reimplement ping-pong

2 files changed, 18 insertions, 0 deletions

diff --git a/core/math/math_funcs.h b/core/math/math_funcs.h
index baff10af98..b3eabd3e7a 100644
--- a/core/math/math_funcs.h
+++ b/core/math/math_funcs.h
@@ -291,6 +291,19 @@ public:
 		return is_zero_approx(range) ? min : value - (range * Math::floor((value - min) / range));
 	}
 
+	static _ALWAYS_INLINE_ float fract(float value) {
+		return value - floor(value);
+	}
+	static _ALWAYS_INLINE_ double fract(double value) {
+		return value - floor(value);
+	}
+	static _ALWAYS_INLINE_ float pingpong(float value, float length) {
+		return (length != 0.0f) ? abs(fract((value - length) / (length * 2.0f)) * length * 2.0f - length) : 0.0f;
+	}
+	static _ALWAYS_INLINE_ double pingpong(double value, double length) {
+		return (length != 0.0) ? abs(fract((value - length) / (length * 2.0)) * length * 2.0 - length) : 0.0;
+	}
+
 	// double only, as these functions are mainly used by the editor and not performance-critical,
 	static double ease(double p_x, double p_c);
 	static int step_decimals(double p_step);
diff --git a/core/variant/variant_utility.cpp b/core/variant/variant_utility.cpp
index 666b582e39..e89bdd4faa 100644
--- a/core/variant/variant_utility.cpp
+++ b/core/variant/variant_utility.cpp
@@ -275,6 +275,10 @@ struct VariantUtilityFunctions {
 		return Math::wrapf(value, min, max);
 	}
 
+	static inline double pingpong(double value, double length) {
+		return Math::pingpong(value, length);
+	}
+
 	static inline Variant max(const Variant **p_args, int p_argcount, Callable::CallError &r_error) {
 		if (p_argcount < 2) {
 			r_error.error = Callable::CallError::CALL_ERROR_TOO_FEW_ARGUMENTS;
@@ -1226,6 +1230,7 @@ void Variant::_register_variant_utility_functions() {
 	FUNCBINDR(clampf, sarray("value", "min", "max"), Variant::UTILITY_FUNC_TYPE_MATH);
 
 	FUNCBINDR(nearest_po2, sarray("value"), Variant::UTILITY_FUNC_TYPE_MATH);
+	FUNCBINDR(pingpong, sarray("value", "length"), Variant::UTILITY_FUNC_TYPE_MATH);
 
 	// Random