Reduce dependencies, added scalar EXT extensions

test/ext/ext_scalar_constants.cpp

@@ -0,0 +1,36 @@
+#include <glm/ext/scalar_constants.hpp>
+
+template <typename valType>
+static int test_epsilon()
+{
+	int Error = 0;
+
+	valType const Test = glm::epsilon<valType>();
+	Error += Test > static_cast<valType>(0) ? 0 : 1;
+
+	return Error;
+}
+
+template <typename valType>
+static int test_pi()
+{
+	int Error = 0;
+
+	valType const Test = glm::pi<valType>();
+	Error += Test > static_cast<valType>(3.14) ? 0 : 1;
+	Error += Test < static_cast<valType>(3.15) ? 0 : 1;
+
+	return Error;
+}
+
+int main()
+{
+	int Error = 0;
+
+	Error += test_epsilon<float>();
+	Error += test_epsilon<double>();
+	Error += test_pi<float>();
+	Error += test_pi<double>();
+
+	return Error;
+}