add utils.sign

modules/utils.lua

@@ -211,4 +211,18 @@ function utils.refract(i, n, ior)
 	return vec3()
 end
 
+--- Get the sign of a number
+-- returns 1 for positive values, -1 for negative and 0 for zero.
+-- @param value
+-- @return number
+function utils.sign(n)
+	if n > 0 then
+		return 1
+	elseif n < 0 then
+		return -1
+	else
+		return 0
+	end
+end
+
 return utils

spec/utils_spec.lua

@@ -44,6 +44,12 @@ describe("utils:", function()
 		v = utils.round(1.3242525)
 		assert.is_true(tolerance(v, 1))
 	end)
+
+	it("checks sign", function()
+		assert.is.equal(utils.sign(-9), -1)
+		assert.is.equal(utils.sign(0), 0)
+		assert.is.equal(utils.sign(12), 1)
+	end)
 end)
 
 --[[