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, 43 insertions, 2 deletions

diff --git a/src/menu.cpp b/src/menu.cpp
index 9a249f8..6a7ffe5 100644
--- a/src/menu.cpp
+++ b/src/menu.cpp
@@ -46,6 +46,11 @@ FeatureState g_triggerbot{true, 603}; // default Mouse4
 FeatureState g_silentaim{true, 602}; // default Mouse3
 FeatureState g_item_esp{true, 0}; // valuable item tags, always-on by default
 FeatureState g_fullbright{false, 0}; // mat_fullbright world lighting
+FeatureState g_world_tint{false, 0}; // material colour modulation
+bool g_tint_world_on = true;
+bool g_tint_sky_on = true;
+int g_tint_world_rgb[3] = {255, 255, 255};
+int g_tint_sky_rgb[3] = {255, 255, 255};
 bool g_item_health = true;
 bool g_item_ammo = true;
 bool g_item_armor = true;
@@ -187,6 +192,12 @@ void config_save() {
           g_silentaim.bind, g_silent_fov);
   fprintf(f, "[fullbright]\nactive=%d\nbind=%d\n", g_fullbright.active,
           g_fullbright.bind);
+  fprintf(f, "[worldtint]\nactive=%d\nbind=%d\nworld=%d\nsky=%d\n"
+             "wr=%d\nwg=%d\nwb=%d\nsr=%d\nsg=%d\nsb=%d\n",
+          g_world_tint.active, g_world_tint.bind, (int)g_tint_world_on,
+          (int)g_tint_sky_on, g_tint_world_rgb[0], g_tint_world_rgb[1],
+          g_tint_world_rgb[2], g_tint_sky_rgb[0], g_tint_sky_rgb[1],
+          g_tint_sky_rgb[2]);
   fprintf(f, "[items]\nactive=%d\nbind=%d\nhealth=%d\nammo=%d\n"
              "armor=%d\nweapons=%d\ncrates=%d\ndistance=%d\nmax_dist=%d\n",
           g_item_esp.active, g_item_esp.bind, (int)g_item_health,
@@ -220,7 +231,8 @@ static bool config_load() {
   char line[256];
   FeatureState *cur = nullptr;
   bool in_esp = false, in_bhop = false, in_aim = false, in_silent = false,
-       in_jumpbug = false, in_spread = false, in_items = false;
+       in_jumpbug = false, in_spread = false, in_items = false,
+       in_tint = false;
   while (fgets(line, sizeof(line), f)) {
     line[strcspn(line, "\r\n")] = 0;
     if (line[0] == '[') {
@@ -240,6 +252,8 @@ static bool config_load() {
         cur = &g_item_esp;
       else if (strstr(line, "[fullbright]"))
         cur = &g_fullbright;
+      else if (strstr(line, "[worldtint]"))
+        cur = &g_world_tint;
       else if (strstr(line, "[aimbot]"))
         cur = &g_aimbot;
       else if (strstr(line, "[triggerbot]"))
@@ -255,6 +269,7 @@ static bool config_load() {
       in_jumpbug = (cur == &g_jumpbug);
       in_spread = (cur == &g_spread);
       in_items = (cur == &g_item_esp);
+      in_tint = (cur == &g_world_tint);
     } else if (cur) {
       char *eq = strchr(line, '=');
       if (!eq)
@@ -325,6 +340,25 @@ static bool config_load() {
         if (v > 180) v = 180;
         g_silent_fov = v;
       }
+      if (in_tint) {
+        if (strcmp(key, "world") == 0)
+          g_tint_world_on = atoi(val) != 0;
+        else if (strcmp(key, "sky") == 0)
+          g_tint_sky_on = atoi(val) != 0;
+        else if (strcmp(key, "wr") == 0 || strcmp(key, "wg") == 0 ||
+                 strcmp(key, "wb") == 0) {
+          int v = atoi(val);
+          if (v < 0) v = 0;
+          if (v > 255) v = 255;
+          g_tint_world_rgb[key[1] == 'r' ? 0 : key[1] == 'g' ? 1 : 2] = v;
+        } else if (strcmp(key, "sr") == 0 || strcmp(key, "sg") == 0 ||
+                   strcmp(key, "sb") == 0) {
+          int v = atoi(val);
+          if (v < 0) v = 0;
+          if (v > 255) v = 255;
+          g_tint_sky_rgb[key[1] == 'r' ? 0 : key[1] == 'g' ? 1 : 2] = v;
+        }
+      }
       if (in_esp) {
         if (strcmp(key, "neutral") == 0)
           g_esp_opt[ESP_OPT_SHOW_NEUTRAL] = atoi(val) != 0;
@@ -378,6 +412,11 @@ void config_reset_defaults() {
     g_esp_opt[i] = true;
   g_item_esp = {true, 0};
   g_fullbright = {false, 0};
+  g_world_tint = {false, 0};
+  g_tint_world_on = true;
+  g_tint_sky_on = true;
+  g_tint_world_rgb[0] = g_tint_world_rgb[1] = g_tint_world_rgb[2] = 255;
+  g_tint_sky_rgb[0] = g_tint_sky_rgb[1] = g_tint_sky_rgb[2] = 255;
   g_item_health = true;
   g_item_ammo = true;
   g_item_armor = true;
@@ -495,7 +534,7 @@ static FeatureState *feature_state(int feature) {
   static FeatureState *feats[FEAT_COUNT] = {
       &g_bhop,    &g_abh,        &g_esp,        &g_aimbot, &g_triggerbot,
       &g_silentaim, &g_jumpbug,  &g_melee,      &g_spread, &g_item_esp,
-      &g_fullbright};
+      &g_fullbright, &g_world_tint};
   if (feature < 0 || feature >= FEAT_COUNT)
     return nullptr;
   return feats[feature];
@@ -701,6 +740,7 @@ void fullbright_update() {
 void outer_draw() {
   poll_keyboard();
   fullbright_update();
+  world_tint_update();
   gui_handle_input();
   // HL2H_DRAW_TEST=1 draws a probe rect without needing the GUI open
   static bool draw_test = getenv("HL2H_DRAW_TEST") != nullptr;
@@ -721,6 +761,7 @@ void outer_draw() {
     if (le != last_local) {
       last_local = le;
       font_reset = true;
+      world_tint_invalidate();
     }
   }
   if (font_reset && g_font) {