From 7a1cc47897a40a63b501fcce0f1749fc4e191102 Mon Sep 17 00:00:00 2001
From: Christophe Riccio <g.truc.creation@gmail.com>
Date: Wed, 4 May 2011 00:54:35 +0100
Subject: [PATCH] Added development tests

---
 test/gtx/gtx-ulp.cpp | 72 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 70 insertions(+), 2 deletions(-)

diff --git a/test/gtx/gtx-ulp.cpp b/test/gtx/gtx-ulp.cpp
index 5dbdb01c..48fe148b 100644
--- a/test/gtx/gtx-ulp.cpp
+++ b/test/gtx/gtx-ulp.cpp
@@ -10,11 +10,79 @@
 #include <glm/glm.hpp>
 #include <glm/gtx/ulp.hpp>
 #include <iostream>
+#include <limits>
+
+namespace
+{
+	template <typename T>
+	T next(T const & x);
+
+#if(GLM_COMPILER & GLM_COMPILER_VC)
+#	include <cfloat>
+	GLM_FUNC_QUALIFIER float next(float const & x)
+	{
+		return _nextafterf(x, std::numeric_limits<float>::max());
+	}
+
+	GLM_FUNC_QUALIFIER double next(double const & x)
+	{
+		return _nextafter(x, std::numeric_limits<double>::max());
+	}
+#else
+#	include <cmath>
+	GLM_FUNC_QUALIFIER float next(float const & x)
+	{
+		return nextafterf(x, std::numeric_limits<float>::max());
+	}
+
+	GLM_FUNC_QUALIFIER double next(double const & x)
+	{
+		return nextafter(x, std::numeric_limits<double>::max());
+	}
+#endif
+
+	template <typename T>
+	GLM_FUNC_QUALIFIER T next(T const & x, std::size_t const & Steps)
+	{
+		T temp = x;
+		for(std::size_t i = 0; i < Steps; ++i)
+			temp = next(temp);
+		return temp;
+	}
+
+	template <typename T>
+	GLM_FUNC_QUALIFIER std::size_t ulp_distance(T const & x, T const & y)
+	{
+		std::size_t ulp = 0;
+		T temp = x;
+
+		while(temp != y)
+		{
+			++ulp;
+			temp = next(temp);
+		}
+
+		return ulp;
+	}
+}//namespace
 
 int test_ulp_float()
 {
-    double Temp = _nextafter(0.01, 0.011);
-    std::cout << Temp << " 0.01, 0.011" << std::endl;
+	std::cout.precision(std::numeric_limits<double>::digits10 + 1);
+
+	float W = 1.0f;
+    float X = next(W);
+	bool TestX = W != X;
+	std::cout << " 1.0f, Next: " << ulp_distance(W, X)<< std::endl;
+	std::cout << " 1.0f, Nextt(1000): " << next(W, 1000)<< std::endl;
+	//std::cout << " 0.01, 0.011: " << ulp_distance(0.00000000001f, 0.000000000011f) << std::endl;
+	//std::cout << " 0.01, 0.011: " << ulp_distance(0.00000000001, 0.000000000011) << std::endl;
+
+	double Y = 1.0;
+    double Z = next(Y);
+	bool TestZ = Y != Z;
+    std::cout << Z << " 0.01, 0.011" << std::endl;
+	std::cout << " 1.0, Next(1000000): " << next(Y, 1000000)<< std::endl;
     
 	std::size_t A = glm::ulp(0.01, 0.02);
 	std::size_t B = glm::ulp(glm::vec2(0.01), glm::vec2(0.02));