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gimp/app/core/gimpimage-contiguous-region.c

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/* 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 <stdlib.h>
#include <glib-object.h>
#include "libgimpcolor/gimpcolor.h"
#include "core-types.h"
#include "base/pixel-region.h"
#include "base/tile.h"
#include "base/tile-manager.h"
#include "gimpchannel.h"
#include "gimpimage.h"
#include "gimpimage-contiguous-region.h"
#include "gimpimage-projection.h"
/* local function prototypes */
static gint pixel_difference (guchar *col1,
guchar *col2,
gboolean antialias,
gint threshold,
gint bytes,
gboolean has_alpha,
gboolean select_transparent);
static void ref_tiles (TileManager *src,
TileManager *mask,
Tile **s_tile,
Tile **m_tile,
gint x,
gint y,
guchar **s,
guchar **m);
static gint find_contiguous_segment (guchar *col,
PixelRegion *src,
PixelRegion *mask,
gint width,
gint bytes,
gboolean has_alpha,
gboolean select_transparent,
gboolean antialias,
gint threshold,
gint initial,
gint *start,
gint *end);
static void find_contiguous_region_helper (PixelRegion *mask,
PixelRegion *src,
gboolean has_alpha,
gboolean select_transparent,
gboolean antialias,
gint threshold,
gint x,
gint y,
guchar *col);
/* public functions */
GimpChannel *
gimp_image_contiguous_region_by_seed (GimpImage *gimage,
GimpDrawable *drawable,
gboolean sample_merged,
gboolean antialias,
gint threshold,
gboolean select_transparent,
gint x,
gint y)
{
PixelRegion srcPR, maskPR;
GimpChannel *mask;
guchar *start;
gboolean has_alpha;
gint bytes;
Tile *tile;
g_return_val_if_fail (GIMP_IS_IMAGE (gimage), NULL);
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
if (sample_merged)
{
pixel_region_init (&srcPR, gimp_image_projection (gimage), 0, 0,
gimage->width, gimage->height, FALSE);
has_alpha =
GIMP_IMAGE_TYPE_HAS_ALPHA (gimp_image_projection_type (gimage));
bytes = gimp_image_projection_bytes (gimage);
}
else
{
pixel_region_init (&srcPR, gimp_drawable_data (drawable),
0, 0,
gimp_item_width (GIMP_ITEM (drawable)),
gimp_item_height (GIMP_ITEM (drawable)),
FALSE);
has_alpha = gimp_drawable_has_alpha (drawable);
if (gimp_drawable_is_indexed (drawable))
bytes = has_alpha ? 4 : 3;
else
bytes = gimp_drawable_bytes (drawable);
}
mask = gimp_channel_new_mask (gimage, srcPR.w, srcPR.h);
pixel_region_init (&maskPR, gimp_drawable_data (GIMP_DRAWABLE (mask)),
0, 0,
gimp_item_width (GIMP_ITEM (mask)),
gimp_item_height (GIMP_ITEM (mask)),
TRUE);
tile = tile_manager_get_tile (srcPR.tiles, x, y, TRUE, FALSE);
if (tile)
{
start = tile_data_pointer (tile, x % TILE_WIDTH, y % TILE_HEIGHT);
if (has_alpha)
{
if (select_transparent)
{
/* don't select transparent regions if the start pixel isn't
* fully transparent
*/
if (start[bytes - 1] > 0)
select_transparent = FALSE;
}
}
else
{
select_transparent = FALSE;
}
find_contiguous_region_helper (&maskPR, &srcPR, has_alpha,
select_transparent, antialias, threshold,
x, y, start);
tile_release (tile, FALSE);
}
return mask;
}
GimpChannel *
gimp_image_contiguous_region_by_color (GimpImage *gimage,
GimpDrawable *drawable,
gboolean sample_merged,
gboolean antialias,
gint threshold,
gboolean select_transparent,
const GimpRGB *color)
{
/* Scan over the gimage's active layer, finding pixels within the specified
* threshold from the given R, G, & B values. If antialiasing is on,
* use the same antialiasing scheme as in fuzzy_select. Modify the gimage's
* mask to reflect the additional selection
*/
GimpChannel *mask;
PixelRegion imagePR, maskPR;
guchar *image_data;
guchar *mask_data;
guchar *idata, *mdata;
guchar rgb[MAX_CHANNELS];
gint has_alpha, indexed;
gint width, height;
gint bytes, color_bytes, alpha;
gint i, j;
gpointer pr;
GimpImageType d_type;
guchar col[MAX_CHANNELS];
g_return_val_if_fail (GIMP_IS_IMAGE (gimage), NULL);
g_return_val_if_fail (GIMP_IS_DRAWABLE (drawable), NULL);
g_return_val_if_fail (color != NULL, NULL);
gimp_rgba_get_uchar (color, &col[0], &col[1], &col[2], &col[3]);
/* Get the image information */
if (sample_merged)
{
bytes = gimp_image_projection_bytes (gimage);
d_type = gimp_image_projection_type (gimage);
has_alpha = GIMP_IMAGE_TYPE_HAS_ALPHA (d_type);
indexed = GIMP_IMAGE_TYPE_IS_INDEXED (d_type);
width = gimage->width;
height = gimage->height;
pixel_region_init (&imagePR, gimp_image_projection (gimage),
0, 0,
width, height,
FALSE);
}
else
{
bytes = gimp_drawable_bytes (drawable);
d_type = gimp_drawable_type (drawable);
has_alpha = gimp_drawable_has_alpha (drawable);
indexed = gimp_drawable_is_indexed (drawable);
width = gimp_item_width (GIMP_ITEM (drawable));
height = gimp_item_height (GIMP_ITEM (drawable));
pixel_region_init (&imagePR, gimp_drawable_data (drawable),
0, 0,
width, height,
FALSE);
}
if (has_alpha)
{
if (select_transparent)
{
/* don't select transparancy if "color" isn't fully transparent
*/
if (col[3] > 0)
select_transparent = FALSE;
}
}
else
{
select_transparent = FALSE;
}
if (indexed)
{
/* indexed colors are always RGB or RGBA */
color_bytes = has_alpha ? 4 : 3;
}
else
{
/* RGB, RGBA, GRAY and GRAYA colors are shaped just like the image */
color_bytes = bytes;
}
alpha = bytes - 1;
mask = gimp_channel_new_mask (gimage, width, height);
pixel_region_init (&maskPR, gimp_drawable_data (GIMP_DRAWABLE (mask)),
0, 0,
width, height,
TRUE);
/* iterate over the entire image */
for (pr = pixel_regions_register (2, &imagePR, &maskPR);
pr != NULL;
pr = pixel_regions_process (pr))
{
image_data = imagePR.data;
mask_data = maskPR.data;
for (i = 0; i < imagePR.h; i++)
{
idata = image_data;
mdata = mask_data;
for (j = 0; j < imagePR.w; j++)
{
/* Get the rgb values for the color */
gimp_image_get_color (gimage, d_type, idata, rgb);
/* Plug the alpha channel in there */
if (has_alpha)
rgb[color_bytes - 1] = idata[alpha];
/* Find how closely the colors match */
*mdata++ = pixel_difference (col, rgb,
antialias, threshold,
color_bytes,
has_alpha, select_transparent);
idata += bytes;
}
image_data += imagePR.rowstride;
mask_data += maskPR.rowstride;
}
}
return mask;
}
/* private functions */
static gint
pixel_difference (guchar *col1,
guchar *col2,
gboolean antialias,
gint threshold,
gint bytes,
gboolean has_alpha,
gboolean select_transparent)
{
gint max = 0;
/* if there is an alpha channel, never select transparent regions */
if (! select_transparent && has_alpha && col2[bytes - 1] == 0)
return 0;
if (select_transparent && has_alpha)
{
max = abs (col1[bytes - 1] - col2[bytes - 1]);
}
else
{
gint diff;
gint b;
if (has_alpha)
bytes--;
for (b = 0; b < bytes; b++)
{
diff = abs (col1[b] - col2[b]);
if (diff > max)
max = diff;
}
}
if (antialias && threshold > 0)
{
gfloat aa = 1.5 - ((gfloat) max / threshold);
if (aa <= 0.0)
return 0;
else if (aa < 0.5)
return (guchar) (aa * 512);
else
return 255;
}
else
{
if (max > threshold)
return 0;
else
return 255;
}
}
static void
ref_tiles (TileManager *src,
TileManager *mask,
Tile **s_tile,
Tile **m_tile,
gint x,
gint y,
guchar **s,
guchar **m)
{
if (*s_tile != NULL)
tile_release (*s_tile, FALSE);
if (*m_tile != NULL)
tile_release (*m_tile, TRUE);
*s_tile = tile_manager_get_tile (src, x, y, TRUE, FALSE);
*m_tile = tile_manager_get_tile (mask, x, y, TRUE, TRUE);
*s = tile_data_pointer (*s_tile, x % TILE_WIDTH, y % TILE_HEIGHT);
*m = tile_data_pointer (*m_tile, x % TILE_WIDTH, y % TILE_HEIGHT);
}
static int
find_contiguous_segment (guchar *col,
PixelRegion *src,
PixelRegion *mask,
gint width,
gint bytes,
gboolean has_alpha,
gboolean select_transparent,
gboolean antialias,
gint threshold,
gint initial,
gint *start,
gint *end)
{
guchar *s;
guchar *m;
guchar diff;
Tile *s_tile = NULL;
Tile *m_tile = NULL;
ref_tiles (src->tiles, mask->tiles,
&s_tile, &m_tile, src->x, src->y, &s, &m);
/* check the starting pixel */
if (! (diff = pixel_difference (col, s, antialias, threshold,
bytes, has_alpha, select_transparent)))
{
tile_release (s_tile, FALSE);
tile_release (m_tile, TRUE);
return FALSE;
}
*m-- = diff;
s -= bytes;
*start = initial - 1;
while (*start >= 0 && diff)
{
if (! ((*start + 1) % TILE_WIDTH))
ref_tiles (src->tiles, mask->tiles,
&s_tile, &m_tile, *start, src->y, &s, &m);
diff = pixel_difference (col, s, antialias, threshold,
bytes, has_alpha, select_transparent);
if ((*m-- = diff))
{
s -= bytes;
(*start)--;
}
}
diff = 1;
*end = initial + 1;
if (*end % TILE_WIDTH && *end < width)
ref_tiles (src->tiles, mask->tiles,
&s_tile, &m_tile, *end, src->y, &s, &m);
while (*end < width && diff)
{
if (! (*end % TILE_WIDTH))
ref_tiles (src->tiles, mask->tiles,
&s_tile, &m_tile, *end, src->y, &s, &m);
diff = pixel_difference (col, s, antialias, threshold,
bytes, has_alpha, select_transparent);
if ((*m++ = diff))
{
s += bytes;
(*end)++;
}
}
tile_release (s_tile, FALSE);
tile_release (m_tile, TRUE);
return TRUE;
}
static void
find_contiguous_region_helper (PixelRegion *mask,
PixelRegion *src,
gboolean has_alpha,
gboolean select_transparent,
gboolean antialias,
gint threshold,
gint x,
gint y,
guchar *col)
{
gint start, end, i;
gint val;
Tile *tile;
if (x < 0 || x >= src->w) return;
if (y < 0 || y >= src->h) return;
tile = tile_manager_get_tile (mask->tiles, x, y, TRUE, FALSE);
val = *(guchar *)(tile_data_pointer (tile,
x % TILE_WIDTH, y % TILE_HEIGHT));
tile_release (tile, FALSE);
if (val != 0)
return;
src->x = x;
src->y = y;
if (! find_contiguous_segment (col, src, mask, src->w, src->bytes,
has_alpha, select_transparent,
antialias, threshold,
x, &start, &end))
return;
for (i = start + 1; i < end; i++)
{
find_contiguous_region_helper (mask, src, has_alpha, select_transparent,
antialias, threshold,
i, y - 1, col);
find_contiguous_region_helper (mask, src, has_alpha, select_transparent,
antialias, threshold,
i, y + 1, col);
}
}
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