Move OpenGL code from GisOpenGL to objects

[grits] / src / objects / gis-object.c

diff --git a/src/objects/gis-object.c b/src/objects/gis-object.c
index ac01a294379b67c512ca585b815fad9407c7079b..735e62e2cb78ff5d8e0b9c964258d0115ce1f100 100644 (file)
--- a/src/objects/gis-object.c
+++ b/src/objects/gis-object.c
@@ -15,30 +15,87 @@
  * 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;
+       }
 
-void gis_point_set_lle(GisPoint *point, gdouble lat, gdouble lon, gdouble elev)
-{
-       point->lat  = lat;
-       point->lon  = lon;
-       point->elev = elev;
-}
+       /* Skip hidden objects */
+       if (object->hidden)
+               return;
 
-void gis_point_free(GisPoint *point)
-{
-       g_free(point);
-}
+       /* 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);
+}
 
-/* GisObject */
+/* GObject stuff */
 G_DEFINE_ABSTRACT_TYPE(GisObject, gis_object, G_TYPE_OBJECT);
 static void gis_object_init(GisObject *object)
 {