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/*
* $Id: inside.c,v 1.5 2003/09/11 16:12:48 markus Exp $
*
****************************************************************************
*
* MODULE: Vector library
*
* AUTHOR(S): Original author CERL, probably Dave Gerdes.
* Update to GRASS 5.7 Radim Blazek.
*
* PURPOSE: Lower level functions for reading/writing/manipulating vectors.
*
* COPYRIGHT: (C) 2001 by the GRASS Development Team
*
* This program is free software under the GNU General Public
* License (>=v2). Read the file COPYING that comes with GRASS
* for details.
*
*****************************************************************************/
#include "gis.h"
#include "Vect.h"
double
dig_x_intersect (
double beg_x,
double end_x,
double beg_y,
double end_y,
double Y)
{
double b, a;
b = (end_x - beg_x) / (end_y - beg_y);
a = beg_x - b * beg_y;
return (a + b * Y);
}
int
dig_in_area_bbox (
P_AREA * Area,
double x, double y)
{
#ifdef GDEBUG
G_debug (3, "BBOX: (x,y) (%lf, %lf)\n", x, y);
G_debug (3, "NSEW: %lf, %lf, %lf, %lf\n", Area->N, Area->S, Area->E, Area->W);
#endif
if (x < Area->W)
return (0);
if (x > Area->E)
return (0);
if (y < Area->S)
return (0);
if (y > Area->N)
return (0);
return (1);
}
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