crossxtex/DirectXTex/BC.h
2015-03-10 15:18:42 -07:00

891 lines
31 KiB
C++

//-------------------------------------------------------------------------------------
// BC.h
//
// Block-compression (BC) functionality
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// http://go.microsoft.com/fwlink/?LinkId=248926
//-------------------------------------------------------------------------------------
#pragma once
#include <assert.h>
#include <directxmath.h>
#include <directxpackedvector.h>
namespace DirectX
{
//-------------------------------------------------------------------------------------
// Constants
//-------------------------------------------------------------------------------------
const uint16_t F16S_MASK = 0x8000; // f16 sign mask
const uint16_t F16EM_MASK = 0x7fff; // f16 exp & mantissa mask
const uint16_t F16MAX = 0x7bff; // MAXFLT bit pattern for XMHALF
#define SIGN_EXTEND(x,nb) ((((x)&(1<<((nb)-1)))?((~0)<<(nb)):0)|(x))
// Because these are used in SAL annotations, they need to remain macros rather than const values
#define NUM_PIXELS_PER_BLOCK 16
#define BC6H_MAX_REGIONS 2
#define BC6H_MAX_INDICES 16
#define BC7_MAX_REGIONS 3
#define BC7_MAX_INDICES 16
const size_t BC6H_NUM_CHANNELS = 3;
const size_t BC6H_MAX_SHAPES = 32;
const size_t BC7_NUM_CHANNELS = 4;
const size_t BC7_MAX_SHAPES = 64;
const int32_t BC67_WEIGHT_MAX = 64;
const uint32_t BC67_WEIGHT_SHIFT = 6;
const int32_t BC67_WEIGHT_ROUND = 32;
extern const int g_aWeights2[4];
extern const int g_aWeights3[8];
extern const int g_aWeights4[16];
enum BC_FLAGS
{
BC_FLAGS_NONE = 0x0,
BC_FLAGS_DITHER_RGB = 0x10000, // Enables dithering for RGB colors for BC1-3
BC_FLAGS_DITHER_A = 0x20000, // Enables dithering for Alpha channel for BC1-3
BC_FLAGS_UNIFORM = 0x40000, // By default, uses perceptual weighting for BC1-3; this flag makes it a uniform weighting
};
//-------------------------------------------------------------------------------------
// Structures
//-------------------------------------------------------------------------------------
class HDRColorA;
class LDRColorA
{
public:
uint8_t r, g, b, a;
LDRColorA() DIRECTX_CTOR_DEFAULT
LDRColorA(uint8_t _r, uint8_t _g, uint8_t _b, uint8_t _a) : r(_r), g(_g), b(_b), a(_a) {}
const uint8_t& operator [] (_In_range_(0,3) size_t uElement) const
{
switch(uElement)
{
case 0: return r;
case 1: return g;
case 2: return b;
case 3: return a;
default: assert(false); return r;
}
}
uint8_t& operator [] (_In_range_(0,3) size_t uElement)
{
switch(uElement)
{
case 0: return r;
case 1: return g;
case 2: return b;
case 3: return a;
default: assert(false); return r;
}
}
LDRColorA operator = (_In_ const HDRColorA& c);
static void InterpolateRGB(_In_ const LDRColorA& c0, _In_ const LDRColorA& c1, _In_ size_t wc, _In_ _In_range_(2, 4) size_t wcprec, _Out_ LDRColorA& out)
{
const int* aWeights = nullptr;
switch(wcprec)
{
case 2: aWeights = g_aWeights2; assert( wc < 4 ); _Analysis_assume_( wc < 4 ); break;
case 3: aWeights = g_aWeights3; assert( wc < 8 ); _Analysis_assume_( wc < 8 ); break;
case 4: aWeights = g_aWeights4; assert( wc < 16 ); _Analysis_assume_( wc < 16 ); break;
default: assert(false); out.r = out.g = out.b = 0; return;
}
out.r = uint8_t((uint32_t(c0.r) * uint32_t(BC67_WEIGHT_MAX - aWeights[wc]) + uint32_t(c1.r) * uint32_t(aWeights[wc]) + BC67_WEIGHT_ROUND) >> BC67_WEIGHT_SHIFT);
out.g = uint8_t((uint32_t(c0.g) * uint32_t(BC67_WEIGHT_MAX - aWeights[wc]) + uint32_t(c1.g) * uint32_t(aWeights[wc]) + BC67_WEIGHT_ROUND) >> BC67_WEIGHT_SHIFT);
out.b = uint8_t((uint32_t(c0.b) * uint32_t(BC67_WEIGHT_MAX - aWeights[wc]) + uint32_t(c1.b) * uint32_t(aWeights[wc]) + BC67_WEIGHT_ROUND) >> BC67_WEIGHT_SHIFT);
}
static void InterpolateA(_In_ const LDRColorA& c0, _In_ const LDRColorA& c1, _In_ size_t wa, _In_range_(2, 4) _In_ size_t waprec, _Out_ LDRColorA& out)
{
const int* aWeights = nullptr;
switch(waprec)
{
case 2: aWeights = g_aWeights2; assert( wa < 4 ); _Analysis_assume_( wa < 4 ); break;
case 3: aWeights = g_aWeights3; assert( wa < 8 ); _Analysis_assume_( wa < 8 ); break;
case 4: aWeights = g_aWeights4; assert( wa < 16 ); _Analysis_assume_( wa < 16 ); break;
default: assert(false); out.a = 0; return;
}
out.a = uint8_t((uint32_t(c0.a) * uint32_t(BC67_WEIGHT_MAX - aWeights[wa]) + uint32_t(c1.a) * uint32_t(aWeights[wa]) + BC67_WEIGHT_ROUND) >> BC67_WEIGHT_SHIFT);
}
static void Interpolate(_In_ const LDRColorA& c0, _In_ const LDRColorA& c1, _In_ size_t wc, _In_ size_t wa, _In_ _In_range_(2, 4) size_t wcprec, _In_ _In_range_(2, 4) size_t waprec, _Out_ LDRColorA& out)
{
InterpolateRGB(c0, c1, wc, wcprec, out);
InterpolateA(c0, c1, wa, waprec, out);
}
};
static_assert( sizeof(LDRColorA) == 4, "Unexpected packing");
class HDRColorA
{
public:
float r, g, b, a;
public:
HDRColorA() DIRECTX_CTOR_DEFAULT
HDRColorA(float _r, float _g, float _b, float _a) : r(_r), g(_g), b(_b), a(_a) {}
HDRColorA(const HDRColorA& c) : r(c.r), g(c.g), b(c.b), a(c.a) {}
HDRColorA(const LDRColorA& c)
{
r = float(c.r) * (1.0f/255.0f);
g = float(c.g) * (1.0f/255.0f);
b = float(c.b) * (1.0f/255.0f);
a = float(c.a) * (1.0f/255.0f);
}
// binary operators
HDRColorA operator + ( _In_ const HDRColorA& c ) const
{
return HDRColorA(r + c.r, g + c.g, b + c.b, a + c.a);
}
HDRColorA operator - ( _In_ const HDRColorA& c ) const
{
return HDRColorA(r - c.r, g - c.g, b - c.b, a - c.a);
}
HDRColorA operator * ( _In_ float f ) const
{
return HDRColorA(r * f, g * f, b * f, a * f);
}
HDRColorA operator / ( _In_ float f ) const
{
float fInv = 1.0f / f;
return HDRColorA(r * fInv, g * fInv, b * fInv, a * fInv);
}
float operator * ( _In_ const HDRColorA& c ) const
{
return r * c.r + g * c.g + b * c.b + a * c.a;
}
// assignment operators
HDRColorA& operator += ( _In_ const HDRColorA& c )
{
r += c.r;
g += c.g;
b += c.b;
a += c.a;
return *this;
}
HDRColorA& operator -= ( _In_ const HDRColorA& c )
{
r -= c.r;
g -= c.g;
b -= c.b;
a -= c.a;
return *this;
}
HDRColorA& operator *= ( _In_ float f )
{
r *= f;
g *= f;
b *= f;
a *= f;
return *this;
}
HDRColorA& operator /= ( _In_ float f )
{
float fInv = 1.0f / f;
r *= fInv;
g *= fInv;
b *= fInv;
a *= fInv;
return *this;
}
HDRColorA& operator = (_In_ const LDRColorA& c)
{
r = (float) c.r;
g = (float) c.g;
b = (float) c.b;
a = (float) c.a;
return *this;
}
HDRColorA& Clamp(_In_ float fMin, _In_ float fMax)
{
r = std::min<float>(fMax, std::max<float>(fMin, r));
g = std::min<float>(fMax, std::max<float>(fMin, g));
b = std::min<float>(fMax, std::max<float>(fMin, b));
a = std::min<float>(fMax, std::max<float>(fMin, a));
return *this;
}
LDRColorA ToLDRColorA() const
{
return LDRColorA((uint8_t) (r + 0.01f), (uint8_t) (g + 0.01f), (uint8_t) (b + 0.01f), (uint8_t) (a + 0.01f));
}
};
inline LDRColorA LDRColorA::operator = (_In_ const HDRColorA& c)
{
LDRColorA ret;
HDRColorA tmp(c);
tmp = tmp.Clamp(0.0f, 1.0f) * 255.0f;
ret.r = uint8_t(tmp.r + 0.001f);
ret.g = uint8_t(tmp.g + 0.001f);
ret.b = uint8_t(tmp.b + 0.001f);
ret.a = uint8_t(tmp.a + 0.001f);
return ret;
}
struct LDREndPntPair
{
LDRColorA A;
LDRColorA B;
};
struct HDREndPntPair
{
HDRColorA A;
HDRColorA B;
};
inline HDRColorA* HDRColorALerp(_Out_ HDRColorA *pOut, _In_ const HDRColorA *pC1, _In_ const HDRColorA *pC2, _In_ float s)
{
pOut->r = pC1->r + s * (pC2->r - pC1->r);
pOut->g = pC1->g + s * (pC2->g - pC1->g);
pOut->b = pC1->b + s * (pC2->b - pC1->b);
pOut->a = pC1->a + s * (pC2->a - pC1->a);
return pOut;
}
#pragma pack(push,1)
// BC1/DXT1 compression (4 bits per texel)
struct D3DX_BC1
{
uint16_t rgb[2]; // 565 colors
uint32_t bitmap; // 2bpp rgb bitmap
};
// BC2/DXT2/3 compression (8 bits per texel)
struct D3DX_BC2
{
uint32_t bitmap[2]; // 4bpp alpha bitmap
D3DX_BC1 bc1; // BC1 rgb data
};
// BC3/DXT4/5 compression (8 bits per texel)
struct D3DX_BC3
{
uint8_t alpha[2]; // alpha values
uint8_t bitmap[6]; // 3bpp alpha bitmap
D3DX_BC1 bc1; // BC1 rgb data
};
#pragma pack(pop)
class INTColor
{
public:
int r, g, b;
int pad;
public:
INTColor() DIRECTX_CTOR_DEFAULT
INTColor(int nr, int ng, int nb) {r = nr; g = ng; b = nb;}
INTColor(const INTColor& c) {r = c.r; g = c.g; b = c.b;}
INTColor operator - ( _In_ const INTColor& c ) const
{
return INTColor(r - c.r, g - c.g, b - c.b);
}
INTColor& operator += ( _In_ const INTColor& c )
{
r += c.r;
g += c.g;
b += c.b;
return *this;
}
INTColor& operator -= ( _In_ const INTColor& c )
{
r -= c.r;
g -= c.g;
b -= c.b;
return *this;
}
INTColor& operator &= ( _In_ const INTColor& c )
{
r &= c.r;
g &= c.g;
b &= c.b;
return *this;
}
int& operator [] ( _In_ uint8_t i )
{
assert(i < sizeof(INTColor) / sizeof(int));
_Analysis_assume_(i < sizeof(INTColor) / sizeof(int));
return ((int*) this)[i];
}
void Set(_In_ const HDRColorA& c, _In_ bool bSigned)
{
PackedVector::XMHALF4 aF16;
XMVECTOR v = XMLoadFloat4( (const XMFLOAT4*)& c );
XMStoreHalf4( &aF16, v );
r = F16ToINT(aF16.x, bSigned);
g = F16ToINT(aF16.y, bSigned);
b = F16ToINT(aF16.z, bSigned);
}
INTColor& Clamp(_In_ int iMin, _In_ int iMax)
{
r = std::min<int>(iMax, std::max<int>(iMin, r));
g = std::min<int>(iMax, std::max<int>(iMin, g));
b = std::min<int>(iMax, std::max<int>(iMin, b));
return *this;
}
INTColor& SignExtend(_In_ const LDRColorA& Prec)
{
r = SIGN_EXTEND(r, Prec.r);
g = SIGN_EXTEND(g, Prec.g);
b = SIGN_EXTEND(b, Prec.b);
return *this;
}
void ToF16(_Out_writes_(3) PackedVector::HALF aF16[3], _In_ bool bSigned) const
{
aF16[0] = INT2F16(r, bSigned);
aF16[1] = INT2F16(g, bSigned);
aF16[2] = INT2F16(b, bSigned);
}
private:
static int F16ToINT(_In_ const PackedVector::HALF& f, _In_ bool bSigned)
{
uint16_t input = *((const uint16_t*) &f);
int out, s;
if(bSigned)
{
s = input & F16S_MASK;
input &= F16EM_MASK;
if(input > F16MAX) out = F16MAX;
else out = input;
out = s ? -out : out;
}
else
{
if(input & F16S_MASK) out = 0;
else out = input;
}
return out;
}
static PackedVector::HALF INT2F16(_In_ int input, _In_ bool bSigned)
{
PackedVector::HALF h;
uint16_t out;
if(bSigned)
{
int s = 0;
if(input < 0)
{
s = F16S_MASK;
input = -input;
}
out = uint16_t(s | input);
}
else
{
assert(input >= 0 && input <= F16MAX);
out = (uint16_t) input;
}
*((uint16_t*) &h) = out;
return h;
}
};
static_assert( sizeof(INTColor) == 16, "Unexpected packing");
struct INTEndPntPair
{
INTColor A;
INTColor B;
};
template< size_t SizeInBytes >
class CBits
{
public:
uint8_t GetBit(_Inout_ size_t& uStartBit) const
{
assert(uStartBit < 128);
_Analysis_assume_(uStartBit < 128);
size_t uIndex = uStartBit >> 3;
uint8_t ret = (m_uBits[uIndex] >> (uStartBit - (uIndex << 3))) & 0x01;
uStartBit++;
return ret;
}
uint8_t GetBits(_Inout_ size_t& uStartBit, _In_ size_t uNumBits) const
{
if(uNumBits == 0) return 0;
assert(uStartBit + uNumBits <= 128 && uNumBits <= 8);
_Analysis_assume_(uStartBit + uNumBits <= 128 && uNumBits <= 8);
uint8_t ret;
size_t uIndex = uStartBit >> 3;
size_t uBase = uStartBit - (uIndex << 3);
if(uBase + uNumBits > 8)
{
size_t uFirstIndexBits = 8 - uBase;
size_t uNextIndexBits = uNumBits - uFirstIndexBits;
ret = (m_uBits[uIndex] >> uBase) | ((m_uBits[uIndex+1] & ((1 << uNextIndexBits) - 1)) << uFirstIndexBits);
}
else
{
ret = (m_uBits[uIndex] >> uBase) & ((1 << uNumBits) - 1);
}
assert(ret < (1 << uNumBits));
uStartBit += uNumBits;
return ret;
}
void SetBit(_Inout_ size_t& uStartBit, _In_ uint8_t uValue)
{
assert(uStartBit < 128 && uValue < 2);
_Analysis_assume_(uStartBit < 128 && uValue < 2);
size_t uIndex = uStartBit >> 3;
size_t uBase = uStartBit - (uIndex << 3);
m_uBits[uIndex] &= ~(1 << uBase);
m_uBits[uIndex] |= uValue << uBase;
uStartBit++;
}
void SetBits(_Inout_ size_t& uStartBit, _In_ size_t uNumBits, _In_ uint8_t uValue)
{
if(uNumBits == 0)
return;
assert(uStartBit + uNumBits <= 128 && uNumBits <= 8);
_Analysis_assume_(uStartBit + uNumBits <= 128 && uNumBits <= 8);
assert(uValue < (1 << uNumBits));
size_t uIndex = uStartBit >> 3;
size_t uBase = uStartBit - (uIndex << 3);
if(uBase + uNumBits > 8)
{
size_t uFirstIndexBits = 8 - uBase;
size_t uNextIndexBits = uNumBits - uFirstIndexBits;
m_uBits[uIndex] &= ~(((1 << uFirstIndexBits) - 1) << uBase);
m_uBits[uIndex] |= uValue << uBase;
m_uBits[uIndex+1] &= ~((1 << uNextIndexBits) - 1);
m_uBits[uIndex+1] |= uValue >> uFirstIndexBits;
}
else
{
m_uBits[uIndex] &= ~(((1 << uNumBits) - 1) << uBase);
m_uBits[uIndex] |= uValue << uBase;
}
uStartBit += uNumBits;
}
private:
uint8_t m_uBits[ SizeInBytes ];
};
// BC6H compression (16 bits per texel)
class D3DX_BC6H : private CBits< 16 >
{
public:
void Decode(_In_ bool bSigned, _Out_writes_(NUM_PIXELS_PER_BLOCK) HDRColorA* pOut) const;
void Encode(_In_ bool bSigned, _In_reads_(NUM_PIXELS_PER_BLOCK) const HDRColorA* const pIn);
private:
#pragma warning(push)
#pragma warning(disable : 4480)
enum EField : uint8_t
{
NA, // N/A
M, // Mode
D, // Shape
RW,
RX,
RY,
RZ,
GW,
GX,
GY,
GZ,
BW,
BX,
BY,
BZ,
};
#pragma warning(pop)
struct ModeDescriptor
{
EField m_eField;
uint8_t m_uBit;
};
struct ModeInfo
{
uint8_t uMode;
uint8_t uPartitions;
bool bTransformed;
uint8_t uIndexPrec;
LDRColorA RGBAPrec[BC6H_MAX_REGIONS][2];
};
#pragma warning(push)
#pragma warning(disable : 4512)
struct EncodeParams
{
float fBestErr;
const bool bSigned;
uint8_t uMode;
uint8_t uShape;
const HDRColorA* const aHDRPixels;
INTEndPntPair aUnqEndPts[BC6H_MAX_SHAPES][BC6H_MAX_REGIONS];
INTColor aIPixels[NUM_PIXELS_PER_BLOCK];
EncodeParams(const HDRColorA* const aOriginal, bool bSignedFormat) :
aHDRPixels(aOriginal), fBestErr(FLT_MAX), bSigned(bSignedFormat)
{
for(size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
{
aIPixels[i].Set(aOriginal[i], bSigned);
}
}
};
#pragma warning(pop)
static int Quantize(_In_ int iValue, _In_ int prec, _In_ bool bSigned);
static int Unquantize(_In_ int comp, _In_ uint8_t uBitsPerComp, _In_ bool bSigned);
static int FinishUnquantize(_In_ int comp, _In_ bool bSigned);
static bool EndPointsFit(_In_ const EncodeParams* pEP, _In_reads_(BC6H_MAX_REGIONS) const INTEndPntPair aEndPts[]);
void GeneratePaletteQuantized(_In_ const EncodeParams* pEP, _In_ const INTEndPntPair& endPts,
_Out_writes_(BC6H_MAX_INDICES) INTColor aPalette[]) const;
float MapColorsQuantized(_In_ const EncodeParams* pEP, _In_reads_(np) const INTColor aColors[], _In_ size_t np, _In_ const INTEndPntPair &endPts) const;
float PerturbOne(_In_ const EncodeParams* pEP, _In_reads_(np) const INTColor aColors[], _In_ size_t np, _In_ uint8_t ch,
_In_ const INTEndPntPair& oldEndPts, _Out_ INTEndPntPair& newEndPts, _In_ float fOldErr, _In_ int do_b) const;
void OptimizeOne(_In_ const EncodeParams* pEP, _In_reads_(np) const INTColor aColors[], _In_ size_t np, _In_ float aOrgErr,
_In_ const INTEndPntPair &aOrgEndPts, _Out_ INTEndPntPair &aOptEndPts) const;
void OptimizeEndPoints(_In_ const EncodeParams* pEP, _In_reads_(BC6H_MAX_REGIONS) const float aOrgErr[],
_In_reads_(BC6H_MAX_REGIONS) const INTEndPntPair aOrgEndPts[],
_Out_writes_all_(BC6H_MAX_REGIONS) INTEndPntPair aOptEndPts[]) const;
static void SwapIndices(_In_ const EncodeParams* pEP, _Inout_updates_all_(BC6H_MAX_REGIONS) INTEndPntPair aEndPts[],
_In_reads_(NUM_PIXELS_PER_BLOCK) size_t aIndices[]);
void AssignIndices(_In_ const EncodeParams* pEP, _In_reads_(BC6H_MAX_REGIONS) const INTEndPntPair aEndPts[],
_Out_writes_(NUM_PIXELS_PER_BLOCK) size_t aIndices[],
_Out_writes_(BC6H_MAX_REGIONS) float aTotErr[]) const;
void QuantizeEndPts(_In_ const EncodeParams* pEP, _Out_writes_(BC6H_MAX_REGIONS) INTEndPntPair* qQntEndPts) const;
void EmitBlock(_In_ const EncodeParams* pEP, _In_reads_(BC6H_MAX_REGIONS) const INTEndPntPair aEndPts[],
_In_reads_(NUM_PIXELS_PER_BLOCK) const size_t aIndices[]);
void Refine(_Inout_ EncodeParams* pEP);
static void GeneratePaletteUnquantized(_In_ const EncodeParams* pEP, _In_ size_t uRegion, _Out_writes_(BC6H_MAX_INDICES) INTColor aPalette[]);
float MapColors(_In_ const EncodeParams* pEP, _In_ size_t uRegion, _In_ size_t np, _In_reads_(np) const size_t* auIndex) const;
float RoughMSE(_Inout_ EncodeParams* pEP) const;
private:
const static ModeDescriptor ms_aDesc[][82];
const static ModeInfo ms_aInfo[];
const static int ms_aModeToInfo[];
};
// BC67 compression (16b bits per texel)
class D3DX_BC7 : private CBits< 16 >
{
public:
void Decode(_Out_writes_(NUM_PIXELS_PER_BLOCK) HDRColorA* pOut) const;
void Encode(_In_reads_(NUM_PIXELS_PER_BLOCK) const HDRColorA* const pIn);
private:
struct ModeInfo
{
uint8_t uPartitions;
uint8_t uPartitionBits;
uint8_t uPBits;
uint8_t uRotationBits;
uint8_t uIndexModeBits;
uint8_t uIndexPrec;
uint8_t uIndexPrec2;
LDRColorA RGBAPrec;
LDRColorA RGBAPrecWithP;
};
#pragma warning(push)
#pragma warning(disable : 4512)
struct EncodeParams
{
uint8_t uMode;
LDREndPntPair aEndPts[BC7_MAX_SHAPES][BC7_MAX_REGIONS];
LDRColorA aLDRPixels[NUM_PIXELS_PER_BLOCK];
const HDRColorA* const aHDRPixels;
EncodeParams(const HDRColorA* const aOriginal) : aHDRPixels(aOriginal) {}
};
#pragma warning(pop)
static uint8_t Quantize(_In_ uint8_t comp, _In_ uint8_t uPrec)
{
assert(0 < uPrec && uPrec <= 8);
uint8_t rnd = (uint8_t) std::min<uint16_t>(255, uint16_t(comp) + (1 << (7 - uPrec)));
return rnd >> (8 - uPrec);
}
static LDRColorA Quantize(_In_ const LDRColorA& c, _In_ const LDRColorA& RGBAPrec)
{
LDRColorA q;
q.r = Quantize(c.r, RGBAPrec.r);
q.g = Quantize(c.g, RGBAPrec.g);
q.b = Quantize(c.b, RGBAPrec.b);
if(RGBAPrec.a)
q.a = Quantize(c.a, RGBAPrec.a);
else
q.a = 255;
return q;
}
static uint8_t Unquantize(_In_ uint8_t comp, _In_ size_t uPrec)
{
assert(0 < uPrec && uPrec <= 8);
comp = comp << (8 - uPrec);
return comp | (comp >> uPrec);
}
static LDRColorA Unquantize(_In_ const LDRColorA& c, _In_ const LDRColorA& RGBAPrec)
{
LDRColorA q;
q.r = Unquantize(c.r, RGBAPrec.r);
q.g = Unquantize(c.g, RGBAPrec.g);
q.b = Unquantize(c.b, RGBAPrec.b);
q.a = RGBAPrec.a > 0 ? Unquantize(c.a, RGBAPrec.a) : 255;
return q;
}
void GeneratePaletteQuantized(_In_ const EncodeParams* pEP, _In_ size_t uIndexMode, _In_ const LDREndPntPair& endpts,
_Out_writes_(BC7_MAX_INDICES) LDRColorA aPalette[]) const;
float PerturbOne(_In_ const EncodeParams* pEP, _In_reads_(np) const LDRColorA colors[], _In_ size_t np, _In_ size_t uIndexMode,
_In_ size_t ch, _In_ const LDREndPntPair &old_endpts,
_Out_ LDREndPntPair &new_endpts, _In_ float old_err, _In_ uint8_t do_b) const;
void Exhaustive(_In_ const EncodeParams* pEP, _In_reads_(np) const LDRColorA aColors[], _In_ size_t np, _In_ size_t uIndexMode,
_In_ size_t ch, _Inout_ float& fOrgErr, _Inout_ LDREndPntPair& optEndPt) const;
void OptimizeOne(_In_ const EncodeParams* pEP, _In_reads_(np) const LDRColorA colors[], _In_ size_t np, _In_ size_t uIndexMode,
_In_ float orig_err, _In_ const LDREndPntPair &orig_endpts, _Out_ LDREndPntPair &opt_endpts) const;
void OptimizeEndPoints(_In_ const EncodeParams* pEP, _In_ size_t uShape, _In_ size_t uIndexMode,
_In_reads_(BC7_MAX_REGIONS) const float orig_err[],
_In_reads_(BC7_MAX_REGIONS) const LDREndPntPair orig_endpts[],
_Out_writes_(BC7_MAX_REGIONS) LDREndPntPair opt_endpts[]) const;
void AssignIndices(_In_ const EncodeParams* pEP, _In_ size_t uShape, _In_ size_t uIndexMode,
_In_reads_(BC7_MAX_REGIONS) LDREndPntPair endpts[],
_Out_writes_(NUM_PIXELS_PER_BLOCK) size_t aIndices[], _Out_writes_(NUM_PIXELS_PER_BLOCK) size_t aIndices2[],
_Out_writes_(BC7_MAX_REGIONS) float afTotErr[]) const;
void EmitBlock(_In_ const EncodeParams* pEP, _In_ size_t uShape, _In_ size_t uRotation, _In_ size_t uIndexMode,
_In_reads_(BC7_MAX_REGIONS) const LDREndPntPair aEndPts[],
_In_reads_(NUM_PIXELS_PER_BLOCK) const size_t aIndex[],
_In_reads_(NUM_PIXELS_PER_BLOCK) const size_t aIndex2[]);
float Refine(_In_ const EncodeParams* pEP, _In_ size_t uShape, _In_ size_t uRotation, _In_ size_t uIndexMode);
float MapColors(_In_ const EncodeParams* pEP, _In_reads_(np) const LDRColorA aColors[], _In_ size_t np, _In_ size_t uIndexMode,
_In_ const LDREndPntPair& endPts, _In_ float fMinErr) const;
static float RoughMSE(_Inout_ EncodeParams* pEP, _In_ size_t uShape, _In_ size_t uIndexMode);
private:
const static ModeInfo ms_aInfo[];
};
//-------------------------------------------------------------------------------------
#pragma warning(push)
#pragma warning(disable : 4127)
template <bool bRange> void OptimizeAlpha(float *pX, float *pY, const float *pPoints, size_t cSteps)
{
static const float pC6[] = { 5.0f/5.0f, 4.0f/5.0f, 3.0f/5.0f, 2.0f/5.0f, 1.0f/5.0f, 0.0f/5.0f };
static const float pD6[] = { 0.0f/5.0f, 1.0f/5.0f, 2.0f/5.0f, 3.0f/5.0f, 4.0f/5.0f, 5.0f/5.0f };
static const float pC8[] = { 7.0f/7.0f, 6.0f/7.0f, 5.0f/7.0f, 4.0f/7.0f, 3.0f/7.0f, 2.0f/7.0f, 1.0f/7.0f, 0.0f/7.0f };
static const float pD8[] = { 0.0f/7.0f, 1.0f/7.0f, 2.0f/7.0f, 3.0f/7.0f, 4.0f/7.0f, 5.0f/7.0f, 6.0f/7.0f, 7.0f/7.0f };
const float *pC = (6 == cSteps) ? pC6 : pC8;
const float *pD = (6 == cSteps) ? pD6 : pD8;
float MAX_VALUE = 1.0f;
float MIN_VALUE;
if (bRange)
{
MIN_VALUE = -1.0f;
}
else
{
MIN_VALUE = 0.0f;
}
// Find Min and Max points, as starting point
float fX = MAX_VALUE;
float fY = MIN_VALUE;
if(8 == cSteps)
{
for(size_t iPoint = 0; iPoint < NUM_PIXELS_PER_BLOCK; iPoint++)
{
if(pPoints[iPoint] < fX)
fX = pPoints[iPoint];
if(pPoints[iPoint] > fY)
fY = pPoints[iPoint];
}
}
else
{
for(size_t iPoint = 0; iPoint < NUM_PIXELS_PER_BLOCK; iPoint++)
{
if(pPoints[iPoint] < fX && pPoints[iPoint] > MIN_VALUE)
fX = pPoints[iPoint];
if(pPoints[iPoint] > fY && pPoints[iPoint] < MAX_VALUE)
fY = pPoints[iPoint];
}
if (fX == fY)
{
fY = MAX_VALUE;
}
}
// Use Newton's Method to find local minima of sum-of-squares error.
float fSteps = (float) (cSteps - 1);
for(size_t iIteration = 0; iIteration < 8; iIteration++)
{
float fScale;
if((fY - fX) < (1.0f / 256.0f))
break;
fScale = fSteps / (fY - fX);
// Calculate new steps
float pSteps[8];
for(size_t iStep = 0; iStep < cSteps; iStep++)
pSteps[iStep] = pC[iStep] * fX + pD[iStep] * fY;
if(6 == cSteps)
{
pSteps[6] = MIN_VALUE;
pSteps[7] = MAX_VALUE;
}
// Evaluate function, and derivatives
float dX = 0.0f;
float dY = 0.0f;
float d2X = 0.0f;
float d2Y = 0.0f;
for(size_t iPoint = 0; iPoint < NUM_PIXELS_PER_BLOCK; iPoint++)
{
float fDot = (pPoints[iPoint] - fX) * fScale;
size_t iStep;
if(fDot <= 0.0f)
iStep = ((6 == cSteps) && (pPoints[iPoint] <= fX * 0.5f)) ? 6 : 0;
else if(fDot >= fSteps)
iStep = ((6 == cSteps) && (pPoints[iPoint] >= (fY + 1.0f) * 0.5f)) ? 7 : (cSteps - 1);
else
iStep = static_cast<int32_t>(fDot + 0.5f);
if(iStep < cSteps)
{
// D3DX had this computation backwards (pPoints[iPoint] - pSteps[iStep])
// this fix improves RMS of the alpha component
float fDiff = pSteps[iStep] - pPoints[iPoint];
dX += pC[iStep] * fDiff;
d2X += pC[iStep] * pC[iStep];
dY += pD[iStep] * fDiff;
d2Y += pD[iStep] * pD[iStep];
}
}
// Move endpoints
if(d2X > 0.0f)
fX -= dX / d2X;
if(d2Y > 0.0f)
fY -= dY / d2Y;
if(fX > fY)
{
float f = fX; fX = fY; fY = f;
}
if((dX * dX < (1.0f / 64.0f)) && (dY * dY < (1.0f / 64.0f)))
break;
}
*pX = (fX < MIN_VALUE) ? MIN_VALUE : (fX > MAX_VALUE) ? MAX_VALUE : fX;
*pY = (fY < MIN_VALUE) ? MIN_VALUE : (fY > MAX_VALUE) ? MAX_VALUE : fY;
}
#pragma warning(pop)
//-------------------------------------------------------------------------------------
// Functions
//-------------------------------------------------------------------------------------
typedef void (*BC_DECODE)(XMVECTOR *pColor, const uint8_t *pBC);
typedef void (*BC_ENCODE)(uint8_t *pDXT, const XMVECTOR *pColor, DWORD flags);
void D3DXDecodeBC1(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(8) const uint8_t *pBC);
void D3DXDecodeBC2(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXDecodeBC3(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXDecodeBC4U(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(8) const uint8_t *pBC);
void D3DXDecodeBC4S(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(8) const uint8_t *pBC);
void D3DXDecodeBC5U(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXDecodeBC5S(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXDecodeBC6HU(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXDecodeBC6HS(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXDecodeBC7(_Out_writes_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_reads_(16) const uint8_t *pBC);
void D3DXEncodeBC1(_Out_writes_(8) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ float alphaRef, _In_ DWORD flags);
// BC1 requires one additional parameter, so it doesn't match signature of BC_ENCODE above
void D3DXEncodeBC2(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC3(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC4U(_Out_writes_(8) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC4S(_Out_writes_(8) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC5U(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC5S(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC6HU(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC6HS(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
void D3DXEncodeBC7(_Out_writes_(16) uint8_t *pBC, _In_reads_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
}; // namespace