My commonly used math-related helper functions in Game Maker Language

math.gml

function map_range(a, b, c, d, value) {
    return (value - a) / (b - a) * (d - c) + c
}

function normalize_arctan2_angle(angle) {
    return (angle > 0) ? angle : angle + 2 * pi
}

function sin01(x) {
    return 0.5 * (sin(x) + 1)
}

function cos01(x) {
    return 0.5 * (cos(x) + 1)
}

function degrees_to_radians(degrees) {
    return degrees / 180 * pi
}

function radians_to_degrees(radians) {
    return radians * 180 / pi
}

function lerp2(a, b, t, threshold = 0.001) {
    if (a == b) {
        return b
    }
    
    if (abs(a - b) < threshold) {
        return b
    }
    
    return lerp(a, b, t)
}