// David Eberly, Geometric Tools, Redmond WA 98052 // Copyright (c) 1998-2021 // Distributed under the Boost Software License, Version 1.0. // https://www.boost.org/LICENSE_1_0.txt // https://www.geometrictools.com/License/Boost/LICENSE_1_0.txt // Version: 4.0.2021.05.06 #pragma once #include #include #include // The queries consider the triangle to be a solid. namespace gte { template class TIQuery, Triangle2> { public: struct Result { Result() : intersect(false) { } bool intersect; }; Result operator()(Segment2 const& segment, Triangle2 const& triangle) { Result result{}; FIQuery, Triangle2> stQuery; result.intersect = stQuery(segment, triangle).intersect; return result; } }; template class FIQuery , Triangle2> : public FIQuery, Triangle2> { public: struct Result : public FIQuery, Triangle2>::Result { // No additional information to compute. }; Result operator()(Segment2 const& segment, Triangle2 const& triangle) { Vector2 segOrigin, segDirection; Real segExtent; segment.GetCenteredForm(segOrigin, segDirection, segExtent); Result result{}; DoQuery(segOrigin, segDirection, segExtent, triangle, result); if (result.numIntersections == 2) { result.point[0] = segOrigin + result.parameter[0] * segDirection; result.point[1] = segOrigin + result.parameter[1] * segDirection; } else if (result.numIntersections == 1) { result.point[0] = segOrigin + result.parameter[0] * segDirection; result.point[1] = result.point[0]; } // else: result set to no-intersection in DoQuery(...) return result; } protected: void DoQuery(Vector2 const& segOrigin, Vector2 const& segDirection, Real segExtent, Triangle2 const& triangle, Result& result) { FIQuery, Triangle2>::DoQuery(segOrigin, segDirection, triangle, result); if (result.intersect) { // The line containing the segment intersects the triangle; // the t-interval is [t0,t1]. The segment intersects the // triangle as long as [t0,t1] overlaps the segment t-interval // [-segExtent,+segExtent]. std::array segInterval{ -segExtent, segExtent }; FIQuery, std::array> iiQuery; auto iiResult = iiQuery(result.parameter, segInterval); if (iiResult.intersect) { result.numIntersections = iiResult.numIntersections; result.parameter = iiResult.overlap; } else { // Set the state to no-intersection. result = Result{}; } } } }; }