2 * Copyright (C) 2009-2011 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 * #GritsPluginEnv 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.
36 static void expose(GritsCallback *callback, GritsOpenGL *opengl, gpointer _env)
38 GritsPluginEnv *env = GRITS_PLUGIN_ENV(_env);
39 g_debug("GritsPluginEnv: expose");
41 gdouble lat, lon, elev;
42 grits_viewer_get_location(env->viewer, &lat, &lon, &elev);
45 gdouble rg = MAX(0, 1-(elev/40000));
46 gdouble blue = MAX(0, 1-(elev/100000));
47 glClearColor(MIN(0.4,rg), MIN(0.4,rg), MIN(1,blue), 1.0f);
48 glClear(GL_COLOR_BUFFER_BIT);
50 /* Attempt to render an atmosphere */
51 glEnable(GL_COLOR_MATERIAL);
52 glDisable(GL_CULL_FACE);
53 glDisable(GL_LIGHTING);
54 glMatrixMode(GL_MODELVIEW);
55 glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
56 grits_viewer_center_position(env->viewer, lat, lon, -EARTH_R);
58 gdouble ds = EARTH_R+elev; // distance to self
59 gdouble da = EARTH_R+300000; // distance to top of atmosphere
60 gdouble dg = EARTH_R-100000; // distance to top of atmosphere
61 gdouble ang = acos(EARTH_R/ds); // angle to horizon
64 gdouble ar = sin(ang)*da; // top of quad fan "atomosphere"j
65 gdouble az = cos(ang)*da; //
67 gdouble gr = sin(ang)*dg; // bottom of quad fan "ground"
68 gdouble gz = cos(ang)*dg; //
70 glBegin(GL_QUAD_STRIP);
71 for (gdouble i = 0; i <= 2*G_PI; i += G_PI/30) {
72 glColor4f(0.3, 0.3, 1.0, 1.0); glVertex3f(gr*sin(i), gr*cos(i), gz);
73 glColor4f(0.3, 0.3, 1.0, 0.0); glVertex3f(ar*sin(i), ar*cos(i), az);
83 * grits_plugin_env_new:
84 * @viewer: the #GritsViewer to use for drawing
85 * @prefs: the #GritsPrefs for storing configurations
87 * Create a new instance of the environment plugin.
89 * Returns: the new #GritsPluginEnv
91 GritsPluginEnv *grits_plugin_env_new(GritsViewer *viewer, GritsPrefs *prefs)
93 g_debug("GritsPluginEnv: new");
94 GritsPluginEnv *env = g_object_new(GRITS_TYPE_PLUGIN_ENV, NULL);
95 env->viewer = g_object_ref(viewer);
98 GritsCallback *callback = grits_callback_new(expose, env);
99 GritsTile *background = grits_tile_new(NULL, NORTH, SOUTH, EAST, WEST);
100 glGenTextures(1, &env->tex);
101 background->data = &env->tex;
105 ref1 = grits_viewer_add(viewer, GRITS_OBJECT(callback), GRITS_LEVEL_BACKGROUND, FALSE);
106 ref2 = grits_viewer_add(viewer, GRITS_OBJECT(background), GRITS_LEVEL_BACKGROUND, FALSE);
107 env->refs = g_list_prepend(env->refs, ref1);
108 env->refs = g_list_prepend(env->refs, ref2);
118 static void grits_plugin_env_plugin_init(GritsPluginInterface *iface);
119 G_DEFINE_TYPE_WITH_CODE(GritsPluginEnv, grits_plugin_env, G_TYPE_OBJECT,
120 G_IMPLEMENT_INTERFACE(GRITS_TYPE_PLUGIN,
121 grits_plugin_env_plugin_init));
122 static void grits_plugin_env_plugin_init(GritsPluginInterface *iface)
124 g_debug("GritsPluginEnv: plugin_init");
125 /* Add methods to the interface */
127 /* Class/Object init */
128 static void grits_plugin_env_init(GritsPluginEnv *env)
130 g_debug("GritsPluginEnv: init");
133 static void grits_plugin_env_dispose(GObject *gobject)
135 g_debug("GritsPluginEnv: dispose");
136 GritsPluginEnv *env = GRITS_PLUGIN_ENV(gobject);
137 /* Drop references */
139 for (GList *cur = env->refs; cur; cur = cur->next)
140 grits_viewer_remove(env->viewer, cur->data);
141 g_list_free(env->refs);
142 g_object_unref(env->viewer);
143 glDeleteTextures(1, &env->tex);
146 G_OBJECT_CLASS(grits_plugin_env_parent_class)->dispose(gobject);
148 static void grits_plugin_env_class_init(GritsPluginEnvClass *klass)
150 g_debug("GritsPluginEnv: class_init");
151 GObjectClass *gobject_class = (GObjectClass*)klass;
152 gobject_class->dispose = grits_plugin_env_dispose;