>& resultpoly, TempMesh& result) -{ - FilterPolygon(resultpoly); - - if( resultpoly.size() > 2 ) - { - result.verts.insert(result.verts.end(), resultpoly.begin(), resultpoly.end()); - result.vertcnt.push_back(static_cast<unsigned int>(resultpoly.size())); - } -} - - -// ------------------------------------------------------------------------------------------------ -void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& result, - const TempMesh& first_operand, - ConversionData& /*conv*/) -{ - ai_assert(hs != NULL); - - const IfcPlane* const plane = hs->BaseSurface->ToPtr<IfcPlane>(); - if(!plane) { - IFCImporter::LogError("expected IfcPlane as base surface for the IfcHalfSpaceSolid"); - return; - } - - // extract plane base position vector and normal vector - IfcVector3 p,n(0.f,0.f,1.f); - if (plane->Position->Axis) { - ConvertDirection(n,plane->Position->Axis.Get()); - } - ConvertCartesianPoint(p,plane->Position->Location); - - if(!IsTrue(hs->AgreementFlag)) { - n *= -1.f; - } - - // clip the current contents of `meshout` against the plane we obtained from the second operand - const std::vector<IfcVector3>& in = first_operand.verts; - std::vector<IfcVector3>& outvert = result.verts; - - std::vector<unsigned int>::const_iterator begin = first_operand.vertcnt.begin(), - end = first_operand.vertcnt.end(), iit; - - outvert.reserve(in.size()); - result.vertcnt.reserve(first_operand.vertcnt.size()); - - unsigned int vidx = 0; - for(iit = begin; iit != end; vidx += *iit++) { - - unsigned int newcount = 0; - bool isAtWhiteSide = (in[vidx] - p) * n > -1e-6; - for( unsigned int i = 0; i < *iit; ++i ) { - const IfcVector3& e0 = in[vidx + i], e1 = in[vidx + (i + 1) % *iit]; - - // does the next segment intersect the plane? - IfcVector3 isectpos; - if( IntersectSegmentPlane(p, n, e0, e1, isAtWhiteSide, isectpos) ) { - if( isAtWhiteSide ) { - // e0 is on the right side, so keep it - outvert.push_back(e0); - outvert.push_back(isectpos); - newcount += 2; - } - else { - // e0 is on the wrong side, so drop it and keep e1 instead - outvert.push_back(isectpos); - ++newcount; - } - isAtWhiteSide = !isAtWhiteSide; - } - else - { - if( isAtWhiteSide ) { - outvert.push_back(e0); - ++newcount; - } - } - } - - if (!newcount) { - continue; - } - - IfcVector3 vmin,vmax; - ArrayBounds(&*(outvert.end()-newcount),newcount,vmin,vmax); - - // filter our IfcFloat points - those may happen if a point lies - // directly on the intersection line. However, due to IfcFloat - // precision a bitwise comparison is not feasible to detect - // this case. - const IfcFloat epsilon = (vmax-vmin).SquareLength() / 1e6f; - FuzzyVectorCompare fz(epsilon); - - std::vector<IfcVector3>::iterator e = std::unique( outvert.end()-newcount, outvert.end(), fz ); - - if (e != outvert.end()) { - newcount -= static_cast<unsigned int>(std::distance(e,outvert.end())); - outvert.erase(e,outvert.end()); - } - if (fz(*( outvert.end()-newcount),outvert.back())) { - outvert.pop_back(); - --newcount; - } - if(newcount > 2) { - result.vertcnt.push_back(newcount); - } - else while(newcount-->0) { - result.verts.pop_back(); - } - - } - IFCImporter::LogDebug("generating CSG geometry by plane clipping (IfcBooleanClippingResult)"); -} - -// ------------------------------------------------------------------------------------------------ -// Check if e0-e1 intersects a sub-segment of the given boundary line. -// note: this functions works on 3D vectors, but performs its intersection checks solely in xy. -// New version takes the supposed inside/outside state as a parameter and treats corner cases as if -// the line stays on that side. This should make corner cases more stable. -// Two million assumptions! Boundary should have all z at 0.0, will be treated as closed, should not have -// segments with length <1e-6, self-intersecting might break the corner case handling... just don't go there, ok? -bool IntersectsBoundaryProfile(const IfcVector3& e0, const IfcVector3& e1, const std::vector<IfcVector3>& boundary, - const bool isStartAssumedInside, std::vector<std::pair<size_t, IfcVector3> >& intersect_results, - const bool halfOpen = false) -{ - ai_assert(intersect_results.empty()); - - // determine winding order - necessary to detect segments going "inwards" or "outwards" from a point directly on the border - // positive sum of angles means clockwise order when looking down the -Z axis - IfcFloat windingOrder = 0.0; - for( size_t i = 0, bcount = boundary.size(); i < bcount; ++i ) { - IfcVector3 b01 = boundary[(i + 1) % bcount] - boundary[i]; - IfcVector3 b12 = boundary[(i + 2) % bcount] - boundary[(i + 1) % bcount]; - IfcVector3 b1_side = IfcVector3(b01.y, -b01.x, 0.0); // rotated 90° clockwise in Z plane - // Warning: rough estimate only. A concave poly with lots of small segments each featuring a small counter rotation - // could fool the accumulation. Correct implementation would be sum( acos( b01 * b2) * sign( b12 * b1_side)) - windingOrder += (b1_side.x*b12.x + b1_side.y*b12.y); - } - windingOrder = windingOrder > 0.0 ? 1.0 : -1.0; - - const IfcVector3 e = e1 - e0; - - for( size_t i = 0, bcount = boundary.size(); i < bcount; ++i ) { - // boundary segment i: b0-b1 - const IfcVector3& b0 = boundary[i]; - const IfcVector3& b1 = boundary[(i + 1) % bcount]; - IfcVector3 b = b1 - b0; - - // segment-segment intersection - // solve b0 + b*s = e0 + e*t for (s,t) - const IfcFloat det = (-b.x * e.y + e.x * b.y); - if( std::abs(det) < 1e-6 ) { - // no solutions (parallel lines) - continue; - } - IfcFloat b_sqlen_inv = 1.0 / b.SquareLength(); - - const IfcFloat x = b0.x - e0.x; - const IfcFloat y = b0.y - e0.y; - const IfcFloat s = (x*e.y - e.x*y) / det; // scale along boundary edge - const IfcFloat t = (x*b.y - b.x*y) / det; // scale along given segment - const IfcVector3 p = e0 + e*t; -#ifdef ASSIMP_BUILD_DEBUG - const IfcVector3 check = b0 + b*s - p; - ai_assert((IfcVector2(check.x, check.y)).SquareLength() < 1e-5); -#endif - - // also calculate the distance of e0 and e1 to the segment. We need to detect the "starts directly on segment" - // and "ends directly at segment" cases - bool startsAtSegment, endsAtSegment; - { - // calculate closest point to each end on the segment, clamp that point to the segment's length, then check - // distance to that point. This approach is like testing if e0 is inside a capped cylinder. - IfcFloat et0 = (b.x*(e0.x - b0.x) + b.y*(e0.y - b0.y)) * b_sqlen_inv; - IfcVector3 closestPosToE0OnBoundary = b0 + std::max(IfcFloat(0.0), std::min(IfcFloat(1.0), et0)) * b; - startsAtSegment = (closestPosToE0OnBoundary - IfcVector3(e0.x, e0.y, 0.0)).SquareLength() < 1e-12; - IfcFloat et1 = (b.x*(e1.x - b0.x) + b.y*(e1.y - b0.y)) * b_sqlen_inv; - IfcVector3 closestPosToE1OnBoundary = b0 + std::max(IfcFloat(0.0), std::min(IfcFloat(1.0), et1)) * b; - endsAtSegment = (closestPosToE1OnBoundary - IfcVector3(e1.x, e1.y, 0.0)).SquareLength() < 1e-12; - } - - // Line segment ends at boundary -> ignore any hit, it will be handled by possibly following segments - if( endsAtSegment && !halfOpen ) - continue; - - // Line segment starts at boundary -> generate a hit only if following that line would change the INSIDE/OUTSIDE - // state. This should catch the case where a connected set of segments has a point directly on the boundary, - // one segment not hitting it because it ends there and the next segment not hitting it because it starts there - // Should NOT generate a hit if the segment only touches the boundary but turns around and stays inside. - if( startsAtSegment ) - { - IfcVector3 inside_dir = IfcVector3(b.y, -b.x, 0.0) * windingOrder; - bool isGoingInside = (inside_dir * e) > 0.0; - if( isGoingInside == isStartAssumedInside ) - continue; - - // only insert the point into the list if it is sufficiently far away from the previous intersection point. - // This way, we avoid duplicate detection if the intersection is directly on the vertex between two segments. - if( !intersect_results.empty() && intersect_results.back().first == i - 1 ) - { - const IfcVector3 diff = intersect_results.back().second - e0; - if( IfcVector2(diff.x, diff.y).SquareLength() < 1e-10 ) - continue; - } - intersect_results.push_back(std::make_pair(i, e0)); - continue; - } - - // for a valid intersection, s and t should be in range [0,1]. Including a bit of epsilon on s, potential double - // hits on two consecutive boundary segments are filtered - if( s >= -1e-6 * b_sqlen_inv && s <= 1.0 + 1e-6*b_sqlen_inv && t >= 0.0 && (t <= 1.0 || halfOpen) ) - { - // only insert the point into the list if it is sufficiently far away from the previous intersection point. - // This way, we avoid duplicate detection if the intersection is directly on the vertex between two segments. - if( !intersect_results.empty() && intersect_results.back().first == i - 1 ) - { - const IfcVector3 diff = intersect_results.back().second - p; - if( IfcVector2(diff.x, diff.y).SquareLength() < 1e-10 ) - continue; - } - intersect_results.push_back(std::make_pair(i, p)); - } - } - - return !intersect_results.empty(); -} - - -// ------------------------------------------------------------------------------------------------ -// note: this functions works on 3D vectors, but performs its intersection checks solely in xy. -bool PointInPoly(const IfcVector3& p, const std::vector<IfcVector3>& boundary) -{ - // even-odd algorithm: take a random vector that extends from p to infinite - // and counts how many times it intersects edges of the boundary. - // because checking for segment intersections is prone to numeric inaccuracies - // or double detections (i.e. when hitting multiple adjacent segments at their - // shared vertices) we do it thrice with different rays and vote on it. - - // the even-odd algorithm doesn't work for points which lie directly on - // the border of the polygon. If any of our attempts produces this result, - // we return false immediately. - - std::vector<std::pair<size_t, IfcVector3> > intersected_boundary; - size_t votes = 0; - - IntersectsBoundaryProfile(p, p + IfcVector3(1.0, 0, 0), boundary, true, intersected_boundary, true); - votes += intersected_boundary.size() % 2; - - intersected_boundary.clear(); - IntersectsBoundaryProfile(p, p + IfcVector3(0, 1.0, 0), boundary, true, intersected_boundary, true); - votes += intersected_boundary.size() % 2; - - intersected_boundary.clear(); - IntersectsBoundaryProfile(p, p + IfcVector3(0.6, -0.6, 0.0), boundary, true, intersected_boundary, true); - votes += intersected_boundary.size() % 2; - - return votes > 1; -} - - -// ------------------------------------------------------------------------------------------------ -void ProcessPolygonalBoundedBooleanHalfSpaceDifference(const IfcPolygonalBoundedHalfSpace* hs, TempMesh& result, - const TempMesh& first_operand, - ConversionData& conv) -{ - ai_assert(hs != NULL); - - const IfcPlane* const plane = hs->BaseSurface->ToPtr<IfcPlane>(); - if(!plane) { - IFCImporter::LogError("expected IfcPlane as base surface for the IfcHalfSpaceSolid"); - return; - } - - // extract plane base position vector and normal vector - IfcVector3 p,n(0.f,0.f,1.f); - if (plane->Position->Axis) { - ConvertDirection(n,plane->Position->Axis.Get()); - } - ConvertCartesianPoint(p,plane->Position->Location); - - if(!IsTrue(hs->AgreementFlag)) { - n *= -1.f; - } - - n.Normalize(); - - // obtain the polygonal bounding volume - std::shared_ptr<TempMesh> profile = std::shared_ptr<TempMesh>(new TempMesh()); - if(!ProcessCurve(hs->PolygonalBoundary, *profile.get(), conv)) { - IFCImporter::LogError("expected valid polyline for boundary of boolean halfspace"); - return; - } - - // determine winding order by calculating the normal. - IfcVector3 profileNormal = TempMesh::ComputePolygonNormal(profile->verts.data(), profile->verts.size()); - - IfcMatrix4 proj_inv; - ConvertAxisPlacement(proj_inv,hs->Position); - - // and map everything into a plane coordinate space so all intersection - // tests can be done in 2D space. - IfcMatrix4 proj = proj_inv; - proj.Inverse(); - - // clip the current contents of `meshout` against the plane we obtained from the second operand - const std::vector<IfcVector3>& in = first_operand.verts; - std::vector<IfcVector3>& outvert = result.verts; - std::vector<unsigned int>& outvertcnt = result.vertcnt; - - outvert.reserve(in.size()); - outvertcnt.reserve(first_operand.vertcnt.size()); - - unsigned int vidx = 0; - std::vector<unsigned int>::const_iterator begin = first_operand.vertcnt.begin(); - std::vector<unsigned int>::const_iterator end = first_operand.vertcnt.end(); - std::vector<unsigned int>::const_iterator iit; - for( iit = begin; iit != end; vidx += *iit++ ) - { - // Our new approach: we cut the poly along the plane, then we intersect the part on the black side of the plane - // against the bounding polygon. All the white parts, and the black part outside the boundary polygon, are kept. - std::vector<IfcVector3> whiteside, blackside; - - { - const IfcVector3* srcVertices = &in[vidx]; - const size_t srcVtxCount = *iit; - if( srcVtxCount == 0 ) - continue; - - IfcVector3 polyNormal = TempMesh::ComputePolygonNormal(srcVertices, srcVtxCount, true); - - // if the poly is parallel to the plane, put it completely on the black or white side - if( std::abs(polyNormal * n) > 0.9999 ) - { - bool isOnWhiteSide = (srcVertices[0] - p) * n > -1e-6; - std::vector<IfcVector3>& targetSide = isOnWhiteSide ? whiteside : blackside; - targetSide.insert(targetSide.end(), srcVertices, srcVertices + srcVtxCount); - } - else - { - // otherwise start building one polygon for each side. Whenever the current line segment intersects the plane - // we put a point there as an end of the current segment. Then we switch to the other side, put a point there, too, - // as a beginning of the current segment, and simply continue accumulating vertices. - bool isCurrentlyOnWhiteSide = ((srcVertices[0]) - p) * n > -1e-6; - for( size_t a = 0; a < srcVtxCount; ++a ) - { - IfcVector3 e0 = srcVertices[a]; - IfcVector3 e1 = srcVertices[(a + 1) % srcVtxCount]; - IfcVector3 ei; - - // put starting point to the current mesh - std::vector<IfcVector3>& trgt = isCurrentlyOnWhiteSide ? whiteside : blackside; - trgt.push_back(srcVertices[a]); - - // if there's an intersection, put an end vertex there, switch to the other side's mesh, - // and add a starting vertex there, too - bool isPlaneHit = IntersectSegmentPlane(p, n, e0, e1, isCurrentlyOnWhiteSide, ei); - if( isPlaneHit ) - { - if( trgt.empty() || (trgt.back() - ei).SquareLength() > 1e-12 ) - trgt.push_back(ei); - isCurrentlyOnWhiteSide = !isCurrentlyOnWhiteSide; - std::vector<IfcVector3>& newtrgt = isCurrentlyOnWhiteSide ? whiteside : blackside; - newtrgt.push_back(ei); - } - } - } - } - - // the part on the white side can be written into the target mesh right away - WritePolygon(whiteside, result); - - // The black part is the piece we need to get rid of, but only the part of it within the boundary polygon. - // So we now need to construct all the polygons that result from BlackSidePoly minus BoundaryPoly. - FilterPolygon(blackside); - - // Complicated, II. We run along the polygon. a) When we're inside the boundary, we run on until we hit an - // intersection, which means we're leaving it. We then start a new out poly there. b) When we're outside the - // boundary, we start collecting vertices until we hit an intersection, then we run along the boundary until we hit - // an intersection, then we switch back to the poly and run on on this one again, and so on until we got a closed - // loop. Then we continue with the path we left to catch potential additional polys on the other side of the - // boundary as described in a) - if( !blackside.empty() ) - { - // poly edge index, intersection point, edge index in boundary poly - std::vector<std::tuple<size_t, IfcVector3, size_t> > intersections; - bool startedInside = PointInPoly(proj * blackside.front(), profile->verts); - bool isCurrentlyInside = startedInside; - - std::vector<std::pair<size_t, IfcVector3> > intersected_boundary; - - for( size_t a = 0; a < blackside.size(); ++a ) - { - const IfcVector3 e0 = proj * blackside[a]; - const IfcVector3 e1 = proj * blackside[(a + 1) % blackside.size()]; - - intersected_boundary.clear(); - IntersectsBoundaryProfile(e0, e1, profile->verts, isCurrentlyInside, intersected_boundary); - // sort the hits by distance from e0 to get the correct in/out/in sequence. Manually :-( I miss you, C++11. - if( intersected_boundary.size() > 1 ) - { - bool keepSorting = true; - while( keepSorting ) - { - keepSorting = false; - for( size_t b = 0; b < intersected_boundary.size() - 1; ++b ) - { - if( (intersected_boundary[b + 1].second - e0).SquareLength() < (intersected_boundary[b].second - e0).SquareLength() ) - { - keepSorting = true; - std::swap(intersected_boundary[b + 1], intersected_boundary[b]); - } - } - } - } - // now add them to the list of intersections - for( size_t b = 0; b < intersected_boundary.size(); ++b ) - intersections.push_back(std::make_tuple(a, proj_inv * intersected_boundary[b].second, intersected_boundary[b].first)); - - // and calculate our new inside/outside state - if( intersected_boundary.size() & 1 ) - isCurrentlyInside = !isCurrentlyInside; - } - - // we got a list of in-out-combinations of intersections. That should be an even number of intersections, or - // we're fucked. - if( (intersections.size() & 1) != 0 ) - { - IFCImporter::LogWarn("Odd number of intersections, can't work with that. Omitting half space boundary check."); - continue; - } - - if( intersections.size() > 1 ) - { - // If we started outside, the first intersection is a out->in intersection. Cycle them so that it - // starts with an intersection leaving the boundary - if( !startedInside ) - for( size_t b = 0; b < intersections.size() - 1; ++b ) - std::swap(intersections[b], intersections[(b + intersections.size() - 1) % intersections.size()]); - - // Filter pairs of out->in->out that lie too close to each other. - for( size_t a = 0; intersections.size() > 0 && a < intersections.size() - 1; /**/ ) - { - if( (std::get<1>(intersections[a]) - std::get<1>(intersections[(a + 1) % intersections.size()])).SquareLength() < 1e-10 ) - intersections.erase(intersections.begin() + a, intersections.begin() + a + 2); - else - a++; - } - if( intersections.size() > 1 && (std::get<1>(intersections.back()) - std::get<1>(intersections.front())).SquareLength() < 1e-10 ) - { - intersections.pop_back(); intersections.erase(intersections.begin()); - } - } - - - // no intersections at all: either completely inside the boundary, so everything gets discarded, or completely outside. - // in the latter case we're implementional lost. I'm simply going to ignore this, so a large poly will not get any - // holes if the boundary is smaller and does not touch it anywhere. - if( intersections.empty() ) - { - // starting point was outside -> everything is outside the boundary -> nothing is clipped -> add black side - // to result mesh unchanged - if( !startedInside ) - { - outvertcnt.push_back(static_cast<unsigned int>(blackside.size())); - outvert.insert(outvert.end(), blackside.begin(), blackside.end()); - continue; - } - else - { - // starting point was inside the boundary -> everything is inside the boundary -> nothing is spared from the - // clipping -> nothing left to add to the result mesh - continue; - } - } - - // determine the direction in which we're marching along the boundary polygon. If the src poly is faced upwards - // and the boundary is also winded this way, we need to march *backwards* on the boundary. - const IfcVector3 polyNormal = IfcMatrix3(proj) * TempMesh::ComputePolygonNormal(blackside.data(), blackside.size()); - bool marchBackwardsOnBoundary = (profileNormal * polyNormal) >= 0.0; - - // Build closed loops from these intersections. Starting from an intersection leaving the boundary we - // walk along the polygon to the next intersection (which should be an IS entering the boundary poly). - // From there we walk along the boundary until we hit another intersection leaving the boundary, - // walk along the poly to the next IS and so on until we're back at the starting point. - // We remove every intersection we "used up", so any remaining intersection is the start of a new loop. - while( !intersections.empty() ) - { - std::vector<IfcVector3> resultpoly; - size_t currentIntersecIdx = 0; - - while( true ) - { - ai_assert(intersections.size() > currentIntersecIdx + 1); - std::tuple<size_t, IfcVector3, size_t> currintsec = intersections[currentIntersecIdx + 0]; - std::tuple<size_t, IfcVector3, size_t> nextintsec = intersections[currentIntersecIdx + 1]; - intersections.erase(intersections.begin() + currentIntersecIdx, intersections.begin() + currentIntersecIdx + 2); - - // we start with an in->out intersection - resultpoly.push_back(std::get<1>(currintsec)); - // climb along the polygon to the next intersection, which should be an out->in - size_t numPolyPoints = (std::get<0>(currintsec) > std::get<0>(nextintsec) ? blackside.size() : 0) - + std::get<0>(nextintsec) - std::get<0>(currintsec); - for( size_t a = 1; a <= numPolyPoints; ++a ) - resultpoly.push_back(blackside[(std::get<0>(currintsec) + a) % blackside.size()]); - // put the out->in intersection - resultpoly.push_back(std::get<1>(nextintsec)); - - // generate segments along the boundary polygon that lie in the poly's plane until we hit another intersection - IfcVector3 startingPoint = proj * std::get<1>(nextintsec); - size_t currentBoundaryEdgeIdx = (std::get<2>(nextintsec) + (marchBackwardsOnBoundary ? 1 : 0)) % profile->verts.size(); - size_t nextIntsecIdx = SIZE_MAX; - while( nextIntsecIdx == SIZE_MAX ) - { - IfcFloat t = 1e10; - - size_t nextBoundaryEdgeIdx = marchBackwardsOnBoundary ? (currentBoundaryEdgeIdx + profile->verts.size() - 1) : currentBoundaryEdgeIdx + 1; - nextBoundaryEdgeIdx %= profile->verts.size(); - // vertices of the current boundary segments - IfcVector3 currBoundaryPoint = profile->verts[currentBoundaryEdgeIdx]; - IfcVector3 nextBoundaryPoint = profile->verts[nextBoundaryEdgeIdx]; - // project the two onto the polygon - if( std::abs(polyNormal.z) > 1e-5 ) - { - currBoundaryPoint.z = startingPoint.z + (currBoundaryPoint.x - startingPoint.x) * polyNormal.x/polyNormal.z + (currBoundaryPoint.y - startingPoint.y) * polyNormal.y/polyNormal.z; - nextBoundaryPoint.z = startingPoint.z + (nextBoundaryPoint.x - startingPoint.x) * polyNormal.x/polyNormal.z + (nextBoundaryPoint.y - startingPoint.y) * polyNormal.y/polyNormal.z; - } - - // build a direction that goes along the boundary border but lies in the poly plane - IfcVector3 boundaryPlaneNormal = ((nextBoundaryPoint - currBoundaryPoint) ^ profileNormal).Normalize(); - IfcVector3 dirAtPolyPlane = (boundaryPlaneNormal ^ polyNormal).Normalize() * (marchBackwardsOnBoundary ? -1.0 : 1.0); - // if we can project the direction to the plane, we can calculate a maximum marching distance along that dir - // until we finish that boundary segment and continue on the next - if( std::abs(polyNormal.z) > 1e-5 ) - { - t = std::min(t, (nextBoundaryPoint - startingPoint).Length()); - } - - // check if the direction hits the loop start - if yes, we got a poly to output - IfcVector3 dirToThatPoint = proj * resultpoly.front() - startingPoint; - IfcFloat tpt = dirToThatPoint * dirAtPolyPlane; - if( tpt > -1e-6 && tpt <= t && (dirToThatPoint - tpt * dirAtPolyPlane).SquareLength() < 1e-10 ) - { - nextIntsecIdx = intersections.size(); // dirty hack to end marching along the boundary and signal the end of the loop - t = tpt; - } - - // also check if the direction hits any in->out intersections earlier. If we hit one, we can switch back - // to marching along the poly border from that intersection point - for( size_t a = 0; a < intersections.size(); a += 2 ) - { - dirToThatPoint = proj * std::get<1>(intersections[a]) - startingPoint; - tpt = dirToThatPoint * dirAtPolyPlane; - if( tpt > -1e-6 && tpt <= t && (dirToThatPoint - tpt * dirAtPolyPlane).SquareLength() < 1e-10 ) - { - nextIntsecIdx = a; // switch back to poly and march on from this in->out intersection - t = tpt; - } - } - - // if we keep marching on the boundary, put the segment end point to the result poly and well... keep marching - if( nextIntsecIdx == SIZE_MAX ) - { - resultpoly.push_back(proj_inv * nextBoundaryPoint); - currentBoundaryEdgeIdx = nextBoundaryEdgeIdx; - startingPoint = nextBoundaryPoint; - } - - // quick endless loop check - if( resultpoly.size() > blackside.size() + profile->verts.size() ) - { - IFCImporter::LogError("Encountered endless loop while clipping polygon against poly-bounded half space."); - break; - } - } - - // we're back on the poly - if this is the intersection we started from, we got a closed loop. - if( nextIntsecIdx >= intersections.size() ) - { - break; - } - - // otherwise it's another intersection. Continue marching from there. - currentIntersecIdx = nextIntsecIdx; - } - - WritePolygon(resultpoly, result); - } - } - } - IFCImporter::LogDebug("generating CSG geometry by plane clipping with polygonal bounding (IfcBooleanClippingResult)"); -} - -// ------------------------------------------------------------------------------------------------ -void ProcessBooleanExtrudedAreaSolidDifference(const IfcExtrudedAreaSolid* as, TempMesh& result, - const TempMesh& first_operand, - ConversionData& conv) -{ - ai_assert(as != NULL); - - // This case is handled by reduction to an instance of the quadrify() algorithm. - // Obviously, this won't work for arbitrarily complex cases. In fact, the first - // operand should be near-planar. Luckily, this is usually the case in Ifc - // buildings. - - std::shared_ptr<TempMesh> meshtmp = std::shared_ptr<TempMesh>(new TempMesh()); - ProcessExtrudedAreaSolid(*as,*meshtmp,conv,false); - - std::vector<TempOpening> openings(1, TempOpening(as,IfcVector3(0,0,0),meshtmp,std::shared_ptr<TempMesh>())); - - result = first_operand; - - TempMesh temp; - - std::vector<IfcVector3>::const_iterator vit = first_operand.verts.begin(); - for(unsigned int pcount : first_operand.vertcnt) { - temp.Clear(); - - temp.verts.insert(temp.verts.end(), vit, vit + pcount); - temp.vertcnt.push_back(pcount); - - // The algorithms used to generate mesh geometry sometimes - // spit out lines or other degenerates which must be - // filtered to avoid running into assertions later on. - - // ComputePolygonNormal returns the Newell normal, so the - // length of the normal is the area of the polygon. - const IfcVector3& normal = temp.ComputeLastPolygonNormal(false); - if (normal.SquareLength() < static_cast<IfcFloat>(1e-5)) { - IFCImporter::LogWarn("skipping degenerate polygon (ProcessBooleanExtrudedAreaSolidDifference)"); - continue; - } - - GenerateOpenings(openings, std::vector<IfcVector3>(1,IfcVector3(1,0,0)), temp, false, true); - result.Append(temp); - - vit += pcount; - } - - IFCImporter::LogDebug("generating CSG geometry by geometric difference to a solid (IfcExtrudedAreaSolid)"); -} - -// ------------------------------------------------------------------------------------------------ -void ProcessBoolean(const IfcBooleanResult& boolean, TempMesh& result, ConversionData& conv) -{ - // supported CSG operations: - // DIFFERENCE - if(const IfcBooleanResult* const clip = boolean.ToPtr<IfcBooleanResult>()) { - if(clip->Operator != "DIFFERENCE") { - IFCImporter::LogWarn("encountered unsupported boolean operator: " + (std::string)clip->Operator); - return; - } - - // supported cases (1st operand): - // IfcBooleanResult -- call ProcessBoolean recursively - // IfcSweptAreaSolid -- obtain polygonal geometry first - - // supported cases (2nd operand): - // IfcHalfSpaceSolid -- easy, clip against plane - // IfcExtrudedAreaSolid -- reduce to an instance of the quadrify() algorithm - - - const IfcHalfSpaceSolid* const hs = clip->SecondOperand->ResolveSelectPtr<IfcHalfSpaceSolid>(conv.db); - const IfcExtrudedAreaSolid* const as = clip->SecondOperand->ResolveSelectPtr<IfcExtrudedAreaSolid>(conv.db); - if(!hs && !as) { - IFCImporter::LogError("expected IfcHalfSpaceSolid or IfcExtrudedAreaSolid as second clipping operand"); - return; - } - - TempMesh first_operand; - if(const IfcBooleanResult* const op0 = clip->FirstOperand->ResolveSelectPtr<IfcBooleanResult>(conv.db)) { - ProcessBoolean(*op0,first_operand,conv); - } - else if (const IfcSweptAreaSolid* const swept = clip->FirstOperand->ResolveSelectPtr<IfcSweptAreaSolid>(conv.db)) { - ProcessSweptAreaSolid(*swept,first_operand,conv); - } - else { - IFCImporter::LogError("expected IfcSweptAreaSolid or IfcBooleanResult as first clipping operand"); - return; - } - - if(hs) { - - const IfcPolygonalBoundedHalfSpace* const hs_bounded = clip->SecondOperand->ResolveSelectPtr<IfcPolygonalBoundedHalfSpace>(conv.db); - if (hs_bounded) { - ProcessPolygonalBoundedBooleanHalfSpaceDifference(hs_bounded, result, first_operand, conv); - } - else { - ProcessBooleanHalfSpaceDifference(hs, result, first_operand, conv); - } - } - else { - ProcessBooleanExtrudedAreaSolidDifference(as, result, first_operand, conv); - } - } - else { - IFCImporter::LogWarn("skipping unknown IfcBooleanResult entity, type is " + boolean.GetClassName()); - } -} - -} // ! IFC -} // ! Assimp - -#endif - |