Add dynamic exposure correction (#12959)

* Add uniform for frame delta time
* Adjust exposure in logarithmic (EV) space
* Add network support and LUA API
* Add testing mod

1 files changed, 9 insertions, 0 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index a35adca60..fb6bc9df8 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -7472,6 +7472,15 @@ child will follow movement and rotation of that bone.
       * `shadows` is a table that controls ambient shadows
         * `intensity` sets the intensity of the shadows from 0 (no shadows, default) to 1 (blackness)
             * This value has no effect on clients who have the "Dynamic Shadows" shader disabled.
+      * `exposure` is a table that controls automatic exposure.
+        The basic exposure factor equation is `e = 2^exposure_correction / clamp(luminance, 2^luminance_min, 2^luminance_max)`
+        * `luminance_min` set the lower luminance boundary to use in the calculation
+        * `luminance_max` set the upper luminance boundary to use in the calculation
+        * `exposure_correction` correct observed exposure by the given EV value
+        * `speed_dark_bright` set the speed of adapting to bright light
+        * `speed_bright_dark` set the speed of adapting to dark scene
+        * `center_weight_power` set the power factor for center-weighted luminance measurement
+
 * `get_lighting()`: returns the current state of lighting for the player.
     * Result is a table with the same fields as `light_definition` in `set_lighting`.
 * `respawn()`: Respawns the player using the same mechanism as the death screen,