1 /*
2  * GStreamer
3  * Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
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  * Thanks to Jerry Huxtable <http://www.jhlabs.com> work on its java
46  * image editor and filters. The algorithms here were extracted from
47  * his code.
48  */
49 
50 /**
51  * SECTION:element-sphere
52  * @title: sphere
53  * @see_also: geometrictransform
54  *
55  * The sphere element applies a 'sphere' geometric transform to the image.
56  *
57  * ## Example launch line
58  * |[
59  * gst-launch-1.0 -v videotestsrc ! sphere ! videoconvert ! autovideosink
60  * ]|
61  *
62  */
63 
64 #ifdef HAVE_CONFIG_H
65 #  include <config.h>
66 #endif
67 
68 #include <gst/gst.h>
69 #include <math.h>
70 
71 #include "gstsphere.h"
72 
73 GST_DEBUG_CATEGORY_STATIC (gst_sphere_debug);
74 #define GST_CAT_DEFAULT gst_sphere_debug
75 
76 enum
77 {
78   PROP_0,
79   PROP_REFRACTION
80 };
81 
82 #define DEFAULT_REFRACTION 1.5
83 
84 #define gst_sphere_parent_class parent_class
85 G_DEFINE_TYPE (GstSphere, gst_sphere, GST_TYPE_CIRCLE_GEOMETRIC_TRANSFORM);
86 
87 static void
gst_sphere_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)88 gst_sphere_set_property (GObject * object, guint prop_id, const GValue * value,
89     GParamSpec * pspec)
90 {
91   GstSphere *sphere;
92   GstGeometricTransform *gt;
93   gdouble v;
94 
95   gt = GST_GEOMETRIC_TRANSFORM_CAST (object);
96   sphere = GST_SPHERE_CAST (object);
97 
98   GST_OBJECT_LOCK (gt);
99   switch (prop_id) {
100     case PROP_REFRACTION:
101       v = g_value_get_double (value);
102       if (v != sphere->refraction) {
103         sphere->refraction = v;
104         gst_geometric_transform_set_need_remap (gt);
105       }
106       break;
107     default:
108       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
109       break;
110   }
111   GST_OBJECT_UNLOCK (gt);
112 }
113 
114 static void
gst_sphere_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)115 gst_sphere_get_property (GObject * object, guint prop_id,
116     GValue * value, GParamSpec * pspec)
117 {
118   GstSphere *sphere;
119 
120   sphere = GST_SPHERE_CAST (object);
121 
122   switch (prop_id) {
123     case PROP_REFRACTION:
124       g_value_set_double (value, sphere->refraction);
125       break;
126     default:
127       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
128       break;
129   }
130 }
131 
132 /* TODO we could have horizontal and vertical 'radius' */
133 static gboolean
sphere_map(GstGeometricTransform * gt,gint x,gint y,gdouble * in_x,gdouble * in_y)134 sphere_map (GstGeometricTransform * gt, gint x, gint y, gdouble * in_x,
135     gdouble * in_y)
136 {
137   GstCircleGeometricTransform *cgt = GST_CIRCLE_GEOMETRIC_TRANSFORM_CAST (gt);
138   GstSphere *sphere = GST_SPHERE_CAST (gt);
139   gdouble dx, dy;
140   gdouble dx2, dy2;
141 
142   dx = x - cgt->precalc_x_center;
143   dy = y - cgt->precalc_y_center;
144   dx2 = dx * dx;
145   dy2 = dy * dy;
146 
147   if (dy2 >=
148       (cgt->precalc_radius2 -
149           (cgt->precalc_radius2 * dx2) / cgt->precalc_radius2)) {
150     *in_x = x;
151     *in_y = y;
152   } else {
153     gdouble r_refraction = 1.0 / sphere->refraction;
154     gdouble z;
155     gdouble z2;
156     gdouble angle;
157     gdouble angle1;
158     gdouble angle2;
159 
160     z = sqrt ((1.0 - dx2 / cgt->precalc_radius2 -
161             dy2 / cgt->precalc_radius2) * (cgt->precalc_radius2));
162     z2 = z * z;
163 
164     /* x */
165     angle = acos (dx / sqrt (dx2 + z2));
166     angle1 = G_PI / 2 - angle;
167     angle2 = asin (sin (angle1) * r_refraction);
168     angle2 = G_PI / 2 - angle - angle2;
169     *in_x = x - tan (angle2) * z;
170 
171     /* y */
172     angle = acos (dy / sqrt (dy2 + z2));
173     angle1 = G_PI / 2 - angle;
174     angle2 = asin (sin (angle1) * r_refraction);
175     angle2 = G_PI / 2 - angle - angle2;
176     *in_y = y - tan (angle2) * z;
177   }
178 
179   GST_DEBUG_OBJECT (sphere, "Inversely mapped %d %d into %lf %lf",
180       x, y, *in_x, *in_y);
181 
182   return TRUE;
183 }
184 
185 static void
gst_sphere_class_init(GstSphereClass * klass)186 gst_sphere_class_init (GstSphereClass * klass)
187 {
188   GObjectClass *gobject_class;
189   GstElementClass *gstelement_class;
190   GstGeometricTransformClass *gstgt_class;
191 
192   gobject_class = (GObjectClass *) klass;
193   gstelement_class = (GstElementClass *) klass;
194   gstgt_class = (GstGeometricTransformClass *) klass;
195 
196   gst_element_class_set_static_metadata (gstelement_class,
197       "sphere",
198       "Transform/Effect/Video",
199       "Applies 'sphere' geometric transform to the image",
200       "Thiago Santos<thiago.sousa.santos@collabora.co.uk>");
201 
202   gobject_class->set_property = gst_sphere_set_property;
203   gobject_class->get_property = gst_sphere_get_property;
204 
205   g_object_class_install_property (gobject_class, PROP_REFRACTION,
206       g_param_spec_double ("refraction", "refraction",
207           "refraction index",
208           -G_MAXDOUBLE, G_MAXDOUBLE, DEFAULT_REFRACTION,
209           GST_PARAM_CONTROLLABLE | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
210 
211   gstgt_class->map_func = sphere_map;
212 }
213 
214 static void
gst_sphere_init(GstSphere * filter)215 gst_sphere_init (GstSphere * filter)
216 {
217   GstGeometricTransform *gt = GST_GEOMETRIC_TRANSFORM (filter);
218 
219   gt->off_edge_pixels = GST_GT_OFF_EDGES_PIXELS_CLAMP;
220   filter->refraction = DEFAULT_REFRACTION;
221 }
222 
223 gboolean
gst_sphere_plugin_init(GstPlugin * plugin)224 gst_sphere_plugin_init (GstPlugin * plugin)
225 {
226   GST_DEBUG_CATEGORY_INIT (gst_sphere_debug, "sphere", 0, "sphere");
227 
228   return gst_element_register (plugin, "sphere", GST_RANK_NONE,
229       GST_TYPE_SPHERE);
230 }
231