/* This file is an image processing operation for GEGL
*
* GEGL is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* GEGL 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2011 Barak Itkin <lightningismyname@gmail.org>
*
* Based on "Spread" (Noise) GIMP plugin
* Copyright (C) 1997 Brian Degenhardt and Federico Mena Quintero
*
* The workshop/whirl-pinch.c and common/pixelise.c were used as
* templates for this op file.
*/
#include "config.h"
#include <glib/gi18n-lib.h>
#ifdef GEGL_CHANT_PROPERTIES
gegl_chant_int (x_amount, _("Horizontal"), 0, 256, 5,
_("Horizontal spread amount"))
gegl_chant_int (y_amount, _("Vertical"), 0, 256, 5,
_("Vertical spread amount"))
#else
#define GEGL_CHANT_TYPE_AREA_FILTER
#define GEGL_CHANT_C_FILE "noise-spread.c"
#include "gegl-chant.h"
#include <math.h>
static void
calc_sample_coords (gint src_x,
gint src_y,
gint x_amount,
gint y_amount,
GRand *gr,
gdouble *x,
gdouble *y)
{
gdouble angle;
gint xdist, ydist;
/* get random angle, x distance, and y distance */
xdist = (x_amount > 0
? g_rand_int_range (gr, -x_amount, x_amount)
: 0);
ydist = (y_amount > 0
? g_rand_int_range (gr, -y_amount, y_amount)
: 0);
angle = g_rand_double_range (gr, -G_PI, G_PI);
*x = src_x + floor (sin (angle) * xdist);
*y = src_y + floor (cos (angle) * ydist);
}
/* Apply the actual transform */
static void
apply_spread (gint x_amount,
gint y_amount,
gint img_width,
gint img_height,
const Babl *format,
GeglBuffer *src,
GeglBuffer *dst,
const GeglRectangle *roi)
{
gfloat *dst_buf;
gint x1, y1; // Noise image
gdouble x, y; // Source Image
GRand *gr = g_rand_new ();
/* Get buffer in which to place dst pixels. */
dst_buf = g_new0 (gfloat, roi->width * roi->height * 4);
for (y1 = 0; y1 < roi->height; y1++) {
for (x1 = 0; x1 < roi->width; x1++) {
calc_sample_coords (x1, y1, x_amount, y_amount, gr, &x, &y);
/* Only displace the pixel if it's within the bounds of the image. */
if (x >= 0 && x < img_width && y >= 0 && y < img_height)
gegl_buffer_sample (src, x, y, NULL, &dst_buf[(y1 * roi->width + x1) * 4], format,
GEGL_SAMPLER_LINEAR, GEGL_ABYSS_NONE);
else /* Else just copy it */
gegl_buffer_sample (src, x1, y1, NULL, &dst_buf[(y1 * roi->width + x1) * 4], format,
GEGL_SAMPLER_LINEAR, GEGL_ABYSS_NONE);
} /* for */
} /* for */
gegl_buffer_sample_cleanup (src);
/* Store dst pixels. */
gegl_buffer_set (dst, roi, 0, format, dst_buf, GEGL_AUTO_ROWSTRIDE);
gegl_buffer_flush(dst);
g_free (dst_buf);
g_rand_free (gr);
}
/*****************************************************************************/
static void
prepare (GeglOperation *operation)
{
GeglChantO *o;
GeglOperationAreaFilter *op_area;
op_area = GEGL_OPERATION_AREA_FILTER (operation);
o = GEGL_CHANT_PROPERTIES (operation);
op_area->left =
op_area->right = o->x_amount;
op_area->top =
op_area->bottom = o->y_amount;
gegl_operation_set_format (operation, "output",
babl_format ("RaGaBaA float"));
}
/* Perform the specified operation.
*/
static gboolean
process (GeglOperation *operation,
GeglBuffer *input,
GeglBuffer *output,
const GeglRectangle *result,
gint level)
{
GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
GeglRectangle boundary = gegl_operation_get_bounding_box (operation);
const Babl *format = babl_format ("RaGaBaA float");
apply_spread ((o->x_amount + 1) / 2,
(o->y_amount + 1) / 2,
boundary.width - 2 * o->x_amount,
boundary.height - 2 * o->y_amount,
format,
input,
output,
result);
return TRUE;
}
static void
gegl_chant_class_init (GeglChantClass *klass)
{
GeglOperationClass *operation_class;
GeglOperationFilterClass *filter_class;
operation_class = GEGL_OPERATION_CLASS (klass);
filter_class = GEGL_OPERATION_FILTER_CLASS (klass);
filter_class->process = process;
operation_class->prepare = prepare;
gegl_operation_class_set_keys (operation_class,
"categories" , "noise",
"name" , "gegl:noise-spread",
"description", _("Noise spread filter"),
NULL);
}
#endif