/*
* Copyright (C) 2014 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file texcompress_bptc.c
* GL_ARB_texture_compression_bptc support.
*/
#include <stdbool.h>
#include "texcompress.h"
#include "texcompress_bptc.h"
#include "util/format_srgb.h"
#include "util/half_float.h"
#include "texstore.h"
#include "macros.h"
#include "image.h"
#define BLOCK_SIZE 4
#define N_PARTITIONS 64
#define BLOCK_BYTES 16
struct bptc_unorm_mode {
int n_subsets;
int n_partition_bits;
bool has_rotation_bits;
bool has_index_selection_bit;
int n_color_bits;
int n_alpha_bits;
bool has_endpoint_pbits;
bool has_shared_pbits;
int n_index_bits;
int n_secondary_index_bits;
};
struct bptc_float_bitfield {
int8_t endpoint;
uint8_t component;
uint8_t offset;
uint8_t n_bits;
bool reverse;
};
struct bptc_float_mode {
bool reserved;
bool transformed_endpoints;
int n_partition_bits;
int n_endpoint_bits;
int n_index_bits;
int n_delta_bits[3];
struct bptc_float_bitfield bitfields[24];
};
struct bit_writer {
uint8_t buf;
int pos;
uint8_t *dst;
};
static const struct bptc_unorm_mode
bptc_unorm_modes[] = {
/* 0 */ { 3, 4, false, false, 4, 0, true, false, 3, 0 },
/* 1 */ { 2, 6, false, false, 6, 0, false, true, 3, 0 },
/* 2 */ { 3, 6, false, false, 5, 0, false, false, 2, 0 },
/* 3 */ { 2, 6, false, false, 7, 0, true, false, 2, 0 },
/* 4 */ { 1, 0, true, true, 5, 6, false, false, 2, 3 },
/* 5 */ { 1, 0, true, false, 7, 8, false, false, 2, 2 },
/* 6 */ { 1, 0, false, false, 7, 7, true, false, 4, 0 },
/* 7 */ { 2, 6, false, false, 5, 5, true, false, 2, 0 }
};
static const struct bptc_float_mode
bptc_float_modes[] = {
/* 00 */
{ false, true, 5, 10, 3, { 5, 5, 5 },
{ { 2, 1, 4, 1, false }, { 2, 2, 4, 1, false }, { 3, 2, 4, 1, false },
{ 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
{ 1, 1, 0, 5, false }, { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false },
{ 1, 2, 0, 5, false }, { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false },
{ 2, 0, 0, 5, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false },
{ 3, 2, 3, 1, false },
{ -1 } }
},
/* 01 */
{ false, true, 5, 7, 3, { 6, 6, 6 },
{ { 2, 1, 5, 1, false }, { 3, 1, 4, 1, false }, { 3, 1, 5, 1, false },
{ 0, 0, 0, 7, false }, { 3, 2, 0, 1, false }, { 3, 2, 1, 1, false },
{ 2, 2, 4, 1, false }, { 0, 1, 0, 7, false }, { 2, 2, 5, 1, false },
{ 3, 2, 2, 1, false }, { 2, 1, 4, 1, false }, { 0, 2, 0, 7, false },
{ 3, 2, 3, 1, false }, { 3, 2, 5, 1, false }, { 3, 2, 4, 1, false },
{ 1, 0, 0, 6, false }, { 2, 1, 0, 4, false }, { 1, 1, 0, 6, false },
{ 3, 1, 0, 4, false }, { 1, 2, 0, 6, false }, { 2, 2, 0, 4, false },
{ 2, 0, 0, 6, false },
{ 3, 0, 0, 6, false },
{ -1 } }
},
/* 00010 */
{ false, true, 5, 11, 3, { 5, 4, 4 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 5, false }, { 0, 0, 10, 1, false }, { 2, 1, 0, 4, false },
{ 1, 1, 0, 4, false }, { 0, 1, 10, 1, false }, { 3, 2, 0, 1, false },
{ 3, 1, 0, 4, false }, { 1, 2, 0, 4, false }, { 0, 2, 10, 1, false },
{ 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 5, false },
{ 3, 2, 2, 1, false }, { 3, 0, 0, 5, false }, { 3, 2, 3, 1, false },
{ -1 } }
},
/* 00011 */
{ false, false, 0, 10, 4, { 10, 10, 10 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 10, false }, { 1, 1, 0, 10, false }, { 1, 2, 0, 10, false },
{ -1 } }
},
/* 00110 */
{ false, true, 5, 11, 3, { 4, 5, 4 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 4, false }, { 0, 0, 10, 1, false }, { 3, 1, 4, 1, false },
{ 2, 1, 0, 4, false }, { 1, 1, 0, 5, false }, { 0, 1, 10, 1, false },
{ 3, 1, 0, 4, false }, { 1, 2, 0, 4, false }, { 0, 2, 10, 1, false },
{ 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 4, false },
{ 3, 2, 0, 1, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 4, false },
{ 2, 1, 4, 1, false }, { 3, 2, 3, 1, false },
{ -1 } }
},
/* 00111 */
{ false, true, 0, 11, 4, { 9, 9, 9 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 9, false }, { 0, 0, 10, 1, false }, { 1, 1, 0, 9, false },
{ 0, 1, 10, 1, false }, { 1, 2, 0, 9, false }, { 0, 2, 10, 1, false },
{ -1 } }
},
/* 01010 */
{ false, true, 5, 11, 3, { 4, 4, 5 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 4, false }, { 0, 0, 10, 1, false }, { 2, 2, 4, 1, false },
{ 2, 1, 0, 4, false }, { 1, 1, 0, 4, false }, { 0, 1, 10, 1, false },
{ 3, 2, 0, 1, false }, { 3, 1, 0, 4, false }, { 1, 2, 0, 5, false },
{ 0, 2, 10, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 4, false },
{ 3, 2, 1, 1, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 4, false },
{ 3, 2, 4, 1, false }, { 3, 2, 3, 1, false },
{ -1 } }
},
/* 01011 */
{ false, true, 0, 12, 4, { 8, 8, 8 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 8, false }, { 0, 0, 10, 2, true }, { 1, 1, 0, 8, false },
{ 0, 1, 10, 2, true }, { 1, 2, 0, 8, false }, { 0, 2, 10, 2, true },
{ -1 } }
},
/* 01110 */
{ false, true, 5, 9, 3, { 5, 5, 5 },
{ { 0, 0, 0, 9, false }, { 2, 2, 4, 1, false }, { 0, 1, 0, 9, false },
{ 2, 1, 4, 1, false }, { 0, 2, 0, 9, false }, { 3, 2, 4, 1, false },
{ 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
{ 1, 1, 0, 5, false }, { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false },
{ 1, 2, 0, 5, false }, { 3, 2, 1, 1, false }, { 2, 2, 0, 4, false },
{ 2, 0, 0, 5, false }, { 3, 2, 2, 1, false }, { 3, 0, 0, 5, false },
{ 3, 2, 3, 1, false },
{ -1 } }
},
/* 01111 */
{ false, true, 0, 16, 4, { 4, 4, 4 },
{ { 0, 0, 0, 10, false }, { 0, 1, 0, 10, false }, { 0, 2, 0, 10, false },
{ 1, 0, 0, 4, false }, { 0, 0, 10, 6, true }, { 1, 1, 0, 4, false },
{ 0, 1, 10, 6, true }, { 1, 2, 0, 4, false }, { 0, 2, 10, 6, true },
{ -1 } }
},
/* 10010 */
{ false, true, 5, 8, 3, { 6, 5, 5 },
{ { 0, 0, 0, 8, false }, { 3, 1, 4, 1, false }, { 2, 2, 4, 1, false },
{ 0, 1, 0, 8, false }, { 3, 2, 2, 1, false }, { 2, 1, 4, 1, false },
{ 0, 2, 0, 8, false }, { 3, 2, 3, 1, false }, { 3, 2, 4, 1, false },
{ 1, 0, 0, 6, false }, { 2, 1, 0, 4, false }, { 1, 1, 0, 5, false },
{ 3, 2, 0, 1, false }, { 3, 1, 0, 4, false }, { 1, 2, 0, 5, false },
{ 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 6, false },
{ 3, 0, 0, 6, false },
{ -1 } }
},
/* 10011 */
{ true /* reserved */ },
/* 10110 */
{ false, true, 5, 8, 3, { 5, 6, 5 },
{ { 0, 0, 0, 8, false }, { 3, 2, 0, 1, false }, { 2, 2, 4, 1, false },
{ 0, 1, 0, 8, false }, { 2, 1, 5, 1, false }, { 2, 1, 4, 1, false },
{ 0, 2, 0, 8, false }, { 3, 1, 5, 1, false }, { 3, 2, 4, 1, false },
{ 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
{ 1, 1, 0, 6, false }, { 3, 1, 0, 4, false }, { 1, 2, 0, 5, false },
{ 3, 2, 1, 1, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 5, false },
{ 3, 2, 2, 1, false }, { 3, 0, 0, 5, false }, { 3, 2, 3, 1, false },
{ -1 } }
},
/* 10111 */
{ true /* reserved */ },
/* 11010 */
{ false, true, 5, 8, 3, { 5, 5, 6 },
{ { 0, 0, 0, 8, false }, { 3, 2, 1, 1, false }, { 2, 2, 4, 1, false },
{ 0, 1, 0, 8, false }, { 2, 2, 5, 1, false }, { 2, 1, 4, 1, false },
{ 0, 2, 0, 8, false }, { 3, 2, 5, 1, false }, { 3, 2, 4, 1, false },
{ 1, 0, 0, 5, false }, { 3, 1, 4, 1, false }, { 2, 1, 0, 4, false },
{ 1, 1, 0, 5, false }, { 3, 2, 0, 1, false }, { 3, 1, 0, 4, false },
{ 1, 2, 0, 6, false }, { 2, 2, 0, 4, false }, { 2, 0, 0, 5, false },
{ 3, 2, 2, 1, false }, { 3, 0, 0, 5, false }, { 3, 2, 3, 1, false },
{ -1 } }
},
/* 11011 */
{ true /* reserved */ },
/* 11110 */
{ false, false, 5, 6, 3, { 6, 6, 6 },
{ { 0, 0, 0, 6, false }, { 3, 1, 4, 1, false }, { 3, 2, 0, 1, false },
{ 3, 2, 1, 1, false }, { 2, 2, 4, 1, false }, { 0, 1, 0, 6, false },
{ 2, 1, 5, 1, false }, { 2, 2, 5, 1, false }, { 3, 2, 2, 1, false },
{ 2, 1, 4, 1, false }, { 0, 2, 0, 6, false }, { 3, 1, 5, 1, false },
{ 3, 2, 3, 1, false }, { 3, 2, 5, 1, false }, { 3, 2, 4, 1, false },
{ 1, 0, 0, 6, false }, { 2, 1, 0, 4, false }, { 1, 1, 0, 6, false },
{ 3, 1, 0, 4, false }, { 1, 2, 0, 6, false }, { 2, 2, 0, 4, false },
{ 2, 0, 0, 6, false }, { 3, 0, 0, 6, false },
{ -1 } }
},
/* 11111 */
{ true /* reserved */ },
};
/* This partition table is used when the mode has two subsets. Each
* partition is represented by a 32-bit value which gives 2 bits per texel
* within the block. The value of the two bits represents which subset to use
* (0 or 1).
*/
static const uint32_t
partition_table1[N_PARTITIONS] = {
0x50505050U, 0x40404040U, 0x54545454U, 0x54505040U,
0x50404000U, 0x55545450U, 0x55545040U, 0x54504000U,
0x50400000U, 0x55555450U, 0x55544000U, 0x54400000U,
0x55555440U, 0x55550000U, 0x55555500U, 0x55000000U,
0x55150100U, 0x00004054U, 0x15010000U, 0x00405054U,
0x00004050U, 0x15050100U, 0x05010000U, 0x40505054U,
0x00404050U, 0x05010100U, 0x14141414U, 0x05141450U,
0x01155440U, 0x00555500U, 0x15014054U, 0x05414150U,
0x44444444U, 0x55005500U, 0x11441144U, 0x05055050U,
0x05500550U, 0x11114444U, 0x41144114U, 0x44111144U,
0x15055054U, 0x01055040U, 0x05041050U, 0x05455150U,
0x14414114U, 0x50050550U, 0x41411414U, 0x00141400U,
0x00041504U, 0x00105410U, 0x10541000U, 0x04150400U,
0x50410514U, 0x41051450U, 0x05415014U, 0x14054150U,
0x41050514U, 0x41505014U, 0x40011554U, 0x54150140U,
0x50505500U, 0x00555050U, 0x15151010U, 0x54540404U,
};
/* This partition table is used when the mode has three subsets. In this case
* the values can be 0, 1 or 2.
*/
static const uint32_t
partition_table2[N_PARTITIONS] = {
0xaa685050U, 0x6a5a5040U, 0x5a5a4200U, 0x5450a0a8U,
0xa5a50000U, 0xa0a05050U, 0x5555a0a0U, 0x5a5a5050U,
0xaa550000U, 0xaa555500U, 0xaaaa5500U, 0x90909090U,
0x94949494U, 0xa4a4a4a4U, 0xa9a59450U, 0x2a0a4250U,
0xa5945040U, 0x0a425054U, 0xa5a5a500U, 0x55a0a0a0U,
0xa8a85454U, 0x6a6a4040U, 0xa4a45000U, 0x1a1a0500U,
0x0050a4a4U, 0xaaa59090U, 0x14696914U, 0x69691400U,
0xa08585a0U, 0xaa821414U, 0x50a4a450U, 0x6a5a0200U,
0xa9a58000U, 0x5090a0a8U, 0xa8a09050U, 0x24242424U,
0x00aa5500U, 0x24924924U, 0x24499224U, 0x50a50a50U,
0x500aa550U, 0xaaaa4444U, 0x66660000U, 0xa5a0a5a0U,
0x50a050a0U, 0x69286928U, 0x44aaaa44U, 0x66666600U,
0xaa444444U, 0x54a854a8U, 0x95809580U, 0x96969600U,
0xa85454a8U, 0x80959580U, 0xaa141414U, 0x96960000U,
0xaaaa1414U, 0xa05050a0U, 0xa0a5a5a0U, 0x96000000U,
0x40804080U, 0xa9a8a9a8U, 0xaaaaaa44U, 0x2a4a5254U
};
static const uint8_t
anchor_indices[][N_PARTITIONS] = {
/* Anchor index values for the second subset of two-subset partitioning */
{
0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,
0xf,0x2,0x8,0x2,0x2,0x8,0x8,0xf,0x2,0x8,0x2,0x2,0x8,0x8,0x2,0x2,
0xf,0xf,0x6,0x8,0x2,0x8,0xf,0xf,0x2,0x8,0x2,0x2,0x2,0xf,0xf,0x6,
0x6,0x2,0x6,0x8,0xf,0xf,0x2,0x2,0xf,0xf,0xf,0xf,0xf,0x2,0x2,0xf
},
/* Anchor index values for the second subset of three-subset partitioning */
{
0x3,0x3,0xf,0xf,0x8,0x3,0xf,0xf,0x8,0x8,0x6,0x6,0x6,0x5,0x3,0x3,
0x3,0x3,0x8,0xf,0x3,0x3,0x6,0xa,0x5,0x8,0x8,0x6,0x8,0x5,0xf,0xf,
0x8,0xf,0x3,0x5,0x6,0xa,0x8,0xf,0xf,0x3,0xf,0x5,0xf,0xf,0xf,0xf,
0x3,0xf,0x5,0x5,0x5,0x8,0x5,0xa,0x5,0xa,0x8,0xd,0xf,0xc,0x3,0x3
},
/* Anchor index values for the third subset of three-subset
* partitioning
*/
{
0xf,0x8,0x8,0x3,0xf,0xf,0x3,0x8,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0x8,
0xf,0x8,0xf,0x3,0xf,0x8,0xf,0x8,0x3,0xf,0x6,0xa,0xf,0xf,0xa,0x8,
0xf,0x3,0xf,0xa,0xa,0x8,0x9,0xa,0x6,0xf,0x8,0xf,0x3,0x6,0x6,0x8,
0xf,0x3,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0xf,0x3,0xf,0xf,0x8
}
};
static int
extract_bits(const uint8_t *block,
int offset,
int n_bits)
{
int byte_index = offset / 8;
int bit_index = offset % 8;
int n_bits_in_byte = MIN2(n_bits, 8 - bit_index);
int result = 0;
int bit = 0;
while (true) {
result |= ((block[byte_index] >> bit_index) &
((1 << n_bits_in_byte) - 1)) << bit;
n_bits -= n_bits_in_byte;
if (n_bits <= 0)
return result;
bit += n_bits_in_byte;
byte_index++;
bit_index = 0;
n_bits_in_byte = MIN2(n_bits, 8);
}
}
static uint8_t
expand_component(uint8_t byte,
int n_bits)
{
/* Expands a n-bit quantity into a byte by copying the most-significant
* bits into the unused least-significant bits.
*/
return byte << (8 - n_bits) | (byte >> (2 * n_bits - 8));
}
static int
extract_unorm_endpoints(const struct bptc_unorm_mode *mode,
const uint8_t *block,
int bit_offset,
uint8_t endpoints[][4])
{
int component;
int subset;
int endpoint;
int pbit;
int n_components;
/* Extract each color component */
for (component = 0; component < 3; component++) {
for (subset = 0; subset < mode->n_subsets; subset++) {
for (endpoint = 0; endpoint < 2; endpoint++) {
endpoints[subset * 2 + endpoint][component] =
extract_bits(block, bit_offset, mode->n_color_bits);
bit_offset += mode->n_color_bits;
}
}
}
/* Extract the alpha values */
if (mode->n_alpha_bits > 0) {
for (subset = 0; subset < mode->n_subsets; subset++) {
for (endpoint = 0; endpoint < 2; endpoint++) {
endpoints[subset * 2 + endpoint][3] =
extract_bits(block, bit_offset, mode->n_alpha_bits);
bit_offset += mode->n_alpha_bits;
}
}
n_components = 4;
} else {
for (subset = 0; subset < mode->n_subsets; subset++)
for (endpoint = 0; endpoint < 2; endpoint++)
endpoints[subset * 2 + endpoint][3] = 255;
n_components = 3;
}
/* Add in the p-bits */
if (mode->has_endpoint_pbits) {
for (subset = 0; subset < mode->n_subsets; subset++) {
for (endpoint = 0; endpoint < 2; endpoint++) {
pbit = extract_bits(block, bit_offset, 1);
bit_offset += 1;
for (component = 0; component < n_components; component++) {
endpoints[subset * 2 + endpoint][component] <<= 1;
endpoints[subset * 2 + endpoint][component] |= pbit;
}
}
}
} else if (mode->has_shared_pbits) {
for (subset = 0; subset < mode->n_subsets; subset++) {
pbit = extract_bits(block, bit_offset, 1);
bit_offset += 1;
for (endpoint = 0; endpoint < 2; endpoint++) {
for (component = 0; component < n_components; component++) {
endpoints[subset * 2 + endpoint][component] <<= 1;
endpoints[subset * 2 + endpoint][component] |= pbit;
}
}
}
}
/* Expand the n-bit values to a byte */
for (subset = 0; subset < mode->n_subsets; subset++) {
for (endpoint = 0; endpoint < 2; endpoint++) {
for (component = 0; component < 3; component++) {
endpoints[subset * 2 + endpoint][component] =
expand_component(endpoints[subset * 2 + endpoint][component],
mode->n_color_bits +
mode->has_endpoint_pbits +
mode->has_shared_pbits);
}
if (mode->n_alpha_bits > 0) {
endpoints[subset * 2 + endpoint][3] =
expand_component(endpoints[subset * 2 + endpoint][3],
mode->n_alpha_bits +
mode->has_endpoint_pbits +
mode->has_shared_pbits);
}
}
}
return bit_offset;
}
static bool
is_anchor(int n_subsets,
int partition_num,
int texel)
{
if (texel == 0)
return true;
switch (n_subsets) {
case 1:
return false;
case 2:
return anchor_indices[0][partition_num] == texel;
case 3:
return (anchor_indices[1][partition_num] == texel ||
anchor_indices[2][partition_num] == texel);
default:
assert(false);
return false;
}
}
static int
count_anchors_before_texel(int n_subsets,
int partition_num,
int texel)
{
int count = 1;
if (texel == 0)
return 0;
switch (n_subsets) {
case 1:
break;
case 2:
if (texel > anchor_indices[0][partition_num])
count++;
break;
case 3:
if (texel > anchor_indices[1][partition_num])
count++;
if (texel > anchor_indices[2][partition_num])
count++;
break;
default:
assert(false);
return 0;
}
return count;
}
static int32_t
interpolate(int32_t a, int32_t b,
int index,
int index_bits)
{
static const uint8_t weights2[] = { 0, 21, 43, 64 };
static const uint8_t weights3[] = { 0, 9, 18, 27, 37, 46, 55, 64 };
static const uint8_t weights4[] =
{ 0, 4, 9, 13, 17, 21, 26, 30, 34, 38, 43, 47, 51, 55, 60, 64 };
static const uint8_t *weights[] = {
NULL, NULL, weights2, weights3, weights4
};
int weight;
weight = weights[index_bits][index];
return ((64 - weight) * a + weight * b + 32) >> 6;
}
static void
apply_rotation(int rotation,
uint8_t *result)
{
uint8_t t;
if (rotation == 0)
return;
rotation--;
t = result[rotation];
result[rotation] = result[3];
result[3] = t;
}
static void
fetch_rgba_unorm_from_block(const uint8_t *block,
uint8_t *result,
int texel)
{
int mode_num = ffs(block[0]);
const struct bptc_unorm_mode *mode;
int bit_offset, secondary_bit_offset;
int partition_num;
int subset_num;
int rotation;
int index_selection;
int index_bits;
int indices[2];
int index;
int anchors_before_texel;
bool anchor;
uint8_t endpoints[3 * 2][4];
uint32_t subsets;
int component;
if (mode_num == 0) {
/* According to the spec this mode is reserved and shouldn't be used. */
memset(result, 0, 3);
result[3] = 0xff;
return;
}
mode = bptc_unorm_modes + mode_num - 1;
bit_offset = mode_num;
partition_num = extract_bits(block, bit_offset, mode->n_partition_bits);
bit_offset += mode->n_partition_bits;
switch (mode->n_subsets) {
case 1:
subsets = 0;
break;
case 2:
subsets = partition_table1[partition_num];
break;
case 3:
subsets = partition_table2[partition_num];
break;
default:
assert(false);
return;
}
if (mode->has_rotation_bits) {
rotation = extract_bits(block, bit_offset, 2);
bit_offset += 2;
} else {
rotation = 0;
}
if (mode->has_index_selection_bit) {
index_selection = extract_bits(block, bit_offset, 1);
bit_offset++;
} else {
index_selection = 0;
}
bit_offset = extract_unorm_endpoints(mode, block, bit_offset, endpoints);
anchors_before_texel = count_anchors_before_texel(mode->n_subsets,
partition_num, texel);
/* Calculate the offset to the secondary index */
secondary_bit_offset = (bit_offset +
BLOCK_SIZE * BLOCK_SIZE * mode->n_index_bits -
mode->n_subsets +
mode->n_secondary_index_bits * texel -
anchors_before_texel);
/* Calculate the offset to the primary index for this texel */
bit_offset += mode->n_index_bits * texel - anchors_before_texel;
subset_num = (subsets >> (texel * 2)) & 3;
anchor = is_anchor(mode->n_subsets, partition_num, texel);
index_bits = mode->n_index_bits;
if (anchor)
index_bits--;
indices[0] = extract_bits(block, bit_offset, index_bits);
if (mode->n_secondary_index_bits) {
index_bits = mode->n_secondary_index_bits;
if (anchor)
index_bits--;
indices[1] = extract_bits(block, secondary_bit_offset, index_bits);
}
index = indices[index_selection];
index_bits = (index_selection ?
mode->n_secondary_index_bits :
mode->n_index_bits);
for (component = 0; component < 3; component++)
result[component] = interpolate(endpoints[subset_num * 2][component],
endpoints[subset_num * 2 + 1][component],
index,
index_bits);
/* Alpha uses the opposite index from the color components */
if (mode->n_secondary_index_bits && !index_selection) {
index = indices[1];
index_bits = mode->n_secondary_index_bits;
} else {
index = indices[0];
index_bits = mode->n_index_bits;
}
result[3] = interpolate(endpoints[subset_num * 2][3],
endpoints[subset_num * 2 + 1][3],
index,
index_bits);
apply_rotation(rotation, result);
}
static void
fetch_bptc_rgba_unorm_bytes(const GLubyte *map,
GLint rowStride, GLint i, GLint j,
GLubyte *texel)
{
const GLubyte *block;
block = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
fetch_rgba_unorm_from_block(block, texel, (i % 4) + (j % 4) * 4);
}
static void
fetch_bptc_rgba_unorm(const GLubyte *map,
GLint rowStride, GLint i, GLint j,
GLfloat *texel)
{
GLubyte texel_bytes[4];
fetch_bptc_rgba_unorm_bytes(map, rowStride, i, j, texel_bytes);
texel[RCOMP] = UBYTE_TO_FLOAT(texel_bytes[0]);
texel[GCOMP] = UBYTE_TO_FLOAT(texel_bytes[1]);
texel[BCOMP] = UBYTE_TO_FLOAT(texel_bytes[2]);
texel[ACOMP] = UBYTE_TO_FLOAT(texel_bytes[3]);
}
static void
fetch_bptc_srgb_alpha_unorm(const GLubyte *map,
GLint rowStride, GLint i, GLint j,
GLfloat *texel)
{
GLubyte texel_bytes[4];
fetch_bptc_rgba_unorm_bytes(map, rowStride, i, j, texel_bytes);
texel[RCOMP] = util_format_srgb_8unorm_to_linear_float(texel_bytes[0]);
texel[GCOMP] = util_format_srgb_8unorm_to_linear_float(texel_bytes[1]);
texel[BCOMP] = util_format_srgb_8unorm_to_linear_float(texel_bytes[2]);
texel[ACOMP] = UBYTE_TO_FLOAT(texel_bytes[3]);
}
static int32_t
sign_extend(int32_t value,
int n_bits)
{
if ((value & (1 << (n_bits - 1)))) {
value |= (~(int32_t) 0) << n_bits;
}
return value;
}
static int
signed_unquantize(int value, int n_endpoint_bits)
{
bool sign;
if (n_endpoint_bits >= 16)
return value;
if (value == 0)
return 0;
sign = false;
if (value < 0) {
sign = true;
value = -value;
}
if (value >= (1 << (n_endpoint_bits - 1)) - 1)
value = 0x7fff;
else
value = ((value << 15) + 0x4000) >> (n_endpoint_bits - 1);
if (sign)
value = -value;
return value;
}
static int
unsigned_unquantize(int value, int n_endpoint_bits)
{
if (n_endpoint_bits >= 15)
return value;
if (value == 0)
return 0;
if (value == (1 << n_endpoint_bits) - 1)
return 0xffff;
return ((value << 15) + 0x4000) >> (n_endpoint_bits - 1);
}
static int
extract_float_endpoints(const struct bptc_float_mode *mode,
const uint8_t *block,
int bit_offset,
int32_t endpoints[][3],
bool is_signed)
{
const struct bptc_float_bitfield *bitfield;
int endpoint, component;
int n_endpoints;
int value;
int i;
if (mode->n_partition_bits)
n_endpoints = 4;
else
n_endpoints = 2;
memset(endpoints, 0, sizeof endpoints[0][0] * n_endpoints * 3);
for (bitfield = mode->bitfields; bitfield->endpoint != -1; bitfield++) {
value = extract_bits(block, bit_offset, bitfield->n_bits);
bit_offset += bitfield->n_bits;
if (bitfield->reverse) {
for (i = 0; i < bitfield->n_bits; i++) {
if (value & (1 << i))
endpoints[bitfield->endpoint][bitfield->component] |=
1 << ((bitfield->n_bits - 1 - i) + bitfield->offset);
}
} else {
endpoints[bitfield->endpoint][bitfield->component] |=
value << bitfield->offset;
}
}
if (mode->transformed_endpoints) {
/* The endpoints are specified as signed offsets from e0 */
for (endpoint = 1; endpoint < n_endpoints; endpoint++) {
for (component = 0; component < 3; component++) {
value = sign_extend(endpoints[endpoint][component],
mode->n_delta_bits[component]);
endpoints[endpoint][component] =
((endpoints[0][component] + value) &
((1 << mode->n_endpoint_bits) - 1));
}
}
}
if (is_signed) {
for (endpoint = 0; endpoint < n_endpoints; endpoint++) {
for (component = 0; component < 3; component++) {
value = sign_extend(endpoints[endpoint][component],
mode->n_endpoint_bits);
endpoints[endpoint][component] =
signed_unquantize(value, mode->n_endpoint_bits);
}
}
} else {
for (endpoint = 0; endpoint < n_endpoints; endpoint++) {
for (component = 0; component < 3; component++) {
endpoints[endpoint][component] =
unsigned_unquantize(endpoints[endpoint][component],
mode->n_endpoint_bits);
}
}
}
return bit_offset;
}
static int32_t
finish_unsigned_unquantize(int32_t value)
{
return value * 31 / 64;
}
static int32_t
finish_signed_unquantize(int32_t value)
{
if (value < 0)
return (-value * 31 / 32) | 0x8000;
else
return value * 31 / 32;
}
static void
fetch_rgb_float_from_block(const uint8_t *block,
float *result,
int texel,
bool is_signed)
{
int mode_num;
const struct bptc_float_mode *mode;
int bit_offset;
int partition_num;
int subset_num;
int index_bits;
int index;
int anchors_before_texel;
int32_t endpoints[2 * 2][3];
uint32_t subsets;
int n_subsets;
int component;
int32_t value;
if (block[0] & 0x2) {
mode_num = (((block[0] >> 1) & 0xe) | (block[0] & 1)) + 2;
bit_offset = 5;
} else {
mode_num = block[0] & 3;
bit_offset = 2;
}
mode = bptc_float_modes + mode_num;
if (mode->reserved) {
memset(result, 0, sizeof result[0] * 3);
result[3] = 1.0f;
return;
}
bit_offset = extract_float_endpoints(mode, block, bit_offset,
endpoints, is_signed);
if (mode->n_partition_bits) {
partition_num = extract_bits(block, bit_offset, mode->n_partition_bits);
bit_offset += mode->n_partition_bits;
subsets = partition_table1[partition_num];
n_subsets = 2;
} else {
partition_num = 0;
subsets = 0;
n_subsets = 1;
}
anchors_before_texel =
count_anchors_before_texel(n_subsets, partition_num, texel);
/* Calculate the offset to the primary index for this texel */
bit_offset += mode->n_index_bits * texel - anchors_before_texel;
subset_num = (subsets >> (texel * 2)) & 3;
index_bits = mode->n_index_bits;
if (is_anchor(n_subsets, partition_num, texel))
index_bits--;
index = extract_bits(block, bit_offset, index_bits);
for (component = 0; component < 3; component++) {
value = interpolate(endpoints[subset_num * 2][component],
endpoints[subset_num * 2 + 1][component],
index,
mode->n_index_bits);
if (is_signed)
value = finish_signed_unquantize(value);
else
value = finish_unsigned_unquantize(value);
result[component] = _mesa_half_to_float(value);
}
result[3] = 1.0f;
}
static void
fetch_bptc_rgb_float(const GLubyte *map,
GLint rowStride, GLint i, GLint j,
GLfloat *texel,
bool is_signed)
{
const GLubyte *block;
block = map + (((rowStride + 3) / 4) * (j / 4) + (i / 4)) * 16;
fetch_rgb_float_from_block(block, texel, (i % 4) + (j % 4) * 4, is_signed);
}
static void
fetch_bptc_rgb_signed_float(const GLubyte *map,
GLint rowStride, GLint i, GLint j,
GLfloat *texel)
{
fetch_bptc_rgb_float(map, rowStride, i, j, texel, true);
}
static void
fetch_bptc_rgb_unsigned_float(const GLubyte *map,
GLint rowStride, GLint i, GLint j,
GLfloat *texel)
{
fetch_bptc_rgb_float(map, rowStride, i, j, texel, false);
}
compressed_fetch_func
_mesa_get_bptc_fetch_func(mesa_format format)
{
switch (format) {
case MESA_FORMAT_BPTC_RGBA_UNORM:
return fetch_bptc_rgba_unorm;
case MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM:
return fetch_bptc_srgb_alpha_unorm;
case MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT:
return fetch_bptc_rgb_signed_float;
case MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT:
return fetch_bptc_rgb_unsigned_float;
default:
return NULL;
}
}
static void
write_bits(struct bit_writer *writer, int n_bits, int value)
{
do {
if (n_bits + writer->pos >= 8) {
*(writer->dst++) = writer->buf | (value << writer->pos);
writer->buf = 0;
value >>= (8 - writer->pos);
n_bits -= (8 - writer->pos);
writer->pos = 0;
} else {
writer->buf |= value << writer->pos;
writer->pos += n_bits;
break;
}
} while (n_bits > 0);
}
static void
get_average_luminance_alpha_unorm(int width, int height,
const uint8_t *src, int src_rowstride,
int *average_luminance, int *average_alpha)
{
int luminance_sum = 0, alpha_sum = 0;
int y, x;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
luminance_sum += src[0] + src[1] + src[2];
alpha_sum += src[3];
src += 4;
}
src += src_rowstride - width * 4;
}
*average_luminance = luminance_sum / (width * height);
*average_alpha = alpha_sum / (width * height);
}
static void
get_rgba_endpoints_unorm(int width, int height,
const uint8_t *src, int src_rowstride,
int average_luminance, int average_alpha,
uint8_t endpoints[][4])
{
int endpoint_luminances[2];
int midpoint;
int sums[2][4];
int endpoint;
int luminance;
uint8_t temp[3];
const uint8_t *p = src;
int rgb_left_endpoint_count = 0;
int alpha_left_endpoint_count = 0;
int y, x, i;
memset(sums, 0, sizeof sums);
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
luminance = p[0] + p[1] + p[2];
if (luminance < average_luminance) {
endpoint = 0;
rgb_left_endpoint_count++;
} else {
endpoint = 1;
}
for (i = 0; i < 3; i++)
sums[endpoint][i] += p[i];
if (p[2] < average_alpha) {
endpoint = 0;
alpha_left_endpoint_count++;
} else {
endpoint = 1;
}
sums[endpoint][3] += p[3];
p += 4;
}
p += src_rowstride - width * 4;
}
if (rgb_left_endpoint_count == 0 ||
rgb_left_endpoint_count == width * height) {
for (i = 0; i < 3; i++)
endpoints[0][i] = endpoints[1][i] =
(sums[0][i] + sums[1][i]) / (width * height);
} else {
for (i = 0; i < 3; i++) {
endpoints[0][i] = sums[0][i] / rgb_left_endpoint_count;
endpoints[1][i] = (sums[1][i] /
(width * height - rgb_left_endpoint_count));
}
}
if (alpha_left_endpoint_count == 0 ||
alpha_left_endpoint_count == width * height) {
endpoints[0][3] = endpoints[1][3] =
(sums[0][3] + sums[1][3]) / (width * height);
} else {
endpoints[0][3] = sums[0][3] / alpha_left_endpoint_count;
endpoints[1][3] = (sums[1][3] /
(width * height - alpha_left_endpoint_count));
}
/* We may need to swap the endpoints to ensure the most-significant bit of
* the first index is zero */
for (endpoint = 0; endpoint < 2; endpoint++) {
endpoint_luminances[endpoint] =
endpoints[endpoint][0] +
endpoints[endpoint][1] +
endpoints[endpoint][2];
}
midpoint = (endpoint_luminances[0] + endpoint_luminances[1]) / 2;
if ((src[0] + src[1] + src[2] <= midpoint) !=
(endpoint_luminances[0] <= midpoint)) {
memcpy(temp, endpoints[0], 3);
memcpy(endpoints[0], endpoints[1], 3);
memcpy(endpoints[1], temp, 3);
}
/* Same for the alpha endpoints */
midpoint = (endpoints[0][3] + endpoints[1][3]) / 2;
if ((src[3] <= midpoint) != (endpoints[0][3] <= midpoint)) {
temp[0] = endpoints[0][3];
endpoints[0][3] = endpoints[1][3];
endpoints[1][3] = temp[0];
}
}
static void
write_rgb_indices_unorm(struct bit_writer *writer,
int src_width, int src_height,
const uint8_t *src, int src_rowstride,
uint8_t endpoints[][4])
{
int luminance;
int endpoint_luminances[2];
int endpoint;
int index;
int y, x;
for (endpoint = 0; endpoint < 2; endpoint++) {
endpoint_luminances[endpoint] =
endpoints[endpoint][0] +
endpoints[endpoint][1] +
endpoints[endpoint][2];
}
/* If the endpoints have the same luminance then we'll just use index 0 for
* all of the texels */
if (endpoint_luminances[0] == endpoint_luminances[1]) {
write_bits(writer, BLOCK_SIZE * BLOCK_SIZE * 2 - 1, 0);
return;
}
for (y = 0; y < src_height; y++) {
for (x = 0; x < src_width; x++) {
luminance = src[0] + src[1] + src[2];
index = ((luminance - endpoint_luminances[0]) * 3 /
(endpoint_luminances[1] - endpoint_luminances[0]));
if (index < 0)
index = 0;
else if (index > 3)
index = 3;
assert(x != 0 || y != 0 || index < 2);
write_bits(writer, (x == 0 && y == 0) ? 1 : 2, index);
src += 4;
}
/* Pad the indices out to the block size */
if (src_width < BLOCK_SIZE)
write_bits(writer, 2 * (BLOCK_SIZE - src_width), 0);
src += src_rowstride - src_width * 4;
}
/* Pad the indices out to the block size */
if (src_height < BLOCK_SIZE)
write_bits(writer, 2 * BLOCK_SIZE * (BLOCK_SIZE - src_height), 0);
}
static void
write_alpha_indices_unorm(struct bit_writer *writer,
int src_width, int src_height,
const uint8_t *src, int src_rowstride,
uint8_t endpoints[][4])
{
int index;
int y, x;
/* If the endpoints have the same alpha then we'll just use index 0 for
* all of the texels */
if (endpoints[0][3] == endpoints[1][3]) {
write_bits(writer, BLOCK_SIZE * BLOCK_SIZE * 3 - 1, 0);
return;
}
for (y = 0; y < src_height; y++) {
for (x = 0; x < src_width; x++) {
index = (((int) src[3] - (int) endpoints[0][3]) * 7 /
((int) endpoints[1][3] - endpoints[0][3]));
if (index < 0)
index = 0;
else if (index > 7)
index = 7;
assert(x != 0 || y != 0 || index < 4);
/* The first index has one less bit */
write_bits(writer, (x == 0 && y == 0) ? 2 : 3, index);
src += 4;
}
/* Pad the indices out to the block size */
if (src_width < BLOCK_SIZE)
write_bits(writer, 3 * (BLOCK_SIZE - src_width), 0);
src += src_rowstride - src_width * 4;
}
/* Pad the indices out to the block size */
if (src_height < BLOCK_SIZE)
write_bits(writer, 3 * BLOCK_SIZE * (BLOCK_SIZE - src_height), 0);
}
static void
compress_rgba_unorm_block(int src_width, int src_height,
const uint8_t *src, int src_rowstride,
uint8_t *dst)
{
int average_luminance, average_alpha;
uint8_t endpoints[2][4];
struct bit_writer writer;
int component, endpoint;
get_average_luminance_alpha_unorm(src_width, src_height, src, src_rowstride,
&average_luminance, &average_alpha);
get_rgba_endpoints_unorm(src_width, src_height, src, src_rowstride,
average_luminance, average_alpha,
endpoints);
writer.dst = dst;
writer.pos = 0;
writer.buf = 0;
write_bits(&writer, 5, 0x10); /* mode 4 */
write_bits(&writer, 2, 0); /* rotation 0 */
write_bits(&writer, 1, 0); /* index selection bit */
/* Write the color endpoints */
for (component = 0; component < 3; component++)
for (endpoint = 0; endpoint < 2; endpoint++)
write_bits(&writer, 5, endpoints[endpoint][component] >> 3);
/* Write the alpha endpoints */
for (endpoint = 0; endpoint < 2; endpoint++)
write_bits(&writer, 6, endpoints[endpoint][3] >> 2);
write_rgb_indices_unorm(&writer,
src_width, src_height,
src, src_rowstride,
endpoints);
write_alpha_indices_unorm(&writer,
src_width, src_height,
src, src_rowstride,
endpoints);
}
static void
compress_rgba_unorm(int width, int height,
const uint8_t *src, int src_rowstride,
uint8_t *dst, int dst_rowstride)
{
int dst_row_diff;
int y, x;
if (dst_rowstride >= width * 4)
dst_row_diff = dst_rowstride - ((width + 3) & ~3) * 4;
else
dst_row_diff = 0;
for (y = 0; y < height; y += BLOCK_SIZE) {
for (x = 0; x < width; x += BLOCK_SIZE) {
compress_rgba_unorm_block(MIN2(width - x, BLOCK_SIZE),
MIN2(height - y, BLOCK_SIZE),
src + x * 4 + y * src_rowstride,
src_rowstride,
dst);
dst += BLOCK_BYTES;
}
dst += dst_row_diff;
}
}
GLboolean
_mesa_texstore_bptc_rgba_unorm(TEXSTORE_PARAMS)
{
const GLubyte *pixels;
const GLubyte *tempImage = NULL;
int rowstride;
if (srcFormat != GL_RGBA ||
srcType != GL_UNSIGNED_BYTE ||
ctx->_ImageTransferState ||
srcPacking->SwapBytes) {
/* convert image to RGBA/ubyte */
GLubyte *tempImageSlices[1];
int rgbaRowStride = 4 * srcWidth * sizeof(GLubyte);
tempImage = malloc(srcWidth * srcHeight * 4 * sizeof(GLubyte));
if (!tempImage)
return GL_FALSE; /* out of memory */
tempImageSlices[0] = (GLubyte *) tempImage;
_mesa_texstore(ctx, dims,
baseInternalFormat,
_mesa_little_endian() ? MESA_FORMAT_R8G8B8A8_UNORM
: MESA_FORMAT_A8B8G8R8_UNORM,
rgbaRowStride, tempImageSlices,
srcWidth, srcHeight, srcDepth,
srcFormat, srcType, srcAddr,
srcPacking);
pixels = tempImage;
rowstride = srcWidth * 4;
} else {
pixels = _mesa_image_address2d(srcPacking, srcAddr, srcWidth, srcHeight,
srcFormat, srcType, 0, 0);
rowstride = _mesa_image_row_stride(srcPacking, srcWidth,
srcFormat, srcType);
}
compress_rgba_unorm(srcWidth, srcHeight,
pixels, rowstride,
dstSlices[0], dstRowStride);
free((void *) tempImage);
return GL_TRUE;
}
static float
get_average_luminance_float(int width, int height,
const float *src, int src_rowstride)
{
float luminance_sum = 0;
int y, x;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
luminance_sum += src[0] + src[1] + src[2];
src += 3;
}
src += (src_rowstride - width * 3 * sizeof (float)) / sizeof (float);
}
return luminance_sum / (width * height);
}
static float
clamp_value(float value, bool is_signed)
{
if (value > 65504.0f)
return 65504.0f;
if (is_signed) {
if (value < -65504.0f)
return -65504.0f;
else
return value;
}
if (value < 0.0f)
return 0.0f;
return value;
}
static void
get_endpoints_float(int width, int height,
const float *src, int src_rowstride,
float average_luminance, float endpoints[][3],
bool is_signed)
{
float endpoint_luminances[2];
float midpoint;
float sums[2][3];
int endpoint, component;
float luminance;
float temp[3];
const float *p = src;
int left_endpoint_count = 0;
int y, x, i;
memset(sums, 0, sizeof sums);
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
luminance = p[0] + p[1] + p[2];
if (luminance < average_luminance) {
endpoint = 0;
left_endpoint_count++;
} else {
endpoint = 1;
}
for (i = 0; i < 3; i++)
sums[endpoint][i] += p[i];
p += 3;
}
p += (src_rowstride - width * 3 * sizeof (float)) / sizeof (float);
}
if (left_endpoint_count == 0 ||
left_endpoint_count == width * height) {
for (i = 0; i < 3; i++)
endpoints[0][i] = endpoints[1][i] =
(sums[0][i] + sums[1][i]) / (width * height);
} else {
for (i = 0; i < 3; i++) {
endpoints[0][i] = sums[0][i] / left_endpoint_count;
endpoints[1][i] = sums[1][i] / (width * height - left_endpoint_count);
}
}
/* Clamp the endpoints to the range of a half float and strip out
* infinities */
for (endpoint = 0; endpoint < 2; endpoint++) {
for (component = 0; component < 3; component++) {
endpoints[endpoint][component] =
clamp_value(endpoints[endpoint][component], is_signed);
}
}
/* We may need to swap the endpoints to ensure the most-significant bit of
* the first index is zero */
for (endpoint = 0; endpoint < 2; endpoint++) {
endpoint_luminances[endpoint] =
endpoints[endpoint][0] +
endpoints[endpoint][1] +
endpoints[endpoint][2];
}
midpoint = (endpoint_luminances[0] + endpoint_luminances[1]) / 2.0f;
if ((src[0] + src[1] + src[2] <= midpoint) !=
(endpoint_luminances[0] <= midpoint)) {
memcpy(temp, endpoints[0], sizeof temp);
memcpy(endpoints[0], endpoints[1], sizeof temp);
memcpy(endpoints[1], temp, sizeof temp);
}
}
static void
write_rgb_indices_float(struct bit_writer *writer,
int src_width, int src_height,
const float *src, int src_rowstride,
float endpoints[][3])
{
float luminance;
float endpoint_luminances[2];
int endpoint;
int index;
int y, x;
for (endpoint = 0; endpoint < 2; endpoint++) {
endpoint_luminances[endpoint] =
endpoints[endpoint][0] +
endpoints[endpoint][1] +
endpoints[endpoint][2];
}
/* If the endpoints have the same luminance then we'll just use index 0 for
* all of the texels */
if (endpoint_luminances[0] == endpoint_luminances[1]) {
write_bits(writer, BLOCK_SIZE * BLOCK_SIZE * 4 - 1, 0);
return;
}
for (y = 0; y < src_height; y++) {
for (x = 0; x < src_width; x++) {
luminance = src[0] + src[1] + src[2];
index = ((luminance - endpoint_luminances[0]) * 15 /
(endpoint_luminances[1] - endpoint_luminances[0]));
if (index < 0)
index = 0;
else if (index > 15)
index = 15;
assert(x != 0 || y != 0 || index < 8);
write_bits(writer, (x == 0 && y == 0) ? 3 : 4, index);
src += 3;
}
/* Pad the indices out to the block size */
if (src_width < BLOCK_SIZE)
write_bits(writer, 4 * (BLOCK_SIZE - src_width), 0);
src += (src_rowstride - src_width * 3 * sizeof (float)) / sizeof (float);
}
/* Pad the indices out to the block size */
if (src_height < BLOCK_SIZE)
write_bits(writer, 4 * BLOCK_SIZE * (BLOCK_SIZE - src_height), 0);
}
static int
get_endpoint_value(float value, bool is_signed)
{
bool sign = false;
int half;
if (is_signed) {
half = _mesa_float_to_half(value);
if (half & 0x8000) {
half &= 0x7fff;
sign = true;
}
half = (32 * half / 31) >> 6;
if (sign)
half = -half & ((1 << 10) - 1);
return half;
} else {
if (value <= 0.0f)
return 0;
half = _mesa_float_to_half(value);
return (64 * half / 31) >> 6;
}
}
static void
compress_rgb_float_block(int src_width, int src_height,
const float *src, int src_rowstride,
uint8_t *dst,
bool is_signed)
{
float average_luminance;
float endpoints[2][3];
struct bit_writer writer;
int component, endpoint;
int endpoint_value;
average_luminance =
get_average_luminance_float(src_width, src_height, src, src_rowstride);
get_endpoints_float(src_width, src_height, src, src_rowstride,
average_luminance, endpoints, is_signed);
writer.dst = dst;
writer.pos = 0;
writer.buf = 0;
write_bits(&writer, 5, 3); /* mode 3 */
/* Write the endpoints */
for (endpoint = 0; endpoint < 2; endpoint++) {
for (component = 0; component < 3; component++) {
endpoint_value =
get_endpoint_value(endpoints[endpoint][component], is_signed);
write_bits(&writer, 10, endpoint_value);
}
}
write_rgb_indices_float(&writer,
src_width, src_height,
src, src_rowstride,
endpoints);
}
static void
compress_rgb_float(int width, int height,
const float *src, int src_rowstride,
uint8_t *dst, int dst_rowstride,
bool is_signed)
{
int dst_row_diff;
int y, x;
if (dst_rowstride >= width * 4)
dst_row_diff = dst_rowstride - ((width + 3) & ~3) * 4;
else
dst_row_diff = 0;
for (y = 0; y < height; y += BLOCK_SIZE) {
for (x = 0; x < width; x += BLOCK_SIZE) {
compress_rgb_float_block(MIN2(width - x, BLOCK_SIZE),
MIN2(height - y, BLOCK_SIZE),
src + x * 3 +
y * src_rowstride / sizeof (float),
src_rowstride,
dst,
is_signed);
dst += BLOCK_BYTES;
}
dst += dst_row_diff;
}
}
static GLboolean
texstore_bptc_rgb_float(TEXSTORE_PARAMS,
bool is_signed)
{
const float *pixels;
const float *tempImage = NULL;
int rowstride;
if (srcFormat != GL_RGB ||
srcType != GL_FLOAT ||
ctx->_ImageTransferState ||
srcPacking->SwapBytes) {
/* convert image to RGB/float */
GLfloat *tempImageSlices[1];
int rgbRowStride = 3 * srcWidth * sizeof(GLfloat);
tempImage = malloc(srcWidth * srcHeight * 3 * sizeof(GLfloat));
if (!tempImage)
return GL_FALSE; /* out of memory */
tempImageSlices[0] = (GLfloat *) tempImage;
_mesa_texstore(ctx, dims,
baseInternalFormat,
MESA_FORMAT_RGB_FLOAT32,
rgbRowStride, (GLubyte **)tempImageSlices,
srcWidth, srcHeight, srcDepth,
srcFormat, srcType, srcAddr,
srcPacking);
pixels = tempImage;
rowstride = srcWidth * sizeof(float) * 3;
} else {
pixels = _mesa_image_address2d(srcPacking, srcAddr, srcWidth, srcHeight,
srcFormat, srcType, 0, 0);
rowstride = _mesa_image_row_stride(srcPacking, srcWidth,
srcFormat, srcType);
}
compress_rgb_float(srcWidth, srcHeight,
pixels, rowstride,
dstSlices[0], dstRowStride,
is_signed);
free((void *) tempImage);
return GL_TRUE;
}
GLboolean
_mesa_texstore_bptc_rgb_signed_float(TEXSTORE_PARAMS)
{
assert(dstFormat == MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT);
return texstore_bptc_rgb_float(ctx, dims, baseInternalFormat,
dstFormat, dstRowStride, dstSlices,
srcWidth, srcHeight, srcDepth,
srcFormat, srcType,
srcAddr, srcPacking,
true /* signed */);
}
GLboolean
_mesa_texstore_bptc_rgb_unsigned_float(TEXSTORE_PARAMS)
{
assert(dstFormat == MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT);
return texstore_bptc_rgb_float(ctx, dims, baseInternalFormat,
dstFormat, dstRowStride, dstSlices,
srcWidth, srcHeight, srcDepth,
srcFormat, srcType,
srcAddr, srcPacking,
false /* unsigned */);
}