[gegl/soc-2012-ops] Soft-glow Operation

[Maxime Nicco <maxnicco src gnome org>]

commit 82820c178d147736d4694aeace0177f736b8e294
Author: Maxime Nicco <maxime nicco gmail fr>
Date:   Tue Jul 17 09:56:51 2012 +0200

    Soft-glow Operation

 operations/common/softglow.c |  232 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 232 insertions(+), 0 deletions(-)
---
diff --git a/operations/common/softglow.c b/operations/common/softglow.c
new file mode 100644
index 0000000..81c5848
--- /dev/null
+++ b/operations/common/softglow.c
@@ -0,0 +1,232 @@
+/* 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 1997 Spencer Kimball
+ * Copyright 2012 Maxime Nicco <maxime nicco gmail com>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_double (glow_radius, _("Glow radius"),   1.0, 50.0, 10.0, _("Glow radius"))
+
+gegl_chant_double (brightness, _("Brightness"),   0.0, 1.0, 0.75, _("Brightness"))
+
+gegl_chant_double (sharpness, _("Sharpness"),   0.0, 1.0, 0.85, _("Sharpness"))
+
+#else
+
+#define GEGL_CHANT_TYPE_AREA_FILTER
+#define GEGL_CHANT_C_FILE       "softglow.c"
+
+#include "gegl-chant.h"
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+#define SIGMOIDAL_BASE   2
+#define SIGMOIDAL_RANGE 20
+
+static void
+grey_blur_buffer(GeglBuffer *input,
+		 gdouble glow_radius,
+		 GeglBuffer **dest)
+{
+  GeglNode *gegl, *image, *write, *blur, *save, *save1;
+  gdouble radius, std_dev;
+
+  gegl = gegl_node_new();
+  image = gegl_node_new_child(gegl,
+			      "operation", "gegl:buffer-source",
+			      "buffer", input,
+			      NULL);
+
+  radius   = fabs (glow_radius) + 1.0;
+  std_dev = sqrt (-(radius * radius) / (2 * log (1.0 / 255.0)));
+  
+  blur =  gegl_node_new_child(gegl,
+			       "operation", "gegl:gaussian-blur",
+			       "std_dev_x", std_dev,
+			       "std_dev_y", std_dev,
+			       NULL);
+
+  write = gegl_node_new_child(gegl,
+			       "operation", "gegl:buffer-sink",
+			       "buffer", dest, NULL);
+
+  save = gegl_node_new_child(gegl,
+			       "operation", "gegl:png-save",
+			       "path", "modif.png", NULL);
+
+  save1 = gegl_node_new_child(gegl,
+			       "operation", "gegl:png-save",
+			       "path", "source.png", NULL);
+  
+  gegl_node_link_many (image, blur, write, NULL);
+  gegl_node_process (write);
+
+  gegl_node_link_many (blur, save, NULL);
+  gegl_node_process (save);
+
+  gegl_node_link_many (image, save1, NULL);
+  gegl_node_process (save1);  
+
+  g_object_unref (gegl);
+}
+
+static void prepare (GeglOperation *operation)
+{    
+  gegl_operation_set_format (operation, "input",
+                             babl_format ("Y'CbCrA float"));
+  gegl_operation_set_format (operation, "output",
+                             babl_format ("RGBA float"));
+
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         GeglBuffer          *output,
+         const GeglRectangle *result,
+         gint                 level)
+{
+  GeglChantO *o                    = GEGL_CHANT_PROPERTIES (operation);
+
+  GeglBuffer *dest, *dest_tmp;
+  GeglSampler *sampler;
+
+  gint n_pixels;
+  gfloat pixel;
+  gfloat *out_pixel;
+  gint x;
+  gint y;
+  gint b;
+  
+
+  gfloat tmp;
+  gdouble val;
+ 
+  
+  gfloat *dst_buf, *dst_tmp, *dst_convert;
+  GeglRectangle *whole_region;
+  gfloat *dst_tmp_ptr, *input_ptr;
+
+  const Babl *rgba            = babl_format ("RGBA float");
+  const Babl *ycbcra          = babl_format ("Y'CbCrA float");
+  
+  whole_region = gegl_operation_source_get_bounding_box (operation, "input");
+
+  dst_buf = g_slice_alloc (result->width * result->height * 4 * sizeof(gfloat));
+  dst_tmp = g_slice_alloc (result->width * result->height * sizeof(gfloat));
+  dst_convert = g_slice_alloc (result->width * result->height * 4 * sizeof(gfloat));
+  dest_tmp = gegl_buffer_new(whole_region, babl_format ("Y' float"));
+
+  gegl_buffer_get (input, result, 1.0, babl_format ("Y'CbCrA float"), dst_buf, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
+
+  x = result->x;
+  y = result->y;
+  n_pixels = result->width * result->height;
+  dst_tmp_ptr = dst_tmp;
+  input_ptr = dst_buf;
+
+  while (n_pixels--)
+  {
+
+    /* compute sigmoidal transfer */
+    val = *input_ptr;
+    val = 1.0 / (1.0 + exp (-(SIGMOIDAL_BASE + (o->sharpness * SIGMOIDAL_RANGE)) * (val - 0.5)));
+    val = val * o->brightness;
+    *dst_tmp_ptr = CLAMP (val, 0.0, 1.0);
+
+    dst_tmp_ptr +=1;
+    input_ptr   +=4;
+
+  }
+
+  gegl_buffer_set_extent(dest_tmp, whole_region);
+  gegl_buffer_set (dest_tmp, whole_region, 0, babl_format ("Y' float"), dst_tmp, GEGL_AUTO_ROWSTRIDE);
+  grey_blur_buffer(dest_tmp, o->glow_radius, &dest);
+  
+  sampler = gegl_buffer_sampler_new (dest,
+				      babl_format ("Y' float"),
+				      GEGL_SAMPLER_LINEAR);
+    
+  x = result->x;
+  y = result->y;
+  n_pixels = result->width * result->height;
+  
+  babl_process (babl_fish (ycbcra ,rgba), dst_buf, dst_convert, n_pixels);
+
+  out_pixel = dst_convert;
+
+  while (n_pixels--)
+    {
+      gegl_sampler_get (sampler,
+			            x,
+                        y,
+                        NULL,
+                        &pixel);
+
+      for (b = 0; b < 3; b++)
+      {
+        tmp = (1.0 - out_pixel[b]) * (1.0 - pixel) ;
+        out_pixel[b] = CLAMP(1.0 - tmp, 0.0, 1.0);
+      }
+
+      out_pixel += 4;
+      
+      x++;
+      if (x>=result->x + result->width)
+        {
+          x=result->x;
+          y++;
+        }
+    }
+
+  gegl_buffer_set (output, result, 0, babl_format ("RGBA float"), dst_convert, GEGL_AUTO_ROWSTRIDE);
+  g_slice_free1 (result->width * result->height * 4 * sizeof(gfloat), dst_buf);
+  g_slice_free1 (result->width * result->height * sizeof(gfloat), dst_tmp);
+  g_slice_free1 (result->width * result->height * sizeof(gfloat), dst_convert);
+ 
+  g_object_unref (sampler);
+  g_object_unref (dest);
+ 
+  whole_region = gegl_operation_source_get_bounding_box (operation, "input");
+  gegl_buffer_set_extent(input, whole_region);
+  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);
+
+  operation_class->prepare = prepare;
+  filter_class->process    = process;
+
+  gegl_operation_class_set_keys (operation_class,
+				 "categories" , "artistic",
+				 "name"       , "gegl:softglow",
+				 "description", _("Softglow effect"),
+				 NULL);
+}
+
+#endif