/* 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 .
*/
#include "config.h"
#include
#include
#include
#include "core-types.h"
#include "gimp.h"
#include "gimpimage.h"
#include "gimppickable.h"
#include "gimppickable-auto-shrink.h"
typedef enum
{
AUTO_SHRINK_NOTHING = 0,
AUTO_SHRINK_ALPHA = 1,
AUTO_SHRINK_COLOR = 2
} AutoShrinkType;
typedef gboolean (* ColorsEqualFunc) (guchar *col1,
guchar *col2);
/* local function prototypes */
static AutoShrinkType gimp_pickable_guess_bgcolor (GimpPickable *pickable,
guchar *color,
gint x1,
gint x2,
gint y1,
gint y2);
static gboolean gimp_pickable_colors_equal (guchar *col1,
guchar *col2);
static gboolean gimp_pickable_colors_alpha (guchar *col1,
guchar *col2);
/* public functions */
GimpAutoShrink
gimp_pickable_auto_shrink (GimpPickable *pickable,
gint start_x,
gint start_y,
gint start_width,
gint start_height,
gint *shrunk_x,
gint *shrunk_y,
gint *shrunk_width,
gint *shrunk_height)
{
GeglBuffer *buffer;
GeglRectangle rect;
ColorsEqualFunc colors_equal_func;
guchar bgcolor[MAX_CHANNELS] = { 0, 0, 0, 0 };
guchar *buf = NULL;
gint x1, y1, x2, y2;
gint width, height;
const Babl *format;
gint x, y, abort;
GimpAutoShrink retval = GIMP_AUTO_SHRINK_UNSHRINKABLE;
g_return_val_if_fail (GIMP_IS_PICKABLE (pickable), FALSE);
g_return_val_if_fail (shrunk_x != NULL, FALSE);
g_return_val_if_fail (shrunk_y != NULL, FALSE);
g_return_val_if_fail (shrunk_width != NULL, FALSE);
g_return_val_if_fail (shrunk_height != NULL, FALSE);
gimp_set_busy (gimp_pickable_get_image (pickable)->gimp);
/* You should always keep in mind that x2 and y2 are the NOT the
* coordinates of the bottomright corner of the area to be
* cropped. They point at the pixel located one to the right and one
* to the bottom.
*/
gimp_pickable_flush (pickable);
buffer = gimp_pickable_get_buffer (pickable);
x1 = MAX (start_x, 0);
y1 = MAX (start_y, 0);
x2 = MIN (start_x + start_width, gegl_buffer_get_width (buffer));
y2 = MIN (start_y + start_height, gegl_buffer_get_height (buffer));
/* By default, return the start values */
*shrunk_x = x1;
*shrunk_y = y1;
*shrunk_width = x2 - x1;
*shrunk_height = y2 - y1;
format = babl_format ("R'G'B'A u8");
switch (gimp_pickable_guess_bgcolor (pickable, bgcolor,
x1, x2 - 1, y1, y2 - 1))
{
case AUTO_SHRINK_ALPHA:
colors_equal_func = gimp_pickable_colors_alpha;
break;
case AUTO_SHRINK_COLOR:
colors_equal_func = gimp_pickable_colors_equal;
break;
default:
goto FINISH;
break;
}
width = x2 - x1;
height = y2 - y1;
/* The following could be optimized further by processing
* the smaller side first instead of defaulting to width --Sven
*/
buf = g_malloc (MAX (width, height) * 4);
/* Check how many of the top lines are uniform/transparent. */
rect.x = x1;
rect.y = 0;
rect.width = width;
rect.height = 1;
abort = FALSE;
for (y = y1; y < y2 && !abort; y++)
{
rect.y = y;
gegl_buffer_get (buffer, &rect, 1.0, format, buf,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
for (x = 0; x < width && !abort; x++)
abort = ! colors_equal_func (bgcolor, buf + x * 4);
}
if (y == y2 && !abort)
{
retval = GIMP_AUTO_SHRINK_EMPTY;
goto FINISH;
}
y1 = y - 1;
/* Check how many of the bottom lines are uniform/transparent. */
rect.x = x1;
rect.y = 0;
rect.width = width;
rect.height = 1;
abort = FALSE;
for (y = y2; y > y1 && !abort; y--)
{
rect.y = y - 1;
gegl_buffer_get (buffer, &rect, 1.0, format, buf,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
for (x = 0; x < width && !abort; x++)
abort = ! colors_equal_func (bgcolor, buf + x * 4);
}
y2 = y + 1;
/* compute a new height for the next operations */
height = y2 - y1;
/* Check how many of the left lines are uniform/transparent. */
rect.x = 0;
rect.y = y1;
rect.width = 1;
rect.height = height;
abort = FALSE;
for (x = x1; x < x2 && !abort; x++)
{
rect.x = x;
gegl_buffer_get (buffer, &rect, 1.0, format, buf,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
for (y = 0; y < height && !abort; y++)
abort = ! colors_equal_func (bgcolor, buf + y * 4);
}
x1 = x - 1;
/* Check how many of the right lines are uniform/transparent. */
rect.x = 0;
rect.y = y1;
rect.width = 1;
rect.height = height;
abort = FALSE;
for (x = x2; x > x1 && !abort; x--)
{
rect.x = x - 1;
gegl_buffer_get (buffer, &rect, 1.0, format, buf,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
for (y = 0; y < height && !abort; y++)
abort = ! colors_equal_func (bgcolor, buf + y * 4);
}
x2 = x + 1;
if (x1 != start_x ||
y1 != start_y ||
x2 - x1 != start_width ||
y2 - y1 != start_height)
{
*shrunk_x = x1;
*shrunk_y = y1;
*shrunk_width = x2 - x1;
*shrunk_height = y2 - y1;
retval = GIMP_AUTO_SHRINK_SHRINK;
}
FINISH:
g_free (buf);
gimp_unset_busy (gimp_pickable_get_image (pickable)->gimp);
return retval;
}
/* private functions */
static AutoShrinkType
gimp_pickable_guess_bgcolor (GimpPickable *pickable,
guchar *color,
gint x1,
gint x2,
gint y1,
gint y2)
{
const Babl *format = babl_format ("R'G'B'A u8");
guchar tl[4];
guchar tr[4];
guchar bl[4];
guchar br[4];
gint i;
for (i = 0; i < 4; i++)
color[i] = 0;
/* First check if there's transparency to crop. If not, guess the
* background-color to see if at least 2 corners are equal.
*/
if (! gimp_pickable_get_pixel_at (pickable, x1, y1, format, tl) ||
! gimp_pickable_get_pixel_at (pickable, x1, y2, format, tr) ||
! gimp_pickable_get_pixel_at (pickable, x2, y1, format, bl) ||
! gimp_pickable_get_pixel_at (pickable, x2, y2, format, br))
{
return AUTO_SHRINK_NOTHING;
}
if ((tl[ALPHA] == 0 && tr[ALPHA] == 0) ||
(tl[ALPHA] == 0 && bl[ALPHA] == 0) ||
(tr[ALPHA] == 0 && br[ALPHA] == 0) ||
(bl[ALPHA] == 0 && br[ALPHA] == 0))
{
return AUTO_SHRINK_ALPHA;
}
if (gimp_pickable_colors_equal (tl, tr) ||
gimp_pickable_colors_equal (tl, bl))
{
memcpy (color, tl, 4);
return AUTO_SHRINK_COLOR;
}
if (gimp_pickable_colors_equal (br, bl) ||
gimp_pickable_colors_equal (br, tr))
{
memcpy (color, br, 4);
return AUTO_SHRINK_COLOR;
}
return AUTO_SHRINK_NOTHING;
}
static gboolean
gimp_pickable_colors_equal (guchar *col1,
guchar *col2)
{
gint b;
for (b = 0; b < 4; b++)
{
if (col1[b] != col2[b])
return FALSE;
}
return TRUE;
}
static gboolean
gimp_pickable_colors_alpha (guchar *dummy,
guchar *col)
{
return (col[ALPHA] == 0);
}