#ifndef UNITY_PACKING_INCLUDED

#define UNITY_PACKING_INCLUDED

//-----------------------------------------------------------------------------

// Normal packing

//-----------------------------------------------------------------------------

float3 PackNormalCartesian(float3 n)

{

return n * 0.5 + 0.5;

}

float3 UnpackNormalCartesian(float3 n)

{

return normalize(n * 2.0 - 1.0);

}

float3 PackNormalMaxComponent(float3 n)

{

// TODO: use max3

return (n / max(abs(n.x), max(abs(n.y), abs(n.z)))) * 0.5 + 0.5;

}

float3 UnpackNormalMaxComponent(float3 n)

{

return normalize(n * 2.0 - 1.0);

}

// Ref: http://jcgt.org/published/0003/02/01/paper.pdf

// Encode with Oct, this function work with any size of output

// return float between [-1, 1]

float2 PackNormalOctEncode(float3 n)

{

float l1norm = dot(abs(n), 1.0);

float2 res0 = n.xy * (1.0 / l1norm);

float2 val = 1.0 - abs(res0.yx);

return (n.zz < float2(0.0, 0.0) ? (res0 >= 0.0 ? val : -val) : res0);

}

float3 UnpackNormalOctEncode(float2 f)

{

float3 n = float3(f.x, f.y, 1.0 - abs(f.x) - abs(f.y));

float2 val = 1.0 - abs(n.yx);

n.xy = (n.zz < float2(0.0, 0.0) ? (n.xy >= 0.0 ? val : -val) : n.xy);

return normalize(n);

}

float3 UnpackNormalRGB(float4 packedNormal, float scale = 1.0)

{

float3 normal;

normal.xyz = packedNormal.rgb * 2.0 - 1.0;

normal.xy *= scale;

return normalize(normal);

}

float3 UnpackNormalAG(float4 packedNormal, float scale = 1.0)

{

float3 normal;

normal.xy = packedNormal.wy * 2.0 - 1.0;

normal.xy *= scale;

normal.z = sqrt(1.0 - saturate(dot(normal.xy, normal.xy)));

return normal;

}

// Unpack normal as DXT5nm (1, y, 0, x) or BC5 (x, y, 0, 1)

float3 UnpackNormalmapRGorAG(float4 packedNormal, float scale = 1.0)

{

// This do the trick

packedNormal.x *= packedNormal.w;

float3 normal;

normal.xy = packedNormal.xy * 2.0 - 1.0;

normal.xy *= scale;

normal.z = sqrt(1.0 - saturate(dot(normal.xy, normal.xy)));

return normal;

}

//-----------------------------------------------------------------------------

// HDR packing

//-----------------------------------------------------------------------------

// Ref: http://realtimecollisiondetection.net/blog/?p=15

float4 PackLogLuv(float3 vRGB)

{

// M matrix, for encoding

const float3x3 M = float3x3(

0.2209, 0.3390, 0.4184,

0.1138, 0.6780, 0.7319,

0.0102, 0.1130, 0.2969);

float4 vResult;

float3 Xp_Y_XYZp = mul(vRGB, M);

Xp_Y_XYZp = max(Xp_Y_XYZp, float3(1e-6, 1e-6, 1e-6));

vResult.xy = Xp_Y_XYZp.xy / Xp_Y_XYZp.z;

float Le = 2.0 * log2(Xp_Y_XYZp.y) + 127.0;

vResult.w = frac(Le);

vResult.z = (Le - (floor(vResult.w*255.0f)) / 255.0f) / 255.0f;

return vResult;

}

float3 UnpackLogLuv(float4 vLogLuv)

{

// Inverse M matrix, for decoding

const float3x3 InverseM = float3x3(

6.0014, -2.7008, -1.7996,

-1.3320, 3.1029, -5.7721,

0.3008, -1.0882, 5.6268);

float Le = vLogLuv.z * 255.0 + vLogLuv.w;

float3 Xp_Y_XYZp;

Xp_Y_XYZp.y = exp2((Le - 127.0) / 2.0);

Xp_Y_XYZp.z = Xp_Y_XYZp.y / vLogLuv.y;

Xp_Y_XYZp.x = vLogLuv.x * Xp_Y_XYZp.z;

float3 vRGB = mul(Xp_Y_XYZp, InverseM);

return max(vRGB, float3(0.0, 0.0, 0.0));

}

// The standard 32-bit HDR color format

uint PackR11G11B10f(float3 rgb)

{

uint r = (f32tof16(rgb.x) << 17) & 0xFFE00000;

uint g = (f32tof16(rgb.y) << 6) & 0x001FFC00;

uint b = (f32tof16(rgb.z) >> 5) & 0x000003FF;

return r | g | b;

}

float3 UnpackR11G11B10f(uint rgb)

{

float r = f16tof32((rgb >> 17) & 0x7FF0);

float g = f16tof32((rgb >> 6) & 0x7FF0);

float b = f16tof32((rgb << 5) & 0x7FE0);

return float3(r, g, b);

}

//-----------------------------------------------------------------------------

// Quaternion packing

//-----------------------------------------------------------------------------

// Ref: https://cedec.cesa.or.jp/2015/session/ENG/14698.html The Rendering Materials of Far Cry 4

/*

// This is GCN intrinsic

uint FindBiggestComponent(float4 q)

{

uint xyzIndex = CubeMapFaceID(q.x, q.y, q.z) * 0.5f;

uint wIndex = 3;

bool wBiggest = abs(q.w) > max3(abs(q.x), qbs(q.y), qbs(q.z));

return wBiggest ? wIndex : xyzIndex;

}

// Pack a quaternion into a 10:10:10:2

float4 PackQuat(float4 quat)

{

uint index = FindBiggestComponent(quat);

if (index == 0) quat = quat.yzwx;

if (index == 1) quat = quat.xzwy;

if (index == 2) quat = quat.xywz;

float4 packedQuat;

packedQuat.xyz = quat.xyz * sign(quat.w) * sqrt(0.5) + 0.5;

packedQuat.w = index / 3.0;

return packedQuat;

}

*/

// Unpack a quaternion from a 10:10:10:2

float4 UnpackQuat(float4 packedQuat)

{

uint index = (uint)(packedQuat.w * 3.0);

float4 quat;

quat.xyz = packedQuat.xyz * sqrt(2.0) - (1.0 / sqrt(2.0));

quat.w = sqrt(1.0 - saturate(dot(quat.xyz, quat.xyz)));

if (index == 0) quat = quat.wxyz;

if (index == 1) quat = quat.xwyz;

if (index == 2) quat = quat.xywz;

return quat;

}

//-----------------------------------------------------------------------------

// Byte packing

//-----------------------------------------------------------------------------

float Pack2Byte(float2 inputs)

{

float2 temp = inputs * float2(255.0, 255.0);

temp.x *= 256.0;

temp = round(temp);

float combined = temp.x + temp.y;

return combined * (1.0 / 65535.0);

}

float2 Unpack2Byte(float inputs)

{

float temp = round(inputs * 65535.0);

float ipart;

float fpart = modf(temp / 256.0, ipart);

float2 result = float2(ipart, round(256.0 * fpart));

return result * (1.0 / float2(255.0, 255.0));

}

// Encode a float in [0..1] and an int in [0..maxi - 1] as a float [0..1] to be store in log2(precision) bit

// maxi must be a power of two and define the number of bit dedicated 0..1 to the int part (log2(maxi))

// Example: precision is 256.0, maxi is 2, i is [0..1] encode on 1 bit. f is [0..1] encode on 7 bit.

// Example: precision is 256.0, maxi is 4, i is [0..3] encode on 2 bit. f is [0..1] encode on 6 bit.

// Example: precision is 256.0, maxi is 8, i is [0..7] encode on 3 bit. f is [0..1] encode on 5 bit.

// ...

// Example: precision is 1024.0, maxi is 8, i is [0..7] encode on 3 bit. f is [0..1] encode on 7 bit.

//...

float PackFloatInt(float f, int i, float maxi, float precision)

{

// Constant

float precisionMinusOne = precision - 1.0;

float t1 = ((precision / maxi) - 1.0) / precisionMinusOne;

float t2 = (precision / maxi) / precisionMinusOne;

return t1 * f + t2 * float(i);

}

void UnpackFloatInt(float val, float maxi, float precision, out float f, out int i)

{

// Constant

float precisionMinusOne = precision - 1.0;

float t1 = ((precision / maxi) - 1.0) / precisionMinusOne;

float t2 = (precision / maxi) / precisionMinusOne;

// extract integer part

i = int(val / t2);

// Now that we have i, solve formula in PackFloatInt for f

//f = (val - t2 * float(i)) / t1 => convert in mads form

f = (-t2 * float(i) + val) / t1;

}

// Define various variante for ease of read

float PackFloatInt8bit(float f, int i, float maxi)

{

return PackFloatInt(f, i, maxi, 255.0);

}

void UnpackFloatInt8bit(float val, float maxi, out float f, out int i)

{

UnpackFloatInt(val, maxi, 255.0, f, i);

}

float PackFloatInt10bit(float f, int i, float maxi)

{

return PackFloatInt(f, i, maxi, 1024.0);

}

void UnpackFloatInt10bit(float val, float maxi, out float f, out int i)

{

UnpackFloatInt(val, maxi, 1024.0, f, i);

}

float PackFloatInt16bit(float f, int i, float maxi)

{

return PackFloatInt(f, i, maxi, 65536.0);

}

void UnpackFloatInt16bit(float val, float maxi, out float f, out int i)

{

UnpackFloatInt(val, maxi, 65536.0, f, i);

}

//-----------------------------------------------------------------------------

// float packing to sint/uint

//-----------------------------------------------------------------------------

// src must be between 0.0 and 1.0

uint PackFloatToUInt(float src, uint size, uint offset)

{

const float maxValue = float((1u << size) - 1u) + 0.5; // Shader compiler should be able to remove this

return uint(src * maxValue) << offset;

}

float UnpackUIntToFloat(uint src, uint size, uint offset)

{

const float invMaxValue = 1.0 / float((1 << size) - 1);

return float(BitFieldExtract(src, size, offset)) * invMaxValue;

}

uint PackR10G10B10A2(float4 rgba)

{

return (PackFloatToUInt(rgba.x, 10, 0) | PackFloatToUInt(rgba.y, 10, 10) | PackFloatToUInt(rgba.z, 10, 20) | PackFloatToUInt(rgba.w, 2, 30));

}

float4 UnpackR10G10B10A2(uint rgba)

{

float4 ouput;

ouput.x = UnpackUIntToFloat(rgba, 10, 0);

ouput.y = UnpackUIntToFloat(rgba, 10, 10);

ouput.z = UnpackUIntToFloat(rgba, 10, 20);

ouput.w = UnpackUIntToFloat(rgba, 2, 30);

return ouput;

}

#endif // UNITY_PACKING_INCLUDED