#include "geoData.h" #include "collections.h" #include "geometricPlane.h" #include #include #include #include #include GeoData::GeoData() { add_property(surface); } GeoData GeoData::loadFromAsciiGrid(const std::filesystem::path & input) { size_t ncols = 0, nrows = 0, xllcorner = 0, yllcorner = 0, cellsize = 0; std::map properties { {"ncols", &ncols}, {"nrows", &nrows}, {"xllcorner", &xllcorner}, {"yllcorner", &yllcorner}, {"cellsize", &cellsize}, }; std::ifstream f {input}; while (!properties.empty()) { std::string property; f >> property; f >> *properties.at(property); properties.erase(property); } xllcorner *= 1000; yllcorner *= 1000; cellsize *= 1000; std::vector vertices; vertices.reserve(ncols * nrows); GeoData mesh; mesh.lowerExtent = {xllcorner, yllcorner, std::numeric_limits::max()}; mesh.upperExtent = {xllcorner + (cellsize * (ncols - 1)), yllcorner + (cellsize * (nrows - 1)), std::numeric_limits::min()}; for (size_t row = 0; row < nrows; ++row) { for (size_t col = 0; col < ncols; ++col) { float heightf = 0; f >> heightf; const auto height = static_cast(std::round(heightf * 1000.F)); mesh.upperExtent.z = std::max(mesh.upperExtent.z, height); mesh.lowerExtent.z = std::min(mesh.lowerExtent.z, height); vertices.push_back(mesh.add_vertex({xllcorner + (col * cellsize), yllcorner + (row * cellsize), height})); } } if (!f.good()) { throw std::runtime_error("Couldn't read terrain file"); } for (size_t row = 1; row < nrows; ++row) { for (size_t col = 1; col < ncols; ++col) { mesh.add_face({ vertices[ncols * (row - 1) + (col - 1)], vertices[ncols * (row - 0) + (col - 0)], vertices[ncols * (row - 0) + (col - 1)], }); mesh.add_face({ vertices[ncols * (row - 1) + (col - 1)], vertices[ncols * (row - 1) + (col - 0)], vertices[ncols * (row - 0) + (col - 0)], }); } } mesh.update_vertex_normals_only(); return mesh; }; constexpr static GlobalDistance GRID_SIZE = 10'000; GeoData GeoData::createFlat(GlobalPosition2D lower, GlobalPosition2D upper, GlobalDistance h) { assert((upper - lower) % GRID_SIZE == GlobalPosition2D {}); GeoData mesh; mesh.lowerExtent = {lower, h}; mesh.upperExtent = {upper, h}; std::vector vertices; for (GlobalDistance row = lower.x; row <= upper.x; row += GRID_SIZE) { for (GlobalDistance col = lower.y; col <= upper.y; col += GRID_SIZE) { vertices.push_back(mesh.add_vertex({col, row, h})); } } const auto n = glm::vec<2, size_t> {((upper - lower) / GRID_SIZE) + 1}; for (auto row = 1U; row < n.x; ++row) { for (auto col = 1U; col < n.y; ++col) { mesh.add_face({ vertices[n.y * (row - 1) + (col - 1)], vertices[n.y * (row - 0) + (col - 0)], vertices[n.y * (row - 0) + (col - 1)], }); mesh.add_face({ vertices[n.y * (row - 1) + (col - 1)], vertices[n.y * (row - 1) + (col - 0)], vertices[n.y * (row - 0) + (col - 0)], }); } } mesh.update_vertex_normals_only(); return mesh; } OpenMesh::FaceHandle GeoData::findPoint(GlobalPosition2D p) const { return findPoint(p, *faces_sbegin()); } GeoData::PointFace::PointFace(const GlobalPosition2D p, const GeoData * mesh) : PointFace {p, mesh, *mesh->faces_sbegin()} { } GeoData::PointFace::PointFace(const GlobalPosition2D p, const GeoData * mesh, FaceHandle start) : PointFace {p, mesh->findPoint(p, start)} { } GeoData::FaceHandle GeoData::PointFace::face(const GeoData * mesh, FaceHandle start) const { if (_face.is_valid()) { assert(mesh->triangleContainsPoint(point, _face)); return _face; } else { return (_face = mesh->findPoint(point, start)); } } GeoData::FaceHandle GeoData::PointFace::face(const GeoData * mesh) const { return face(mesh, *mesh->faces_sbegin()); } namespace { template typename Op> [[nodiscard]] constexpr inline auto pointLineOp(const GlobalPosition2D p, const GlobalPosition2D e1, const GlobalPosition2D e2) { return Op {}(CalcDistance(e2.x - e1.x) * CalcDistance(p.y - e1.y), CalcDistance(e2.y - e1.y) * CalcDistance(p.x - e1.x)); } constexpr auto pointLeftOfLine = pointLineOp; constexpr auto pointLeftOfOrOnLine = pointLineOp; static_assert(pointLeftOfLine({1, 2}, {1, 1}, {2, 2})); static_assert(pointLeftOfLine({2, 1}, {2, 2}, {1, 1})); static_assert(pointLeftOfLine({2, 2}, {1, 2}, {2, 1})); static_assert(pointLeftOfLine({1, 1}, {2, 1}, {1, 2})); static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310000000, 490000000}, {310050000, 490050000})); static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310050000, 490050000}, {310000000, 490050000})); static_assert(pointLeftOfOrOnLine({310000000, 490000000}, {310000000, 490050000}, {310000000, 490000000})); [[nodiscard]] constexpr inline bool linesCross( const GlobalPosition2D a1, const GlobalPosition2D a2, const GlobalPosition2D b1, const GlobalPosition2D b2) { return (pointLeftOfLine(a2, b1, b2) == pointLeftOfLine(a1, b2, b1)) && (pointLeftOfLine(b1, a1, a2) == pointLeftOfLine(b2, a2, a1)); } static_assert(linesCross({1, 1}, {2, 2}, {1, 2}, {2, 1})); static_assert(linesCross({2, 2}, {1, 1}, {1, 2}, {2, 1})); [[nodiscard]] constexpr inline bool linesCrossLtR( const GlobalPosition2D a1, const GlobalPosition2D a2, const GlobalPosition2D b1, const GlobalPosition2D b2) { return pointLeftOfLine(a2, b1, b2) && pointLeftOfLine(a1, b2, b1) && pointLeftOfLine(b1, a1, a2) && pointLeftOfLine(b2, a2, a1); } static_assert(linesCrossLtR({1, 1}, {2, 2}, {1, 2}, {2, 1})); static_assert(!linesCrossLtR({2, 2}, {1, 1}, {1, 2}, {2, 1})); constexpr GlobalPosition3D positionOnTriangle(const GlobalPosition2D point, const GeoData::Triangle<3> & t) { const CalcPosition3D a = t[1] - t[0], b = t[2] - t[0]; const auto n = crossProduct(a, b); return {point, ((n.x * t[0].x) + (n.y * t[0].y) + (n.z * t[0].z) - (n.x * point.x) - (n.y * point.y)) / n.z}; } static_assert(positionOnTriangle({7, -2}, {{1, 2, 3}, {1, 0, 1}, {-2, 1, 0}}) == GlobalPosition3D {7, -2, 3}); } OpenMesh::FaceHandle GeoData::findPoint(GlobalPosition2D p, OpenMesh::FaceHandle f) const { while (f.is_valid() && !triangleContainsPoint(p, triangle<2>(f))) { for (auto next = cfh_iter(f); next.is_valid(); ++next) { f = opposite_face_handle(*next); if (f.is_valid()) { const auto e1 = point(to_vertex_handle(*next)); const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(*next))); if (pointLeftOfLine(p, e1, e2)) { break; } } f.reset(); } } return f; } GlobalPosition3D GeoData::positionAt(const PointFace & p) const { return positionOnTriangle(p.point, triangle<3>(p.face(this))); } [[nodiscard]] GeoData::IntersectionResult GeoData::intersectRay(const Ray & ray) const { return intersectRay(ray, findPoint(ray.start)); } [[nodiscard]] GeoData::IntersectionResult GeoData::intersectRay(const Ray & ray, FaceHandle face) const { GeoData::IntersectionResult out; walkUntil(PointFace {ray.start, face}, ray.start.xy() + (ray.direction.xy() * RelativePosition2D(upperExtent.xy() - lowerExtent.xy())), [&out, &ray, this](FaceHandle face) { BaryPosition bari {}; RelativeDistance dist {}; const auto t = triangle<3>(face); if (ray.intersectTriangle(t.x, t.y, t.z, bari, dist)) { out.emplace(t * bari, face); return true; } return false; }); return out; } void GeoData::walk(const PointFace & from, const GlobalPosition2D to, const std::function & op) const { walkUntil(from, to, [&op](const auto & fh) { op(fh); return false; }); } void GeoData::walkUntil(const PointFace & from, const GlobalPosition2D to, const std::function & op) const { auto f = from.face(this); if (!f.is_valid()) { const auto entryEdge = findEntry(from.point, to); if (!entryEdge.is_valid()) { return; } f = opposite_face_handle(entryEdge); } FaceHandle previousFace; while (f.is_valid() && !op(f)) { for (auto next = cfh_iter(f); next.is_valid(); ++next) { f = opposite_face_handle(*next); if (f.is_valid() && f != previousFace) { const auto e1 = point(to_vertex_handle(*next)); const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(*next))); if (linesCrossLtR(from.point, to, e1, e2)) { previousFace = f; break; } } f.reset(); } } } void GeoData::boundaryWalk(const std::function & op) const { boundaryWalk(op, findBoundaryStart()); } void GeoData::boundaryWalk(const std::function & op, HalfedgeHandle start) const { assert(is_boundary(start)); boundaryWalkUntil( [&op](auto heh) { op(heh); return false; }, start); } void GeoData::boundaryWalkUntil(const std::function & op) const { boundaryWalkUntil(op, findBoundaryStart()); } void GeoData::boundaryWalkUntil(const std::function & op, HalfedgeHandle start) const { assert(is_boundary(start)); if (!op(start)) { for (auto heh = next_halfedge_handle(start); heh != start; heh = next_halfedge_handle(heh)) { if (op(heh)) { break; } } } } GeoData::HalfedgeHandle GeoData::findEntry(const GlobalPosition2D from, const GlobalPosition2D to) const { HalfedgeHandle entry; boundaryWalkUntil([this, from, to, &entry](auto he) { const auto e1 = point(to_vertex_handle(he)); const auto e2 = point(to_vertex_handle(opposite_halfedge_handle(he))); if (linesCrossLtR(from, to, e1, e2)) { entry = he; return true; } return false; }); return entry; } bool GeoData::triangleContainsPoint(const GlobalPosition2D p, const Triangle<2> & t) { return pointLeftOfOrOnLine(p, t[0], t[1]) && pointLeftOfOrOnLine(p, t[1], t[2]) && pointLeftOfOrOnLine(p, t[2], t[0]); } bool GeoData::triangleContainsPoint(const GlobalPosition2D p, FaceHandle face) const { return triangleContainsPoint(p, triangle<2>(face)); } GeoData::HalfedgeHandle GeoData::findBoundaryStart() const { return *std::find_if(halfedges_sbegin(), halfedges_end(), [this](const auto heh) { return is_boundary(heh); }); } [[nodiscard]] RelativePosition3D GeoData::difference(const HalfedgeHandle heh) const { return point(to_vertex_handle(heh)) - point(from_vertex_handle(heh)); } [[nodiscard]] RelativeDistance GeoData::length(const HalfedgeHandle heh) const { return glm::length(difference(heh)); } [[nodiscard]] GlobalPosition3D GeoData::centre(const HalfedgeHandle heh) const { return point(from_vertex_handle(heh)) + (difference(heh) / 2.F); } void GeoData::update_vertex_normals_only() { update_vertex_normals_only(vertices_sbegin()); } void GeoData::update_vertex_normals_only(VertexIter start) { std::for_each(start, vertices_end(), [this](const auto vh) { if (normal(vh) == Normal3D {}) { Normal3D n; calc_vertex_normal_correct(vh, n); this->set_normal(vh, glm::normalize(n)); } }); } bool GeoData::triangleOverlapsTriangle(const Triangle<2> & a, const Triangle<2> & b) { return triangleContainsPoint(a.x, b) || triangleContainsPoint(a.y, b) || triangleContainsPoint(a.z, b) || triangleContainsPoint(b.x, a) || triangleContainsPoint(b.y, a) || triangleContainsPoint(b.z, a) || linesCross(a.x, a.y, b.x, b.y) || linesCross(a.x, a.y, b.y, b.z) || linesCross(a.x, a.y, b.z, b.x) || linesCross(a.y, a.z, b.x, b.y) || linesCross(a.y, a.z, b.y, b.z) || linesCross(a.y, a.z, b.z, b.x) || linesCross(a.z, a.x, b.x, b.y) || linesCross(a.z, a.x, b.y, b.z) || linesCross(a.z, a.x, b.z, b.x); } bool GeoData::triangleContainsTriangle(const Triangle<2> & a, const Triangle<2> & b) { return triangleContainsPoint(a.x, b) && triangleContainsPoint(a.y, b) && triangleContainsPoint(a.z, b); } void GeoData::split(FaceHandle _fh) { // Collect halfedges of face const HalfedgeHandle he0 = halfedge_handle(_fh); const HalfedgeHandle he1 = next_halfedge_handle(he0); const HalfedgeHandle he2 = next_halfedge_handle(he1); const EdgeHandle eh0 = edge_handle(he0); const EdgeHandle eh1 = edge_handle(he1); const EdgeHandle eh2 = edge_handle(he2); // Collect points of face const VertexHandle p0 = to_vertex_handle(he0); const VertexHandle p1 = to_vertex_handle(he1); const VertexHandle p2 = to_vertex_handle(he2); // Calculate midpoint coordinates const Point new0 = centre(he0); const Point new1 = centre(he1); const Point new2 = centre(he2); // Add vertices at midpoint coordinates const VertexHandle v0 = add_vertex(new0); const VertexHandle v1 = add_vertex(new1); const VertexHandle v2 = add_vertex(new2); const bool split0 = !is_boundary(eh0); const bool split1 = !is_boundary(eh1); const bool split2 = !is_boundary(eh2); // delete original face delete_face(_fh, false); // split boundary edges of deleted face ( if not boundary ) if (split0) { split(eh0, v0); } if (split1) { split(eh1, v1); } if (split2) { split(eh2, v2); } // Retriangulate add_face(v0, p0, v1); add_face(p2, v0, v2); add_face(v2, v1, p1); add_face(v2, v0, v1); } void GeoData::setHeights(const std::span triangleStrip, const Surface & newFaceSurface) { static const RelativeDistance MAX_SLOPE = 1.5F; static const RelativeDistance MIN_ARC = 0.01F; if (triangleStrip.size() < 3) { return; } const auto initialVertexCount = static_cast(n_vertices()); // Create new vertices std::vector newVerts; newVerts.reserve(newVerts.size()); std::transform(triangleStrip.begin(), triangleStrip.end(), std::back_inserter(newVerts), [this](const auto tsVert) { return add_vertex(tsVert); }); // Create new faces const auto initialFaceCount = static_cast(n_faces()); std::for_each(strip_begin(newVerts), strip_end(newVerts), [this](const auto & newVert) { const auto [a, b, c] = newVert; add_face(a, b, c); }); for (auto fhi = FaceIter {*this, FaceHandle {initialFaceCount}, true}; fhi != faces_end(); fhi++) { static constexpr auto MAX_FACE_AREA = 100'000'000.F; const auto fh = *fhi; if (triangle<3>(fh).area() > MAX_FACE_AREA) { split(fh); } } std::vector newFaces; std::copy_if(FaceIter {*this, FaceHandle {initialFaceCount}, true}, faces_end(), std::back_inserter(newFaces), [this](FaceHandle fh) { return !this->status(fh).deleted(); }); // Extrude corners struct Extrusion { VertexHandle boundaryVertex, extrusionVertex; Direction3D lowerLimit, upperLimit; }; std::vector extrusionExtents; boundaryWalk( [this, &extrusionExtents](const auto boundaryHeh) { const auto prevBoundaryHeh = prev_halfedge_handle(boundaryHeh); const auto prevBoundaryVertex = from_vertex_handle(prevBoundaryHeh); const auto boundaryVertex = from_vertex_handle(boundaryHeh); const auto nextBoundaryVertex = to_vertex_handle(boundaryHeh); const auto p0 = point(prevBoundaryVertex); const auto p1 = point(boundaryVertex); const auto p2 = point(nextBoundaryVertex); const auto e0 = glm::normalize(vector_normal(RelativePosition2D(p1 - p0))); const auto e1 = glm::normalize(vector_normal(RelativePosition2D(p2 - p1))); const auto addExtrusionFor = [this, &extrusionExtents, boundaryVertex, p1](Direction2D direction) { const auto doExtrusion = [this](VertexHandle & extrusionVertex, Direction2D direction, GlobalPosition3D boundaryVertex, RelativeDistance vert) { const auto extrusionDir = glm::normalize(direction || vert); if (!extrusionVertex.is_valid()) { if (const auto intersect = intersectRay({boundaryVertex, extrusionDir})) { auto splitVertex = split(intersect->second, intersect->first); extrusionVertex = splitVertex; } else if (const auto intersect = intersectRay({boundaryVertex + GlobalPosition3D {1, 1, 0}, extrusionDir})) { auto splitVertex = split(intersect->second, intersect->first); extrusionVertex = splitVertex; } else if (const auto intersect = intersectRay({boundaryVertex + GlobalPosition3D {1, 0, 0}, extrusionDir})) { auto splitVertex = split(intersect->second, intersect->first); extrusionVertex = splitVertex; } } return extrusionDir; }; VertexHandle extrusionVertex; extrusionExtents.emplace_back(boundaryVertex, extrusionVertex, doExtrusion(extrusionVertex, direction, p1, -MAX_SLOPE), doExtrusion(extrusionVertex, direction, p1, MAX_SLOPE)); assert(extrusionVertex.is_valid()); }; if (const Arc arc {e0, e1}; arc.length() < MIN_ARC) { addExtrusionFor(normalize(e0 + e1) / cosf(arc.length() / 2.F)); } else if (arc.length() < pi) { // Previous half edge end to current half end start arc tangents const auto limit = std::ceil(arc.length() * 5.F / pi); const auto inc = arc.length() / limit; for (float step = 0; step <= limit; step += 1.F) { addExtrusionFor(sincosf(arc.first + (step * inc))); } } else { // Single tangent bisecting the difference addExtrusionFor(normalize(e0 + e1) / sinf((arc.length() - pi) / 2.F)); } }, *voh_begin(newVerts.front())); // Cut existing terrain extrusionExtents.emplace_back(extrusionExtents.front()); // Circular next std::vector> boundaryFaces; for (const auto & [first, second] : extrusionExtents | std::views::adjacent<2>) { const auto p0 = point(first.boundaryVertex); const auto p1 = point(second.boundaryVertex); const auto bdir = RelativePosition3D(p1 - p0); const auto make_plane = [p0](auto y, auto z) { return GeometricPlaneT {p0, crossProduct(y, z)}; }; const auto planes = ((first.boundaryVertex == second.boundaryVertex) ? std::array {make_plane(second.lowerLimit, first.lowerLimit), make_plane(second.upperLimit, first.upperLimit), } : std::array { make_plane(bdir, second.lowerLimit), make_plane(bdir, second.upperLimit), }); assert(planes.front().normal.z > 0.F); assert(planes.back().normal.z > 0.F); auto & out = boundaryFaces.emplace_back(); out.emplace_back(first.boundaryVertex); out.emplace_back(first.extrusionVertex); for (auto currentVertex = first.extrusionVertex; !find_halfedge(currentVertex, second.extrusionVertex).is_valid();) { [[maybe_unused]] const auto n = std::any_of(voh_begin(currentVertex), voh_end(currentVertex), [&](const auto currentVertexOut) { const auto next = next_halfedge_handle(currentVertexOut); const auto nextVertex = to_vertex_handle(next); const auto startVertex = from_vertex_handle(next); if (nextVertex == *++out.rbegin()) { // This half edge goes back to the previous vertex return false; } const auto edge = edge_handle(next); const auto ep0 = point(startVertex); const auto ep1 = point(nextVertex); if (planes.front().getRelation(ep1) == GeometricPlane::PlaneRelation::Below || planes.back().getRelation(ep1) == GeometricPlane::PlaneRelation::Above) { return false; } const auto diff = RelativePosition3D(ep1 - ep0); const auto length = glm::length(diff); const auto dir = diff / length; const Ray r {ep1, -dir}; const auto dists = planes * [r](const auto & plane) { RelativeDistance dist {}; if (r.intersectPlane(plane.origin, plane.normal, dist)) { return dist; } return INFINITY; }; const auto dist = *std::min_element(dists.begin(), dists.end()); const auto splitPos = ep1 - (dir * dist); if (dist <= length) { currentVertex = split(edge, splitPos); out.emplace_back(currentVertex); return true; } return false; }); assert(n); } out.emplace_back(second.extrusionVertex); if (first.boundaryVertex != second.boundaryVertex) { out.emplace_back(second.boundaryVertex); } } // Remove old faces std::set visited; auto removeOld = [&](auto & self, const auto face) -> void { if (visited.insert(face).second) { std::for_each(fh_begin(face), fh_end(face), [&](const auto fh) { const auto b1 = to_vertex_handle(fh); const auto b2 = from_vertex_handle(fh); if (opposite_face_handle(fh).is_valid() && std::none_of(boundaryFaces.begin(), boundaryFaces.end(), [b2, b1](const auto & bf) { return std::adjacent_find(bf.begin(), bf.end(), [b2, b1](const auto v1, const auto v2) { return b1 == v1 && b2 == v2; }) != bf.end(); })) { self(self, opposite_face_handle(fh)); } }); delete_face(face, false); } }; removeOld(removeOld, findPoint(triangleStrip.front())); std::for_each(boundaryFaces.begin(), boundaryFaces.end(), [&](auto & boundaryFace) { std::reverse(boundaryFace.begin(), boundaryFace.end()); add_face(boundaryFace); }); // Tidy up update_vertex_normals_only(VertexIter {*this, vertex_handle(initialVertexCount), true}); std::for_each(newFaces.begin(), newFaces.end(), [&newFaceSurface, this](const auto fh) { property(surface, fh) = &newFaceSurface; }); }