World: add Fullbright visual feature

- New Visuals card with the usual Active + Bind; default off. Unbound+Active
  is always-on, a bind makes it hold-to-brighten.
- Resolve VEngineCvar004 and set mat_fullbright 1/0 through FindVar (slot 12)
  and ConVar::SetValue(int) (slot 11), bypassing the console cheat gate.
  Fall back to ClientCmd if the cvar interface is unavailable.
- Reapply after map loads/respawns and persist [fullbright] active/bind.
- Log on/off; show an error toast if the cvar cannot be applied.

1 files changed, 63 insertions, 0 deletions

diff --git a/src/hl2h.cpp b/src/hl2h.cpp
index f95f6ed..ebb9b14 100644
--- a/src/hl2h.cpp
+++ b/src/hl2h.cpp
@@ -123,6 +123,42 @@ float getfov(const QAngle &my_view, const QAngle &aim_ang) {
 
 static int g_modified_logged = 0;
 
+// VEngineCvar004 / ICvar vtable: IAppSystem has 5 slots, then
+// AllocateDLLIdentifier, RegisterConCommand, UnregisterConCommand,
+// UnregisterConCommands, GetCommandLineValue, FindCommandBase,
+// FindCommandBase const, FindVar -> slot 12.
+// ConCommandBase has two dtor slots, then IsCommand, IsFlagSet, AddFlags,
+// GetName, GetHelpText, IsRegistered, GetDLLIdentifier; ConVar then adds
+// SetValue(const char*), SetValue(float), SetValue(int) -> slot 11.
+bool cvar_set_int(const char *name, int value) {
+  if (!name)
+    return false;
+  if (g_iface.cvar) {
+    using FindVarFn = void *(*)(void *, const char *);
+    void *var = vfunc<FindVarFn>(g_iface.cvar, 12)(g_iface.cvar, name);
+    if (var) {
+      using GetNameFn = const char *(*)(void *);
+      const char *got = vfunc<GetNameFn>(var, 5)(var);
+      if (got && strcmp(got, name) == 0) {
+        using SetIntFn = void (*)(void *, int);
+        vfunc<SetIntFn>(var, 11)(var, value);
+        return true;
+      }
+    }
+  }
+  // Fallback for an engine that does not expose VEngineCvar004: ClientCmd
+  // slot 7. Cheat-protected cvars may still be rejected.
+  if (g_iface.engine) {
+    char cmd[96];
+    snprintf(cmd, sizeof(cmd), "%s %d", name, value);
+    using CmdFn = void (*)(void *, const char *);
+    vfunc<CmdFn>(g_iface.engine, 7)(g_iface.engine, cmd);
+    logd("cvar: fallback command '%s'", cmd);
+    return true;
+  }
+  return false;
+}
+
 void note_modified(const CUserCmd *cmd, int flags, const float *vel) {
   // recompute usercmd CRC after modification
   fix_verified_crc(cmd->command_number, usercmd_checksum(cmd));
@@ -563,6 +599,7 @@ static void do_move(int seq, float frametime) {
     bones_clear();
     aimbot_reset_lock();
     silentaim_reset_lock();
+    fullbright_invalidate();
   }
 
   if (feature_active(FEAT_SPREAD)) {
@@ -908,10 +945,36 @@ static void *setup_thread(void *) {
   g_iface.engineserver = ef("VEngineServer021", nullptr);
   g_iface.debugoverlay = ef("VDebugOverlay003", nullptr);
   g_iface.enginetrace = ef("EngineTraceClient003", nullptr);
+  static const char *cvar_names[] = {"VEngineCvar004", "VEngineCvar007",
+                                     "VEngineCvar003", "IVEngineCvar004",
+                                     nullptr};
+  for (int i = 0; cvar_names[i] && !g_iface.cvar; i++) {
+    g_iface.cvar = ef(cvar_names[i], nullptr);
+    if (!g_iface.cvar)
+      g_iface.cvar = cf(cvar_names[i], nullptr);
+  }
+  if (!g_iface.cvar) {
+    size_t slash = g_engine.path.find_last_of('/');
+    if (slash != std::string::npos) {
+      std::string path =
+          g_engine.path.substr(0, slash + 1) + "libvstdlib.so";
+      void *h = dlopen(path.c_str(), RTLD_NOLOAD | RTLD_LAZY | RTLD_GLOBAL);
+      if (!h)
+        h = dlopen(path.c_str(), RTLD_LAZY | RTLD_GLOBAL);
+      if (h) {
+        auto vf = (CreateInterfaceFn)dlsym(h, "CreateInterface");
+        if (vf) {
+          for (int i = 0; cvar_names[i] && !g_iface.cvar; i++)
+            g_iface.cvar = vf(cvar_names[i], nullptr);
+        }
+      }
+    }
+  }
   logf("modelinfo: %p (VModelInfoClient006)", g_iface.modelinfo);
   logf("engineserver: %p (VEngineServer021), debugoverlay: %p, "
        "enginetrace: %p (EngineTraceClient003)",
        g_iface.engineserver, g_iface.debugoverlay, g_iface.enginetrace);
+  logf("cvar: %p (VEngineCvar004)", g_iface.cvar);
 
   resolve_netvars();
   if (!g_net.ok())