[gthumb] added the 'lomo' special effect

[Paolo Bacchilega <paobac src gnome org>]

commit d6c0894435cc693d0807579fe176522f206085d3
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Wed Jan 7 13:02:14 2015 +0100

    added the 'lomo' special effect

 extensions/file_tools/gth-file-tool-lomo.c |  185 ++++++++++++++++++++++++++++
 extensions/file_tools/gth-file-tool-lomo.h |   33 +++++
 extensions/file_tools/main.c               |    2 +
 3 files changed, 220 insertions(+), 0 deletions(-)
---
diff --git a/extensions/file_tools/gth-file-tool-lomo.c b/extensions/file_tools/gth-file-tool-lomo.c
new file mode 100644
index 0000000..c085325
--- /dev/null
+++ b/extensions/file_tools/gth-file-tool-lomo.c
@@ -0,0 +1,185 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+/*
+ *  GThumb
+ *
+ *  Copyright (C) 2014 Free Software Foundation, Inc.
+ *
+ *  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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <math.h>
+#include <gthumb.h>
+#include "cairo-blur.h"
+#include "cairo-effects.h"
+#include "gth-curve.h"
+#include "gth-file-tool-lomo.h"
+
+
+static void
+lomo_init (GthAsyncTask *task,
+          gpointer      user_data)
+{
+       gimp_op_init ();
+}
+
+
+static gpointer
+lomo_exec (GthAsyncTask *task,
+          gpointer      user_data)
+{
+       cairo_surface_t *original;
+       cairo_surface_t *source;
+       GthCurve        *curve[GTH_HISTOGRAM_N_CHANNELS];
+       cairo_format_t   format;
+       int              width;
+       int              height;
+       int              source_stride;
+       cairo_surface_t *destination;
+       int              destination_stride;
+       cairo_surface_t *blurred;
+       int              blurred_stride;
+       unsigned char   *p_source_line;
+       unsigned char   *p_destination_line;
+       unsigned char   *p_blurred_line;
+       unsigned char   *p_source;
+       unsigned char   *p_destination;
+       unsigned char   *p_blurred;
+       gboolean         cancelled = FALSE;
+       double           progress;
+       int              x, y;
+       double           center_x, center_y, radius, d;
+       unsigned char    red, green, blue, alpha;
+       unsigned char    image_red, image_green, image_blue, image_alpha;
+       unsigned char    layer_red, layer_green, layer_blue, layer_alpha;
+       unsigned char    temp;
+       int              c;
+
+       /* curves layer */
+
+       original = gth_image_task_get_source_surface (GTH_IMAGE_TASK (task));
+       source = _cairo_image_surface_copy (original);
+
+       curve[GTH_HISTOGRAM_CHANNEL_VALUE] = gth_curve_new_for_points (GTH_TYPE_BEZIER, 0);
+       curve[GTH_HISTOGRAM_CHANNEL_RED] = gth_curve_new_for_points (GTH_TYPE_BEZIER, 4, 0, 0, 56, 45, 195, 
197, 255, 216);
+       curve[GTH_HISTOGRAM_CHANNEL_GREEN] = gth_curve_new_for_points (GTH_TYPE_BEZIER, 4, 0, 0, 65, 40, 162, 
174, 238, 255);
+       curve[GTH_HISTOGRAM_CHANNEL_BLUE] = gth_curve_new_for_points (GTH_TYPE_BEZIER, 4, 0, 0, 68, 79, 210, 
174, 255, 255);
+       if (! cairo_image_surface_apply_curves (source, curve, task)) {
+               cairo_surface_destroy (source);
+               cairo_surface_destroy (original);
+               return NULL;
+       }
+
+       format = cairo_image_surface_get_format (source);
+       width = cairo_image_surface_get_width (source);
+       height = cairo_image_surface_get_height (source);
+       source_stride = cairo_image_surface_get_stride (source);
+
+       cairo_surface_destroy (original);
+
+       /* other effects */
+
+       blurred = _cairo_image_surface_copy (source);
+       blurred_stride = cairo_image_surface_get_stride (blurred);
+       if (! _cairo_image_surface_blur (blurred, 1, task)) {
+               cairo_surface_destroy (blurred);
+               cairo_surface_destroy (source);
+               return NULL;
+       }
+
+       center_x = width / 2.0;
+       center_y = height / 2.0;
+       radius = MAX (width, height) / 2.0;
+
+       destination = cairo_image_surface_create (format, width, height);
+       destination_stride = cairo_image_surface_get_stride (destination);
+
+       p_source_line = _cairo_image_surface_flush_and_get_data (source);
+       p_blurred_line = _cairo_image_surface_flush_and_get_data (blurred);
+       p_destination_line = _cairo_image_surface_flush_and_get_data (destination);
+       for (y = 0; y < height; y++) {
+               gth_async_task_get_data (task, NULL, &cancelled, NULL);
+               if (cancelled)
+                       break;
+
+               progress = (double) y / height;
+               gth_async_task_set_data (task, NULL, NULL, &progress);
+
+               p_source = p_source_line;
+               p_blurred = p_blurred_line;
+               p_destination = p_destination_line;
+               for (x = 0; x < width; x++) {
+                       d = sqrt (SQR (x - center_x) + SQR (y - center_y));
+                       d = CLAMP_PIXEL ((d >= radius) ? 0 : 255 - (255.0 * (d / radius)));
+
+                       CAIRO_GET_RGBA (p_source, image_red, image_green, image_blue, image_alpha);
+
+                       /* blurred image layer with a radial mask (to blur the edges) */
+
+                       CAIRO_GET_RGBA (p_blurred, layer_red, layer_green, layer_blue, layer_alpha);
+                       layer_alpha = 255 - d;
+                       image_red = GIMP_OP_NORMAL (layer_red, image_red, layer_alpha);
+                       image_green = GIMP_OP_NORMAL (layer_green, image_green, layer_alpha);
+                       image_blue = GIMP_OP_NORMAL (layer_blue, image_blue, layer_alpha);
+
+                       /* radial grandient layer in overlay mode */
+
+                       layer_green = layer_blue = layer_red = d;
+                       layer_alpha = 255;
+
+                       red = GIMP_OP_SOFT_LIGHT (layer_red, image_red);
+                       green = GIMP_OP_SOFT_LIGHT (layer_green, image_green);
+                       blue = GIMP_OP_SOFT_LIGHT (layer_blue, image_blue);
+                       alpha = ADD_ALPHA (image_alpha, layer_alpha);
+
+                       p_destination[CAIRO_RED] = GIMP_OP_NORMAL (red, image_red, alpha);
+                       p_destination[CAIRO_GREEN] = GIMP_OP_NORMAL (green, image_green, alpha);
+                       p_destination[CAIRO_BLUE] = GIMP_OP_NORMAL (blue, image_blue, alpha);
+                       p_destination[CAIRO_ALPHA] = GIMP_OP_NORMAL (255, image_alpha, alpha);
+
+                       p_source += 4;
+                       p_blurred += 4;
+                       p_destination += 4;
+               }
+               p_source_line += source_stride;
+               p_blurred_line += blurred_stride;
+               p_destination_line += destination_stride;
+       }
+
+       if (! cancelled) {
+               cairo_surface_mark_dirty (destination);
+               gth_image_task_set_destination_surface (GTH_IMAGE_TASK (task), destination);
+       }
+
+       cairo_surface_destroy (destination);
+       cairo_surface_destroy (blurred);
+       cairo_surface_destroy (source);
+
+       for (c = GTH_HISTOGRAM_CHANNEL_VALUE; c <= GTH_HISTOGRAM_CHANNEL_BLUE; c++)
+               g_object_unref (curve[c]);
+
+       return NULL;
+}
+
+
+void
+lomo_add_to_special_effects (GthFilterGrid *grid)
+{
+       gth_filter_grid_add_filter (grid,
+                                   GTH_FILTER_GRID_NEW_FILTER_ID,
+                                   gth_image_task_new (_("Applying changes"), lomo_init, lomo_exec, NULL, 
NULL, NULL),
+                                   _("Lomo"),
+                                   NULL);
+}
diff --git a/extensions/file_tools/gth-file-tool-lomo.h b/extensions/file_tools/gth-file-tool-lomo.h
new file mode 100644
index 0000000..e5f10e1
--- /dev/null
+++ b/extensions/file_tools/gth-file-tool-lomo.h
@@ -0,0 +1,33 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+/*
+ *  GThumb
+ *
+ *  Copyright (C) 2014 Free Software Foundation, Inc.
+ *
+ *  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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GTH_FILE_TOOL_LOMO_H
+#define GTH_FILE_TOOL_LOMO_H
+
+#include <gthumb.h>
+
+G_BEGIN_DECLS
+
+void lomo_add_to_special_effects (GthFilterGrid *);
+
+G_END_DECLS
+
+#endif /* GTH_FILE_TOOL_LOMO_H */
diff --git a/extensions/file_tools/main.c b/extensions/file_tools/main.c
index 7ae9483..b3b6614 100644
--- a/extensions/file_tools/main.c
+++ b/extensions/file_tools/main.c
@@ -31,6 +31,7 @@
 #include "gth-file-tool-effects.h"
 #include "gth-file-tool-flip.h"
 #include "gth-file-tool-grayscale.h"
+#include "gth-file-tool-lomo.h"
 #include "gth-file-tool-mirror.h"
 #include "gth-file-tool-negative.h"
 #include "gth-file-tool-redo.h"
@@ -82,6 +83,7 @@ gthumb_extension_activate (void)
        gth_hook_add_callback ("add-special-effect", 30, G_CALLBACK (cherry_add_to_special_effects), NULL);
        gth_hook_add_callback ("add-special-effect", 40, G_CALLBACK (grapes_add_to_special_effects), NULL);
        gth_hook_add_callback ("add-special-effect", 50, G_CALLBACK (instagram_add_to_special_effects), NULL);
+       gth_hook_add_callback ("add-special-effect", 60, G_CALLBACK (lomo_add_to_special_effects), NULL);
        gth_hook_add_callback ("add-special-effect", 70, G_CALLBACK (vintage_add_to_special_effects), NULL);
        gth_hook_add_callback ("add-special-effect", 80, G_CALLBACK (negative_add_to_special_effects), NULL);
 }