optimize: implement scale and clamp lua functions in C

stepmania/Themes/default/Scripts/Utilities.lua

@@ -30,16 +30,6 @@ function TableMetricLookup( t, group )
 	return ret
 end
 
--- Scales x so that l1 corresponds to l2 and h1 corresponds to h2.
-function scale( x, l1, h1, l2, h2 )
-	return (((x) - (l1)) * ((h2) - (l2)) / ((h1) - (l1)) + (l2))
-end
-
--- Scales x so that l1 corresponds to l2 and h1 corresponds to h2.
-function scale( x, l1, h1, l2, h2 )
-	return (((x) - (l1)) * ((h2) - (l2)) / ((h1) - (l1)) + (l2))
-end
-
 function split( delimiter, text )
 	local list = {}
 	local pos = 1
@@ -64,10 +54,6 @@ function join( delimiter, list )
 	return ret
 end
 
-function clamp(val,low,high)
-	return math.max( low, math.min(val,high) )
-end
-
 function wrap(val,n)
 	local x = val
 	Trace( "wrap "..x.." "..n )

stepmania/src/LuaManager.cpp

@@ -469,6 +469,14 @@ LuaFunction( Trace, Trace(SArg(1)) );
 #include "ProductInfo.h"
 LuaFunction( ProductVersion, (CString) PRODUCT_VER );
 
+static float scale( float x, float l1, float h1, float l2, float h2 )
+{
+	return SCALE( x, l1, h1, l2, h2 );
+}
+LuaFunction( scale, scale(FArg(1), FArg(2), FArg(3), FArg(4), FArg(5)) );
+
+LuaFunction( clamp, clamp(FArg(1), FArg(2), FArg(3)) );
+
 /*
  * (c) 2004 Glenn Maynard
  * All rights reserved.