Math

SalamiVG ships with some math-y functions

hypot

hypot(x: number, y: number): number

Returns the hypothenuse of a right triangle where origin is at (0, 0) and the corner is at (x, y). This is equivalent to the Euclidean length of the vector, e.g. vec2(x, y).length() === hypoth(x, y)

Examples:

• hypot(3, 4) === 5
• vec2(3, 4).length() === hypoth(3, 4)

isWithin

isWithin(min: number, max: number, value: number): boolean

Returns true when value is in the range [min, max]. This can sometimes be useful when dealing with floating point arithmetic.

Examples:

• isWithin(2.001, 1.998, 1.999) === true

isWithinError

isWithinError(target: number, error: number, value: number): boolean

Identical to isWithin, but the arguments are arranged differently so you can check for an "error" amount around a target value.

Examples:

• isWithinError(2, 0.002, 1.999) === true

smallestAngularDifference

smallestAngularDifference(angle1: Radians, angle2: Radians): Radians

Returns the smallest angular difference between two angles, regardless of their orientation. This is sometimes useful when two angles can exist on opposite sides of the π/-π or 0/2π boundaries.

Examples:

• smallestAngularDifference(2 * Math.PI - 0.05, 0.05) === 0.1
• smallestAngularDifference(-Math.PI - 0.05, Math.PI + 0.05) === 0.1

angleOfVertex

angleOfVertex(a: Vector2, b: Vector2, c: Vector2): Radians

Three points define an angle. The vertex of the angle is b. Points a and c are the two end points.

Examples:

• angleOfVertex(vec2(2, 0), vec2(0, 0), vec2(4, 4)) === Math.PI / 4

haveSameSign

haveSameSign(a: number, b: number): boolean

Returns true when the two numbers have the same sign (i.e. are both positive, or both negative)

Examples:

• haveSameSign(1, 2) === true
• haveSameSign(1, -2) === false

toFixedPrecision

toFixedPrecision(value: number, precision: number): number

Similar to toFixed, but returns a number with a fixed amount of precision. Decimals are rounded at the level of precision specified.

Examples:

• toFixedPrecision(1.23456, 1) === 1.2
• toFixedPrecision(1.23456, 2) === 1.23
• toFixedPrecision(1.23456, 4) === 1.2345