blender-archive/source/blender/blenlib/intern/lasso_2d.c

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 */

/** \file
 * \ingroup bli
 */

#include "DNA_vec_types.h"

#include "BLI_math.h"
#include "BLI_strict_flags.h"

#include "BLI_lasso_2d.h" /* own include */

void BLI_lasso_boundbox(rcti *rect, const int mcords[][2], const unsigned int moves)
{
	unsigned int a;

	rect->xmin = rect->xmax = mcords[0][0];
	rect->ymin = rect->ymax = mcords[0][1];

	for (a = 1; a < moves; a++) {
		if      (mcords[a][0] < rect->xmin) rect->xmin = mcords[a][0];
		else if (mcords[a][0] > rect->xmax) rect->xmax = mcords[a][0];
		if      (mcords[a][1] < rect->ymin) rect->ymin = mcords[a][1];
		else if (mcords[a][1] > rect->ymax) rect->ymax = mcords[a][1];
	}
}


bool BLI_lasso_is_point_inside(const int mcords[][2], const unsigned int moves,
                               const int sx, const int sy,
                               const int error_value)
{
	if (sx == error_value || moves == 0) {
		return false;
	}
	else {
		int pt[2] = {sx, sy};
		return isect_point_poly_v2_int(pt, mcords, moves, true);
	}
}

/* edge version for lasso select. we assume boundbox check was done */
bool BLI_lasso_is_edge_inside(const int mcords[][2], const unsigned int moves,
                              int x0, int y0, int x1, int y1,
                              const int error_value)
{

	if (x0 == error_value || x1 == error_value || moves == 0) {
		return false;
	}

	const int v1[2] = {x0, y0}, v2[2] = {x1, y1};

	/* check points in lasso */
	if (BLI_lasso_is_point_inside(mcords, moves, v1[0], v1[1], error_value)) return true;
	if (BLI_lasso_is_point_inside(mcords, moves, v2[0], v2[1], error_value)) return true;

	/* no points in lasso, so we have to intersect with lasso edge */

	if (isect_seg_seg_v2_int(mcords[0], mcords[moves - 1], v1, v2) > 0) return true;
	for (unsigned int a = 0; a < moves - 1; a++) {
		if (isect_seg_seg_v2_int(mcords[a], mcords[a + 1], v1, v2) > 0) return true;
	}

	return false;
}