gis_viewer_get_location(env->viewer, &lat, &lon, &elev);
/* Misc */
- gdouble rg = MAX(0, 1-(elev/20000));
- gdouble blue = MAX(0, 1-(elev/50000));
- glClearColor(MIN(0.65,rg), MIN(0.65,rg), MIN(1,blue), 1.0f);
+ gdouble rg = MAX(0, 1-(elev/40000));
+ gdouble blue = MAX(0, 1-(elev/100000));
+ glClearColor(MIN(0.4,rg), MIN(0.4,rg), MIN(1,blue), 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
/* Attempt to render an atmosphere */
- /*
glEnable(GL_COLOR_MATERIAL);
glDisable(GL_CULL_FACE);
glDisable(GL_LIGHTING);
+ glMatrixMode(GL_MODELVIEW);
+ glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);
+ gis_viewer_center_position(env->viewer, lat, lon, -EARTH_R);
- glBlendFunc(GL_ONE, GL_ONE);
+ gdouble ds = EARTH_R+elev; // distance to self
+ gdouble da = EARTH_R+300000; // distance to top of atmosphere
+ gdouble dg = EARTH_R-100000; // distance to top of atmosphere
+ gdouble ang = acos(EARTH_R/ds); // angle to horizon
+ ang = MAX(ang,0.1);
- glMatrixMode(GL_MODELVIEW);
+ gdouble ar = sin(ang)*da; // top of quad fan "atomosphere"j
+ gdouble az = cos(ang)*da; //
+
+ gdouble gr = sin(ang)*dg; // bottom of quad fan "ground"
+ gdouble gz = cos(ang)*dg; //
- elev = -EARTH_R;
- for (elev = -EARTH_R; elev < 0; elev += EARTH_R/10) {
- glPushMatrix();
- glColor4f(0.3, 0.3, 1.0, 0.2);
- gis_viewer_center_position(env->viewer, lat, lon, elev);
-
- glBegin(GL_TRIANGLE_FAN);
- glVertex3f(0, 0, 0);
- for (gdouble i = 0; i <= 2*G_PI; i += G_PI/10) {
- gint rad = 1*EARTH_R + 300000;
- glVertex3f(rad*sin(i), rad*cos(i), 0);
- g_message("%f %f %f", 3*EARTH_R*sin(i), 3*EARTH_R*cos(i), 0.);
- }
- glEnd();
- glPopMatrix();
+ glBegin(GL_QUAD_STRIP);
+ for (gdouble i = 0; i <= 2*G_PI; i += G_PI/30) {
+ glColor4f(0.3, 0.3, 1.0, 1.0); glVertex3f(gr*sin(i), gr*cos(i), gz);
+ glColor4f(0.3, 0.3, 1.0, 0.0); glVertex3f(ar*sin(i), ar*cos(i), az);
}
- */
+ glEnd();
}