gimp/app/core/gimparea.c

109 lines
2.5 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib-object.h>
#include "core-types.h"
#include "gimparea.h"
#define OVERHEAD 25 /* in units of pixel area */
GimpArea *
gimp_area_new (gint x1,
gint y1,
gint x2,
gint y2)
{
GimpArea *area = g_slice_new (GimpArea);
area->x1 = x1;
area->y1 = y1;
area->x2 = x2;
area->y2 = y2;
return area;
}
void
gimp_area_free (GimpArea *area)
{
g_slice_free (GimpArea, area);
}
/*
* As far as I can tell, this function takes a GimpArea and unifies it with
* an existing list of GimpAreas, trying to avoid overdraw. [adam]
*/
GSList *
gimp_area_list_process (GSList *list,
GimpArea *area)
{
GSList *retval;
GSList *l;
retval = g_slist_prepend (NULL, area);
for (l = list; l; l = g_slist_next (l))
{
GimpArea *this = l->data;
gint area1;
gint area2;
gint area3;
area1 = (area->x2 - area->x1) * (area->y2 - area->y1) + OVERHEAD;
area2 = (this->x2 - this->x1) * (this->y2 - this->y1) + OVERHEAD;
area3 = ((MAX (this->x2, area->x2) - MIN (this->x1, area->x1)) *
(MAX (this->y2, area->y2) - MIN (this->y1, area->y1)) + OVERHEAD);
if (area1 + area2 < area3)
{
retval = g_slist_prepend (retval, this);
}
else
{
area->x1 = MIN (area->x1, this->x1);
area->y1 = MIN (area->y1, this->y1);
area->x2 = MAX (area->x2, this->x2);
area->y2 = MAX (area->y2, this->y2);
g_slice_free (GimpArea, this);
}
}
if (list)
g_slist_free (list);
return retval;
}
void
gimp_area_list_free (GSList *areas)
{
GSList *list;
for (list = areas; list; list = list->next)
gimp_area_free (list->data);
g_slist_free (areas);
}