diff --git a/clip/fold.h b/clip/fold.h
new file mode 100644
index 0000000..3b7c46b
--- /dev/null
+++ b/clip/fold.h
@@ -0,0 +1,40 @@
+#pragma once
+
+namespace trnr {
+// folds the wave from -1 to 1
+inline float fold(float& sample)
+{
+	while (sample > 1.0 || sample < -1.0) {
+
+		if (sample > 1.0) {
+			sample = 2.0 - sample;
+		} else if (sample < -1.0) {
+			sample = -2.0 - sample;
+		}
+	}
+	return sample;
+}
+
+// folds the positive part of the wave independently from the negative part.
+inline float fold_bipolar(float& sample)
+{
+	// fold positive values
+	if (sample > 1.0) {
+		sample = 2.0 - sample;
+
+		if (sample < 0.0) { sample = -sample; }
+
+		return fold(sample);
+	}
+	// fold negative values
+	else if (sample < -1.0) {
+		sample = -2.0 - sample;
+
+		if (sample > 0.0) { sample = -sample; }
+
+		return fold(sample);
+	} else {
+		return sample;
+	}
+}
+}; // namespace trnr