address feedback

Author: BMagnu

code/nebula/neb.h

@@ -25,9 +25,6 @@ class ship;
 class object;
 
 extern bool Nebula_sexp_used;
-// fog near and far values for rendering the background nebula
-extern float Neb_backg_fog_near;
-extern float Neb_backg_fog_far;
 
 // nebula rendering mode
 #define NEB2_RENDER_NONE								0			// no rendering

code/scripting/api/libs/mission.cpp

@@ -2329,7 +2329,7 @@ ADE_VIRTVAR(NebulaClipDistance, l_Mission, "number", "Gets or sets the distance
 	float fog_clip = 0.0f;
 
 	if (ADE_SETTING_VAR && ade_get_args(L, "*f", &fog_clip))
-		Neb2_fog_clip_distance = fog_clip;
+		Neb2_fog_clip_distance = std::max(0.f, fog_clip);
 
 	return ade_set_args(L, "f", Neb2_fog_clip_distance);
 }
@@ -2339,7 +2339,7 @@ ADE_VIRTVAR(NebulaSkyboxClipDistance, l_Mission, "number", "Gets or sets the dis
 	float fog_clip = 0.0f;
 
 	if (ADE_SETTING_VAR && ade_get_args(L, "*f", &fog_clip))
-		Neb2_fog_skybox_clip_distance = fog_clip;
+		Neb2_fog_skybox_clip_distance = std::max(0.f, fog_clip);
 
 	return ade_set_args(L, "f", Neb2_fog_skybox_clip_distance);
 }
@@ -2349,7 +2349,7 @@ ADE_VIRTVAR(NebulaVisibility, l_Mission, "number", "Gets or sets the visibility
 	float fog_visibility = 0.0f;
 
 	if (ADE_SETTING_VAR && ade_get_args(L, "*f", &fog_visibility))
-		Neb2_fog_1000m_visibility = fog_visibility;
+		Neb2_fog_1000m_visibility = std::clamp(fog_visibility, 0.0f, 1.0f);
 
 	return ade_set_args(L, "f", Neb2_fog_1000m_visibility);
 }