+//-------------------------------------------------------------------------------------
+// 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
+//-------------------------------------------------------------------------------------
+
+#if defined(_MSC_VER) && (_MSC_VER > 1000)
+#pragma once
+#endif
+
+#include <assert.h>
+
+#ifdef USE_XNAMATH
+#include <xnamath.h>
+#else
+#include <directxmath.h>
+#include <directxpackedvector.h>
+#endif
+
+#include <float.h>
+
+#pragma warning(push)
+#pragma warning(disable : 4005)
+#include <stdint.h>
+#pragma warning(pop)
+
+namespace DirectX
+{
+
+#ifndef USE_XNAMATH
+typedef PackedVector::HALF HALF;
+typedef PackedVector::XMHALF4 XMHALF4;
+typedef PackedVector::XMU565 XMU565;
+#endif
+
+//-------------------------------------------------------------------------------------
+// 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 uint32_t BC67_WEIGHT_MAX = 64;
+const uint32_t BC67_WEIGHT_SHIFT = 6;
+const uint32_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() {}
+ 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_ 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_ 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_ size_t wcprec, _In_ size_t waprec, _Out_ LDRColorA& out)
+ {
+ InterpolateRGB(c0, c1, wc, wcprec, out);
+ InterpolateA(c0, c1, wa, waprec, out);
+ }
+};
+
+class HDRColorA
+{
+public:
+ float r, g, b, a;
+
+public:
+ HDRColorA() {}
+ 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;
+
+public:
+ INTColor() {}
+ 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)
+ {
+ 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_cap_c_(3) 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 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 HALF INT2F16(_In_ int input, _In_ bool bSigned)
+ {
+ 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;
+ }
+};
+
+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 ];
+};
+
+#pragma warning(push)
+#pragma warning(disable : 4127 4480 4512)
+
+// BC6H compression (16 bits per texel)
+class D3DX_BC6H : private CBits< 16 >
+{
+public:
+ void Decode(_In_ bool bSigned, _Out_cap_c_(NUM_PIXELS_PER_BLOCK) HDRColorA* pOut) const;
+ void Encode(_In_ bool bSigned, _In_count_c_(NUM_PIXELS_PER_BLOCK) const HDRColorA* const pIn);
+
+private:
+ enum EField : uint8_t
+ {
+ NA, // N/A
+ M, // Mode
+ D, // Shape
+ RW,
+ RX,
+ RY,
+ RZ,
+ GW,
+ GX,
+ GY,
+ GZ,
+ BW,
+ BX,
+ BY,
+ BZ,
+ };
+
+ 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];
+ };
+
+ 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);
+ }
+ }
+ };
+
+ 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_count_c_(BC6H_MAX_REGIONS) const INTEndPntPair aEndPts[]);
+
+ void GeneratePaletteQuantized(_In_ const EncodeParams* pEP, _In_ const INTEndPntPair& endPts,
+ _Out_cap_c_(BC6H_MAX_INDICES) INTColor aPalette[]) const;
+ float MapColorsQuantized(_In_ const EncodeParams* pEP, _In_count_(np) const INTColor aColors[], _In_ size_t np, _In_ const INTEndPntPair &endPts) const;
+ float PerturbOne(_In_ const EncodeParams* pEP, _In_count_(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_count_(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_count_c_(BC6H_MAX_REGIONS) const float aOrgErr[],
+ _In_count_c_(BC6H_MAX_REGIONS) const INTEndPntPair aOrgEndPts[],
+ _Inout_count_c_(BC6H_MAX_REGIONS) INTEndPntPair aOptEndPts[]) const;
+ static void SwapIndices(_In_ const EncodeParams* pEP, _Inout_count_c_(BC6H_MAX_REGIONS) INTEndPntPair aEndPts[],
+ _In_count_c_(NUM_PIXELS_PER_BLOCK) size_t aIndices[]);
+ void AssignIndices(_In_ const EncodeParams* pEP, _In_count_c_(BC6H_MAX_REGIONS) const INTEndPntPair aEndPts[],
+ _Out_cap_c_(NUM_PIXELS_PER_BLOCK) size_t aIndices[],
+ _Out_cap_c_(BC6H_MAX_REGIONS) float aTotErr[]) const;
+ void QuantizeEndPts(_In_ const EncodeParams* pEP, _Out_cap_c_(BC6H_MAX_REGIONS) INTEndPntPair* qQntEndPts) const;
+ void EmitBlock(_In_ const EncodeParams* pEP, _In_count_c_(BC6H_MAX_REGIONS) const INTEndPntPair aEndPts[],
+ _In_count_c_(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_cap_c_(BC6H_MAX_INDICES) INTColor aPalette[]);
+ float MapColors(_In_ const EncodeParams* pEP, _In_ size_t uRegion, _In_ size_t np, _In_count_(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_cap_c_(NUM_PIXELS_PER_BLOCK) HDRColorA* pOut) const;
+ void Encode(_In_count_c_(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;
+ };
+
+ 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) {}
+ };
+
+ 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_cap_c_(BC7_MAX_INDICES) LDRColorA aPalette[]) const;
+ float PerturbOne(_In_ const EncodeParams* pEP, _In_count_(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_count_(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_count_(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_count_c_(BC7_MAX_REGIONS) const float orig_err[],
+ _In_count_c_(BC7_MAX_REGIONS) const LDREndPntPair orig_endpts[],
+ _Out_cap_c_(BC7_MAX_REGIONS) LDREndPntPair opt_endpts[]) const;
+ void AssignIndices(_In_ const EncodeParams* pEP, _In_ size_t uShape, _In_ size_t uIndexMode,
+ _In_count_c_(BC7_MAX_REGIONS) LDREndPntPair endpts[],
+ _Out_cap_c_(NUM_PIXELS_PER_BLOCK) size_t aIndices[], _Out_cap_c_(NUM_PIXELS_PER_BLOCK) size_t aIndices2[],
+ _Out_cap_c_(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_count_c_(BC7_MAX_REGIONS) const LDREndPntPair aEndPts[],
+ _In_count_c_(NUM_PIXELS_PER_BLOCK) const size_t aIndex[],
+ _In_count_c_(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_count_(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[];
+};
+
+//-------------------------------------------------------------------------------------
+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_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(8) const uint8_t *pBC);
+void D3DXDecodeBC2(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+void D3DXDecodeBC3(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+void D3DXDecodeBC4U(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(8) const uint8_t *pBC);
+void D3DXDecodeBC4S(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(8) const uint8_t *pBC);
+void D3DXDecodeBC5U(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+void D3DXDecodeBC5S(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+void D3DXDecodeBC6HU(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+void D3DXDecodeBC6HS(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+void D3DXDecodeBC7(_Out_cap_c_(NUM_PIXELS_PER_BLOCK) XMVECTOR *pColor, _In_count_c_(16) const uint8_t *pBC);
+
+void D3DXEncodeBC1(_Out_cap_c_(8) uint8_t *pBC, _In_count_c_(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_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC3(_Out_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC4U(_Out_cap_c_(8) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC4S(_Out_cap_c_(8) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC5U(_Out_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC5S(_Out_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC6HU(_Out_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC6HS(_Out_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+void D3DXEncodeBC7(_Out_cap_c_(16) uint8_t *pBC, _In_count_c_(NUM_PIXELS_PER_BLOCK) const XMVECTOR *pColor, _In_ DWORD flags);
+
+}; // namespace