* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+/**
+ * SECTION:gis-object
+ * @short_description: Base class for drawing operations
+ *
+ * Objects in libgis are things which can be added to the viewer and will be
+ * displayed to the user. Each object has information such as it's location and
+ * level of detail which are used by the viewer to determine which objects
+ * should be drawn.
+ *
+ * Each #GisObject is also a #GObject, but not every GObject in libgis is a
+ * GisObject. The "Object" part of the name is just coincidence.
+ */
+
#include <config.h>
+#include <math.h>
+#include <GL/gl.h>
+
#include "gis-object.h"
-/* GisPoint */
-GisPoint *gis_point_new()
+
+/*************
+ * GisObject *
+ *************/
+/**
+ * gis_object_draw:
+ * @object: the object
+ * @opengl: the viewer the object is being displayed in
+ *
+ * Perform any OpenGL commands necessasairy to draw the object.
+ *
+ * The GL_PROJECTION and GL_MODELVIEW matricies and GL_ALL_ATTRIB_BITS will be
+ * restored to the default state after the call to draw.
+ */
+void gis_object_draw(GisObject *object, GisOpenGL *opengl)
{
- return g_new0(GisPoint, 1);
+ GisObjectClass *klass = GIS_OBJECT_GET_CLASS(object);
+ if (!klass->draw) {
+ g_warning("GisObject: draw - Unimplemented");
+ return;
+ }
+
+ /* Skip hidden objects */
+ if (object->hidden)
+ return;
+
+ /* Skip out of range objects */
+ if (object->lod > 0) {
+ /* LOD test */
+ gdouble eye[3], obj[3];
+ gis_viewer_get_location(GIS_VIEWER(opengl), &eye[0], &eye[1], &eye[2]);
+ gdouble elev = eye[2];
+ lle2xyz(eye[0], eye[1], eye[2], &eye[0], &eye[1], &eye[2]);
+ lle2xyz(object->center.lat, object->center.lon, object->center.elev,
+ &obj[0], &obj[1], &obj[2]);
+ gdouble dist = distd(obj, eye);
+ if (object->lod < dist)
+ return;
+
+ /* Horizon testing */
+ gdouble c = EARTH_R+elev;
+ gdouble a = EARTH_R;
+ gdouble horizon = sqrt(c*c - a*a);
+ if (dist > horizon)
+ return;
+ }
+
+ /* Save state, draw, restore state */
+ g_mutex_lock(opengl->sphere_lock);
+ glPushAttrib(GL_ALL_ATTRIB_BITS);
+ glMatrixMode(GL_PROJECTION); glPushMatrix();
+ glMatrixMode(GL_MODELVIEW); glPushMatrix();
+
+ klass->draw(object, opengl);
+
+ glPopAttrib();
+ glMatrixMode(GL_PROJECTION); glPopMatrix();
+ glMatrixMode(GL_MODELVIEW); glPopMatrix();
+ g_mutex_unlock(opengl->sphere_lock);
}
-void gis_point_set_lle(GisPoint *self, gdouble lat, gdouble lon, gdouble elev)
+/* GObject stuff */
+G_DEFINE_ABSTRACT_TYPE(GisObject, gis_object, G_TYPE_OBJECT);
+static void gis_object_init(GisObject *object)
{
- self->lat = lat;
- self->lon = lon;
- self->elev = elev;
}
-void gis_point_free(GisPoint *self)
+static void gis_object_class_init(GisObjectClass *klass)
{
- g_free(self);
}
-
-
-/* GisObject */
-G_DEFINE_TYPE(GisObject, gis_object, G_TYPE_OBJECT);
-static void gis_object_init(GisObject *self) { }
-static void gis_object_class_init(GisObjectClass *klass) { }