World: add skybox changer

New Visuals -> Skybox card with a runtime sv_skyname override using the same
mechanism as the stock skybox_swapper entity. The choice list is the HL2
skybox set extracted from the game VPKs.

The map's own sky is captured from loaded materials (SkyBox group, parsing
skybox/<name>... face names) before the first override, so turning the
feature off or picking "Map default" restores it; a level change restores it
implicitly. Sky changes invalidate the world tint so new sky materials are
tinted as well.

GUI: add a CK_CHOICE control (value box with < / > zones).

1 files changed, 9 insertions, 2 deletions

diff --git a/src/hl2h.h b/src/hl2h.h
index 877afac..3cb131d 100644
--- a/src/hl2h.h
+++ b/src/hl2h.h
@@ -180,7 +180,8 @@ enum FeatureId {
   FEAT_FULLBRIGHT = 10,
   FEAT_WORLD_TINT = 11,
   FEAT_FOG = 12,
-  FEAT_COUNT = 13
+  FEAT_SKYBOX = 13,
+  FEAT_COUNT = 14
 };
 enum EspOption {
   ESP_OPT_SHOW_NEUTRAL = 0,
@@ -213,11 +214,15 @@ struct FeatureState {
 
 extern FeatureState g_bhop, g_abh, g_jumpbug, g_melee, g_spread, g_esp,
     g_aimbot, g_triggerbot, g_silentaim, g_item_esp, g_fullbright,
-    g_world_tint, g_fog;
+    g_world_tint, g_fog, g_skybox;
 extern bool g_tint_world_on, g_tint_sky_on, g_tint_prop_on;
 extern int g_tint_world_rgb[3], g_tint_sky_rgb[3], g_tint_prop_rgb[3];
 extern bool g_fog_skybox, g_fog_disable;
 extern int g_fog_rgb[3], g_fog_start, g_fog_end;
+extern int g_skybox_choice;
+int skybox_option_count();
+const char *skybox_option_name(int i);
+const char *const *skybox_options();
 extern bool g_bhop_autostrafe;
 extern bool g_jumpbug_assist;
 extern bool g_spread_no_spread;
@@ -260,6 +265,8 @@ void world_tint_update();
 void world_tint_invalidate();
 void fog_update();
 void fog_invalidate();
+void skybox_update();
+void skybox_invalidate();
 bool resolve_server_netvars();
 int server_entity_health(int idx, int *maxhealth, int *lifestate, void **base_out);
 bool server_set_velocity_z(int idx, float vz);