--- /dev/null
+/*
+ * 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 "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];
+};
+
+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;
+ }
+}
projects / platform / upstream / mesa.git / commitdiff