sat.h

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/*                           S A T . H
 * BRL-CAD
 *
 * Copyright (c) 2025-2026 United States Government as represented by
 * the U.S. Army Research Laboratory.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * version 2.1 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this file; see the file named COPYING for more
 * information.
 */
/*----------------------------------------------------------------------*/
/* @file sat.h */
/** @addtogroup bg_sat */
/** @{ */
 
/**
 * @brief
 *
 * Implementation of Separating Axis Theorem intersection tests
 *
 */
 
#ifndef BG_SAT_H
#define BG_SAT_H
 
#include "common.h"
#include "vmath.h"
#include "bg/defines.h"
 
__BEGIN_DECLS
 
/**
 * Test for an intersection between a line and an Axis-Aligned Bounding Box (AABB).
 *
 * Returns 1 if they intersect, 0 otherwise.
 */
BG_EXPORT extern int
bg_sat_line_aabb(
        const point_t origin, const vect_t ldir,
        const point_t aabb_center, const vect_t aabb_extent
        );
 
/**
 * Test for an intersection between a line and an Oriented Bounding Box (OBB).
 *
 * Returns 1 if they intersect, 0 otherwise.
 */
BG_EXPORT extern int
bg_sat_line_obb(
        const point_t origin, const vect_t ldir,
        const point_t obb_center, const vect_t obb_extent1, const vect_t obb_extent2, const vect_t obb_extent3
        );
 
/**
 * Test for an intersection between a triangle and an Axis-Aligned Bounding Box (AABB).
 *
 * Returns 1 if they intersect, 0 otherwise.
 */
BG_EXPORT extern int
bg_sat_tri_aabb(
        const point_t v1, const point_t v2, const point_t v3,
        const point_t aabb_center, const vect_t aabb_extent
        );
 
/**
 * Test for an intersection between a triangle and an Oriented Bounding Box (OBB).
 *
 * Returns 1 if they intersect, 0 otherwise.
 */
BG_EXPORT extern int
bg_sat_tri_obb(
        const point_t v1, const point_t v2, const point_t v3,
        const point_t obb_center, const vect_t obb_extent1, const vect_t obb_extent2, const vect_t obb_extent3
        );
 
/**
 * Test for an intersection between an Axis-Aligned Bounding Box (AABB) and an
 * Oriented Bounding Box (OBB). The latter is defined by a center point and
 * three perpendicular vectors from the center to the centers of the various
 * faces.
 *
 * Returns 1 if they intersect, 0 otherwise.
 */
BG_EXPORT extern int
bg_sat_aabb_obb(
        const point_t aabb_min, const point_t aabb_max,
        const point_t obb_center, const vect_t obb_extent1, const vect_t obb_extent2, const vect_t obb_extent3
        );
 
/**
 * Test for an intersection between two Oriented Bounding Boxes (OBBs). The
 * boxes are defined by a center point and three perpendicular vectors from the
 * center to the centers of the various faces.
 *
 * Returns 1 if they intersect, 0 otherwise.
 */
BG_EXPORT extern int
bg_sat_obb_obb(
        const point_t obb1_center, const vect_t obb1_extent1, const vect_t obb1_extent2, const vect_t obb1_extent3,
        const point_t obb2_center, const vect_t obb2_extent1, const vect_t obb2_extent2, const vect_t obb2_extent3
        );
 
 
__END_DECLS
 
#endif  /* BG_SAT_H */
/** @} */
/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * indent-tabs-mode: t
 * c-file-style: "stroustrup"
 * End:
 * ex: shiftwidth=4 tabstop=8
 */