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/* Dia -- an diagram creation/manipulation program
* Copyright (C) 1998 Alexander Larsson
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "connectionpoint.h"
/* Returns the available directions on a slope.
* The right-hand side of the line is assumed to be within the object,
* and thus not available. */
gint
find_slope_directions(Point from, Point to)
{
gint dirs;
gint slope;
if (fabs(from.y-to.y) < 0.0000001)
return (from.x > to.x?DIR_SOUTH:DIR_NORTH);
if (fabs(from.x-to.x) < 0.0000001)
return (from.y > to.y?DIR_WEST:DIR_EAST);
point_sub(&to, &from);
slope = fabs(to.y/to.x);
dirs = 0;
if (slope < 2) { /* Flat enough to allow north-south */
if (to.x > 0) { /* The outside is north, not south */
dirs |= DIR_NORTH;
} else {
dirs |= DIR_SOUTH;
}
}
if (slope > .5) { /* Steep enough to allow east-west */
if (to.y > 0) { /* The outside is east, not west */
dirs |= DIR_EAST;
} else {
dirs |= DIR_WEST;
}
}
return dirs;
}
/** Update the object-settable parts of a connectionpoints.
* p: A ConnectionPoint pointer (non-NULL).
* x: The x coordinate of the connectionpoint.
* y: The y coordinate of the connectionpoint.
* dirs: The directions that are open for connections on this point.
*/
void
connpoint_update(ConnectionPoint *p, real x, real y, gint dirs)
{
p->pos.x = x;
p->pos.y = y;
p->directions = dirs;
}
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