World: add world/sky material colour modulation

Port Amalgam's modulation approach: obtain IMaterialSystem from the already
loaded materialsystem.so (VMaterialSystem080) and walk materials with
FirstMaterial/NextMaterial/GetMaterial. ColorModulate the "World textures"
group (sky names excluded) and the "SkyBox textures"/sky-named group.

The walk runs only when the enabled groups or colours change, restores white
when disabled, and re-applies after level changes. Before touching materials,
GetNumMaterials() and the first material's name/group are sanity-checked so a
wrong vtable slot logs and aborts instead of walking garbage.

GUI: "World tint" card with world/sky toggles and RGB sliders; config section
[worldtint].

1 files changed, 8 insertions, 2 deletions

diff --git a/src/hl2h.h b/src/hl2h.h
index 2824d3c..e90ba91 100644
--- a/src/hl2h.h
+++ b/src/hl2h.h
@@ -178,7 +178,8 @@ enum FeatureId {
   FEAT_SPREAD = 8,
   FEAT_ITEM_ESP = 9,
   FEAT_FULLBRIGHT = 10,
-  FEAT_COUNT = 11
+  FEAT_WORLD_TINT = 11,
+  FEAT_COUNT = 12
 };
 enum EspOption {
   ESP_OPT_SHOW_NEUTRAL = 0,
@@ -210,7 +211,10 @@ 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_aimbot, g_triggerbot, g_silentaim, g_item_esp, g_fullbright,
+    g_world_tint;
+extern bool g_tint_world_on, g_tint_sky_on;
+extern int g_tint_world_rgb[3], g_tint_sky_rgb[3];
 extern bool g_bhop_autostrafe;
 extern bool g_jumpbug_assist;
 extern bool g_spread_no_spread;
@@ -248,6 +252,8 @@ void resolve_netvars();
 bool cvar_set_int(const char *name, int value);
 void fullbright_update();
 void fullbright_invalidate();
+void world_tint_update();
+void world_tint_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);