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: Base class for drawing operations
22 * Objects in libgis are things which can be added to the viewer and will be
23 * displayed to the user. Each object has information such as it's location and
24 * level of detail which are used by the viewer to determine which objects
27 * Each #GisObject is also a #GObject, but not every GObject in libgis is a
28 * GisObject. The "Object" part of the name is just coincidence.
35 #include "gis-object.h"
44 * @opengl: the viewer the object is being displayed in
46 * Perform any OpenGL commands necessasairy to draw the object.
48 * The GL_PROJECTION and GL_MODELVIEW matricies and GL_ALL_ATTRIB_BITS will be
49 * restored to the default state after the call to draw.
51 void gis_object_draw(GisObject *object, GisOpenGL *opengl)
53 GisObjectClass *klass = GIS_OBJECT_GET_CLASS(object);
55 g_warning("GisObject: draw - Unimplemented");
59 /* Skip hidden objects */
63 /* Skip out of range objects */
64 if (object->lod > 0) {
66 gdouble eye[3], obj[3];
67 gis_viewer_get_location(GIS_VIEWER(opengl), &eye[0], &eye[1], &eye[2]);
68 gdouble elev = eye[2];
69 lle2xyz(eye[0], eye[1], eye[2], &eye[0], &eye[1], &eye[2]);
70 lle2xyz(object->center.lat, object->center.lon, object->center.elev,
71 &obj[0], &obj[1], &obj[2]);
72 gdouble dist = distd(obj, eye);
73 if (object->lod < dist)
77 gdouble c = EARTH_R+elev;
79 gdouble horizon = sqrt(c*c - a*a);
84 /* Save state, draw, restore state */
85 g_mutex_lock(opengl->sphere_lock);
86 glPushAttrib(GL_ALL_ATTRIB_BITS);
87 glMatrixMode(GL_PROJECTION); glPushMatrix();
88 glMatrixMode(GL_MODELVIEW); glPushMatrix();
90 klass->draw(object, opengl);
93 glMatrixMode(GL_PROJECTION); glPopMatrix();
94 glMatrixMode(GL_MODELVIEW); glPopMatrix();
95 g_mutex_unlock(opengl->sphere_lock);
99 G_DEFINE_ABSTRACT_TYPE(GisObject, gis_object, G_TYPE_OBJECT);
100 static void gis_object_init(GisObject *object)
104 static void gis_object_class_init(GisObjectClass *klass)