Gamma: clamp slider to the engine's 2.6 cap, defer readback

The engine clamps mat_monitorgamma at 2.6, so the 2.8..3.0 end of the slider
did nothing. Read the value back one tick later (ClientCmd is queued) and
interpose SDL_SetWindowGammaRamp to see whether the engine pushes a ramp at
all.

1 files changed, 10 insertions, 5 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index 4df44bd..fc73214 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -239,11 +239,16 @@ vocabulary / decisions.
   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). The gamma value is read back through
-  `ICvar::FindVar` and logged (`view: gamma request ..., cvar reports ...`)
-  to distinguish a rejected command from an OS gamma ramp the compositor
-  ignores. Both live in the always-on `Camera / display` card
-  (`[view] fov/vmfov/gamma`).
+  (`[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
+  (`view: gamma request ..., cvar reports ...`) to distinguish a rejected
+  command from an OS gamma ramp the compositor ignores. `SDL_SetWindowGammaRamp`
+  is also interposed (first 12 calls log `gamma: SDL_SetWindowGammaRamp
+  mid=...`) to see whether the engine ever pushes a ramp after the slider
+  moves; if it does and the screen does not change, the compositor is
+  discarding it. Both live in the always-on
+  `Camera / display` card (`[view] fov/vmfov/gamma`).
 
 ## Map transitions