Ziglang linear interpolation

math.zig

// Linear Interpolation Functions

const std = @import("std");
const math = std.math;

fn lerp(x: f16, y: f16, a: f16) f16 {
    return x * (1 - a) + y * a;
}

fn invLerp(x: f16, y: f16, a: f16) f16 {
    return clamp((a - x) / (y - x), 0, 1);
}

fn clamp(a: f16, min: f16, max: f16) f16 {
    return math.min(max, math.max(min, a));
}

fn range(x1: f16, y1: f16, x2: f16, y2: f16, a: f16) f16 {
    return lerp(x2, y2, invLerp(x1, y1, a));
}

pub fn main() !void {
    const max: f16 = 255;
    var value: f16 = 51;
    const percentage = value / max * 100;
    std.debug.print("lerp {d} \n", .{lerp(0, 7, percentage) / 100});
    std.debug.print("invLerp {d} \n", .{invLerp(0, 255, value)});

    std.debug.print("range {d} \n", .{range(0, 255, 0, 7, value)});
}