563 lines
17 KiB
C++
563 lines
17 KiB
C++
//-------------------------------------------------------------------------------------
|
|
// BC4BC5.cpp
|
|
//
|
|
// Block-compression (BC) functionality for BC4 and BC5 (DirectX 10 texture compression)
|
|
//
|
|
// Copyright (c) Microsoft Corporation. All rights reserved.
|
|
// Licensed under the MIT License.
|
|
//
|
|
// http://go.microsoft.com/fwlink/?LinkId=248926
|
|
//-------------------------------------------------------------------------------------
|
|
|
|
#include "DirectXTexP.h"
|
|
|
|
#include "BC.h"
|
|
|
|
using namespace DirectX;
|
|
|
|
//------------------------------------------------------------------------------------
|
|
// Constants
|
|
//------------------------------------------------------------------------------------
|
|
|
|
// Because these are used in SAL annotations, they need to remain macros rather than const values
|
|
#define BLOCK_LEN 4
|
|
// length of each block in texel
|
|
|
|
#define BLOCK_SIZE (BLOCK_LEN * BLOCK_LEN)
|
|
// total texels in a 4x4 block.
|
|
|
|
namespace
|
|
{
|
|
//------------------------------------------------------------------------------------
|
|
// Structures
|
|
//-------------------------------------------------------------------------------------
|
|
|
|
#pragma warning(push)
|
|
#pragma warning(disable : 4201)
|
|
|
|
// BC4U/BC5U
|
|
struct BC4_UNORM
|
|
{
|
|
float R(size_t uOffset) const noexcept
|
|
{
|
|
size_t uIndex = GetIndex(uOffset);
|
|
return DecodeFromIndex(uIndex);
|
|
}
|
|
|
|
float DecodeFromIndex(size_t uIndex) const noexcept
|
|
{
|
|
if (uIndex == 0)
|
|
return float(red_0) / 255.0f;
|
|
if (uIndex == 1)
|
|
return float(red_1) / 255.0f;
|
|
float fred_0 = float(red_0) / 255.0f;
|
|
float fred_1 = float(red_1) / 255.0f;
|
|
if (red_0 > red_1)
|
|
{
|
|
uIndex -= 1;
|
|
return (fred_0 * float(7u - uIndex) + fred_1 * float(uIndex)) / 7.0f;
|
|
}
|
|
else
|
|
{
|
|
if (uIndex == 6)
|
|
return 0.0f;
|
|
if (uIndex == 7)
|
|
return 1.0f;
|
|
uIndex -= 1;
|
|
return (fred_0 * float(5u - uIndex) + fred_1 * float(uIndex)) / 5.0f;
|
|
}
|
|
}
|
|
|
|
size_t GetIndex(size_t uOffset) const noexcept
|
|
{
|
|
return static_cast<size_t>((data >> (3 * uOffset + 16)) & 0x07);
|
|
}
|
|
|
|
void SetIndex(size_t uOffset, size_t uIndex) noexcept
|
|
{
|
|
data &= ~(uint64_t(0x07) << (3 * uOffset + 16));
|
|
data |= (uint64_t(uIndex) << (3 * uOffset + 16));
|
|
}
|
|
|
|
union
|
|
{
|
|
struct
|
|
{
|
|
uint8_t red_0;
|
|
uint8_t red_1;
|
|
uint8_t indices[6];
|
|
};
|
|
uint64_t data;
|
|
};
|
|
};
|
|
|
|
// BC4S/BC5S
|
|
struct BC4_SNORM
|
|
{
|
|
float R(size_t uOffset) const noexcept
|
|
{
|
|
size_t uIndex = GetIndex(uOffset);
|
|
return DecodeFromIndex(uIndex);
|
|
}
|
|
|
|
float DecodeFromIndex(size_t uIndex) const noexcept
|
|
{
|
|
int8_t sred_0 = (red_0 == -128) ? -127 : red_0;
|
|
int8_t sred_1 = (red_1 == -128) ? -127 : red_1;
|
|
|
|
if (uIndex == 0)
|
|
return float(sred_0) / 127.0f;
|
|
if (uIndex == 1)
|
|
return float(sred_1) / 127.0f;
|
|
float fred_0 = float(sred_0) / 127.0f;
|
|
float fred_1 = float(sred_1) / 127.0f;
|
|
if (red_0 > red_1)
|
|
{
|
|
uIndex -= 1;
|
|
return (fred_0 * float(7u - uIndex) + fred_1 * float(uIndex)) / 7.0f;
|
|
}
|
|
else
|
|
{
|
|
if (uIndex == 6)
|
|
return -1.0f;
|
|
if (uIndex == 7)
|
|
return 1.0f;
|
|
uIndex -= 1;
|
|
return (fred_0 * float(5u - uIndex) + fred_1 * float(uIndex)) / 5.0f;
|
|
}
|
|
}
|
|
|
|
size_t GetIndex(size_t uOffset) const noexcept
|
|
{
|
|
return static_cast<size_t>((data >> (3 * uOffset + 16)) & 0x07);
|
|
}
|
|
|
|
void SetIndex(size_t uOffset, size_t uIndex) noexcept
|
|
{
|
|
data &= ~(uint64_t(0x07) << (3 * uOffset + 16));
|
|
data |= (uint64_t(uIndex) << (3 * uOffset + 16));
|
|
}
|
|
|
|
union
|
|
{
|
|
struct
|
|
{
|
|
int8_t red_0;
|
|
int8_t red_1;
|
|
uint8_t indices[6];
|
|
};
|
|
uint64_t data;
|
|
};
|
|
};
|
|
|
|
#pragma warning(pop)
|
|
|
|
//-------------------------------------------------------------------------------------
|
|
// Convert a floating point value to an 8-bit SNORM
|
|
//-------------------------------------------------------------------------------------
|
|
void inline FloatToSNorm(_In_ float fVal, _Out_ int8_t *piSNorm) noexcept
|
|
{
|
|
const uint32_t dwMostNeg = (1 << (8 * sizeof(int8_t) - 1));
|
|
|
|
if (isnan(fVal))
|
|
fVal = 0;
|
|
else
|
|
if (fVal > 1)
|
|
fVal = 1; // Clamp to 1
|
|
else
|
|
if (fVal < -1)
|
|
fVal = -1; // Clamp to -1
|
|
|
|
fVal = fVal * static_cast<int8_t>(dwMostNeg - 1);
|
|
|
|
if (fVal >= 0)
|
|
fVal += .5f;
|
|
else
|
|
fVal -= .5f;
|
|
|
|
*piSNorm = static_cast<int8_t>(fVal);
|
|
}
|
|
|
|
|
|
//------------------------------------------------------------------------------
|
|
void FindEndPointsBC4U(
|
|
_In_reads_(BLOCK_SIZE) const float theTexelsU[],
|
|
_Out_ uint8_t &endpointU_0,
|
|
_Out_ uint8_t &endpointU_1) noexcept
|
|
{
|
|
// The boundary of codec for signed/unsigned format
|
|
const float MIN_NORM = 0.f;
|
|
const float MAX_NORM = 1.f;
|
|
|
|
// Find max/min of input texels
|
|
float fBlockMax = theTexelsU[0];
|
|
float fBlockMin = theTexelsU[0];
|
|
for (size_t i = 0; i < BLOCK_SIZE; ++i)
|
|
{
|
|
if (theTexelsU[i] < fBlockMin)
|
|
{
|
|
fBlockMin = theTexelsU[i];
|
|
}
|
|
else if (theTexelsU[i] > fBlockMax)
|
|
{
|
|
fBlockMax = theTexelsU[i];
|
|
}
|
|
}
|
|
|
|
// If there are boundary values in input texels, should use 4 interpolated color values to guarantee
|
|
// the exact code of the boundary values.
|
|
bool bUsing4BlockCodec = (MIN_NORM == fBlockMin || MAX_NORM == fBlockMax);
|
|
|
|
// Using Optimize
|
|
float fStart, fEnd;
|
|
|
|
if (!bUsing4BlockCodec)
|
|
{
|
|
// 6 interpolated color values
|
|
OptimizeAlpha<false>(&fStart, &fEnd, theTexelsU, 8);
|
|
|
|
auto iStart = static_cast<uint8_t>(fStart * 255.0f);
|
|
auto iEnd = static_cast<uint8_t>(fEnd * 255.0f);
|
|
|
|
endpointU_0 = iEnd;
|
|
endpointU_1 = iStart;
|
|
}
|
|
else
|
|
{
|
|
// 4 interpolated color values
|
|
OptimizeAlpha<false>(&fStart, &fEnd, theTexelsU, 6);
|
|
|
|
auto iStart = static_cast<uint8_t>(fStart * 255.0f);
|
|
auto iEnd = static_cast<uint8_t>(fEnd * 255.0f);
|
|
|
|
endpointU_1 = iEnd;
|
|
endpointU_0 = iStart;
|
|
}
|
|
}
|
|
|
|
void FindEndPointsBC4S(
|
|
_In_reads_(BLOCK_SIZE) const float theTexelsU[],
|
|
_Out_ int8_t &endpointU_0,
|
|
_Out_ int8_t &endpointU_1) noexcept
|
|
{
|
|
// The boundary of codec for signed/unsigned format
|
|
const float MIN_NORM = -1.f;
|
|
const float MAX_NORM = 1.f;
|
|
|
|
// Find max/min of input texels
|
|
float fBlockMax = theTexelsU[0];
|
|
float fBlockMin = theTexelsU[0];
|
|
for (size_t i = 0; i < BLOCK_SIZE; ++i)
|
|
{
|
|
if (theTexelsU[i] < fBlockMin)
|
|
{
|
|
fBlockMin = theTexelsU[i];
|
|
}
|
|
else if (theTexelsU[i] > fBlockMax)
|
|
{
|
|
fBlockMax = theTexelsU[i];
|
|
}
|
|
}
|
|
|
|
// If there are boundary values in input texels, should use 4 interpolated color values to guarantee
|
|
// the exact code of the boundary values.
|
|
bool bUsing4BlockCodec = (MIN_NORM == fBlockMin || MAX_NORM == fBlockMax);
|
|
|
|
// Using Optimize
|
|
float fStart, fEnd;
|
|
|
|
if (!bUsing4BlockCodec)
|
|
{
|
|
// 6 interpolated color values
|
|
OptimizeAlpha<true>(&fStart, &fEnd, theTexelsU, 8);
|
|
|
|
int8_t iStart, iEnd;
|
|
FloatToSNorm(fStart, &iStart);
|
|
FloatToSNorm(fEnd, &iEnd);
|
|
|
|
endpointU_0 = iEnd;
|
|
endpointU_1 = iStart;
|
|
}
|
|
else
|
|
{
|
|
// 4 interpolated color values
|
|
OptimizeAlpha<true>(&fStart, &fEnd, theTexelsU, 6);
|
|
|
|
int8_t iStart, iEnd;
|
|
FloatToSNorm(fStart, &iStart);
|
|
FloatToSNorm(fEnd, &iEnd);
|
|
|
|
endpointU_1 = iEnd;
|
|
endpointU_0 = iStart;
|
|
}
|
|
}
|
|
|
|
|
|
//------------------------------------------------------------------------------
|
|
inline void FindEndPointsBC5U(
|
|
_In_reads_(BLOCK_SIZE) const float theTexelsU[],
|
|
_In_reads_(BLOCK_SIZE) const float theTexelsV[],
|
|
_Out_ uint8_t &endpointU_0,
|
|
_Out_ uint8_t &endpointU_1,
|
|
_Out_ uint8_t &endpointV_0,
|
|
_Out_ uint8_t &endpointV_1) noexcept
|
|
{
|
|
//Encoding the U and V channel by BC4 codec separately.
|
|
FindEndPointsBC4U(theTexelsU, endpointU_0, endpointU_1);
|
|
FindEndPointsBC4U(theTexelsV, endpointV_0, endpointV_1);
|
|
}
|
|
|
|
inline void FindEndPointsBC5S(
|
|
_In_reads_(BLOCK_SIZE) const float theTexelsU[],
|
|
_In_reads_(BLOCK_SIZE) const float theTexelsV[],
|
|
_Out_ int8_t &endpointU_0,
|
|
_Out_ int8_t &endpointU_1,
|
|
_Out_ int8_t &endpointV_0,
|
|
_Out_ int8_t &endpointV_1) noexcept
|
|
{
|
|
//Encoding the U and V channel by BC4 codec separately.
|
|
FindEndPointsBC4S(theTexelsU, endpointU_0, endpointU_1);
|
|
FindEndPointsBC4S(theTexelsV, endpointV_0, endpointV_1);
|
|
}
|
|
|
|
|
|
//------------------------------------------------------------------------------
|
|
void FindClosestUNORM(
|
|
_Inout_ BC4_UNORM* pBC,
|
|
_In_reads_(NUM_PIXELS_PER_BLOCK) const float theTexelsU[]) noexcept
|
|
{
|
|
float rGradient[8];
|
|
for (size_t i = 0; i < 8; ++i)
|
|
{
|
|
rGradient[i] = pBC->DecodeFromIndex(i);
|
|
}
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
size_t uBestIndex = 0;
|
|
float fBestDelta = 100000;
|
|
for (size_t uIndex = 0; uIndex < 8; uIndex++)
|
|
{
|
|
float fCurrentDelta = fabsf(rGradient[uIndex] - theTexelsU[i]);
|
|
if (fCurrentDelta < fBestDelta)
|
|
{
|
|
uBestIndex = uIndex;
|
|
fBestDelta = fCurrentDelta;
|
|
}
|
|
}
|
|
pBC->SetIndex(i, uBestIndex);
|
|
}
|
|
}
|
|
|
|
void FindClosestSNORM(
|
|
_Inout_ BC4_SNORM* pBC,
|
|
_In_reads_(NUM_PIXELS_PER_BLOCK) const float theTexelsU[]) noexcept
|
|
{
|
|
float rGradient[8];
|
|
for (size_t i = 0; i < 8; ++i)
|
|
{
|
|
rGradient[i] = pBC->DecodeFromIndex(i);
|
|
}
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
size_t uBestIndex = 0;
|
|
float fBestDelta = 100000;
|
|
for (size_t uIndex = 0; uIndex < 8; uIndex++)
|
|
{
|
|
float fCurrentDelta = fabsf(rGradient[uIndex] - theTexelsU[i]);
|
|
if (fCurrentDelta < fBestDelta)
|
|
{
|
|
uBestIndex = uIndex;
|
|
fBestDelta = fCurrentDelta;
|
|
}
|
|
}
|
|
pBC->SetIndex(i, uBestIndex);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//=====================================================================================
|
|
// Entry points
|
|
//=====================================================================================
|
|
|
|
//-------------------------------------------------------------------------------------
|
|
// BC4 Compression
|
|
//-------------------------------------------------------------------------------------
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXDecodeBC4U(XMVECTOR *pColor, const uint8_t *pBC) noexcept
|
|
{
|
|
assert(pColor && pBC);
|
|
static_assert(sizeof(BC4_UNORM) == 8, "BC4_UNORM should be 8 bytes");
|
|
|
|
auto pBC4 = reinterpret_cast<const BC4_UNORM*>(pBC);
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
#pragma prefast(suppress:22103, "writing blocks in two halves confuses tool")
|
|
pColor[i] = XMVectorSet(pBC4->R(i), 0, 0, 1.0f);
|
|
}
|
|
}
|
|
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXDecodeBC4S(XMVECTOR *pColor, const uint8_t *pBC) noexcept
|
|
{
|
|
assert(pColor && pBC);
|
|
static_assert(sizeof(BC4_SNORM) == 8, "BC4_SNORM should be 8 bytes");
|
|
|
|
auto pBC4 = reinterpret_cast<const BC4_SNORM*>(pBC);
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
#pragma prefast(suppress:22103, "writing blocks in two halves confuses tool")
|
|
pColor[i] = XMVectorSet(pBC4->R(i), 0, 0, 1.0f);
|
|
}
|
|
}
|
|
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXEncodeBC4U(uint8_t *pBC, const XMVECTOR *pColor, uint32_t flags) noexcept
|
|
{
|
|
UNREFERENCED_PARAMETER(flags);
|
|
|
|
assert(pBC && pColor);
|
|
static_assert(sizeof(BC4_UNORM) == 8, "BC4_UNORM should be 8 bytes");
|
|
|
|
memset(pBC, 0, sizeof(BC4_UNORM));
|
|
auto pBC4 = reinterpret_cast<BC4_UNORM*>(pBC);
|
|
float theTexelsU[NUM_PIXELS_PER_BLOCK];
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
theTexelsU[i] = XMVectorGetX(pColor[i]);
|
|
}
|
|
|
|
FindEndPointsBC4U(theTexelsU, pBC4->red_0, pBC4->red_1);
|
|
FindClosestUNORM(pBC4, theTexelsU);
|
|
}
|
|
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXEncodeBC4S(uint8_t *pBC, const XMVECTOR *pColor, uint32_t flags) noexcept
|
|
{
|
|
UNREFERENCED_PARAMETER(flags);
|
|
|
|
assert(pBC && pColor);
|
|
static_assert(sizeof(BC4_SNORM) == 8, "BC4_SNORM should be 8 bytes");
|
|
|
|
memset(pBC, 0, sizeof(BC4_UNORM));
|
|
auto pBC4 = reinterpret_cast<BC4_SNORM*>(pBC);
|
|
float theTexelsU[NUM_PIXELS_PER_BLOCK];
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
theTexelsU[i] = XMVectorGetX(pColor[i]);
|
|
}
|
|
|
|
FindEndPointsBC4S(theTexelsU, pBC4->red_0, pBC4->red_1);
|
|
FindClosestSNORM(pBC4, theTexelsU);
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------------------
|
|
// BC5 Compression
|
|
//-------------------------------------------------------------------------------------
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXDecodeBC5U(XMVECTOR *pColor, const uint8_t *pBC) noexcept
|
|
{
|
|
assert(pColor && pBC);
|
|
static_assert(sizeof(BC4_UNORM) == 8, "BC4_UNORM should be 8 bytes");
|
|
|
|
auto pBCR = reinterpret_cast<const BC4_UNORM*>(pBC);
|
|
auto pBCG = reinterpret_cast<const BC4_UNORM*>(pBC + sizeof(BC4_UNORM));
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
#pragma prefast(suppress:22103, "writing blocks in two halves confuses tool")
|
|
pColor[i] = XMVectorSet(pBCR->R(i), pBCG->R(i), 0, 1.0f);
|
|
}
|
|
}
|
|
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXDecodeBC5S(XMVECTOR *pColor, const uint8_t *pBC) noexcept
|
|
{
|
|
assert(pColor && pBC);
|
|
static_assert(sizeof(BC4_SNORM) == 8, "BC4_SNORM should be 8 bytes");
|
|
|
|
auto pBCR = reinterpret_cast<const BC4_SNORM*>(pBC);
|
|
auto pBCG = reinterpret_cast<const BC4_SNORM*>(pBC + sizeof(BC4_SNORM));
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
#pragma prefast(suppress:22103, "writing blocks in two halves confuses tool")
|
|
pColor[i] = XMVectorSet(pBCR->R(i), pBCG->R(i), 0, 1.0f);
|
|
}
|
|
}
|
|
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXEncodeBC5U(uint8_t *pBC, const XMVECTOR *pColor, uint32_t flags) noexcept
|
|
{
|
|
UNREFERENCED_PARAMETER(flags);
|
|
|
|
assert(pBC && pColor);
|
|
static_assert(sizeof(BC4_UNORM) == 8, "BC4_UNORM should be 8 bytes");
|
|
|
|
memset(pBC, 0, sizeof(BC4_UNORM) * 2);
|
|
auto pBCR = reinterpret_cast<BC4_UNORM*>(pBC);
|
|
auto pBCG = reinterpret_cast<BC4_UNORM*>(pBC + sizeof(BC4_UNORM));
|
|
float theTexelsU[NUM_PIXELS_PER_BLOCK];
|
|
float theTexelsV[NUM_PIXELS_PER_BLOCK];
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
XMFLOAT4A clr;
|
|
XMStoreFloat4A(&clr, pColor[i]);
|
|
theTexelsU[i] = clr.x;
|
|
theTexelsV[i] = clr.y;
|
|
}
|
|
|
|
FindEndPointsBC5U(
|
|
theTexelsU,
|
|
theTexelsV,
|
|
pBCR->red_0,
|
|
pBCR->red_1,
|
|
pBCG->red_0,
|
|
pBCG->red_1);
|
|
|
|
FindClosestUNORM(pBCR, theTexelsU);
|
|
FindClosestUNORM(pBCG, theTexelsV);
|
|
}
|
|
|
|
_Use_decl_annotations_
|
|
void DirectX::D3DXEncodeBC5S(uint8_t *pBC, const XMVECTOR *pColor, uint32_t flags) noexcept
|
|
{
|
|
UNREFERENCED_PARAMETER(flags);
|
|
|
|
assert(pBC && pColor);
|
|
static_assert(sizeof(BC4_SNORM) == 8, "BC4_SNORM should be 8 bytes");
|
|
|
|
memset(pBC, 0, sizeof(BC4_UNORM) * 2);
|
|
auto pBCR = reinterpret_cast<BC4_SNORM*>(pBC);
|
|
auto pBCG = reinterpret_cast<BC4_SNORM*>(pBC + sizeof(BC4_SNORM));
|
|
float theTexelsU[NUM_PIXELS_PER_BLOCK];
|
|
float theTexelsV[NUM_PIXELS_PER_BLOCK];
|
|
|
|
for (size_t i = 0; i < NUM_PIXELS_PER_BLOCK; ++i)
|
|
{
|
|
XMFLOAT4A clr;
|
|
XMStoreFloat4A(&clr, pColor[i]);
|
|
theTexelsU[i] = clr.x;
|
|
theTexelsV[i] = clr.y;
|
|
}
|
|
|
|
FindEndPointsBC5S(
|
|
theTexelsU,
|
|
theTexelsV,
|
|
pBCR->red_0,
|
|
pBCR->red_1,
|
|
pBCG->red_0,
|
|
pBCG->red_1);
|
|
|
|
FindClosestSNORM(pBCR, theTexelsU);
|
|
FindClosestSNORM(pBCG, theTexelsV);
|
|
}
|