From 406bb666ea9d76f02a71c86a284ec5013ea5df4c Mon Sep 17 00:00:00 2001
From: Christophe Riccio <mail@g-truc.net>
Date: Wed, 14 Sep 2011 10:21:04 +0100
Subject: [PATCH] Fixed and tested all packing functions

---
 glm/core/func_packing.inl       | 19 ++++++++++---------
 test/core/core_func_packing.cpp | 12 ++++++------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/glm/core/func_packing.inl b/glm/core/func_packing.inl
index 5acbe96e..c08d4ac6 100644
--- a/glm/core/func_packing.inl
+++ b/glm/core/func_packing.inl
@@ -87,14 +87,15 @@ GLM_FUNC_QUALIFIER detail::uint32 packUnorm4x8(detail::tvec4<detail::float32> co
 
 GLM_FUNC_QUALIFIER detail::tvec4<detail::float32> unpackUnorm4x8(detail::uint32 const & p)
 {	
-	detail::uint8 A(detail::uint8(p >> 0));
-	detail::uint8 B(detail::uint8(p >> 8));
-	detail::uint8 C(detail::uint8(p >> 16));
-	detail::uint8 D(detail::uint8(p >> 24));
+	detail::uint32 Mask8((1 << 8) - 1);
+	detail::uint32 A((p >>  0) & Mask8);
+	detail::uint32 B((p >>  8) & Mask8);
+	detail::uint32 C((p >> 16) & Mask8);
+	detail::uint32 D((p >> 24) & Mask8);
 	return detail::tvec4<detail::float32>(
 		A * 1.0f / 255.0f, 
-		B * 1.0f / 255.0f,
-		C * 1.0f / 255.0f,
+		B * 1.0f / 255.0f, 
+		C * 1.0f / 255.0f, 
 		D * 1.0f / 255.0f);
 }
 	
@@ -114,9 +115,9 @@ GLM_FUNC_QUALIFIER detail::uint32 packSnorm4x8(detail::tvec4<detail::float32> co
 	detail::uint32 Pack = (detail::uint32(D.u) << 24) | (detail::uint32(C.u) << 16) | (detail::uint32(B.u) << 8) | (detail::uint32(A.u) << 0);
 	return Pack;
 }
-
+	
 GLM_FUNC_QUALIFIER detail::tvec4<detail::float32> unpackSnorm4x8(detail::uint32 const & p)
-{
+{	
 	union iu
 	{
 		detail::int8 i;
@@ -130,7 +131,7 @@ GLM_FUNC_QUALIFIER detail::tvec4<detail::float32> unpackSnorm4x8(detail::uint32
 	D.u = detail::uint8((p >> 24) & Mask8);
 	vec4 Pack(A.i, B.i, C.i, D.i);
 	
-	return clamp(Pack, -1.0f, 1.0f);
+	return clamp(Pack * 1.0f / 127.0f, -1.0f, 1.0f);
 }
 
 GLM_FUNC_QUALIFIER double packDouble2x32(detail::tvec2<detail::uint32> const & v)
diff --git a/test/core/core_func_packing.cpp b/test/core/core_func_packing.cpp
index 19a1f4b4..48198314 100644
--- a/test/core/core_func_packing.cpp
+++ b/test/core/core_func_packing.cpp
@@ -27,7 +27,7 @@ int test_packUnorm2x16()
 		glm::vec2 B(A[i]);
 		glm::uint32 C = glm::packUnorm2x16(B);
 		glm::vec2 D = glm::unpackUnorm2x16(C);
-		Error += glm::all(glm::equalEpsilon(B, D, 0.0001f)) ? 0 : 1;
+		Error += glm::all(glm::equalEpsilon(B, D, 1.0f / 65535.f)) ? 0 : 1;
 		assert(!Error);
 	}
 	
@@ -48,8 +48,8 @@ int test_packSnorm2x16()
 		glm::vec2 B(A[i]);
 		glm::uint32 C = glm::packSnorm2x16(B);
 		glm::vec2 D = glm::unpackSnorm2x16(C);
-		Error += glm::all(glm::equalEpsilon(B, D, 0.0001f)) ? 0 : 1;
-		//assert(!Error);
+		Error += glm::all(glm::equalEpsilon(B, D, 1.0f / 32767.0f * 2.0f)) ? 0 : 1;
+		assert(!Error);
 	}
 	
 	return Error;
@@ -68,7 +68,7 @@ int test_packUnorm4x8()
 		glm::vec4 B(A[i]);
 		glm::uint32 C = glm::packUnorm4x8(B);
 		glm::vec4 D = glm::unpackUnorm4x8(C);
-		Error += glm::all(glm::equalEpsilon(B, D, 0.0001f)) ? 0 : 1;
+		Error += glm::all(glm::equalEpsilon(B, D, 1.0f / 255.f)) ? 0 : 1;
 		assert(!Error);
 	}
 	
@@ -88,8 +88,8 @@ int test_packSnorm4x8()
 		glm::vec4 B(A[i]);
 		glm::uint32 C = glm::packSnorm4x8(B);
 		glm::vec4 D = glm::unpackSnorm4x8(C);
-		Error += glm::all(glm::equalEpsilon(B, D, 0.0001f)) ? 0 : 1;
-		//assert(!Error);
+		Error += glm::all(glm::equalEpsilon(B, D, 1.0f / 127.f)) ? 0 : 1;
+		assert(!Error);
 	}
 	
 	return Error;