Add periodic functions

src/scalar.ts

@@ -429,6 +429,60 @@ export namespace scalar {
 	 */
 	export const invsqrt = inverseSqrt
 
+	/**
+	 * Returns a sawtooth wave with the given period. Basically, the output will be the input value modulo `period`, but returns 1 when the phase is 1. The shape of the wave will be continous for the negative ranges, so when phase is negative integer, the output will be 0, else if phase is negative float, the output will be 1 - fractional part of phase.
+	 * @see https://www.geogebra.org/calculator/d3grfqqe
+	 *
+	 * @param x the input value
+	 * @param period the period of the wave
+	 * @category Periodic Functions
+	 *
+	 * @shorthands
+	 * - {@link ramp}
+	 *
+	 */
+	export function sawtooth(x: number, period = 1): number {
+		x /= period
+
+		if (x === 1) return 1
+		if (x < 0) return (1 + (x % 1)) % 1
+		return x % 1
+	}
+
+	/**
+	 * Alias for {@link sawtooth}
+	 * @category Shorthands
+	 */
+	export const ramp = sawtooth
+
+	/**
+	 * Returns a triangle wave with the given period. The output ranges from 0 to 1.
+	 * @see https://www.geogebra.org/calculator/d3grfqqe
+	 *
+	 * @param x The input value
+	 * @param period The period of the wave
+	 * @category Periodic Functions
+	 */
+	export function triangle(x: number, period = 1): number {
+		x /= period
+
+		return 1 - Math.abs(1 - 2 * (Math.abs(x) % 1))
+	}
+
+	/**
+	 * Returns a cosine wave with the given period. The output ranges from 0 to 1, and y = 0 when x = 0.
+	 *
+	 * @see https://www.geogebra.org/calculator/d3grfqqe
+	 * @param v the input value
+	 * @param period the period of the wave
+	 * @category Periodic Functions
+	 */
+	export function coswave(v: number, period = 1): number {
+		v = (v * Math.PI * 2) / period
+		console.log({v})
+		return (-Math.cos(v) + 1) / 2
+	}
+
 	/**
 	 * Returns whether or not the numbers have approximately the same.
 	 *

typedoc.json

@@ -14,6 +14,7 @@
 		"Constants",
 		"Generators",
 		"Functions",
+		"Periodic Functions",
 		"Shorthands"
 	],
 	"blockTags": ["@shorthands"]