Remove gamma slider; keep HDR brightness

Wayland/XWayland discards window gamma ramps, so mat_monitorgamma could not
work on the development setup. Drop the slider, config key and readback.
Keep the in-engine HDR tonemap brightness and document that Fullbright turns
tonemapping off.

5 files changed, 19 insertions, 72 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index e0af84a..5c91b5c 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -21,7 +21,7 @@ covers ESP, aimbot, triggerbot and silent aim.
   - `HL2H_NO_SERVER=1` — disable server-side health reads.
 - Config: `$XDG_CONFIG_HOME/hl2hake/config`, falling back to
   `~/.config/hl2hake/config`. Plain INI, saved on every change. New sections:
-  `[view]` (camera FOV, viewmodel FOV, gamma x10) and `[movement]`
+  `[view]` (camera FOV, viewmodel FOV, HDR brightness) and `[movement]`
   (crouch-jump, edge jump).
 
 ## Runtime architecture
@@ -237,19 +237,17 @@ vocabulary / decisions.
   client netvar every tick. The camera slider is 40..140 (stock 75) and the
   viewmodel slider 20..120 (stock 54); 0 is not allowed (old configs with 0
   migrate to the stock value).
-- `viewmodel_fov` and `mat_monitorgamma` are client cvars; applied through
-  `ClientCmd` when their slider changes. Gamma is stored as x10
-  (`[view] gamma=22` = 2.2) and the slider stops at 26 because the engine
-  clamps `mat_monitorgamma` at 2.6. The value is read back through
-  `ICvar::FindVar` on the next tick (ClientCmd is queued) and logged. The
-  engine does apply the ramp (`SDL_SetWindowGammaRamp` was called with
-  changing midpoints), but a Wayland/XWayland compositor discards it, so on
-  this setup the slider has no visible effect.
+- `viewmodel_fov` is a client cvar, applied through `ClientCmd` when its
+  slider changes.
 - `HDR brightness` (`[view] tonemap`, x10, 0 = automatic) sets
   `mat_force_tonemap_scale`. This is in-engine tonemapping for HDR maps and
-  does not depend on the window system applying a gamma ramp; 10 = 1.0.
-  Both live in the always-on `Camera / display` card
-  (`[view] fov/vmfov/gamma/tonemap`).
+  does not depend on the window system; 10 = 1.0. It has no visible effect
+  while Fullbright is on (fullbright bypasses tonemapping).
+- `mat_monitorgamma` was tried and removed: the engine applies the ramp (SDL
+  receives changing midpoints), but Wayland/XWayland compositors discard
+  window gamma ramps, so the slider did nothing on the development setup.
+- Both controls live in the always-on `Camera / display` card
+  (`[view] fov/vmfov/tonemap`).
 
 ## Map transitions
 
diff --git a/src/gui.cpp b/src/gui.cpp
index 83dc0a5..59c4364 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -411,20 +411,17 @@ static void build_cards() {
   g_ctrls[g_nctrl - 1].zero_unlimited = true;
 
   int view = add_card(2, nullptr, "Camera / display",
-                      "Camera FOV, viewmodel FOV and monitor gamma.", true);
+                      "Camera FOV, viewmodel FOV and HDR brightness.", true);
   add_slider(view, "Camera FOV",
              "World camera field of view (40-140; stock 75).", 40, 140,
              &g_fov_camera);
   add_slider(view, "Viewmodel FOV",
              "Weapon model field of view (20-120; stock 54).", 20, 120,
              &g_fov_viewmodel);
-  add_slider(view, "Gamma x10",
-             "mat_monitorgamma x10: 16 = 1.6, 26 = 2.6 (engine max), stock "
-             "is 22. Uses the OS gamma ramp; some compositors ignore it.",
-             16, 26, &g_gamma);
   add_slider(view, "HDR brightness",
              "mat_force_tonemap_scale x10 (0 = automatic). In-engine "
-             "brightness for HDR maps; 10 = 1.0.",
+             "brightness for HDR maps; 10 = 1.0. No effect while Fullbright "
+             "is on.",
              0, 30, &g_tonemap);
 
   add_card(2, &g_fullbright, "Fullbright",
@@ -2245,22 +2242,6 @@ SDL_WarpMouseGlobal(int x, int y) {
     real_warp_global(x, y);
 }
 
-// Diagnostic: tell whether mat_monitorgamma reaches the SDL gamma ramp at all.
-static int (*real_set_gamma_ramp)(void *, const unsigned short *,
-                                  const unsigned short *,
-                                  const unsigned short *) = nullptr;
-
-extern "C" __attribute__((visibility("default"))) int
-SDL_SetWindowGammaRamp(void *window, const unsigned short *r,
-                       const unsigned short *g, const unsigned short *b) {
-  if (!real_set_gamma_ramp)
-    real_set_gamma_ramp = (int (*)(void *, const unsigned short *,
-                                   const unsigned short *,
-                                   const unsigned short *))dlsym(
-        RTLD_NEXT, "SDL_SetWindowGammaRamp");
-  return real_set_gamma_ramp ? real_set_gamma_ramp(window, r, g, b) : -1;
-}
-
 static unsigned int (*real_get_rel_mouse)(int *, int *) = nullptr;
 static int (*real_poll_event)(void *) = nullptr;
 
diff --git a/src/hl2h.cpp b/src/hl2h.cpp
index a037bac..ca7ee85 100644
--- a/src/hl2h.cpp
+++ b/src/hl2h.cpp
@@ -655,13 +655,13 @@ static void install_uniform_random_hook() {
 }
 
 // ---------------------------------------------------------------------------
-// camera / viewmodel FOV and gamma
+// camera / viewmodel FOV and HDR brightness
 // ---------------------------------------------------------------------------
 //
 // The rendered camera FOV is derived from C_BasePlayer::m_iDefaultFOV every
 // frame (CViewRender::OnRenderStart copies it into default_fov), so writing
 // the client netvar is enough and needs no server command. The viewmodel FOV
-// and monitor gamma are plain client cvars.
+// is a plain client cvar.
 
 static void view_settings_apply(void *ent) {
   if (g_net.default_fov >= 0 && ent)
@@ -673,33 +673,9 @@ static void view_settings_apply(void *ent) {
     console_cmd(cmd);
     last_vm = g_fov_viewmodel;
   }
-  static int last_gamma = 22;
-  static int pending_gamma = -1;
-  if (g_gamma != last_gamma) {
-    char cmd[48];
-    snprintf(cmd, sizeof(cmd), "mat_monitorgamma %d.%d", g_gamma / 10,
-             g_gamma % 10);
-    console_cmd(cmd);
-    pending_gamma = g_gamma;
-    last_gamma = g_gamma;
-  }
-  if (pending_gamma >= 0) {
-    // ClientCmd is queued, so read the cvar on the next tick to see the value
-    // the engine actually accepted (it clamps mat_monitorgamma at 2.6).
-    float got = -1.0f;
-    if (g_iface.cvar) {
-      using FindFn = void *(*)(void *, const char *);
-      void *v = vfunc<FindFn>(g_iface.cvar, 12)(g_iface.cvar,
-                                                "mat_monitorgamma");
-      if (v)
-        got = *(float *)((uintptr_t)v + 0x2c); // ConVar m_Value.f
-    }
-    logf("view: gamma request %d.%d, cvar reports %.2f", pending_gamma / 10,
-         pending_gamma % 10, got);
-    pending_gamma = -1;
-  }
   // In-engine brightness for HDR maps. Unlike mat_monitorgamma this does not
-  // depend on the window system applying a gamma ramp.
+  // depend on the window system applying a gamma ramp. Fullbright bypasses
+  // tonemapping, so the slider only has a visible effect while it is off.
   static int last_tonemap = 0;
   static int pending_tonemap = -1;
   if (g_tonemap != last_tonemap) {
diff --git a/src/hl2h.h b/src/hl2h.h
index a050feb..f1e72be 100644
--- a/src/hl2h.h
+++ b/src/hl2h.h
@@ -248,7 +248,6 @@ extern bool g_auto_crouchjump;
 extern bool g_edge_jump;
 extern int g_fov_camera;
 extern int g_fov_viewmodel;
-extern int g_gamma;
 extern int g_tonemap;
 extern int g_esp_col_hostile[3];
 extern int g_esp_col_neutral[3];
diff --git a/src/menu.cpp b/src/menu.cpp
index 033c0f9..020d2c5 100644
--- a/src/menu.cpp
+++ b/src/menu.cpp
@@ -81,7 +81,6 @@ bool g_auto_crouchjump = false;
 bool g_edge_jump = false;
 int g_fov_camera = 75;    // HL2's stock camera FOV
 int g_fov_viewmodel = 54; // HL2's stock viewmodel FOV
-int g_gamma = 22;       // mat_monitorgamma x10, stock 2.2
 int g_tonemap = 0;      // mat_force_tonemap_scale x10, 0 = automatic
 int g_esp_col_hostile[3] = {255, 60, 60};
 int g_esp_col_neutral[3] = {220, 220, 220};
@@ -249,8 +248,8 @@ void config_save() {
           g_esp_col_neutral[0], g_esp_col_neutral[1], g_esp_col_neutral[2],
           g_esp_col_friendly[0], g_esp_col_friendly[1],
           g_esp_col_friendly[2]);
-  fprintf(f, "[view]\nfov=%d\nvmfov=%d\ngamma=%d\ntonemap=%d\n",
-          g_fov_camera, g_fov_viewmodel, g_gamma, g_tonemap);
+  fprintf(f, "[view]\nfov=%d\nvmfov=%d\ntonemap=%d\n", g_fov_camera,
+          g_fov_viewmodel, g_tonemap);
   fprintf(f, "[movement]\ncrouchjump=%d\nedgejump=%d\n",
           (int)g_auto_crouchjump, (int)g_edge_jump);
   gui_config_write(f);
@@ -405,11 +404,6 @@ static bool config_load() {
           lo = 20;
           hi = 120;
           stock = 54;
-        } else if (strcmp(key, "gamma") == 0) {
-          dst = &g_gamma;
-          lo = 16;
-          hi = 26; // the engine clamps mat_monitorgamma at 2.6
-          stock = 22;
         } else if (strcmp(key, "tonemap") == 0) {
           dst = &g_tonemap;
           lo = 0;
@@ -610,7 +604,6 @@ void config_reset_defaults() {
   g_edge_jump = false;
   g_fov_camera = 75;
   g_fov_viewmodel = 54;
-  g_gamma = 22;
   g_tonemap = 0;
   g_esp_col_hostile[0] = 255;
   g_esp_col_hostile[1] = 60;