1 /*
2 * GStreamer
3 * Copyright (C) 2010 Filippo Argiolas <filippo.argiolas@gmail.com>
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Alternatively, the contents of this file may be used under the
24 * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
25 * which case the following provisions apply instead of the ones
26 * mentioned above:
27 *
28 * This library is free software; you can redistribute it and/or
29 * modify it under the terms of the GNU Library General Public
30 * License as published by the Free Software Foundation; either
31 * version 2 of the License, or (at your option) any later version.
32 *
33 * This library is distributed in the hope that it will be useful,
34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
36 * Library General Public License for more details.
37 *
38 * You should have received a copy of the GNU Library General Public
39 * License along with this library; if not, write to the
40 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
41 * Boston, MA 02110-1301, USA.
42 */
43
44 /**
45 * SECTION:element-tunnel
46 * @title: tunnel
47 * @see_also: geometrictransform
48 *
49 * Tunnel is a geometric image transform element. It applies a light tunnel
50 * effect.
51 *
52 * ## Example launch line
53 * |[
54 * gst-launch-1.0 -v videotestsrc ! tunnel ! videoconvert ! autovideosink
55 * ]|
56 *
57 */
58
59 #ifdef HAVE_CONFIG_H
60 # include <config.h>
61 #endif
62
63 #include <gst/gst.h>
64 #include <math.h>
65
66 #include "gsttunnel.h"
67 #include "geometricmath.h"
68
69 GST_DEBUG_CATEGORY_STATIC (gst_tunnel_debug);
70 #define GST_CAT_DEFAULT gst_tunnel_debug
71
72 #define gst_tunnel_parent_class parent_class
73 G_DEFINE_TYPE (GstTunnel, gst_tunnel, GST_TYPE_CIRCLE_GEOMETRIC_TRANSFORM);
74
75 static gboolean
tunnel_map(GstGeometricTransform * gt,gint x,gint y,gdouble * in_x,gdouble * in_y)76 tunnel_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
77 gdouble * in_y)
78 {
79 GstCircleGeometricTransform *cgt = GST_CIRCLE_GEOMETRIC_TRANSFORM_CAST (gt);
80 #ifndef GST_DISABLE_GST_DEBUG
81 GstTunnel *tunnel = GST_TUNNEL_CAST (gt);
82 #endif
83
84 gdouble norm_x, norm_y;
85 gdouble width = gt->width;
86 gdouble height = gt->height;
87 gdouble r;
88
89
90 /* normalize in ((-1.0, -1.0), (1.0, 1.0) and traslate the center */
91 /* plus a little trick to obtain a perfect circle, normalize in a
92 * square with sides equal to MAX(width, height) */
93 norm_x = 2.0 * (x - cgt->x_center * width) / MAX (width, height);
94 norm_y = 2.0 * (y - cgt->y_center * height) / MAX (width, height);
95
96 /* calculate radius, normalize to 1 for future convenience */
97 r = sqrt (0.5 * (norm_x * norm_x + norm_y * norm_y));
98
99 /* do nothing if r < radius */
100 /* zoom otherwise */
101 norm_x *= CLAMP (r, 0.0, cgt->radius) / r;
102 norm_y *= CLAMP (r, 0.0, cgt->radius) / r;
103
104 /* unnormalize */
105 *in_x = 0.5 * (norm_x) * MAX (width, height) + cgt->x_center * width;
106 *in_y = 0.5 * (norm_y) * MAX (width, height) + cgt->y_center * height;
107
108 GST_DEBUG_OBJECT (tunnel, "Inversely mapped %d %d into %lf %lf",
109 x, y, *in_x, *in_y);
110
111 return TRUE;
112 }
113
114 static void
gst_tunnel_class_init(GstTunnelClass * klass)115 gst_tunnel_class_init (GstTunnelClass * klass)
116 {
117 GstElementClass *gstelement_class;
118 GstGeometricTransformClass *gstgt_class;
119
120 gstelement_class = (GstElementClass *) klass;
121 gstgt_class = (GstGeometricTransformClass *) klass;
122
123 gst_element_class_set_static_metadata (gstelement_class,
124 "tunnel",
125 "Transform/Effect/Video",
126 "Light tunnel effect", "Filippo Argiolas <filippo.argiolas@gmail.com>");
127
128 gstgt_class->map_func = tunnel_map;
129 }
130
131 static void
gst_tunnel_init(GstTunnel * filter)132 gst_tunnel_init (GstTunnel * filter)
133 {
134 GstGeometricTransform *gt = GST_GEOMETRIC_TRANSFORM (filter);
135
136 gt->off_edge_pixels = GST_GT_OFF_EDGES_PIXELS_CLAMP;
137 }
138
139 gboolean
gst_tunnel_plugin_init(GstPlugin * plugin)140 gst_tunnel_plugin_init (GstPlugin * plugin)
141 {
142 GST_DEBUG_CATEGORY_INIT (gst_tunnel_debug, "tunnel", 0, "tunnel");
143
144 return gst_element_register (plugin, "tunnel", GST_RANK_NONE,
145 GST_TYPE_TUNNEL);
146 }
147