[gegl] Port tile-glass to GEGL

[Daniel Sabo <daniels src gnome org>]

commit a61c116873d74b8c7eaee30836a59bc1fe05ebd3
Author: Denis Knoepfle <penpal denis web de>
Date:   Fri May 16 03:31:18 2014 -0700

    Port tile-glass to GEGL

 operations/common/Makefile.am  |    1 +
 operations/common/tile-glass.c |  251 ++++++++++++++++++++++++++++++++++++++++
 po/POTFILES.in                 |    1 +
 3 files changed, 253 insertions(+), 0 deletions(-)
---
diff --git a/operations/common/Makefile.am b/operations/common/Makefile.am
index b798037..1b7a5ad 100644
--- a/operations/common/Makefile.am
+++ b/operations/common/Makefile.am
@@ -111,6 +111,7 @@ op_LTLIBRARIES = \
        threshold.la \
        tile-seamless.la \
        tile.la \
+       tile-glass.la \
        unsharp-mask.la \
        value-invert.la \
        vignette.la \
diff --git a/operations/common/tile-glass.c b/operations/common/tile-glass.c
new file mode 100644
index 0000000..cf31a00
--- /dev/null
+++ b/operations/common/tile-glass.c
@@ -0,0 +1,251 @@
+/* This file is an image processing operation for GEGL
+ *
+ * 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 3 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/>.
+ *
+ * Contains code originaly from GIMP tile-glass.c, copyright
+ * Karl-Johan Andersson and Tim Copperfield.
+ *
+ * Glass Tile (sequential version) ported to GEGL:
+ * Copyright 2014 Denis Knoepfle
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_int (tileWidth, _("Tile Width"),
+                   10, 50, 25,
+                   _("Tile Width"))
+
+gegl_chant_int (tileHeight, _("Tile Height"),
+                   10, 50, 25,
+                   _("Tile Height"))
+
+#else
+
+#define GEGL_CHANT_TYPE_AREA_FILTER
+#define GEGL_CHANT_C_FILE "tile-glass.c"
+
+#include "gegl-chant.h"
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+static void
+prepare (GeglOperation *operation)
+{
+  const Babl *input_format = gegl_operation_get_source_format (operation, "input");
+  const Babl *format;
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+
+  GeglOperationAreaFilter *area = GEGL_OPERATION_AREA_FILTER (operation);
+
+  if (input_format == NULL || babl_format_has_alpha (input_format))
+    format = babl_format ("R'G'B'A float");
+  else
+    format = babl_format ("R'G'B' float");
+
+  area->left = area->right = o->tileWidth - 1;
+  area->top = area->bottom = o->tileHeight - 1;
+
+  gegl_operation_set_format (operation, "input", format);
+  gegl_operation_set_format (operation, "output", format);
+}
+
+static GeglRectangle
+get_bounding_box (GeglOperation *operation)
+{
+  GeglRectangle *region;
+
+  region = gegl_operation_source_get_bounding_box (operation, "input");
+
+  if (region != NULL)
+    return *region;
+  else
+    return *GEGL_RECTANGLE (0, 0, 0, 0);
+}
+
+static void
+tile_glass (GeglBuffer          *src,
+            GeglBuffer          *dst,
+            const GeglRectangle *dst_rect, /* region of interest */
+            const Babl          *format,
+            gint                 tileWidth,
+            gint                 tileHeight)
+{
+  gint components;
+  gfloat *src_row_buf;
+  gfloat *dst_row_buf;
+  const GeglRectangle *extent;
+  GeglRectangle src_bufrect, dst_bufrect;
+
+  gint row, col, i;
+  gint x1, y1, y2;
+  gint dst_xoffs, src_x0, xright_abyss, src_rowwidth;
+
+  gint xpixel1, xpixel2;
+  gint ypixel2;
+  gint xhalf, xoffs, xmiddle, xplus;
+  gint yhalf, yoffs, ymiddle, yplus;
+
+  extent = gegl_buffer_get_extent (dst);
+
+  x1 = dst_rect->x;
+  y1 = dst_rect->y;
+  y2 = y1 + dst_rect->height;
+
+  xhalf = tileWidth  / 2;
+  yhalf = tileHeight / 2;
+
+  xplus = tileWidth  % 2;
+  yplus = tileHeight % 2;
+
+  dst_xoffs = x1 % tileWidth + xplus;
+  src_x0 = x1 - dst_xoffs;
+  xright_abyss = 2 * ((x1 + dst_rect->width) % tileWidth);
+  if (xright_abyss > tileWidth - 2)
+    xright_abyss = tileWidth - 2;
+  src_rowwidth = dst_xoffs + dst_rect->width + xright_abyss;
+
+  yoffs = y1 % tileHeight;
+  ymiddle = y1 - yoffs;
+  if (yoffs >= yhalf)
+    {
+      ymiddle += tileHeight;
+      yoffs -= tileHeight;
+    }
+
+  components = babl_format_get_n_components (format);
+
+  src_row_buf = g_new (gfloat, src_rowwidth * components);
+  dst_row_buf = g_new (gfloat, dst_rect->width * components);
+  gegl_rectangle_set (&src_bufrect, src_x0, 0, src_rowwidth, 1);
+  gegl_rectangle_set (&dst_bufrect, x1, 0, dst_rect->width, 1);
+
+  /* loop through rows */
+  for (row = y1; row < y2; ++row)
+    {
+      /* no need to clamp as abyss policy does that */
+      ypixel2 = ymiddle + yoffs * 2;
+
+      src_bufrect.y = ypixel2;
+      gegl_buffer_get (src, &src_bufrect, 1.0, format, src_row_buf, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_CLAMP);
+
+      yoffs++;
+
+      /* if current offset = half, do a displacement next time around */
+      if (yoffs == yhalf)
+        {
+          ymiddle += tileHeight;
+          yoffs = - (yhalf + yplus);
+        }
+
+      xoffs = x1 % tileWidth;
+      xmiddle = x1 - xoffs;
+      if (xoffs >= xhalf)
+        {
+          xmiddle += tileWidth;
+          xoffs -= tileWidth;
+        }
+
+      /* loop through columns */
+      for (col = 0; col < dst_rect->width; ++col)
+        {
+          xpixel1 = (xmiddle + xoffs - x1) * components;
+          if (xmiddle + xoffs * 2 + dst_xoffs < extent->width)
+            {
+              xpixel2 = (xmiddle + xoffs * 2 - x1 + dst_xoffs) * components;
+            }
+          else
+            {
+              xpixel2 = (xmiddle + xoffs - x1 + dst_xoffs) * components;
+            }
+
+          for (i = 0; i < components; ++i)
+            {
+              dst_row_buf[xpixel1 + i] = src_row_buf[xpixel2 + i];
+            }
+
+          xoffs++;
+
+          if (xoffs == xhalf)
+            {
+              xmiddle += tileWidth;
+              xoffs = - (xhalf + xplus);
+            }
+        }
+
+      /* write result row to dest */
+      dst_bufrect.y = row;
+      gegl_buffer_set (dst, &dst_bufrect, 0, format, dst_row_buf, GEGL_AUTO_ROWSTRIDE);
+    }
+
+  g_free (src_row_buf);
+  g_free (dst_row_buf);
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         GeglBuffer          *input,
+         GeglBuffer          *output,
+         const GeglRectangle *result,
+         gint                 level)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+  const Babl *format = gegl_operation_get_format (operation, "input");
+
+  tile_glass (input, output, result, format, o->tileWidth, o->tileHeight);
+
+  return TRUE;
+}
+
+static void
+finalize (GObject *object)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (object);
+
+  if (o->chant_data)
+    {
+      o->chant_data = NULL;
+    }
+
+  G_OBJECT_CLASS (gegl_chant_parent_class)->finalize (object);
+}
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GObjectClass             *object_class;
+  GeglOperationClass       *operation_class;
+  GeglOperationFilterClass *filter_class;
+
+  object_class    = G_OBJECT_CLASS (klass);
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  filter_class    = GEGL_OPERATION_FILTER_CLASS (klass);
+
+  object_class->finalize            = finalize;
+  operation_class->prepare          = prepare;
+  operation_class->get_bounding_box = get_bounding_box;
+  filter_class->process             = process;
+
+  gegl_operation_class_set_keys (operation_class,
+    "categories",  "artistic",
+    "license",     "GPL3+",
+    "name",        "gegl:tile-glass",
+    "description", _("Creates the effect of watching on the picture through thick glass "),
+    NULL);
+}
+
+#endif
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 6d1b72d..33ae2c6 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -103,6 +103,7 @@ operations/common/svg-saturate.c
 operations/common/texturize-canvas.c
 operations/common/threshold.c
 operations/common/tile.c
+operations/common/tile-glass.c
 operations/common/tile-seamless.c
 operations/common/unsharp-mask.c
 operations/common/value-invert.c