gegl r2774 - in trunk: . operations/workshop

[ok svn gnome org]

Author: ok
Date: Sun Nov 16 22:45:06 2008
New Revision: 2774
URL: http://svn.gnome.org/viewvc/gegl?rev=2774&view=rev

Log:
* operations/workshop/linear-gradient.c: added a linear gradient
renderer.


Added:
   trunk/operations/workshop/linear-gradient.c
Modified:
   trunk/ChangeLog

Added: trunk/operations/workshop/linear-gradient.c
==============================================================================
--- (empty file)
+++ trunk/operations/workshop/linear-gradient.c	Sun Nov 16 22:45:06 2008
@@ -0,0 +1,144 @@
+/* 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 2008 Ãyvind KolÃs <pippin gimp org>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_CHANT_PROPERTIES
+
+gegl_chant_double (x1,        _("x1"),  -1000.0, 1000.0, 25.0, "")
+gegl_chant_double (y1,        _("y1"),  -1000.0, 1000.0, 25.0, "")
+gegl_chant_double (x2,        _("x2"),  -1000.0, 1000.0, 150.0, "")
+gegl_chant_double (y2,        _("y2"),  -1000.0, 1000.0, 150.0, "")
+gegl_chant_color (color1,   _("Color"), "black",
+                  _("one end of gradient"))
+gegl_chant_color (color2,   _("Other color"), "white",
+                  _("one end of gradient"))
+
+#else
+
+#define GEGL_CHANT_TYPE_POINT_RENDER
+#define GEGL_CHANT_C_FILE       "linear-gradient.c"
+
+#include "gegl-chant.h"
+
+static void
+prepare (GeglOperation *operation)
+{
+  gegl_operation_set_format (operation, "output", babl_format ("RGBA float"));
+}
+
+static GeglRectangle
+get_bounding_box (GeglOperation *operation)
+{
+  GeglRectangle result = {-10000000, -10000000, 20000000, 20000000};
+  return result;
+}
+
+static gfloat dist(gfloat x1, gfloat y1, gfloat x2, gfloat y2)
+{
+  return sqrt(  (x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
+}
+
+static gboolean
+process (GeglOperation       *operation,
+         void                *out_buf,
+         glong                n_pixels,
+         const GeglRectangle *roi)
+{
+  GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
+  gfloat     *out_pixel = out_buf;
+  gfloat      color1[4];
+  gfloat      color2[4];
+  gint        x, y;
+  gfloat      dx, dy;
+
+  gfloat length = dist (o->x1, o->y1, o->x2, o->y2);
+
+  gegl_color_get_rgba (o->color1,
+                       &color1[0],
+                       &color1[1],
+                       &color1[2],
+                       &color1[3]);
+  gegl_color_get_rgba (o->color2,
+                       &color2[0],
+                       &color2[1],
+                       &color2[2],
+                       &color2[3]);
+
+
+  x= roi->x;
+  y= roi->y;
+
+  dx = (o->x2-o->x1)/length;
+  dy = (o->y2-o->y1)/length;
+
+  while (n_pixels--)
+    {
+      gfloat v;
+      gint c;
+
+      if (length == 0.0)
+        v = 0.5;
+      else
+        {
+          v = (dx * x + dy * y) / length;
+
+          if (v < 0.0)
+            v = 0.0;
+          else if (v>1.0)
+            v = 1.0;
+        }
+
+      for (c=0;c<4;c++)
+        out_pixel[c]=color1[c] * v + color2[c] * (1.0-v);
+
+      out_pixel += 4;
+
+      /* update x and y coordinates */
+      if (++x>=roi->x + roi->width)
+        {
+          x=roi->x;
+          y++;
+      }
+    }
+
+  return  TRUE;
+}
+
+
+static void
+gegl_chant_class_init (GeglChantClass *klass)
+{
+  GeglOperationClass            *operation_class;
+  GeglOperationPointRenderClass *point_render_class;
+
+  operation_class = GEGL_OPERATION_CLASS (klass);
+  point_render_class = GEGL_OPERATION_POINT_RENDER_CLASS (klass);
+
+  point_render_class->process = process;
+  operation_class->get_bounding_box = get_bounding_box;
+  operation_class->prepare = prepare;
+  operation_class->no_cache = TRUE;
+
+  operation_class->name        = "gegl:linear-gradient";
+  operation_class->categories  = "render";
+  operation_class->description = _("linear gradient renderer");
+}
+
+#endif