[gegl/soc-2012-ops: 24/29] Noise-hsv Operation

[Maxime Nicco <maxnicco src gnome org>]

commit 80e0edddcc85bea5e017e91452cf416455a7cf2d
Author: Maxime Nicco <maxime nicco gmail fr>
Date:   Thu Jul 26 12:03:35 2012 +0200

    Noise-hsv Operation
    
    Need soc-2012-ops babl branch to work.

 operations/common/noise-hsv.c |  182 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 182 insertions(+), 0 deletions(-)
---
diff --git a/operations/common/noise-hsv.c b/operations/common/noise-hsv.c
new file mode 100644
index 0000000..c0a90c5
--- /dev/null
+++ b/operations/common/noise-hsv.c
@@ -0,0 +1,182 @@
+/* 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 1995 Spencer Kimball and Peter Mattis
+ * Copyright 1996 Torsten Martinsen
+ * Copyright 2000 Tim Copperfield <timecop japan co jp>
+ * Copyright 2012 Maxime Nicco <maxime nicco gmail com>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_int (holdness, _("Holdness"),   1, 8, 2, _("Holdness"))
+
+gegl_chant_double (hue_distance, _("Hue"),   0.0, 180.0, 3.0, _("Hue"))
+
+gegl_chant_double (saturation_distance, _("Saturation"),   0.0, 1.0, 0.04, _("Saturation"))
+
+gegl_chant_double (value_distance, _("Value"),   0.0, 1.0, 0.04, _("Value"))
+
+#else
+
+#define GEGL_CHANT_TYPE_POINT_FILTER
+#define GEGL_CHANT_C_FILE       "noise-hsv.c"
+
+#include "gegl-chant.h"
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+static gfloat
+randomize_value (gfloat     now,
+                 gfloat     min,
+                 gfloat     max,
+                 gboolean   wraps_around,
+                 gfloat     rand_max,
+                 gint       holdness)
+{
+  gint    flag, i;
+  gdouble rand_val, new_val, steps;
+
+  steps = max - min + 0.5;
+  rand_val = g_random_double ();
+
+  for (i = 1; i < holdness; i++)
+  {
+    double tmp = g_random_double ();
+    if (tmp < rand_val)
+      rand_val = tmp;
+  }
+
+  flag = (g_random_double () < 0.5) ? -1 : 1;
+  new_val = now + flag * fmod (rand_max * rand_val, steps);
+
+  if (new_val < min)
+  {
+    if (wraps_around)
+      new_val += steps;
+    else
+      new_val = min;
+  }
+
+  if (max < new_val)
+  {
+    if (wraps_around)
+      new_val -= steps;
+    else
+      new_val = max;
+  }
+
+  return new_val;
+}
+
+static void prepare (GeglOperation *operation)
+{
+  gegl_operation_set_format (operation, "input", babl_format ("RGBA float"));
+  gegl_operation_set_format (operation, "output", babl_format ("RGBA float"));
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         void                *in_buf,
+         void                *out_buf,
+         glong                n_pixels,
+         const GeglRectangle *roi,
+         gint                 level)
+{
+  GeglChantO *o  = GEGL_CHANT_PROPERTIES (operation);
+
+  gint i;
+  gfloat *out_pixel_ptr;
+
+  gfloat   * GEGL_ALIGNED in_pixel;
+  gfloat   * GEGL_ALIGNED in_pixel_hsv;
+  gfloat   * GEGL_ALIGNED out_pixel_hsv;
+  gfloat   * GEGL_ALIGNED out_pixel;
+
+  gfloat    hue, saturation, value, alpha;
+
+  const Babl *hsva = babl_format ("HSVA float");
+  const Babl *rgba = babl_format ("RGBA float");
+
+  in_pixel      = in_buf;
+  out_pixel     = out_buf;
+  in_pixel_hsv  = g_slice_alloc (n_pixels * 4 * sizeof(gfloat));
+  out_pixel_hsv = g_slice_alloc (n_pixels * 4 * sizeof(gfloat));
+
+
+  babl_process (babl_fish (rgba, hsva), in_pixel, in_pixel_hsv, n_pixels);
+
+  out_pixel_ptr = out_pixel_hsv;
+
+  for (i = 0; i < n_pixels; i++)
+  {
+    hue        = in_pixel_hsv[0];
+    saturation = in_pixel_hsv[1];
+    value      = in_pixel_hsv[2];
+    alpha      = in_pixel_hsv[3];
+
+    /* there is no need for scattering hue of desaturated pixels here */
+    if ((o->hue_distance > 0) && (saturation > 0))
+      hue = randomize_value (hue, 0.0, 359.0, TRUE, o->hue_distance, o->holdness);
+
+    /* desaturated pixels get random hue before increasing saturation */
+    if (o->saturation_distance > 0) {
+      if (saturation == 0)
+        hue = g_random_double_range (0.0, 360.0);
+      saturation = randomize_value (saturation, 0.0, 1.0, FALSE, o->saturation_distance, o->holdness);
+    }
+
+    if (o->value_distance > 0)
+      value = randomize_value (value, 0.0, 1.0, FALSE, o->value_distance, o->holdness);
+
+      out_pixel_ptr[0] = hue;
+      out_pixel_ptr[1] = saturation;
+      out_pixel_ptr[2] = value;
+      out_pixel_ptr[3] = alpha;
+
+    in_pixel_hsv  += 4;
+    out_pixel_ptr += 4;
+
+  }
+
+  babl_process (babl_fish (hsva, rgba), out_pixel_hsv, out_pixel, n_pixels);
+
+  return TRUE;
+}
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GeglOperationClass            *operation_class;
+  GeglOperationPointFilterClass *point_filter_class;
+
+  operation_class    = GEGL_OPERATION_CLASS (klass);
+  point_filter_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
+
+  operation_class->prepare = prepare;
+  point_filter_class->process = process;
+
+  gegl_operation_class_set_keys (operation_class,
+      "name",       "gegl:noise-hsv",
+      "categories", "noise",
+      "description", _("Randomize hue/saturation/value independently"),
+      NULL);
+}
+
+#endif