Add sky effects

diff --git a/src/plugins/env.c b/src/plugins/env.c
index 1a0110c49a24def9c56d040d6daa937fda2b7ca9..2952487f36cb52e12bba1692a4e08634737d3e07 100644 (file)
--- a/src/plugins/env.c
+++ b/src/plugins/env.c
@@ -44,38 +44,37 @@ static void expose(GisCallback *callback, GisOpenGL *opengl, gpointer _env)
        gis_viewer_get_location(env->viewer, &lat, &lon, &elev);
 
        /* Misc */
        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 */
        glClear(GL_COLOR_BUFFER_BIT);
 
        /* Attempt to render an atmosphere */

-       /*

        glEnable(GL_COLOR_MATERIAL);
        glDisable(GL_CULL_FACE);
        glDisable(GL_LIGHTING);
        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();

 }
 
 
 }