/* -*- tab-width: 4; -*- */
/* vi: set sw=2 ts=4 expandtab: */
/* Copyright 2019-2020 The Khronos Group Inc.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @~English
* @brief Utilities for creating data format descriptors.
*/
/*
* Author: Andrew Garrard
*/
#include <stdlib.h>
#include <KHR/khr_df.h>
#include "dfd.h"
typedef enum { i_COLOR, i_NON_COLOR } channels_infotype;
static uint32_t *writeHeader(int numSamples, int bytes, int suffix,
channels_infotype infotype)
{
uint32_t *DFD = (uint32_t *) malloc(sizeof(uint32_t) *
(1 + KHR_DF_WORD_SAMPLESTART +
numSamples * KHR_DF_WORD_SAMPLEWORDS));
uint32_t* BDFD = DFD+1;
DFD[0] = sizeof(uint32_t) *
(1 + KHR_DF_WORD_SAMPLESTART +
numSamples * KHR_DF_WORD_SAMPLEWORDS);
BDFD[KHR_DF_WORD_VENDORID] =
(KHR_DF_VENDORID_KHRONOS << KHR_DF_SHIFT_VENDORID) |
(KHR_DF_KHR_DESCRIPTORTYPE_BASICFORMAT << KHR_DF_SHIFT_DESCRIPTORTYPE);
BDFD[KHR_DF_WORD_VERSIONNUMBER] =
(KHR_DF_VERSIONNUMBER_LATEST << KHR_DF_SHIFT_VERSIONNUMBER) |
(((uint32_t)sizeof(uint32_t) *
(KHR_DF_WORD_SAMPLESTART +
numSamples * KHR_DF_WORD_SAMPLEWORDS)
<< KHR_DF_SHIFT_DESCRIPTORBLOCKSIZE));
BDFD[KHR_DF_WORD_MODEL] =
((KHR_DF_MODEL_RGBSDA << KHR_DF_SHIFT_MODEL) | /* Only supported model */
(KHR_DF_FLAG_ALPHA_STRAIGHT << KHR_DF_SHIFT_FLAGS));
if (infotype == i_COLOR) {
BDFD[KHR_DF_WORD_PRIMARIES] |= KHR_DF_PRIMARIES_BT709 << KHR_DF_SHIFT_PRIMARIES; /* Assumed */
} else {
BDFD[KHR_DF_WORD_PRIMARIES] |= KHR_DF_PRIMARIES_UNSPECIFIED << KHR_DF_SHIFT_PRIMARIES;
}
if (suffix == s_SRGB) {
BDFD[KHR_DF_WORD_TRANSFER] |= KHR_DF_TRANSFER_SRGB << KHR_DF_SHIFT_TRANSFER;
} else {
BDFD[KHR_DF_WORD_TRANSFER] |= KHR_DF_TRANSFER_LINEAR << KHR_DF_SHIFT_TRANSFER;
}
BDFD[KHR_DF_WORD_TEXELBLOCKDIMENSION0] = 0; /* Only 1x1x1x1 texel blocks supported */
BDFD[KHR_DF_WORD_BYTESPLANE0] = bytes; /* bytesPlane0 = bytes, bytesPlane3..1 = 0 */
BDFD[KHR_DF_WORD_BYTESPLANE4] = 0; /* bytesPlane7..5 = 0 */
return DFD;
}
static uint32_t setChannelFlags(uint32_t channel, enum VkSuffix suffix)
{
switch (suffix) {
case s_UNORM: break;
case s_SNORM:
channel |=
KHR_DF_SAMPLE_DATATYPE_SIGNED;
break;
case s_USCALED: break;
case s_SSCALED:
channel |=
KHR_DF_SAMPLE_DATATYPE_SIGNED;
break;
case s_UINT: break;
case s_SINT:
channel |=
KHR_DF_SAMPLE_DATATYPE_SIGNED;
break;
case s_SFLOAT:
channel |=
KHR_DF_SAMPLE_DATATYPE_FLOAT |
KHR_DF_SAMPLE_DATATYPE_SIGNED;
break;
case s_UFLOAT:
channel |=
KHR_DF_SAMPLE_DATATYPE_FLOAT;
break;
case s_SRGB:
if (channel == KHR_DF_CHANNEL_RGBSDA_ALPHA) {
channel |= KHR_DF_SAMPLE_DATATYPE_LINEAR;
}
break;
}
return channel;
}
static void writeSample(uint32_t *DFD, int sampleNo, int channel,
int bits, int offset,
int topSample, int bottomSample, enum VkSuffix suffix)
{
// Use this to avoid type-punning complaints from the gcc optimizer
// with -Wall.
union {
uint32_t i;
float f;
} lower, upper;
uint32_t *sample = DFD + 1 + KHR_DF_WORD_SAMPLESTART + sampleNo * KHR_DF_WORD_SAMPLEWORDS;
if (channel == 3) channel = KHR_DF_CHANNEL_RGBSDA_ALPHA;
if (channel == 3) channel = KHR_DF_CHANNEL_RGBSDA_ALPHA;
channel = setChannelFlags(channel, suffix);
sample[KHR_DF_SAMPLEWORD_BITOFFSET] =
(offset << KHR_DF_SAMPLESHIFT_BITOFFSET) |
((bits - 1) << KHR_DF_SAMPLESHIFT_BITLENGTH) |
(channel << KHR_DF_SAMPLESHIFT_CHANNELID);
sample[KHR_DF_SAMPLEWORD_SAMPLEPOSITION_ALL] = 0;
switch (suffix) {
case s_UNORM:
case s_SRGB:
default:
if (bits > 32) {
upper.i = 0xFFFFFFFFU;
} else {
upper.i = (uint32_t)((1U << bits) - 1U);
}
lower.i = 0U;
break;
case s_SNORM:
if (bits > 32) {
upper.i = 0x7FFFFFFF;
} else {
upper.i = topSample ? (1U << (bits - 1)) - 1 : (1U << bits) - 1;
}
lower.i = ~upper.i;
if (bottomSample) lower.i += 1;
break;
case s_USCALED:
case s_UINT:
upper.i = bottomSample ? 1U : 0U;
lower.i = 0U;
break;
case s_SSCALED:
case s_SINT:
upper.i = bottomSample ? 1U : 0U;
lower.i = ~0U;
break;
case s_SFLOAT:
upper.f = 1.0f;
lower.f = -1.0f;
break;
case s_UFLOAT:
upper.f = 1.0f;
lower.f = 0.0f;
break;
}
sample[KHR_DF_SAMPLEWORD_SAMPLELOWER] = lower.i;
sample[KHR_DF_SAMPLEWORD_SAMPLEUPPER] = upper.i;
}
/**
* @~English
* @brief Create a Data Format Descriptor for an unpacked format.
*
* @param bigEndian Set to 1 for big-endian byte ordering and
0 for little-endian byte ordering.
* @param numChannels The number of color channels.
* @param bytes The number of bytes per channel.
* @param redBlueSwap Normally channels appear in consecutive R, G, B, A order
* in memory; redBlueSwap inverts red and blue, allowing
* B, G, R, A.
* @param suffix Indicates the format suffix for the type.
*
* @return A data format descriptor in malloc'd data. The caller is responsible
* for freeing the descriptor.
**/
uint32_t *createDFDUnpacked(int bigEndian, int numChannels, int bytes,
int redBlueSwap, enum VkSuffix suffix)
{
uint32_t *DFD;
if (bigEndian) {
int channelCounter, channelByte;
/* Number of samples = number of channels * bytes per channel */
DFD = writeHeader(numChannels * bytes, numChannels * bytes, suffix, i_COLOR);
/* First loop over the channels */
for (channelCounter = 0; channelCounter < numChannels; ++channelCounter) {
int channel = channelCounter;
if (redBlueSwap && (channel == 0 || channel == 2)) {
channel ^= 2;
}
/* Loop over the bytes that constitute a channel */
for (channelByte = 0; channelByte < bytes; ++channelByte) {
writeSample(DFD, channelCounter * bytes + channelByte, channel,
8, 8 * (channelCounter * bytes + bytes - channelByte - 1),
channelByte == bytes-1, channelByte == 0, suffix);
}
}
} else { /* Little-endian */
int sampleCounter;
/* One sample per channel */
DFD = writeHeader(numChannels, numChannels * bytes, suffix, i_COLOR);
for (sampleCounter = 0; sampleCounter < numChannels; ++sampleCounter) {
int channel = sampleCounter;
if (redBlueSwap && (channel == 0 || channel == 2)) {
channel ^= 2;
}
writeSample(DFD, sampleCounter, channel,
8 * bytes, 8 * sampleCounter * bytes,
1, 1, suffix);
}
}
return DFD;
}
/**
* @~English
* @brief Create a Data Format Descriptor for a packed format.
*
* @param bigEndian Big-endian flag: Set to 1 for big-endian byte ordering and
* 0 for little-endian byte ordering.
* @param numChannels The number of color channels.
* @param bits[] An array of length numChannels.
* Each entry is the number of bits composing the channel, in
* order starting at bit 0 of the packed type.
* @param channels[] An array of length numChannels.
* Each entry enumerates the channel type: 0 = red, 1 = green,
* 2 = blue, 15 = alpha, in order starting at bit 0 of the
* packed type. These values match channel IDs for RGBSDA in
* the Khronos Data Format header. To simplify iteration
* through channels, channel id 3 is a synonym for alpha.
* @param suffix Indicates the format suffix for the type.
*
* @return A data format descriptor in malloc'd data. The caller is responsible
* for freeing the descriptor.
**/
uint32_t *createDFDPacked(int bigEndian, int numChannels,
int bits[], int channels[],
enum VkSuffix suffix)
{
uint32_t *DFD = 0;
if (numChannels == 6) {
/* Special case E5B9G9R9 */
DFD = writeHeader(numChannels, 4, s_UFLOAT, i_COLOR);
writeSample(DFD, 0, 0,
9, 0,
1, 1, s_UNORM);
KHR_DFDSETSVAL((DFD+1), 0, SAMPLEUPPER, 8448);
writeSample(DFD, 1, 0 | KHR_DF_SAMPLE_DATATYPE_EXPONENT,
5, 27,
1, 1, s_UNORM);
KHR_DFDSETSVAL((DFD+1), 1, SAMPLELOWER, 15);
KHR_DFDSETSVAL((DFD+1), 1, SAMPLEUPPER, 31);
writeSample(DFD, 2, 1,
9, 9,
1, 1, s_UNORM);
KHR_DFDSETSVAL((DFD+1), 2, SAMPLEUPPER, 8448);
writeSample(DFD, 3, 1 | KHR_DF_SAMPLE_DATATYPE_EXPONENT,
5, 27,
1, 1, s_UNORM);
KHR_DFDSETSVAL((DFD+1), 3, SAMPLELOWER, 15);
KHR_DFDSETSVAL((DFD+1), 3, SAMPLEUPPER, 31);
writeSample(DFD, 4, 2,
9, 18,
1, 1, s_UNORM);
KHR_DFDSETSVAL((DFD+1), 4, SAMPLEUPPER, 8448);
writeSample(DFD, 5, 2 | KHR_DF_SAMPLE_DATATYPE_EXPONENT,
5, 27,
1, 1, s_UNORM);
KHR_DFDSETSVAL((DFD+1), 5, SAMPLELOWER, 15);
KHR_DFDSETSVAL((DFD+1), 5, SAMPLEUPPER, 31);
} else if (bigEndian) {
/* No packed format is larger than 32 bits. */
/* No packed channel crosses more than two bytes. */
int totalBits = 0;
int bitChannel[32];
int beChannelStart[4];
int channelCounter;
int bitOffset = 0;
int BEMask;
int numSamples = numChannels;
int sampleCounter;
for (channelCounter = 0; channelCounter < numChannels; ++channelCounter) {
beChannelStart[channelCounter] = totalBits;
totalBits += bits[channelCounter];
}
BEMask = (totalBits - 1) & 0x18;
for (channelCounter = 0; channelCounter < numChannels; ++channelCounter) {
bitChannel[bitOffset ^ BEMask] = channelCounter;
if (((bitOffset + bits[channelCounter] - 1) & ~7) != (bitOffset & ~7)) {
/* Continuation sample */
bitChannel[((bitOffset + bits[channelCounter] - 1) & ~7) ^ BEMask] = channelCounter;
numSamples++;
}
bitOffset += bits[channelCounter];
}
DFD = writeHeader(numSamples, totalBits >> 3, suffix, i_COLOR);
sampleCounter = 0;
for (bitOffset = 0; bitOffset < totalBits;) {
if (bitChannel[bitOffset] == -1) {
/* Done this bit, so this is the lower half of something. */
/* We must therefore jump to the end of the byte and continue. */
bitOffset = (bitOffset + 8) & ~7;
} else {
/* Start of a channel? */
int thisChannel = bitChannel[bitOffset];
if ((beChannelStart[thisChannel] ^ BEMask) == bitOffset) {
/* Must be just one sample if we hit it first. */
writeSample(DFD, sampleCounter++, channels[thisChannel],
bits[thisChannel], bitOffset,
1, 1, suffix);
bitOffset += bits[thisChannel];
} else {
/* Two samples. Move to the end of the first one we hit when we're done. */
int firstSampleBits = 8 - (beChannelStart[thisChannel] & 0x7); /* Rest of the byte */
int secondSampleBits = bits[thisChannel] - firstSampleBits; /* Rest of the bits */
writeSample(DFD, sampleCounter++, channels[thisChannel],
firstSampleBits, beChannelStart[thisChannel] ^ BEMask,
0, 1, suffix);
/* Mark that we've already handled this sample */
bitChannel[beChannelStart[thisChannel] ^ BEMask] = -1;
writeSample(DFD, sampleCounter++, channels[thisChannel],
secondSampleBits, bitOffset,
1, 0, suffix);
bitOffset += secondSampleBits;
}
}
}
} else { /* Little-endian */
int sampleCounter;
int totalBits = 0;
int bitOffset = 0;
for (sampleCounter = 0; sampleCounter < numChannels; ++sampleCounter) {
totalBits += bits[sampleCounter];
}
/* One sample per channel */
DFD = writeHeader(numChannels, totalBits >> 3, suffix, i_COLOR);
for (sampleCounter = 0; sampleCounter < numChannels; ++sampleCounter) {
writeSample(DFD, sampleCounter, channels[sampleCounter],
bits[sampleCounter], bitOffset,
1, 1, suffix);
bitOffset += bits[sampleCounter];
}
}
return DFD;
}
static khr_df_model_e compModelMapping[] = {
KHR_DF_MODEL_BC1A, /*!< BC1, aka DXT1, no alpha. */
KHR_DF_MODEL_BC1A, /*!< BC1, aka DXT1, punch-through alpha. */
KHR_DF_MODEL_BC2, /*!< BC2, aka DXT2 and DXT3. */
KHR_DF_MODEL_BC3, /*!< BC3, aka DXT4 and DXT5. */
KHR_DF_MODEL_BC4, /*!< BC4. */
KHR_DF_MODEL_BC5, /*!< BC5. */
KHR_DF_MODEL_BC6H, /*!< BC6h HDR format. */
KHR_DF_MODEL_BC7, /*!< BC7. */
KHR_DF_MODEL_ETC2, /*!< ETC2 no alpha. */
KHR_DF_MODEL_ETC2, /*!< ETC2 punch-through alpha. */
KHR_DF_MODEL_ETC2, /*!< ETC2 independent alpha. */
KHR_DF_MODEL_ETC2, /*!< R11 ETC2 single-channel. */
KHR_DF_MODEL_ETC2, /*!< R11G11 ETC2 dual-channel. */
KHR_DF_MODEL_ASTC, /*!< ASTC. */
KHR_DF_MODEL_ETC1S, /*!< ETC1S. */
KHR_DF_MODEL_PVRTC, /*!< PVRTC(1). */
KHR_DF_MODEL_PVRTC2 /*!< PVRTC2. */
};
static uint32_t compSampleCount[] = {
1U, /*!< BC1, aka DXT1, no alpha. */
1U, /*!< BC1, aka DXT1, punch-through alpha. */
2U, /*!< BC2, aka DXT2 and DXT3. */
2U, /*!< BC3, aka DXT4 and DXT5. */
1U, /*!< BC4. */
2U, /*!< BC5. */
1U, /*!< BC6h HDR format. */
1U, /*!< BC7. */
1U, /*!< ETC2 no alpha. */
2U, /*!< ETC2 punch-through alpha. */
2U, /*!< ETC2 independent alpha. */
1U, /*!< R11 ETC2 single-channel. */
2U, /*!< R11G11 ETC2 dual-channel. */
1U, /*!< ASTC. */
1U, /*!< ETC1S. */
1U, /*!< PVRTC. */
1U /*!< PVRTC2. */
};
static khr_df_model_channels_e compFirstChannel[] = {
KHR_DF_CHANNEL_BC1A_COLOR, /*!< BC1, aka DXT1, no alpha. */
KHR_DF_CHANNEL_BC1A_ALPHAPRESENT, /*!< BC1, aka DXT1, punch-through alpha. */
KHR_DF_CHANNEL_BC2_ALPHA, /*!< BC2, aka DXT2 and DXT3. */
KHR_DF_CHANNEL_BC3_ALPHA, /*!< BC3, aka DXT4 and DXT5. */
KHR_DF_CHANNEL_BC4_DATA, /*!< BC4. */
KHR_DF_CHANNEL_BC5_RED, /*!< BC5. */
KHR_DF_CHANNEL_BC6H_COLOR, /*!< BC6h HDR format. */
KHR_DF_CHANNEL_BC7_COLOR, /*!< BC7. */
KHR_DF_CHANNEL_ETC2_COLOR, /*!< ETC2 no alpha. */
KHR_DF_CHANNEL_ETC2_COLOR, /*!< ETC2 punch-through alpha. */
KHR_DF_CHANNEL_ETC2_ALPHA, /*!< ETC2 independent alpha. */
KHR_DF_CHANNEL_ETC2_RED, /*!< R11 ETC2 single-channel. */
KHR_DF_CHANNEL_ETC2_RED, /*!< R11G11 ETC2 dual-channel. */
KHR_DF_CHANNEL_ASTC_DATA, /*!< ASTC. */
KHR_DF_CHANNEL_ETC1S_RGB, /*!< ETC1S. */
KHR_DF_CHANNEL_PVRTC_COLOR, /*!< PVRTC. */
KHR_DF_CHANNEL_PVRTC2_COLOR /*!< PVRTC2. */
};
static khr_df_model_channels_e compSecondChannel[] = {
KHR_DF_CHANNEL_BC1A_COLOR, /*!< BC1, aka DXT1, no alpha. */
KHR_DF_CHANNEL_BC1A_ALPHAPRESENT, /*!< BC1, aka DXT1, punch-through alpha. */
KHR_DF_CHANNEL_BC2_COLOR, /*!< BC2, aka DXT2 and DXT3. */
KHR_DF_CHANNEL_BC3_COLOR, /*!< BC3, aka DXT4 and DXT5. */
KHR_DF_CHANNEL_BC4_DATA, /*!< BC4. */
KHR_DF_CHANNEL_BC5_GREEN, /*!< BC5. */
KHR_DF_CHANNEL_BC6H_COLOR, /*!< BC6h HDR format. */
KHR_DF_CHANNEL_BC7_COLOR, /*!< BC7. */
KHR_DF_CHANNEL_ETC2_COLOR, /*!< ETC2 no alpha. */
KHR_DF_CHANNEL_ETC2_ALPHA, /*!< ETC2 punch-through alpha. */
KHR_DF_CHANNEL_ETC2_COLOR, /*!< ETC2 independent alpha. */
KHR_DF_CHANNEL_ETC2_RED, /*!< R11 ETC2 single-channel. */
KHR_DF_CHANNEL_ETC2_GREEN, /*!< R11G11 ETC2 dual-channel. */
KHR_DF_CHANNEL_ASTC_DATA, /*!< ASTC. */
KHR_DF_CHANNEL_ETC1S_RGB, /*!< ETC1S. */
KHR_DF_CHANNEL_PVRTC_COLOR, /*!< PVRTC. */
KHR_DF_CHANNEL_PVRTC2_COLOR /*!< PVRTC2. */
};
static uint32_t compSecondChannelOffset[] = {
0U, /*!< BC1, aka DXT1, no alpha. */
0U, /*!< BC1, aka DXT1, punch-through alpha. */
64U, /*!< BC2, aka DXT2 and DXT3. */
64U, /*!< BC3, aka DXT4 and DXT5. */
0U, /*!< BC4. */
64U, /*!< BC5. */
0U, /*!< BC6h HDR format. */
0U, /*!< BC7. */
0U, /*!< ETC2 no alpha. */
0U, /*!< ETC2 punch-through alpha. */
64U, /*!< ETC2 independent alpha. */
0U, /*!< R11 ETC2 single-channel. */
64U, /*!< R11G11 ETC2 dual-channel. */
0U, /*!< ASTC. */
0U, /*!< ETC1S. */
0U, /*!< PVRTC. */
0U /*!< PVRTC2. */
};
static uint32_t compChannelBits[] = {
64U, /*!< BC1, aka DXT1, no alpha. */
64U, /*!< BC1, aka DXT1, punch-through alpha. */
64U, /*!< BC2, aka DXT2 and DXT3. */
64U, /*!< BC3, aka DXT4 and DXT5. */
64U, /*!< BC4. */
64U, /*!< BC5. */
128U, /*!< BC6h HDR format. */
128U, /*!< BC7. */
64U, /*!< ETC2 no alpha. */
64U, /*!< ETC2 punch-through alpha. */
64U, /*!< ETC2 independent alpha. */
64U, /*!< R11 ETC2 single-channel. */
64U, /*!< R11G11 ETC2 dual-channel. */
128U, /*!< ASTC. */
64U, /*!< ETC1S. */
64U, /*!< PVRTC. */
64U /*!< PVRTC2. */
};
static uint32_t compBytes[] = {
8U, /*!< BC1, aka DXT1, no alpha. */
8U, /*!< BC1, aka DXT1, punch-through alpha. */
16U, /*!< BC2, aka DXT2 and DXT3. */
16U, /*!< BC3, aka DXT4 and DXT5. */
8U, /*!< BC4. */
16U, /*!< BC5. */
16U, /*!< BC6h HDR format. */
16U, /*!< BC7. */
8U, /*!< ETC2 no alpha. */
8U, /*!< ETC2 punch-through alpha. */
16U, /*!< ETC2 independent alpha. */
8U, /*!< R11 ETC2 single-channel. */
16U, /*!< R11G11 ETC2 dual-channel. */
16U, /*!< ASTC. */
8U, /*!< ETC1S. */
8U, /*!< PVRTC. */
8U /*!< PVRTC2. */
};
/**
* @~English
* @brief Create a Data Format Descriptor for a compressed format.
*
* @param compScheme Vulkan-style compression scheme enumeration.
* @param bwidth Block width in texel coordinates.
* @param bheight Block height in texel coordinates.
* @param bdepth Block depth in texel coordinates.
* @author Mark Callow, Edgewise Consulting.
* @param suffix Indicates the format suffix for the type.
*
* @return A data format descriptor in malloc'd data. The caller is responsible
* for freeing the descriptor.
**/
uint32_t *createDFDCompressed(enum VkCompScheme compScheme, int bwidth, int bheight, int bdepth,
enum VkSuffix suffix)
{
uint32_t *DFD = 0;
uint32_t numSamples = compSampleCount[compScheme];
uint32_t* BDFD;
uint32_t *sample;
uint32_t channel;
// Use union to avoid type-punning complaints from gcc optimizer
// with -Wall.
union {
uint32_t i;
float f;
} lower, upper;
DFD = (uint32_t *) malloc(sizeof(uint32_t) *
(1 + KHR_DF_WORD_SAMPLESTART +
numSamples * KHR_DF_WORD_SAMPLEWORDS));
BDFD = DFD+1;
DFD[0] = sizeof(uint32_t) *
(1 + KHR_DF_WORD_SAMPLESTART +
numSamples * KHR_DF_WORD_SAMPLEWORDS);
BDFD[KHR_DF_WORD_VENDORID] =
(KHR_DF_VENDORID_KHRONOS << KHR_DF_SHIFT_VENDORID) |
(KHR_DF_KHR_DESCRIPTORTYPE_BASICFORMAT << KHR_DF_SHIFT_DESCRIPTORTYPE);
BDFD[KHR_DF_WORD_VERSIONNUMBER] =
(KHR_DF_VERSIONNUMBER_LATEST << KHR_DF_SHIFT_VERSIONNUMBER) |
(((uint32_t)sizeof(uint32_t) *
(KHR_DF_WORD_SAMPLESTART +
numSamples * KHR_DF_WORD_SAMPLEWORDS)
<< KHR_DF_SHIFT_DESCRIPTORBLOCKSIZE));
BDFD[KHR_DF_WORD_MODEL] =
((compModelMapping[compScheme] << KHR_DF_SHIFT_MODEL) |
(KHR_DF_PRIMARIES_BT709 << KHR_DF_SHIFT_PRIMARIES) | /* Assumed */
(KHR_DF_FLAG_ALPHA_STRAIGHT << KHR_DF_SHIFT_FLAGS));
if (suffix == s_SRGB) {
BDFD[KHR_DF_WORD_TRANSFER] |= KHR_DF_TRANSFER_SRGB << KHR_DF_SHIFT_TRANSFER;
} else {
BDFD[KHR_DF_WORD_TRANSFER] |= KHR_DF_TRANSFER_LINEAR << KHR_DF_SHIFT_TRANSFER;
}
BDFD[KHR_DF_WORD_TEXELBLOCKDIMENSION0] =
(bwidth - 1) | ((bheight - 1) << KHR_DF_SHIFT_TEXELBLOCKDIMENSION1) | ((bdepth - 1) << KHR_DF_SHIFT_TEXELBLOCKDIMENSION2);
/* bytesPlane0 = bytes, bytesPlane3..1 = 0 */
BDFD[KHR_DF_WORD_BYTESPLANE0] = compBytes[compScheme];
BDFD[KHR_DF_WORD_BYTESPLANE4] = 0; /* bytesPlane7..5 = 0 */
sample = BDFD + KHR_DF_WORD_SAMPLESTART;
channel = compFirstChannel[compScheme];
channel = setChannelFlags(channel, suffix);
sample[KHR_DF_SAMPLEWORD_BITOFFSET] =
(0 << KHR_DF_SAMPLESHIFT_BITOFFSET) |
((compChannelBits[compScheme] - 1) << KHR_DF_SAMPLESHIFT_BITLENGTH) |
(channel << KHR_DF_SAMPLESHIFT_CHANNELID);
sample[KHR_DF_SAMPLEWORD_SAMPLEPOSITION_ALL] = 0;
switch (suffix) {
case s_UNORM:
case s_SRGB:
default:
upper.i = 0xFFFFFFFFU;
lower.i = 0U;
break;
case s_SNORM:
upper.i = 0x7FFFFFFF;
lower.i = ~upper.i;
break;
case s_USCALED:
case s_UINT:
upper.i = 1U;
lower.i = 0U;
break;
case s_SSCALED:
case s_SINT:
upper.i = 1U;
lower.i = ~0U;
break;
case s_SFLOAT:
upper.f = 1.0f;
lower.f = -1.0f;
break;
case s_UFLOAT:
upper.f = 1.0f;
lower.f = 0.0f;
break;
}
sample[KHR_DF_SAMPLEWORD_SAMPLELOWER] = lower.i;
sample[KHR_DF_SAMPLEWORD_SAMPLEUPPER] = upper.i;
if (compSampleCount[compScheme] > 1) {
sample += KHR_DF_WORD_SAMPLEWORDS;
channel = compSecondChannel[compScheme];
channel = setChannelFlags(channel, suffix);
sample[KHR_DF_SAMPLEWORD_BITOFFSET] =
(compSecondChannelOffset[compScheme] << KHR_DF_SAMPLESHIFT_BITOFFSET) |
((compChannelBits[compScheme] - 1) << KHR_DF_SAMPLESHIFT_BITLENGTH) |
(channel << KHR_DF_SAMPLESHIFT_CHANNELID);
sample[KHR_DF_SAMPLEWORD_SAMPLEPOSITION_ALL] = 0;
sample[KHR_DF_SAMPLEWORD_SAMPLELOWER] = lower.i;
sample[KHR_DF_SAMPLEWORD_SAMPLEUPPER] = upper.i;
}
return DFD;
}
/**
* @~English
* @brief Create a Data Format Descriptor for a depth-stencil format.
*
* @param depthBits The numeber of bits in the depth channel.
* @param stencilBits The numeber of bits in the stencil channel.
* @param sizeBytes The total byte size of the texel.
*
* @return A data format descriptor in malloc'd data. The caller is responsible
* for freeing the descriptor.
**/
uint32_t *createDFDDepthStencil(int depthBits,
int stencilBits,
int sizeBytes)
{
/* N.B. Little-endian is assumed. */
uint32_t *DFD = 0;
DFD = writeHeader((depthBits > 0) + (stencilBits > 0),
sizeBytes, s_UNORM, i_NON_COLOR);
if (depthBits == 32) {
writeSample(DFD, 0, KHR_DF_CHANNEL_RGBSDA_DEPTH,
32, 0,
1, 1, s_SFLOAT);
} else if (depthBits > 0) {
writeSample(DFD, 0, KHR_DF_CHANNEL_RGBSDA_DEPTH,
depthBits, 0,
1, 1, s_UNORM);
}
if (stencilBits > 0) {
if (depthBits > 0) {
writeSample(DFD, 1, KHR_DF_CHANNEL_RGBSDA_STENCIL,
stencilBits, depthBits,
1, 1, s_UINT);
} else {
writeSample(DFD, 0, KHR_DF_CHANNEL_RGBSDA_STENCIL,
stencilBits, 0,
1, 1, s_UINT);
}
}
return DFD;
}