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