Lua utillib.

examples/resources/lib/utillib.lua

@@ -0,0 +1,166 @@
+-- Define useful global stuff.
+
+local utillib = {}
+
+function utillib.tableClone( org )
+	return { table.unpack( org ) }
+end
+
+function utillib.deepCopy( orig )
+    local copy
+
+    if type( orig ) == "table" then
+        copy = {}
+
+        for orig_key, orig_value in next, orig, nil do
+			-- If object has clone method use that. Mainly for vector libraries.
+			if type( orig_value ) == "table" and type( orig_value.clone ) == "function" then
+				copy[ utillib.deep_copy( orig_key ) ] = orig_value:clone()
+			else
+				copy[ utillib.deep_copy( orig_key ) ] = utillib.deep_copy( orig_value )
+			end
+        end
+
+        setmetatable( copy, utillib.deep_copy( getmetatable( orig ) ) )
+    else -- number, string, boolean, etc.
+        copy = orig
+    end
+
+    return copy
+end
+
+function utillib.sign( v )
+	if 0 <= v then
+		return 1
+	elseif v < 0 then
+		return -1
+	end
+end
+
+function utillib.clamp( val, min, max )
+	return math.max( min, math.min( val, max ) )
+end
+
+-- Returns changed value ( value to be changed, index, bit )
+function utillib.setBit( v, i, b )
+	if b then
+		return v | 1 << i
+	else 
+		return v & ~( 1 << i )
+	end
+end
+
+function utillib.toggleBit( v, i )
+	return v ~ ( 1 << i )
+end
+
+function utillib.getBit( v, i )
+	if v == nil then
+		return false
+	end
+
+	return v & ( 1 << i ) > 0
+end
+
+function utillib.utf8Sub( s, i, j )
+	assert( utillib.isstring( s ) )
+
+	i = i or 1
+	j = j or -1
+
+	if i < 1 or j < 1 then
+	   local n = utf8.len(s)
+	   if not n then return nil end
+	   if i < 0 then i = n + 1 + i end
+	   if j < 0 then j = n + 1 + j end
+	   if i < 0 then i = 1 elseif i > n then i = n end
+	   if j < 0 then j = 1 elseif j > n then j = n end
+	end
+
+	if j < i then return "" end
+
+	i = utf8.offset( s, i )
+	j = utf8.offset( s, j + 1 )
+	
+	if i and j then
+		return s:sub( i, j - 1 )
+	elseif i then
+		return s:sub( i )
+	else
+		return ""
+	end
+end
+
+function utillib.round( v )
+	return math.tointeger( v + 0.5 - ( v + 0.5 ) % 1 )
+end
+
+function utillib.tableLen( t )
+	if not utillib.istable( t ) then
+		return 0
+	end
+
+    local count = 0
+
+	for _ in pairs(t) do
+		count = count + 1
+	end
+
+    return count
+end
+
+function utillib.split( str, sep )
+	assert( utillib.isstring( str ) )
+
+	if sep == nil then
+		sep = "%s"
+	end
+
+	local t = {}
+
+	for str in string.gmatch( str, "([^"..sep.."]+)" ) do
+		table.insert( t, str )
+	end
+
+	return t
+end
+
+function utillib.wrapAngleDeg( angle )
+	assert( utillib.isnumber( angle ) )
+
+	if angle < 0 then
+		return math.fmod( angle, 360.0 ) + 360.0
+	else
+		return math.fmod( angle, 360.0 )
+	end
+end
+
+function utillib.wrapAngleRad( angle )
+	assert( utillib.isnumber( angle ) )
+
+	if angle < 0 then
+		return math.fmod( angle, PI * 2 ) + PI * 2
+	else
+		return math.fmod( angle, PI * 2 )
+	end
+end
+
+function utillib.lerp( a, b, f )
+	return ( a * ( 1.0 - f ) ) + ( b * f )
+end
+
+function utillib.toBoolean( v )
+	if utillib.isstring( v ) then
+		if v == "1" or string.lower( v ) == "true" then
+			return true
+		elseif v == "0" or string.lower( v ) == "false" then
+			return false
+		end
+	elseif utillib.isnumber( v ) then
+		return 0 < v
+	end
+
+	return false
+end
+
+return utillib