geometrictransform: new filter "mirror"

Ports gleffects "mirror" filter to geometrictransform.
Simple yet effective mirror effect, splits the image into halves and
reflect the first into the second.

https://bugzilla.gnome.org/show_bug.cgi?id=625722

1 files changed, 128 insertions, 0 deletions

diff --git a/gst/geometrictransform/gstmirror.c b/gst/geometrictransform/gstmirror.c
new file mode 100644
index 000000000..d2cbc1848
--- /dev/null
+++ b/gst/geometrictransform/gstmirror.c
@@ -0,0 +1,128 @@
+/*
+ * GStreamer
+ * Copyright (C) 2010 Filippo Argiolas <filippo.argiolas@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <gst/gst.h>
+#include <math.h>
+
+#include "gstmirror.h"
+
+GST_DEBUG_CATEGORY_STATIC (gst_mirror_debug);
+#define GST_CAT_DEFAULT gst_mirror_debug
+
+GST_BOILERPLATE (GstMirror, gst_mirror, GstGeometricTransform,
+    GST_TYPE_GEOMETRIC_TRANSFORM);
+
+/* GObject vmethod implementations */
+
+static void
+gst_mirror_base_init (gpointer gclass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (gclass);
+
+  gst_element_class_set_details_simple (element_class,
+      "mirror",
+      "Transform/Effect/Video",
+      "Split the image into two halves and reflect one over each other",
+      "Filippo Argiolas <filippo.argiolas@gmail.com");
+}
+
+static gboolean
+mirror_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
+    gdouble * in_y)
+{
+  GstMirror *mirror = GST_MIRROR_CAST (gt);
+
+  gdouble hw = gt->width / 2.0;
+
+  /* possible parameters:
+     - split horizontal/vertical
+     - reflect left half into right half or viceversa
+     - reflect top half into bottom half or viceversa
+   */
+  if (x > hw)
+    *in_x = gt->width - 1 - x;
+  else
+    *in_x = x;
+
+  *in_y = y;
+
+  GST_DEBUG_OBJECT (mirror, "Inversely mapped %d %d into %lf %lf",
+      x, y, *in_x, *in_y);
+
+  return TRUE;
+}
+
+static void
+gst_mirror_class_init (GstMirrorClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstGeometricTransformClass *gstgt_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstgt_class = (GstGeometricTransformClass *) klass;
+
+  parent_class = g_type_class_peek_parent (klass);
+
+  gstgt_class->map_func = mirror_map;
+}
+
+static void
+gst_mirror_init (GstMirror * filter, GstMirrorClass * gclass)
+{
+  GstGeometricTransform *gt = GST_GEOMETRIC_TRANSFORM (filter);
+
+  gt->off_edge_pixels = GST_GT_OFF_EDGES_PIXELS_CLAMP;
+}
+
+gboolean
+gst_mirror_plugin_init (GstPlugin * plugin)
+{
+  GST_DEBUG_CATEGORY_INIT (gst_mirror_debug, "mirror", 0, "mirror");
+
+  return gst_element_register (plugin, "mirror", GST_RANK_NONE,
+      GST_TYPE_MIRROR);
+}