gimp/app/core/gimpimage-snap.c

393 lines
9.6 KiB
C

/* The GIMP -- an 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 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 <glib-object.h>
#include "core-types.h"
#include "gimp.h"
#include "gimpimage.h"
#include "gimpimage-grid.h"
#include "gimpimage-guides.h"
#include "gimpimage-snap.h"
#include "gimp-intl.h"
/* public functions */
gboolean
gimp_image_snap_x (GimpImage *gimage,
gdouble x,
gint *tx,
gdouble epsilon_x,
gboolean snap_to_guides,
gboolean snap_to_grid)
{
GList *list;
GimpGuide *guide;
GimpGrid *grid;
gdouble xspacing;
gdouble xoffset;
gdouble mindist = G_MAXDOUBLE;
gdouble dist;
gdouble i;
gboolean snapped = FALSE;
g_return_val_if_fail (GIMP_IS_IMAGE (gimage), FALSE);
g_return_val_if_fail (tx != NULL, FALSE);
if (! snap_to_guides && ! snap_to_grid)
return FALSE;
*tx = ROUND (x);
if (x < 0 || x >= gimage->width)
return FALSE;
if (snap_to_guides && gimage->guides != NULL)
{
for (list = gimage->guides; list; list = g_list_next (list))
{
guide = (GimpGuide *) list->data;
if (guide->position < 0)
continue;
if (guide->orientation == GIMP_ORIENTATION_VERTICAL)
{
dist = ABS (guide->position - x);
if (dist < MIN (epsilon_x, mindist))
{
mindist = dist;
*tx = guide->position;
snapped = TRUE;
}
}
}
}
if (snap_to_grid && gimage->grid != NULL)
{
grid = gimp_image_get_grid (gimage);
g_object_get (grid,
"xspacing", &xspacing,
"xoffset", &xoffset,
NULL);
for (i = xoffset; i <= gimage->width; i += xspacing)
{
if (i < 0)
continue;
dist = ABS (i - x);
if (dist < MIN (epsilon_x, mindist))
{
mindist = dist;
*tx = i;
snapped = TRUE;
}
}
}
return snapped;
}
gboolean
gimp_image_snap_y (GimpImage *gimage,
gdouble y,
gint *ty,
gdouble epsilon_y,
gboolean snap_to_guides,
gboolean snap_to_grid)
{
GList *list;
GimpGuide *guide;
GimpGrid *grid;
gdouble yspacing;
gdouble yoffset;
gdouble mindist = G_MAXDOUBLE;
gdouble dist;
gdouble i;
gboolean snapped = FALSE;
g_return_val_if_fail (GIMP_IS_IMAGE (gimage), FALSE);
g_return_val_if_fail (ty != NULL, FALSE);
if (! snap_to_guides && ! snap_to_grid)
return FALSE;
*ty = ROUND (y);
if (y < 0 || y >= gimage->height)
return FALSE;
if (snap_to_guides && gimage->guides != NULL)
{
for (list = gimage->guides; list; list = g_list_next (list))
{
guide = (GimpGuide *) list->data;
if (guide->position < 0)
continue;
if (guide->orientation == GIMP_ORIENTATION_HORIZONTAL)
{
dist = ABS (guide->position - y);
if (dist < MIN (epsilon_y, mindist))
{
mindist = dist;
*ty = guide->position;
snapped = TRUE;
}
}
}
}
if (snap_to_grid && gimage->grid != NULL)
{
grid = gimp_image_get_grid (gimage);
g_object_get (grid,
"yspacing", &yspacing,
"yoffset", &yoffset,
NULL);
for (i = yoffset; i <= gimage->height; i += yspacing)
{
if (i < 0)
continue;
dist = ABS (i - y);
if (dist < MIN (epsilon_y, mindist))
{
mindist = dist;
*ty = i;
snapped = TRUE;
}
}
}
return snapped;
}
gboolean
gimp_image_snap_point (GimpImage *gimage,
gdouble x,
gdouble y,
gint *tx,
gint *ty,
gdouble epsilon_x,
gdouble epsilon_y,
gboolean snap_to_guides,
gboolean snap_to_grid)
{
GList *list;
GimpGuide *guide;
GimpGrid *grid;
gdouble xspacing, yspacing;
gdouble xoffset, yoffset;
gdouble minxdist, minydist;
gdouble dist;
gdouble i;
gboolean snapped = FALSE;
g_return_val_if_fail (GIMP_IS_IMAGE (gimage), FALSE);
g_return_val_if_fail (tx != NULL, FALSE);
g_return_val_if_fail (ty != NULL, FALSE);
if (! snap_to_guides && ! snap_to_grid)
return FALSE;
*tx = ROUND (x);
*ty = ROUND (y);
if (x < 0 || x >= gimage->width ||
y < 0 || y >= gimage->height)
{
return FALSE;
}
minxdist = G_MAXDOUBLE;
minydist = G_MAXDOUBLE;
if (snap_to_guides && gimage->guides != NULL)
{
for (list = gimage->guides; list; list = g_list_next (list))
{
guide = (GimpGuide *) list->data;
if (guide->position < 0)
continue;
switch (guide->orientation)
{
case GIMP_ORIENTATION_HORIZONTAL:
dist = ABS (guide->position - y);
if (dist < MIN (epsilon_y, minydist))
{
minydist = dist;
*ty = guide->position;
snapped = TRUE;
}
break;
case GIMP_ORIENTATION_VERTICAL:
dist = ABS (guide->position - x);
if (dist < MIN (epsilon_x, minxdist))
{
minxdist = dist;
*tx = guide->position;
snapped = TRUE;
}
break;
default:
break;
}
}
}
if (snap_to_grid && gimage->grid != NULL)
{
grid = gimp_image_get_grid (gimage);
g_object_get (grid,
"xspacing", &xspacing,
"yspacing", &yspacing,
"xoffset", &xoffset,
"yoffset", &yoffset,
NULL);
for (i = xoffset; i <= gimage->width; i += xspacing)
{
if (i < 0)
continue;
dist = ABS (i - x);
if (dist < MIN (epsilon_x, minxdist))
{
minxdist = dist;
*tx = i;
snapped = TRUE;
}
}
for (i = yoffset; i <= gimage->height; i += yspacing)
{
if (i < 0)
continue;
dist = ABS (i - y);
if (dist < MIN (epsilon_y, minydist))
{
minydist = dist;
*ty = i;
snapped = TRUE;
}
}
}
return snapped;
}
gboolean
gimp_image_snap_rectangle (GimpImage *gimage,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gint *tx1,
gint *ty1,
gdouble epsilon_x,
gdouble epsilon_y,
gboolean snap_to_guides,
gboolean snap_to_grid)
{
gint nx1, ny1;
gint nx2, ny2;
gboolean snap1, snap2, snap3, snap4;
g_return_val_if_fail (GIMP_IS_IMAGE (gimage), FALSE);
g_return_val_if_fail (tx1 != NULL, FALSE);
g_return_val_if_fail (ty1 != NULL, FALSE);
if (! snap_to_guides && ! snap_to_grid)
return FALSE;
*tx1 = ROUND (x1);
*ty1 = ROUND (y1);
snap1 = gimp_image_snap_x (gimage, x1, &nx1,
epsilon_x,
snap_to_guides,
snap_to_grid);
snap2 = gimp_image_snap_x (gimage, x2, &nx2,
epsilon_x,
snap_to_guides,
snap_to_grid);
snap3 = gimp_image_snap_y (gimage, y1, &ny1,
epsilon_y,
snap_to_guides,
snap_to_grid);
snap4 = gimp_image_snap_y (gimage, y2, &ny2,
epsilon_y,
snap_to_guides,
snap_to_grid);
if (snap1 && snap2)
{
if (ABS (x1 - nx1) > ABS (x2 - nx2))
snap1 = FALSE;
else
snap2 = FALSE;
}
if (snap1)
*tx1 = nx1;
else if (snap2)
*tx1 = ROUND (x1 + (nx2 - x2));
if (snap3 && snap4)
{
if (ABS (y1 - ny1) > ABS (y2 - ny2))
snap3 = FALSE;
else
snap4 = FALSE;
}
if (snap3)
*ty1 = ny1;
else if (snap4)
*ty1 = ROUND (y1 + (ny2 - y2));
return (snap1 || snap2 || snap3 || snap4);
}