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Diffstat (limited to 'core/math/convex_hull.h')
| -rw-r--r-- | core/math/convex_hull.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/core/math/convex_hull.h b/core/math/convex_hull.h new file mode 100644 index 0000000000..ba7be9c5e8 --- /dev/null +++ b/core/math/convex_hull.h @@ -0,0 +1,112 @@ +/*************************************************************************/ +/* convex_hull.h */ +/*************************************************************************/ +/* This file is part of: */ +/* GODOT ENGINE */ +/* https://godotengine.org */ +/*************************************************************************/ +/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */ +/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */ +/* */ +/* Permission is hereby granted, free of charge, to any person obtaining */ +/* a copy of this software and associated documentation files (the */ +/* "Software"), to deal in the Software without restriction, including */ +/* without limitation the rights to use, copy, modify, merge, publish, */ +/* distribute, sublicense, and/or sell copies of the Software, and to */ +/* permit persons to whom the Software is furnished to do so, subject to */ +/* the following conditions: */ +/* */ +/* The above copyright notice and this permission notice shall be */ +/* included in all copies or substantial portions of the Software. */ +/* */ +/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ +/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ +/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ +/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ +/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ +/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ +/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ +/*************************************************************************/ + +/* +Copyright (c) 2011 Ole Kniemeyer, MAXON, www.maxon.net +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: +1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef CONVEX_HULL_H +#define CONVEX_HULL_H + +#include "core/math/geometry_3d.h" +#include "core/math/vector3.h" +#include "core/templates/local_vector.h" +#include "core/templates/vector.h" + +/// Convex hull implementation based on Preparata and Hong +/// See http://code.google.com/p/bullet/issues/detail?id=275 +/// Ole Kniemeyer, MAXON Computer GmbH +class ConvexHullComputer { +public: + class Edge { + private: + int32_t next = 0; + int32_t reverse = 0; + int32_t target_vertex = 0; + + friend class ConvexHullComputer; + + public: + int32_t get_source_vertex() const { + return (this + reverse)->target_vertex; + } + + int32_t get_target_vertex() const { + return target_vertex; + } + + const Edge *get_next_edge_of_vertex() const // clockwise list of all edges of a vertex + { + return this + next; + } + + const Edge *get_next_edge_of_face() const // counter-clockwise list of all edges of a face + { + return (this + reverse)->get_next_edge_of_vertex(); + } + + const Edge *get_reverse_edge() const { + return this + reverse; + } + }; + + // Vertices of the output hull + Vector<Vector3> vertices; + + // Edges of the output hull + LocalVector<Edge> edges; + + // Faces of the convex hull. Each entry is an index into the "edges" array pointing to an edge of the face. Faces are planar n-gons + LocalVector<int32_t> faces; + + /* + Compute convex hull of "count" vertices stored in "coords". + If "shrink" is positive, the convex hull is shrunken by that amount (each face is moved by "shrink" length units + towards the center along its normal). + If "shrinkClamp" is positive, "shrink" is clamped to not exceed "shrinkClamp * innerRadius", where "innerRadius" + is the minimum distance of a face to the center of the convex hull. + The returned value is the amount by which the hull has been shrunken. If it is negative, the amount was so large + that the resulting convex hull is empty. + The output convex hull can be found in the member variables "vertices", "edges", "faces". + */ + real_t compute(const Vector3 *p_coords, int32_t p_count, real_t p_shrink, real_t p_shrink_clamp); + + static Error convex_hull(const Vector<Vector3> &p_points, Geometry3D::MeshData &r_mesh); +}; + +#endif // CONVEX_HULL_H |