Functions: add sign from boolean function with unit tests

src/lib/mathlib/math/Functions.hpp

@@ -54,6 +54,17 @@ int signNoZero(T val)
 	return (T(0) <= val) - (val < T(0));
 }
 
+/**
+ * Sign function based on a boolean
+ *
+ * @param[in] positive Truth value to take the sign from
+ * @return 1 if positive is true, -1 if positive is false
+ */
+inline int signFromBool(bool positive)
+{
+	return positive ? 1 : -1;
+}
+
 template<typename T>
 T sq(T val)
 {

src/lib/mathlib/math/FunctionsTest.cpp

@@ -47,6 +47,15 @@ TEST(FunctionsTest, signNoZero)
 	EXPECT_FLOAT_EQ(signNoZero(123.456f), 1.f);
 }
 
+TEST(FunctionsTest, signFromBool)
+{
+	EXPECT_EQ(signFromBool(true), 1);
+	EXPECT_EQ(signFromBool(false), -1);
+	EXPECT_EQ(signFromBool(100), 1);
+	EXPECT_EQ(signFromBool(-100), 1);
+	EXPECT_EQ(signFromBool(0), -1);
+}
+
 TEST(FunctionsTest, expo)
 {
 	// input value limits