X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=builtin_data%2F_sky.glsl;h=1dbda5793f2d838018b1f8558ede2da7f03437da;hb=2f2048a186c6a10f04999d8a01a3bcf63adc7c75;hp=3493b5a48e92711bcf9a0ceaa7d53871bb753b35;hpb=9208e0ff263a287e456e082a4a8b8fd0bbd41f9e;p=libs%2Fgl.git

diff --git a/builtin_data/_sky.glsl b/builtin_data/_sky.glsl
index 3493b5a4..1dbda579 100644
--- a/builtin_data/_sky.glsl
+++ b/builtin_data/_sky.glsl
@@ -88,13 +88,8 @@ float ray_sphere_intersect(vec3 ray_start, vec3 ray_dir, vec3 sphere_center, flo
 	if(d_sq>r_sq)
 		return -1.0;
 
-	float offset = sqrt(r_sq-d_sq);
-	if(offset<t)
-		return t-offset;
-	else if(offset>-t)
-		return t+offset;
-	else
-		return -1.0;
+	float offset = sqrt(r_sq-d_sq)*sign(sphere_radius);
+	return t-offset;
 }
 
 #pragma MSP stage(fragment)
@@ -110,7 +105,7 @@ OpticalPathInfo raymarch_path(float start_height, vec3 look_dir)
 	vec3 path_extinction = vec3(0.0);
 
 	float ground_t = ray_sphere_intersect(pos, look_dir, planet_center, planet_radius);
-	float space_t = ray_sphere_intersect(pos, look_dir, planet_center, planet_radius+atmosphere_thickness);
+	float space_t = ray_sphere_intersect(pos, look_dir, planet_center, -(planet_radius+atmosphere_thickness));
 	float ray_length = (ground_t>0.0 ? ground_t : space_t);
 	float step_size = ray_length/n_steps;
 
@@ -123,11 +118,15 @@ OpticalPathInfo raymarch_path(float start_height, vec3 look_dir)
 
 		AtmosphericEvents ev = calculate_events(height);
 		vec3 transmittance = exp(-path_extinction);
-		vec3 in_transmittance = texture(transmittance_lookup, vec2(sqrt(height/atmosphere_thickness), light_z)).rgb;
-		vec3 in_luminance = (ev.rayleigh_scatter*p_rayleigh+ev.mie_scatter*p_mie)*step_size;
-		if(i==n_steps && ground_t>0.0)
-			in_luminance += ground_albedo*light_z/PI;
-		path_luminance += transmittance*in_transmittance*in_luminance;
+		float in_ground_t = ray_sphere_intersect(pos, light_dir, planet_center, planet_radius);
+		if(in_ground_t<0.0)
+		{
+			vec3 in_transmittance = texture(transmittance_lookup, vec2(sqrt(height/atmosphere_thickness), light_z)).rgb;
+			vec3 in_luminance = (ev.rayleigh_scatter*p_rayleigh+ev.mie_scatter*p_mie)*step_size;
+			if(i==n_steps && ground_t>0.0 && light_z>0.0)
+				in_luminance += ground_albedo*light_z/PI;
+			path_luminance += transmittance*in_transmittance*in_luminance;
+		}
 
 		path_extinction += total_extinction(ev)*step_size;
 		pos += look_dir*step_size;