sample-coolGame/lua_modules/cpml/spec/utils_spec.lua

local vec3      = require "modules.vec3"
local utils     = require "modules.utils"
local constants = require "modules.constants"

local function tolerance(v, t)
	return math.abs(v - t) < 1e-6
end

describe("utils:", function()
	it("interpolates between two numbers", function()
		assert.is_true(tolerance(utils.lerp(0, 1, 0.5), 0.5))
	end)

	it("interpolates between two vectors", function()
		local a = vec3(0, 0, 0)
		local b = vec3(1, 1, 1)
		local c = vec3(0.5, 0.5, 0.5)
		assert.is.equal(utils.lerp(a, b, 0.5), c)

		a = vec3(5, 5, 5)
		b = vec3(0, 0, 0)
		c = vec3(2.5, 2.5, 2.5)
		assert.is.equal(utils.lerp(a, b, 0.5), c)
	end)

	it("decays exponentially", function()
		local v = utils.decay(0, 1, 0.5, 1)
		assert.is_true(tolerance(v, 0.39346934028737))
	end)
end)

--[[
clamp(value, min, max)
deadzone(value, size)
threshold(value, threshold)
tolerance(value, threshold)
map(value, min_in, max_in, min_out, max_out)
lerp(progress, low, high)
smoothstep(progress, low, high)
round(value, precision)
wrap(value, limit)
is_pot(value)
project_on(out, a, b)
project_from(out, a, b)
mirror_on(out, a, b)
reflect(out, i, n)
refract(out, i, n, ior)
angle_to(a, b)
angle_between(a, b)
--]]