diff --git a/src/utils.c b/src/utils.c
index 62e5a3b..e5167df 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -162,6 +162,10 @@ SYMBOL_EXPORT double Lerp(double left, double right, double pos) {
 	return left + (right - left) * pos;
 }
 
+SYMBOL_EXPORT double Sign(double val) {
+	return val / fabs(val);
+}
+
 /* linear filtering code written by SiegeLord */
 SYMBOL_EXPORT ALLEGRO_COLOR InterpolateColor(ALLEGRO_COLOR c1, ALLEGRO_COLOR c2, float frac) {
 	return al_map_rgba_f(c1.r + frac * (c2.r - c1.r),
diff --git a/src/utils.h b/src/utils.h
index b1a6611..dd96730 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -61,6 +61,7 @@ double VectorLength(double x, double y, double z);
 double Wrap(double left, double right, double val);
 double Clamp(double left, double right, double val);
 double Lerp(double left, double right, double pos);
+double Sign(double val);
 
 ALLEGRO_COLOR InterpolateColor(ALLEGRO_COLOR c1, ALLEGRO_COLOR c2, float frac);
 void ScaleBitmap(ALLEGRO_BITMAP* source, int width, int height);