lua - add bindings to get frame duration

apps/openmw/mwlua/luabindings.cpp

@@ -86,6 +86,7 @@ namespace MWLua
         api["getRealTime"] = []() {
             return std::chrono::duration<double>(std::chrono::steady_clock::now().time_since_epoch()).count();
         };
+        api["getRealFrameDuration"] = []() { return MWBase::Environment::get().getFrameDuration(); };
 
         if (!global)
             return;

files/lua_api/openmw/core.lua

@@ -55,6 +55,11 @@
 -- @function [parent=#core] getRealTime
 -- @return #number
 
+---
+-- Frame duration in seconds
+-- @function [parent=#core] getRealFrameDuration
+-- @return #number
+
 ---
 -- Get a GMST setting from content files.
 -- @function [parent=#core] getGMST

files/lua_api/openmw/world.lua

@@ -111,6 +111,11 @@
 -- @function [parent=#world] setGameTimeScale
 -- @param #number ratio
 
+---
+-- Frame duration in seconds
+-- @function [parent=#world] getRealFrameDuration
+-- @return #number
+
 ---
 -- Whether the world is paused (onUpdate doesn't work when the world is paused).
 -- @function [parent=#world] isWorldPaused