Optimized GTC packing functions

glm/core/func_packing.inl

@@ -49,30 +49,32 @@ namespace glm
 	GLM_FUNC_QUALIFIER vec2 unpackSnorm2x16(uint32 const & p)
 	{
 		vec2 Unpack(*reinterpret_cast<i16vec2*>(const_cast<uint32*>(&p)));
-		return clamp(Unpack * 1.0f / 32767.0f, -1.0f, 1.0f);
+		return clamp(
+			Unpack * 3.0518509475997192297128208258309e-5f, //1.0f / 32767.0f,
+			-1.0f, 1.0f);
 	}
 
 	GLM_FUNC_QUALIFIER uint32 packUnorm4x8(vec4 const & v)
 	{
-		glm::u8vec4 Topack(round(clamp(v, 0.0f, 1.0f) * 255.0f));
+		u8vec4 Topack(round(clamp(v, 0.0f, 1.0f) * 255.0f));
 		return *reinterpret_cast<uint32*>(&Topack);
 	}
 
 	GLM_FUNC_QUALIFIER vec4 unpackUnorm4x8(uint32 const & p)
 	{
-		glm::vec4 Unpack(*reinterpret_cast<glm::u8vec4*>(const_cast<uint32*>(&p)));
+		vec4 Unpack(*reinterpret_cast<u8vec4*>(const_cast<uint32*>(&p)));
-		return Unpack * 0.003921568627451f; // 1 / 255
+		return Unpack * float(0.0039215686274509803921568627451); // 1 / 255
 	}
 	
 	GLM_FUNC_QUALIFIER uint32 packSnorm4x8(vec4 const & v)
 	{
-		glm::i8vec4 Topack(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
+		i8vec4 Topack(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
 		return *reinterpret_cast<uint32*>(&Topack);
 	}
 	
 	GLM_FUNC_QUALIFIER glm::vec4 unpackSnorm4x8(uint32 const & p)
 	{
-		glm::vec4 Unpack(*reinterpret_cast<glm::i8vec4*>(const_cast<uint32*>(&p)));
+		vec4 Unpack(*reinterpret_cast<i8vec4*>(const_cast<uint32*>(&p)));
 		return clamp(
 			Unpack * 0.0078740157480315f, // 1.0f / 127.0f
 			-1.0f, 1.0f);

glm/gtc/packing.inl

@@ -221,253 +221,142 @@ namespace detail
 		uint32 pack;
 	};
 
-	union unorm4x16
-	{
-		struct
-		{
-			uint16 x;
-			uint16 y;
-			uint16 z;
-			uint16 w;
-		} data;
-		uint64 pack;
-	};
-
-	union snorm4x16
-	{
-		struct
-		{
-			int16 x;
-			int16 y;
-			int16 z;
-			int16 w;
-		} data;
-		uint64 pack;
-	};
-
-	union snorm1x16
-	{
-		int16 data;
-		uint16 pack;
-	};
-
-	union half1x16
-	{
-		hdata data;
-		uint16 pack;
-	};
-
-	union half4x16
-	{
-		struct
-		{
-			hdata x;
-			hdata y;
-			hdata z;
-			hdata w;
-		} data;
-		uint64 pack;
-	};
-
-	union unorm1x8
-	{
-		uint8 data;
-		uint8 pack;
-	};
-	
-	union unorm2x8
-	{
-		struct
-		{
-			uint8 x;
-			uint8 y;
-		} data;
-		uint16 pack;
-	};
-
-	union snorm1x8
-	{
-		int8 data;
-		uint8 pack;
-	};
-	
-	union snorm2x8
-	{
-		struct
-		{
-			int8 x;
-			int8 y;
-		} data;
-		uint16 pack;
-	};
 }//namespace detail
 
 	GLM_FUNC_QUALIFIER uint8 packUnorm1x8(float const & v)
 	{
-		int8 Scaled(int8(round(clamp(v, -1.0f, 1.0f) * 255.0f)));
+		return static_cast<uint8>(round(clamp(v, 0.0f, 1.0f) * 255.0f));
-		detail::unorm1x8 Packing;
-		Packing.data = Scaled;
-		return Packing.pack;
 	}
 	
-	GLM_FUNC_QUALIFIER float unpackUnorm1x8(uint8 p)
+	GLM_FUNC_QUALIFIER float unpackUnorm1x8(uint8 const & p)
 	{
-		detail::unorm1x8 Packing;
+		float Unpack(static_cast<float>(*const_cast<uint8*>(&p)));
-		Packing.pack = p;
+		return Unpack * float(0.0039215686274509803921568627451); // 1 / 255
-		float Unpacked(Packing.data);
-		return Unpacked * float(0.0039215686274509803921568627451);
 	}
 	
 	GLM_FUNC_QUALIFIER uint16 packUnorm2x8(vec2 const & v)
 	{
-		i8vec2 Scaled(round(clamp(v ,-1.0f, 1.0f) * 255.0f));
+		u8vec2 Topack(round(clamp(v, 0.0f, 1.0f) * 255.0f));
-		detail::unorm2x8 Packing;
+		return *reinterpret_cast<uint16*>(&Topack);
-		Packing.data.x = Scaled.x;
-		Packing.data.y = Scaled.y;
-		return Packing.pack;
 	}
 	
-	GLM_FUNC_QUALIFIER vec2 unpackUnorm2x8(uint16 p)
+	GLM_FUNC_QUALIFIER vec2 unpackUnorm2x8(uint16 const & p)
 	{
-		detail::unorm2x8 Packing;
+		vec2 Unpack(*reinterpret_cast<u8vec2*>(const_cast<uint16*>(&p)));
-		Packing.pack = p;
+		return Unpack * float(0.0039215686274509803921568627451); // 1 / 255
-		vec2 Unpacked(Packing.data.x, Packing.data.y);
-		return Unpacked * float(0.0039215686274509803921568627451);
 	}
 
 	GLM_FUNC_QUALIFIER uint8 packSnorm1x8(float const & v)
 	{
-		glm::int8 Scaled(int8(round(clamp(v ,-1.0f, 1.0f) * 127.0f)));
+		int8 Topack(static_cast<int8>(round(clamp(v ,-1.0f, 1.0f) * 127.0f)));
-		detail::snorm1x8 Packing;
+		return *reinterpret_cast<uint8*>(&Topack);
-		Packing.data = Scaled;
-		return Packing.pack;
 	}
 	
-	GLM_FUNC_QUALIFIER float unpackSnorm1x8(uint8 p)
+	GLM_FUNC_QUALIFIER float unpackSnorm1x8(uint8 const & p)
 	{
-		detail::snorm1x8 Packing;
+		float Unpack(static_cast<float>(*const_cast<uint8*>(&p)));
-		Packing.pack = p;
+		return clamp(
-		float Unpacked(Packing.data);
+			Unpack * 0.00787401574803149606299212598425f, // 1.0f / 127.0f
-		return clamp(Unpacked * float(0.00787401574803149606299212598425), -1.0f, 1.0f);
+			-1.0f, 1.0f);
 	}
 	
 	GLM_FUNC_QUALIFIER uint16 packSnorm2x8(vec2 const & v)
 	{
-		glm::i8vec2 Scaled(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
+		i8vec2 Topack(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
-		detail::snorm2x8 Packing;
+		return *reinterpret_cast<uint16*>(&Topack);
-		Packing.data.x = Scaled.x;
-		Packing.data.y = Scaled.y;
-		return Packing.pack;
 	}
 	
-	GLM_FUNC_QUALIFIER vec2 unpackSnorm2x8(uint16 p)
+	GLM_FUNC_QUALIFIER vec2 unpackSnorm2x8(uint16 const & p)
 	{
-		detail::snorm2x8 Packing;
+		vec2 Unpack(*reinterpret_cast<i8vec2*>(const_cast<uint16*>(&p)));
-		Packing.pack = p;
+		return clamp(
-		vec2 Unpacked(Packing.data.x, Packing.data.y);
+			Unpack * 0.00787401574803149606299212598425f, // 1.0f / 127.0f
-		return clamp(Unpacked * float(0.00787401574803149606299212598425), -1.0f, 1.0f);
+			-1.0f, 1.0f);
 	}
 	
-	GLM_FUNC_QUALIFIER uint16 packUnorm1x16(float s)
+	GLM_FUNC_QUALIFIER uint16 packUnorm1x16(float const & s)
 	{
-		return uint16(round(clamp(s, 0.0f, 1.0f) * 65535.0f));
+		return static_cast<uint16>(round(clamp(s, 0.0f, 1.0f) * 65535.0f));
 	}
 
-	GLM_FUNC_QUALIFIER float unpackUnorm1x16(uint16 p)
+	GLM_FUNC_QUALIFIER float unpackUnorm1x16(uint16 const & p)
 	{
-		return float(p) * 1.0f / 65535.0f;
+		float Unpack = static_cast<float>(*const_cast<uint16*>(&p));
+		return Unpack * 1.5259021896696421759365224689097e-5f; // 1.0 / 65535.0
 	}
 
 	GLM_FUNC_QUALIFIER uint64 packUnorm4x16(vec4 const & v)
 	{
-		i16vec4 Scaled(round(clamp(v, 0.0f, 1.0f) * 65535.0f));
+		u16vec4 Topack(round(clamp(v , 0.0f, 1.0f) * 65535.0f));
-		detail::unorm4x16 Packing;
+		return *reinterpret_cast<uint64*>(&Topack);
-		Packing.data.x = Scaled[0];
-		Packing.data.y = Scaled[1];
-		Packing.data.z = Scaled[2];
-		Packing.data.w = Scaled[3];
-		return Packing.pack;
 	}
 
 	GLM_FUNC_QUALIFIER vec4 unpackUnorm4x16(uint64 const & p)
 	{
-		detail::unorm4x16 Packing;
+		vec4 Unpack(*reinterpret_cast<u16vec4*>(const_cast<uint64*>(&p)));
-		vec4 Result(
+		return Unpack * 1.5259021896696421759365224689097e-5f; // 1.0 / 65535.0
-			float(Packing.data.x),
-			float(Packing.data.y),
-			float(Packing.data.z),
-			float(Packing.data.w));
-		Result *= float(1.5259021896696421759365224689097e-5); // 1.0 / 65535.0
-		return Result;
 	}
 
-	GLM_FUNC_QUALIFIER uint16 packSnorm1x16(float v)
+	GLM_FUNC_QUALIFIER uint16 packSnorm1x16(float const & v)
 	{
-		float Scaled = clamp(v ,-1.0f, 1.0f) * 32767.0f;
+		int16 Topack = static_cast<int16>(round(clamp(v ,-1.0f, 1.0f) * 32767.0f));
-		detail::snorm1x16 Packing;
+		return *reinterpret_cast<uint16*>(&Topack);
-		Packing.data = detail::int16(Scaled);
-		return Packing.pack;
 	}
 
-	GLM_FUNC_QUALIFIER float unpackSnorm1x16(uint16 p)
+	GLM_FUNC_QUALIFIER float unpackSnorm1x16(uint16 const & p)
 	{
-		detail::snorm1x16 Packing;
+		float Unpack = static_cast<float>(*const_cast<uint16*>(&p));
-		Packing.pack = p;
+		return clamp(
-		return clamp(float(Packing.data) * float(3.0518509475997192297128208258309e-5), -1.0f, 1.0f); //1.0f / 32767.0f
+			Unpack * 3.0518509475997192297128208258309e-5f, //1.0f / 32767.0f, 
+			-1.0f, 1.0f);
 	}
 
 	GLM_FUNC_QUALIFIER uint64 packSnorm4x16(vec4 const & v)
 	{
-		i16vec4 Scaled(clamp(v ,-1.0f, 1.0f) * 32767.0f);
+		i16vec4 Topack = static_cast<i16vec4>(round(clamp(v ,-1.0f, 1.0f) * 32767.0f));
-		detail::snorm4x16 Packing;
+		return *reinterpret_cast<uint64*>(&Topack);
-		Packing.data.x = Scaled.x;
-		Packing.data.y = Scaled.y;
-		Packing.data.z = Scaled.z;
-		Packing.data.w = Scaled.w;
-		return Packing.pack;
 	}
 
 	GLM_FUNC_QUALIFIER vec4 unpackSnorm4x16(uint64 const & p)
 	{
-		detail::snorm4x16 Packing;
+		vec4 Unpack(*reinterpret_cast<i16vec4*>(const_cast<uint64*>(&p)));
-		Packing.pack = p;
+		return clamp(
-		vec4 Unpacked(Packing.data.x, Packing.data.y, Packing.data.z, Packing.data.w);
+			Unpack * 3.0518509475997192297128208258309e-5f, //1.0f / 32767.0f,
-		return clamp(Unpacked * float(3.0518509475997192297128208258309e-5), -1.0f, 1.0f); //1.0f / 32767.0f
+			-1.0f, 1.0f);
 	}
 
 	GLM_FUNC_DECL uint16 packHalf1x16(float const & v)
 	{
-		detail::half1x16 Packing;
+		int16 Topack = detail::toFloat16(v);
-		Packing.data = detail::toFloat16(v);
+		return *reinterpret_cast<uint16*>(&Topack);
-		return Packing.pack;
 	}
 
 	GLM_FUNC_DECL float unpackHalf1x16(uint16 const & v)
 	{
-		detail::half1x16 Packing;
+		int16 Unpack(*reinterpret_cast<int16*>(const_cast<uint16*>(&v)));
-		Packing.pack = v;
+		return detail::toFloat32(Unpack);
-		return detail::toFloat32(Packing.data);
 	}
 
 	GLM_FUNC_DECL uint64 packHalf4x16(glm::vec4 const & v)
 	{
-		detail::half4x16 Packing;
+		i16vec4 Unpack(
-		Packing.data.x = detail::toFloat16(v.x);
+			detail::toFloat16(v.x),
-		Packing.data.y = detail::toFloat16(v.y);
+			detail::toFloat16(v.y),
-		Packing.data.z = detail::toFloat16(v.z);
+			detail::toFloat16(v.z),
-		Packing.data.w = detail::toFloat16(v.w);
+			detail::toFloat16(v.w));
-		return Packing.pack;
+
+		return *reinterpret_cast<uint64*>(&Unpack);
 	}
 
 	GLM_FUNC_DECL glm::vec4 unpackHalf4x16(uint64 const & v)
 	{
-		detail::half4x16 Packing;
+		i16vec4 Unpack = *reinterpret_cast<i16vec4*>(const_cast<uint64*>(&v));
-		Packing.pack = v;
+	
-		return glm::vec4(
+		return vec4(
-			detail::toFloat32(Packing.data.x),
+			detail::toFloat32(Unpack.x), 
-			detail::toFloat32(Packing.data.y),
+			detail::toFloat32(Unpack.y), 
-			detail::toFloat32(Packing.data.z),
+			detail::toFloat32(Unpack.z), 
-			detail::toFloat32(Packing.data.w));
+			detail::toFloat32(Unpack.w));
 	}
 
 	GLM_FUNC_QUALIFIER uint32 packI3x10_1x2(ivec4 const & v)