2 * Copyright (C) 2009-2010 Andy Spencer <andy753421@gmail.com>
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * @short_description: Environment plugin
22 * #GisPluginEnv provides environmental information such as sky images. It can
23 * also paint a blank overlay on the surface so that other plugins can draw
24 * transparent overlays nicely.
28 #include <gtk/gtkgl.h>
38 static void expose(GisCallback *callback, GisOpenGL *opengl, gpointer _env)
40 GisPluginEnv *env = GIS_PLUGIN_ENV(_env);
41 g_debug("GisPluginEnv: expose");
43 gdouble lat, lon, elev;
44 gis_viewer_get_location(env->viewer, &lat, &lon, &elev);
47 gdouble rg = MAX(0, 1-(elev/40000));
48 gdouble blue = MAX(0, 1-(elev/100000));
49 glClearColor(MIN(0.4,rg), MIN(0.4,rg), MIN(1,blue), 1.0f);
50 glClear(GL_COLOR_BUFFER_BIT);
52 /* Attempt to render an atmosphere */
53 glEnable(GL_COLOR_MATERIAL);
54 glDisable(GL_CULL_FACE);
55 glDisable(GL_LIGHTING);
56 glMatrixMode(GL_MODELVIEW);
57 glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
58 gis_viewer_center_position(env->viewer, lat, lon, -EARTH_R);
60 gdouble ds = EARTH_R+elev; // distance to self
61 gdouble da = EARTH_R+300000; // distance to top of atmosphere
62 gdouble dg = EARTH_R-100000; // distance to top of atmosphere
63 gdouble ang = acos(EARTH_R/ds); // angle to horizon
66 gdouble ar = sin(ang)*da; // top of quad fan "atomosphere"j
67 gdouble az = cos(ang)*da; //
69 gdouble gr = sin(ang)*dg; // bottom of quad fan "ground"
70 gdouble gz = cos(ang)*dg; //
72 glBegin(GL_QUAD_STRIP);
73 for (gdouble i = 0; i <= 2*G_PI; i += G_PI/30) {
74 glColor4f(0.3, 0.3, 1.0, 1.0); glVertex3f(gr*sin(i), gr*cos(i), gz);
75 glColor4f(0.3, 0.3, 1.0, 0.0); glVertex3f(ar*sin(i), ar*cos(i), az);
86 * @viewer: the #GisViewer to use for drawing
87 * @prefs: the #GisPrefs for storing configurations
89 * Create a new instance of the environment plugin.
91 * Returns: the new #GisPluginEnv
93 GisPluginEnv *gis_plugin_env_new(GisViewer *viewer, GisPrefs *prefs)
95 g_debug("GisPluginEnv: new");
96 GisPluginEnv *env = g_object_new(GIS_TYPE_PLUGIN_ENV, NULL);
97 env->viewer = g_object_ref(viewer);
100 GisCallback *callback = gis_callback_new(expose, env);
101 GisTile *background = gis_tile_new(NULL, NORTH, SOUTH, EAST, WEST);
102 glGenTextures(1, &env->tex);
103 background->data = &env->tex;
107 ref1 = gis_viewer_add(viewer, GIS_OBJECT(callback), GIS_LEVEL_BACKGROUND, FALSE);
108 ref2 = gis_viewer_add(viewer, GIS_OBJECT(background), GIS_LEVEL_BACKGROUND, FALSE);
109 env->refs = g_list_prepend(env->refs, ref1);
110 env->refs = g_list_prepend(env->refs, ref2);
120 static void gis_plugin_env_plugin_init(GisPluginInterface *iface);
121 G_DEFINE_TYPE_WITH_CODE(GisPluginEnv, gis_plugin_env, G_TYPE_OBJECT,
122 G_IMPLEMENT_INTERFACE(GIS_TYPE_PLUGIN,
123 gis_plugin_env_plugin_init));
124 static void gis_plugin_env_plugin_init(GisPluginInterface *iface)
126 g_debug("GisPluginEnv: plugin_init");
127 /* Add methods to the interface */
129 /* Class/Object init */
130 static void gis_plugin_env_init(GisPluginEnv *env)
132 g_debug("GisPluginEnv: init");
135 static void gis_plugin_env_dispose(GObject *gobject)
137 g_debug("GisPluginEnv: dispose");
138 GisPluginEnv *env = GIS_PLUGIN_ENV(gobject);
139 /* Drop references */
141 for (GList *cur = env->refs; cur; cur = cur->next)
142 gis_viewer_remove(env->viewer, cur->data);
143 g_list_free(env->refs);
144 g_object_unref(env->viewer);
145 glDeleteTextures(1, &env->tex);
148 G_OBJECT_CLASS(gis_plugin_env_parent_class)->dispose(gobject);
150 static void gis_plugin_env_class_init(GisPluginEnvClass *klass)
152 g_debug("GisPluginEnv: class_init");
153 GObjectClass *gobject_class = (GObjectClass*)klass;
154 gobject_class->dispose = gis_plugin_env_dispose;