lseg.h

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/*                        L S E G . H
 * BRL-CAD
 *
 * Copyright (c) 2004-2023 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 lseg.h */
/** @addtogroup bg_lseg */
/** @{ */
 
/**
 *  @brief Functions for working with line segments
 */
 
#ifndef BG_LSEG_H
#define BG_LSEG_H
 
#include "common.h"
#include "vmath.h"
#include "bv.h"
#include "bg/defines.h"
 
__BEGIN_DECLS
 
/* Compute the closest point on the line segment P0->P1 to point Q.  Returns
 * the distance squared from Q to the closest point and the closest point in
 * question if c is non-NULL.
 */
BG_EXPORT double
bg_distsq_lseg3_pt(point_t *c, const point_t P0, const point_t P1, const point_t Q);
 
/* Compute the closest points on the line segments P0->P1 and Q0->Q1.  Returns
 * the distance squared between the closest points and (optionally) the closest
 * points in question (c1 is the point on P0->P1, c2 is the point on Q0->Q1).
 */
BG_EXPORT double
bg_distsq_lseg3_lseg3(point_t *c1, point_t *c2,
        const point_t P0, const point_t P1, const point_t Q0, const point_t Q1);
 
 
/* Logic for snapping points to their closes view lines.
 * TODO - really should make this generic to any line set, not just the
 * bv structures. */
 
/* Snap sample 2D point to lines active in the view */
BG_EXPORT extern int bv_snap_lines_2d(struct bview *v, fastf_t *fx, fastf_t *fy);
 
/* Snap sample 2D point to grid active in the view */
BG_EXPORT extern int bv_snap_grid_2d(struct bview *v, fastf_t *fx, fastf_t *fy);
 
/* Snap sample 3D point to lines active in the view */
BG_EXPORT extern int bv_snap_lines_3d(point_t *out_pt, struct bview *v, point_t *p);
 
 
BG_EXPORT extern void bv_view_center_linesnap(struct bview *v);
 
 
 
__END_DECLS
 
#endif  /* BG_LSEG_H */
/** @} */
/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * indent-tabs-mode: t
 * c-file-style: "stroustrup"
 * End:
 * ex: shiftwidth=4 tabstop=8
 */