convex_hull.cpp | Explore in Territory

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/*  convex_hull.cpp                                                       */
/**************************************************************************/
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/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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/*
 * Based on Godot's patched VHACD-version of Bullet's btConvexHullComputer.
 * See /thirdparty/vhacd/btConvexHullComputer.cpp at 64403ddcab9f1dca2408f0a412a22d899708bbb1
 * In turn, based on /src/LinearMath/btConvexHullComputer.cpp in <https://github.com/bulletphysics/bullet3>
 * at 73b217fb07e7e3ce126caeb28ab3c9ddd0718467
 *
 * Changes:
 * - int32_t is consistently used instead of int in some cases
 * - integrated patch db0d6c92927f5a1358b887f2645c11f3014f0e8a from Bullet (CWE-190 integer overflow in btConvexHullComputer)
 * - adapted to Godot's code style
 * - replaced Bullet's types (e.g. vectors) with Godot's
 * - replaced custom Pool implementation with PagedAllocator
 */

/*
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.
*/

#include "convex_hull.h"

#include "core/error/error_macros.h"
#include "core/math/aabb.h"
#include "core/math/math_defs.h"
#include "core/os/memory.h"
#include "core/templates/oa_hash_map.h"
#include "core/templates/paged_allocator.h"

#include <string.h>

//#define DEBUG_CONVEX_HULL
//#define SHOW_ITERATIONS

// -- GODOT start --
// Assembly optimizations are not used at the moment.
//#define USE_X86_64_ASM
// -- GODOT end --

#ifdef DEBUG_ENABLED
#define CHULL_ASSERT(m_cond) …
#else
#define CHULL_ASSERT …
#endif

#if defined(DEBUG_CONVEX_HULL) || defined(SHOW_ITERATIONS)
#include <stdio.h>
#endif

// Convex hull implementation based on Preparata and Hong
// Ole Kniemeyer, MAXON Computer GmbH
class ConvexHullInternal { … };

ConvexHullInternal::Int128 ConvexHullInternal::Int128::operator*(int64_t b) const { … }

ConvexHullInternal::Int128 ConvexHullInternal::Int128::mul(int64_t a, int64_t b) { … }

ConvexHullInternal::Int128 ConvexHullInternal::Int128::mul(uint64_t a, uint64_t b) { … }

int32_t ConvexHullInternal::Rational64::compare(const Rational64 &b) const { … }

int32_t ConvexHullInternal::Rational128::compare(const Rational128 &b) const { … }

int32_t ConvexHullInternal::Rational128::compare(int64_t b) const { … }

ConvexHullInternal::Edge *ConvexHullInternal::new_edge_pair(Vertex *p_from, Vertex *p_to) { … }

bool ConvexHullInternal::merge_projection(IntermediateHull &r_h0, IntermediateHull &r_h1, Vertex *&r_c0, Vertex *&r_c1) { … }

void ConvexHullInternal::compute_internal(int32_t p_start, int32_t p_end, IntermediateHull &r_result) { … }

#ifdef DEBUG_CONVEX_HULL
void ConvexHullInternal::IntermediateHull::print() {
	printf("    Hull\n");
	for (Vertex *v = min_xy; v;) {
		printf("      ");
		v->print();
		if (v == max_xy) {
			printf(" max_xy");
		}
		if (v == min_yx) {
			printf(" min_yx");
		}
		if (v == max_yx) {
			printf(" max_yx");
		}
		if (v->next->prev != v) {
			printf(" Inconsistency");
		}
		printf("\n");
		v = v->next;
		if (v == min_xy) {
			break;
		}
	}
	if (min_xy) {
		min_xy->copy = (min_xy->copy == -1) ? -2 : -1;
		min_xy->print_graph();
	}
}

void ConvexHullInternal::Vertex::print_graph() {
	print();
	printf("\nEdges\n");
	Edge *e = edges;
	if (e) {
		do {
			e->print();
			printf("\n");
			e = e->next;
		} while (e != edges);
		do {
			Vertex *v = e->target;
			if (v->copy != copy) {
				v->copy = copy;
				v->print_graph();
			}
			e = e->next;
		} while (e != edges);
	}
}
#endif

ConvexHullInternal::Orientation ConvexHullInternal::get_orientation(const Edge *p_prev, const Edge *p_next, const Point32 &p_s, const Point32 &p_t) { … }

ConvexHullInternal::Edge *ConvexHullInternal::find_max_angle(bool p_ccw, const Vertex *p_start, const Point32 &p_s, const Point64 &p_rxs, const Point64 &p_sxrxs, Rational64 &p_min_cot) { … }

void ConvexHullInternal::find_edge_for_coplanar_faces(Vertex *p_c0, Vertex *p_c1, Edge *&p_e0, Edge *&p_e1, const Vertex *p_stop0, const Vertex *p_stop1) { … }

void ConvexHullInternal::merge(IntermediateHull &p_h0, IntermediateHull &p_h1) { … }

struct PointComparator { … };

void ConvexHullInternal::compute(const Vector3 *p_coords, int32_t p_count) { … }

Vector3 ConvexHullInternal::to_gd_vector(const Point32 &p_v) { … }

Vector3 ConvexHullInternal::get_gd_normal(Face *p_face) { … }

Vector3 ConvexHullInternal::get_coordinates(const Vertex *p_v) { … }

real_t ConvexHullInternal::shrink(real_t p_amount, real_t p_clamp_amount) { … }

bool ConvexHullInternal::shift_face(Face *p_face, real_t p_amount, LocalVector<Vertex *> &p_stack) { … }

static int32_t get_vertex_copy(ConvexHullInternal::Vertex *p_vertex, LocalVector<ConvexHullInternal::Vertex *> &p_vertices) { … }

real_t ConvexHullComputer::compute(const Vector3 *p_coords, int32_t p_count, real_t p_shrink, real_t p_shrink_clamp) { … }

Error ConvexHullComputer::convex_hull(const Vector<Vector3> &p_points, Geometry3D::MeshData &r_mesh) { … }
godot/core/math/convex_hull.cpp
