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)));
-		return Unpack * 0.003921568627451f; // 1 / 255
+		vec4 Unpack(*reinterpret_cast<u8vec4*>(const_cast<uint32*>(&p)));
+		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

@@ -42,18 +42,18 @@ namespace detail
 		// 0x7f800000 => 01111111 10000000 00000000 00000000
 		// 0x00008000 => 00000000 00000000 10000000 00000000
 		return
-        ((f >> 16) & 0x8000) | // sign
-        ((((f & 0x7f800000) - 0x38000000) >> 13) & 0x7c00) | // exponential
-        ((f >> 13) & 0x03ff); // Mantissa
+		((f >> 16) & 0x8000) | // sign
+		((((f & 0x7f800000) - 0x38000000) >> 13) & 0x7c00) | // exponential
+		((f >> 13) & 0x03ff); // Mantissa
 	}
-    
+
 	glm::uint32 float2packed11(glm::uint32 const & f)
 	{
 		// 10 bits    =>                         EE EEEFFFFF
 		// 11 bits    =>                        EEE EEFFFFFF
 		// Half bits  =>                   SEEEEEFF FFFFFFFF
 		// Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF
-        
+
 		// 0x000007c0 => 00000000 00000000 00000111 11000000
 		// 0x00007c00 => 00000000 00000000 01111100 00000000
 		// 0x000003ff => 00000000 00000000 00000011 11111111
@@ -61,17 +61,17 @@ namespace detail
 		// 0x7f800000 => 01111111 10000000 00000000 00000000
 		// 0x00008000 => 00000000 00000000 10000000 00000000
 		return
-        	((((f & 0x7f800000) - 0x38000000) >> 17) & 0x07c0) | // exponential
-       		((f >> 17) & 0x003f); // Mantissa
+			((((f & 0x7f800000) - 0x38000000) >> 17) & 0x07c0) | // exponential
+			((f >> 17) & 0x003f); // Mantissa
 	}
-    
- 	glm::uint32 packed11ToFloat(glm::uint32 const & p)
+
+	glm::uint32 packed11ToFloat(glm::uint32 const & p)
 	{
 		// 10 bits    =>                         EE EEEFFFFF
 		// 11 bits    =>                        EEE EEFFFFFF
 		// Half bits  =>                   SEEEEEFF FFFFFFFF
 		// Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF
-        
+
 		// 0x000007c0 => 00000000 00000000 00000111 11000000
 		// 0x00007c00 => 00000000 00000000 01111100 00000000
 		// 0x000003ff => 00000000 00000000 00000011 11111111
@@ -79,8 +79,8 @@ namespace detail
 		// 0x7f800000 => 01111111 10000000 00000000 00000000
 		// 0x00008000 => 00000000 00000000 10000000 00000000
 		return
-        	((((p & 0x07c0) << 17) + 0x38000000) & 0x7f800000) | // exponential
-       		((p & 0x003f) << 17); // Mantissa
+			((((p & 0x07c0) << 17) + 0x38000000) & 0x7f800000) | // exponential
+			((p & 0x003f) << 17); // Mantissa
 	}
 
 	glm::uint32 float2packed10(glm::uint32 const & f)
@@ -89,7 +89,7 @@ namespace detail
 		// 11 bits    =>                        EEE EEFFFFFF
 		// Half bits  =>                   SEEEEEFF FFFFFFFF
 		// Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF
-        
+
 		// 0x0000001F => 00000000 00000000 00000000 00011111
 		// 0x0000003F => 00000000 00000000 00000000 00111111
 		// 0x000003E0 => 00000000 00000000 00000011 11100000
@@ -100,17 +100,17 @@ namespace detail
 		// 0x7f800000 => 01111111 10000000 00000000 00000000
 		// 0x00008000 => 00000000 00000000 10000000 00000000
 		return
-        	((((f & 0x7f800000) - 0x38000000) >> 18) & 0x03E0) | // exponential
-        	((f >> 18) & 0x001f); // Mantissa
+			((((f & 0x7f800000) - 0x38000000) >> 18) & 0x03E0) | // exponential
+			((f >> 18) & 0x001f); // Mantissa
 	}
-    
+
 	glm::uint32 packed10ToFloat(glm::uint32 const & p)
 	{
 		// 10 bits    =>                         EE EEEFFFFF
 		// 11 bits    =>                        EEE EEFFFFFF
 		// Half bits  =>                   SEEEEEFF FFFFFFFF
 		// Float bits => SEEEEEEE EFFFFFFF FFFFFFFF FFFFFFFF
-        
+
 		// 0x0000001F => 00000000 00000000 00000000 00011111
 		// 0x0000003F => 00000000 00000000 00000000 00111111
 		// 0x000003E0 => 00000000 00000000 00000011 11100000
@@ -121,21 +121,21 @@ namespace detail
 		// 0x7f800000 => 01111111 10000000 00000000 00000000
 		// 0x00008000 => 00000000 00000000 10000000 00000000
 		return
-        	((((p & 0x03E0) << 18) + 0x38000000) & 0x7f800000) | // exponential
-       		((p & 0x001f) << 18); // Mantissa
+			((((p & 0x03E0) << 18) + 0x38000000) & 0x7f800000) | // exponential
+			((p & 0x001f) << 18); // Mantissa
 	}
 
 	glm::uint half2float(glm::uint const & h)
 	{
 		return ((h & 0x8000) << 16) | ((( h & 0x7c00) + 0x1C000) << 13) | ((h & 0x03FF) << 13);
 	}
-    
-    union uif
-    {
-        glm::uint i;
-        float f;
-    };
-    
+
+	union uif
+	{
+		glm::uint i;
+		float f;
+	};
+
 	glm::uint floatTo11bit(float x)
 	{
 		if(x == 0.0f)
@@ -144,12 +144,12 @@ namespace detail
 			return ~0;
 		else if(glm::isinf(x))
 			return 0x1f << 6;
-        
+
 		uif Union;
 		Union.f = x;
 		return float2packed11(Union.i);
 	}
-    
+
 	float packed11bitToFloat(glm::uint x)
 	{
 		if(x == 0)
@@ -158,7 +158,7 @@ namespace detail
 			return ~0;//NaN
 		else if(x == (0x1f << 6))
 			return ~0;//Inf
-        
+
 		uif Union;
 		Union.i = packed11ToFloat(x);
 		return Union.f;
@@ -172,7 +172,7 @@ namespace detail
 			return ~0;
 		else if(glm::isinf(x))
 			return 0x1f << 5;
-        
+
 		uif Union;
 		Union.f = x;
 		return float2packed10(Union.i);
@@ -186,12 +186,12 @@ namespace detail
 			return ~0;//NaN
 		else if(x == (0x1f << 5))
 			return ~0;//Inf
-        
+
 		uif Union;
 		Union.i = packed10ToFloat(x);
 		return Union.f;
 	}
-    
+
 	glm::uint f11_f11_f10(float x, float y, float z)
 	{
 		return ((floatTo11bit(x) & ((1 << 11) - 1)) << 0) |  ((floatTo11bit(y) & ((1 << 11) - 1)) << 11) | ((floatTo10bit(z) & ((1 << 10) - 1)) << 22);
@@ -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)));
-		detail::unorm1x8 Packing;
-		Packing.data = Scaled;
-		return Packing.pack;
+		return static_cast<uint8>(round(clamp(v, 0.0f, 1.0f) * 255.0f));
 	}
 	
-	GLM_FUNC_QUALIFIER float unpackUnorm1x8(uint8 p)
+	GLM_FUNC_QUALIFIER float unpackUnorm1x8(uint8 const & p)
 	{
-		detail::unorm1x8 Packing;
-		Packing.pack = p;
-		float Unpacked(Packing.data);
-		return Unpacked * float(0.0039215686274509803921568627451);
+		float Unpack(static_cast<float>(*const_cast<uint8*>(&p)));
+		return Unpack * float(0.0039215686274509803921568627451); // 1 / 255
 	}
 	
 	GLM_FUNC_QUALIFIER uint16 packUnorm2x8(vec2 const & v)
 	{
-		i8vec2 Scaled(round(clamp(v ,-1.0f, 1.0f) * 255.0f));
-		detail::unorm2x8 Packing;
-		Packing.data.x = Scaled.x;
-		Packing.data.y = Scaled.y;
-		return Packing.pack;
+		u8vec2 Topack(round(clamp(v, 0.0f, 1.0f) * 255.0f));
+		return *reinterpret_cast<uint16*>(&Topack);
 	}
 	
-	GLM_FUNC_QUALIFIER vec2 unpackUnorm2x8(uint16 p)
+	GLM_FUNC_QUALIFIER vec2 unpackUnorm2x8(uint16 const & p)
 	{
-		detail::unorm2x8 Packing;
-		Packing.pack = p;
-		vec2 Unpacked(Packing.data.x, Packing.data.y);
-		return Unpacked * float(0.0039215686274509803921568627451);
+		vec2 Unpack(*reinterpret_cast<u8vec2*>(const_cast<uint16*>(&p)));
+		return Unpack * float(0.0039215686274509803921568627451); // 1 / 255
 	}
 
 	GLM_FUNC_QUALIFIER uint8 packSnorm1x8(float const & v)
 	{
-		glm::int8 Scaled(int8(round(clamp(v ,-1.0f, 1.0f) * 127.0f)));
-		detail::snorm1x8 Packing;
-		Packing.data = Scaled;
-		return Packing.pack;
+		int8 Topack(static_cast<int8>(round(clamp(v ,-1.0f, 1.0f) * 127.0f)));
+		return *reinterpret_cast<uint8*>(&Topack);
 	}
 	
-	GLM_FUNC_QUALIFIER float unpackSnorm1x8(uint8 p)
+	GLM_FUNC_QUALIFIER float unpackSnorm1x8(uint8 const & p)
 	{
-		detail::snorm1x8 Packing;
-		Packing.pack = p;
-		float Unpacked(Packing.data);
-		return clamp(Unpacked * float(0.00787401574803149606299212598425), -1.0f, 1.0f);
+		float Unpack(static_cast<float>(*const_cast<uint8*>(&p)));
+		return clamp(
+			Unpack * 0.00787401574803149606299212598425f, // 1.0f / 127.0f
+			-1.0f, 1.0f);
 	}
 	
 	GLM_FUNC_QUALIFIER uint16 packSnorm2x8(vec2 const & v)
 	{
-		glm::i8vec2 Scaled(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
-		detail::snorm2x8 Packing;
-		Packing.data.x = Scaled.x;
-		Packing.data.y = Scaled.y;
-		return Packing.pack;
+		i8vec2 Topack(round(clamp(v ,-1.0f, 1.0f) * 127.0f));
+		return *reinterpret_cast<uint16*>(&Topack);
 	}
 	
-	GLM_FUNC_QUALIFIER vec2 unpackSnorm2x8(uint16 p)
+	GLM_FUNC_QUALIFIER vec2 unpackSnorm2x8(uint16 const & p)
 	{
-		detail::snorm2x8 Packing;
-		Packing.pack = p;
-		vec2 Unpacked(Packing.data.x, Packing.data.y);
-		return clamp(Unpacked * float(0.00787401574803149606299212598425), -1.0f, 1.0f);
+		vec2 Unpack(*reinterpret_cast<i8vec2*>(const_cast<uint16*>(&p)));
+		return clamp(
+			Unpack * 0.00787401574803149606299212598425f, // 1.0f / 127.0f
+			-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));
-		detail::unorm4x16 Packing;
-		Packing.data.x = Scaled[0];
-		Packing.data.y = Scaled[1];
-		Packing.data.z = Scaled[2];
-		Packing.data.w = Scaled[3];
-		return Packing.pack;
+		u16vec4 Topack(round(clamp(v , 0.0f, 1.0f) * 65535.0f));
+		return *reinterpret_cast<uint64*>(&Topack);
 	}
 
 	GLM_FUNC_QUALIFIER vec4 unpackUnorm4x16(uint64 const & p)
 	{
-		detail::unorm4x16 Packing;
-		vec4 Result(
-			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;
+		vec4 Unpack(*reinterpret_cast<u16vec4*>(const_cast<uint64*>(&p)));
+		return Unpack * 1.5259021896696421759365224689097e-5f; // 1.0 / 65535.0
 	}
 
-	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;
-		detail::snorm1x16 Packing;
-		Packing.data = detail::int16(Scaled);
-		return Packing.pack;
+		int16 Topack = static_cast<int16>(round(clamp(v ,-1.0f, 1.0f) * 32767.0f));
+		return *reinterpret_cast<uint16*>(&Topack);
 	}
 
-	GLM_FUNC_QUALIFIER float unpackSnorm1x16(uint16 p)
+	GLM_FUNC_QUALIFIER float unpackSnorm1x16(uint16 const & p)
 	{
-		detail::snorm1x16 Packing;
-		Packing.pack = p;
-		return clamp(float(Packing.data) * float(3.0518509475997192297128208258309e-5), -1.0f, 1.0f); //1.0f / 32767.0f
+		float Unpack = static_cast<float>(*const_cast<uint16*>(&p));
+		return clamp(
+			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);
-		detail::snorm4x16 Packing;
-		Packing.data.x = Scaled.x;
-		Packing.data.y = Scaled.y;
-		Packing.data.z = Scaled.z;
-		Packing.data.w = Scaled.w;
-		return Packing.pack;
+		i16vec4 Topack = static_cast<i16vec4>(round(clamp(v ,-1.0f, 1.0f) * 32767.0f));
+		return *reinterpret_cast<uint64*>(&Topack);
 	}
 
 	GLM_FUNC_QUALIFIER vec4 unpackSnorm4x16(uint64 const & p)
 	{
-		detail::snorm4x16 Packing;
-		Packing.pack = p;
-		vec4 Unpacked(Packing.data.x, Packing.data.y, Packing.data.z, Packing.data.w);
-		return clamp(Unpacked * float(3.0518509475997192297128208258309e-5), -1.0f, 1.0f); //1.0f / 32767.0f
+		vec4 Unpack(*reinterpret_cast<i16vec4*>(const_cast<uint64*>(&p)));
+		return clamp(
+			Unpack * 3.0518509475997192297128208258309e-5f, //1.0f / 32767.0f,
+			-1.0f, 1.0f);
 	}
 
 	GLM_FUNC_DECL uint16 packHalf1x16(float const & v)
 	{
-		detail::half1x16 Packing;
-		Packing.data = detail::toFloat16(v);
-		return Packing.pack;
+		int16 Topack = detail::toFloat16(v);
+		return *reinterpret_cast<uint16*>(&Topack);
 	}
 
 	GLM_FUNC_DECL float unpackHalf1x16(uint16 const & v)
 	{
-		detail::half1x16 Packing;
-		Packing.pack = v;
-		return detail::toFloat32(Packing.data);
+		int16 Unpack(*reinterpret_cast<int16*>(const_cast<uint16*>(&v)));
+		return detail::toFloat32(Unpack);
 	}
 
 	GLM_FUNC_DECL uint64 packHalf4x16(glm::vec4 const & v)
 	{
-		detail::half4x16 Packing;
-		Packing.data.x = detail::toFloat16(v.x);
-		Packing.data.y = detail::toFloat16(v.y);
-		Packing.data.z = detail::toFloat16(v.z);
-		Packing.data.w = detail::toFloat16(v.w);
-		return Packing.pack;
+		i16vec4 Unpack(
+			detail::toFloat16(v.x),
+			detail::toFloat16(v.y),
+			detail::toFloat16(v.z),
+			detail::toFloat16(v.w));
+
+		return *reinterpret_cast<uint64*>(&Unpack);
 	}
 
 	GLM_FUNC_DECL glm::vec4 unpackHalf4x16(uint64 const & v)
 	{
-		detail::half4x16 Packing;
-		Packing.pack = v;
-		return glm::vec4(
-			detail::toFloat32(Packing.data.x),
-			detail::toFloat32(Packing.data.y),
-			detail::toFloat32(Packing.data.z),
-			detail::toFloat32(Packing.data.w));
+		i16vec4 Unpack = *reinterpret_cast<i16vec4*>(const_cast<uint64*>(&v));
+	
+		return vec4(
+			detail::toFloat32(Unpack.x), 
+			detail::toFloat32(Unpack.y), 
+			detail::toFloat32(Unpack.z), 
+			detail::toFloat32(Unpack.w));
 	}
 
 	GLM_FUNC_QUALIFIER uint32 packI3x10_1x2(ivec4 const & v)
@@ -557,19 +446,19 @@ namespace detail
 	}
 
 	GLM_FUNC_QUALIFIER uint32 packF2x11_1x10(vec3 const & v)
-    {
-        return 
-            ((detail::floatTo11bit(v.x) & ((1 << 11) - 1)) <<  0) |
-            ((detail::floatTo11bit(v.y) & ((1 << 11) - 1)) << 11) |
-            ((detail::floatTo10bit(v.z) & ((1 << 10) - 1)) << 22);
-    }
-    
+	{
+		return 
+			((detail::floatTo11bit(v.x) & ((1 << 11) - 1)) <<  0) |
+			((detail::floatTo11bit(v.y) & ((1 << 11) - 1)) << 11) |
+			((detail::floatTo10bit(v.z) & ((1 << 10) - 1)) << 22);
+	}
+
 	GLM_FUNC_QUALIFIER vec3 unpackF2x11_1x10(uint32 const & v)
-    {
-    	return vec3(
-    		detail::packed11bitToFloat(v >> 0), 
-    		detail::packed11bitToFloat(v >> 11), 
-    		detail::packed10bitToFloat(v >> 22));
-    }
+	{
+		return vec3(
+			detail::packed11bitToFloat(v >> 0), 
+			detail::packed11bitToFloat(v >> 11), 
+			detail::packed10bitToFloat(v >> 22));
+	}
 
 }//namespace glm