- Fixed integer pow from GTX_integer with null exponent #658

glm/gtx/integer.hpp

@@ -31,7 +31,7 @@ namespace glm
 
 	//! Returns x raised to the y power. 
 	//! From GLM_GTX_integer extension.
-	GLM_FUNC_DECL int pow(int x, int y);
+	GLM_FUNC_DECL int pow(int x, uint y);
 
 	//! Returns the positive square root of x.
 	//! From GLM_GTX_integer extension.

glm/gtx/integer.inl

@@ -4,10 +4,11 @@
 namespace glm
 {
 	// pow
-	GLM_FUNC_QUALIFIER int pow(int x, int y)
+	GLM_FUNC_QUALIFIER int pow(int x, uint y)
 	{
 		if(y == 0)
-			return 1;
+			return x >= 0 ? 1 : -1;
+
 		int result = x;
 		for(int i = 1; i < y; ++i)
 			result *= x;
@@ -111,6 +112,9 @@ namespace detail
 
 	GLM_FUNC_QUALIFIER uint pow(uint x, uint y)
 	{
+		if (y == 0)
+			return 1u;
+
 		uint result = x;
 		for(uint i = 1; i < y; ++i)
 			result *= x;

readme.md

@@ -85,6 +85,7 @@ glm::mat4 camera(float Translate, glm::vec2 const & Rotate)
 - Fixed references to GLM_FORCE_RADIANS which was removed #642
 - Fixed glm::fastInverseSqrt to use fast inverse square #640
 - Fixed axisAngle NaN #638
+- Fixed integer pow from GTX_integer with null exponent #658
 
 #### Deprecation:
 - Requires Visual Studio 2013, GCC 4.7, Clang 3.4, Cuda 7, ICC 2013 or a C++11 compiler

test/gtx/gtx_integer.cpp

@@ -52,6 +52,47 @@ int test_nlz()
 	return Error;
 }
 
+int test_pow_uint()
+{
+	int Error = 0;
+
+	glm::uint const p0 = glm::pow(2u, 0u);
+	Error += p0 == 1u ? 0 : 1;
+
+	glm::uint const p1 = glm::pow(2u, 1u);
+	Error += p1 == 2u ? 0 : 1;
+
+	glm::uint const p2 = glm::pow(2u, 2u);
+	Error += p2 == 4u ? 0 : 1;
+
+	return Error;
+}
+
+int test_pow_int()
+{
+	int Error = 0;
+
+	int const p0 = glm::pow(2, 0u);
+	Error += p0 == 1 ? 0 : 1;
+
+	int const p1 = glm::pow(2, 1u);
+	Error += p1 == 2 ? 0 : 1;
+
+	int const p2 = glm::pow(2, 2u);
+	Error += p2 == 4 ? 0 : 1;
+
+	int const p0n = glm::pow(-2, 0u);
+	Error += p0n == -1 ? 0 : 1;
+
+	int const p1n = glm::pow(-2, 1u);
+	Error += p1n == -2 ? 0 : 1;
+
+	int const p2n = glm::pow(-2, 2u);
+	Error += p2n == 4 ? 0 : 1;
+
+	return Error;
+}
+
 int main()
 {
 	int Error = 0;
@@ -59,6 +100,8 @@ int main()
 	Error += test_nlz();
 //	Error += test_floor_log2();
 	Error += test_log2();
+	Error += test_pow_uint();
+	Error += test_pow_int();
 
 	return Error;
 }