/* * 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. */ /* * Included by texcompress_bptc and gallium to define BPTC decoding routines. */ #include "util/format_srgb.h" #include "util/half_float.h" #include "macros.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); } #ifdef BPTC_BLOCK_DECODE static void decompress_rgba_unorm_block(int src_width, int src_height, const uint8_t *block, uint8_t *dst_row, int dst_rowstride) { 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; unsigned x, y; if (mode_num == 0) { /* According to the spec this mode is reserved and shouldn't be used. */ for(y = 0; y < src_height; y += 1) { uint8_t *result = dst_row; memset(result, 0, 4 * src_width); for(x = 0; x < src_width; x += 1) { result[3] = 0xff; result += 4; } dst_row += dst_rowstride; } 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); for(y = 0; y < src_height; y += 1) { uint8_t *result = dst_row; for(x = 0; x < src_width; x += 1) { int texel; texel = x + y * 4; 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); result += 4; } dst_row += dst_rowstride; } } static void decompress_rgba_unorm(int width, int height, const uint8_t *src, int src_rowstride, uint8_t *dst, int dst_rowstride) { int src_row_diff; int y, x; if (src_rowstride >= width * 4) src_row_diff = src_rowstride - ((width + 3) & ~3) * 4; else src_row_diff = 0; for (y = 0; y < height; y += BLOCK_SIZE) { for (x = 0; x < width; x += BLOCK_SIZE) { decompress_rgba_unorm_block(MIN2(width - x, BLOCK_SIZE), MIN2(height - y, BLOCK_SIZE), src, dst + x * 4 + y * dst_rowstride, dst_rowstride); src += BLOCK_BYTES; } src += src_row_diff; } } #endif // BPTC_BLOCK_DECODE 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; } #ifdef BPTC_BLOCK_DECODE static void decompress_rgb_float_block(unsigned src_width, unsigned src_height, const uint8_t *block, float *dst_row, unsigned dst_rowstride, 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; unsigned x, y; 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) { for(y = 0; y < src_height; y += 1) { float *result = dst_row; memset(result, 0, sizeof result[0] * 4 * src_width); for(x = 0; x < src_width; x += 1) { result[3] = 1.0f; result += 4; } dst_row += dst_rowstride / sizeof dst_row[0]; } 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; } for(y = 0; y < src_height; y += 1) { float *result = dst_row; for(x = 0; x < src_width; x += 1) { int texel; texel = x + y * 4; 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; result += 4; } dst_row += dst_rowstride / sizeof dst_row[0]; } } static void decompress_rgb_float(int width, int height, const uint8_t *src, int src_rowstride, float *dst, int dst_rowstride, bool is_signed) { int src_row_diff; int y, x; if (src_rowstride >= width * 4) src_row_diff = src_rowstride - ((width + 3) & ~3) * 4; else src_row_diff = 0; for (y = 0; y < height; y += BLOCK_SIZE) { for (x = 0; x < width; x += BLOCK_SIZE) { decompress_rgb_float_block(MIN2(width - x, BLOCK_SIZE), MIN2(height - y, BLOCK_SIZE), src, (dst + x * 4 + (y * dst_rowstride / sizeof dst[0])), dst_rowstride, is_signed); src += BLOCK_BYTES; } src += src_row_diff; } } #endif // BPTC_BLOCK_DECODE 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; } } 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; } }