gstreamer/gst/geometrictransform/gsttunnel.c

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/*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-tunnel
* @see_also: geometrictransform
*
* Tunnel is a geometric image transform element. It applies a light tunnel
* effect.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch-1.0 -v videotestsrc ! tunnel ! videoconvert ! autovideosink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst.h>
#include <math.h>
#include "gsttunnel.h"
#include "geometricmath.h"
GST_DEBUG_CATEGORY_STATIC (gst_tunnel_debug);
#define GST_CAT_DEFAULT gst_tunnel_debug
#define gst_tunnel_parent_class parent_class
G_DEFINE_TYPE (GstTunnel, gst_tunnel, GST_TYPE_CIRCLE_GEOMETRIC_TRANSFORM);
static gboolean
tunnel_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
gdouble * in_y)
{
GstCircleGeometricTransform *cgt = GST_CIRCLE_GEOMETRIC_TRANSFORM_CAST (gt);
#ifndef GST_DISABLE_GST_DEBUG
GstTunnel *tunnel = GST_TUNNEL_CAST (gt);
#endif
gdouble norm_x, norm_y;
gdouble width = gt->width;
gdouble height = gt->height;
gdouble r;
/* normalize in ((-1.0, -1.0), (1.0, 1.0) and traslate the center */
/* plus a little trick to obtain a perfect circle, normalize in a
* square with sides equal to MAX(width, height) */
norm_x = 2.0 * (x - cgt->x_center * width) / MAX (width, height);
norm_y = 2.0 * (y - cgt->y_center * height) / MAX (width, height);
/* calculate radius, normalize to 1 for future convenience */
r = sqrt (0.5 * (norm_x * norm_x + norm_y * norm_y));
/* do nothing if r < radius */
/* zoom otherwise */
norm_x *= CLAMP (r, 0.0, cgt->radius) / r;
norm_y *= CLAMP (r, 0.0, cgt->radius) / r;
/* unnormalize */
*in_x = 0.5 * (norm_x) * MAX (width, height) + cgt->x_center * width;
*in_y = 0.5 * (norm_y) * MAX (width, height) + cgt->y_center * height;
GST_DEBUG_OBJECT (tunnel, "Inversely mapped %d %d into %lf %lf",
x, y, *in_x, *in_y);
return TRUE;
}
static void
gst_tunnel_class_init (GstTunnelClass * klass)
{
GstElementClass *gstelement_class;
GstGeometricTransformClass *gstgt_class;
gstelement_class = (GstElementClass *) klass;
gstgt_class = (GstGeometricTransformClass *) klass;
gst_element_class_set_static_metadata (gstelement_class,
"tunnel",
"Transform/Effect/Video",
"Light tunnel effect", "Filippo Argiolas <filippo.argiolas@gmail.com>");
gstgt_class->map_func = tunnel_map;
}
static void
gst_tunnel_init (GstTunnel * filter)
{
GstGeometricTransform *gt = GST_GEOMETRIC_TRANSFORM (filter);
gt->off_edge_pixels = GST_GT_OFF_EDGES_PIXELS_CLAMP;
}
gboolean
gst_tunnel_plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (gst_tunnel_debug, "tunnel", 0, "tunnel");
return gst_element_register (plugin, "tunnel", GST_RANK_NONE,
GST_TYPE_TUNNEL);
}