// SPDX-License-Identifier: Apache-2.0 // ---------------------------------------------------------------------------- // Copyright 2011-2022 Arm Limited // // Licensed under the Apache License, Version 2.0 (the "License"); you may not // use this file except in compliance with the License. You may obtain a copy // of the License at: // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the // License for the specific language governing permissions and limitations // under the License. // ---------------------------------------------------------------------------- /** * @brief Functions to generate block size descriptor and decimation tables. */ #include "astcenc_internal.h" /** * @brief Decode the properties of an encoded 2D block mode. * * @param block_mode The encoded block mode. * @param[out] x_weights The number of weights in the X dimension. * @param[out] y_weights The number of weights in the Y dimension. * @param[out] is_dual_plane True if this block mode has two weight planes. * @param[out] quant_mode The quantization level for the weights. * @param[out] weight_bits The storage bit count for the weights. * * @return Returns true if a valid mode, false otherwise. */ static bool decode_block_mode_2d( unsigned int block_mode, unsigned int& x_weights, unsigned int& y_weights, bool& is_dual_plane, unsigned int& quant_mode, unsigned int& weight_bits ) { unsigned int base_quant_mode = (block_mode >> 4) & 1; unsigned int H = (block_mode >> 9) & 1; unsigned int D = (block_mode >> 10) & 1; unsigned int A = (block_mode >> 5) & 0x3; x_weights = 0; y_weights = 0; if ((block_mode & 3) != 0) { base_quant_mode |= (block_mode & 3) << 1; unsigned int B = (block_mode >> 7) & 3; switch ((block_mode >> 2) & 3) { case 0: x_weights = B + 4; y_weights = A + 2; break; case 1: x_weights = B + 8; y_weights = A + 2; break; case 2: x_weights = A + 2; y_weights = B + 8; break; case 3: B &= 1; if (block_mode & 0x100) { x_weights = B + 2; y_weights = A + 2; } else { x_weights = A + 2; y_weights = B + 6; } break; } } else { base_quant_mode |= ((block_mode >> 2) & 3) << 1; if (((block_mode >> 2) & 3) == 0) { return false; } unsigned int B = (block_mode >> 9) & 3; switch ((block_mode >> 7) & 3) { case 0: x_weights = 12; y_weights = A + 2; break; case 1: x_weights = A + 2; y_weights = 12; break; case 2: x_weights = A + 6; y_weights = B + 6; D = 0; H = 0; break; case 3: switch ((block_mode >> 5) & 3) { case 0: x_weights = 6; y_weights = 10; break; case 1: x_weights = 10; y_weights = 6; break; case 2: case 3: return false; } break; } } unsigned int weight_count = x_weights * y_weights * (D + 1); quant_mode = (base_quant_mode - 2) + 6 * H; is_dual_plane = D != 0; weight_bits = get_ise_sequence_bitcount(weight_count, static_cast<quant_method>(quant_mode)); return (weight_count <= BLOCK_MAX_WEIGHTS && weight_bits >= BLOCK_MIN_WEIGHT_BITS && weight_bits <= BLOCK_MAX_WEIGHT_BITS); } /** * @brief Decode the properties of an encoded 3D block mode. * * @param block_mode The encoded block mode. * @param[out] x_weights The number of weights in the X dimension. * @param[out] y_weights The number of weights in the Y dimension. * @param[out] z_weights The number of weights in the Z dimension. * @param[out] is_dual_plane True if this block mode has two weight planes. * @param[out] quant_mode The quantization level for the weights. * @param[out] weight_bits The storage bit count for the weights. * * @return Returns true if a valid mode, false otherwise. */ static bool decode_block_mode_3d( unsigned int block_mode, unsigned int& x_weights, unsigned int& y_weights, unsigned int& z_weights, bool& is_dual_plane, unsigned int& quant_mode, unsigned int& weight_bits ) { unsigned int base_quant_mode = (block_mode >> 4) & 1; unsigned int H = (block_mode >> 9) & 1; unsigned int D = (block_mode >> 10) & 1; unsigned int A = (block_mode >> 5) & 0x3; x_weights = 0; y_weights = 0; z_weights = 0; if ((block_mode & 3) != 0) { base_quant_mode |= (block_mode & 3) << 1; unsigned int B = (block_mode >> 7) & 3; unsigned int C = (block_mode >> 2) & 0x3; x_weights = A + 2; y_weights = B + 2; z_weights = C + 2; } else { base_quant_mode |= ((block_mode >> 2) & 3) << 1; if (((block_mode >> 2) & 3) == 0) { return false; } int B = (block_mode >> 9) & 3; if (((block_mode >> 7) & 3) != 3) { D = 0; H = 0; } switch ((block_mode >> 7) & 3) { case 0: x_weights = 6; y_weights = B + 2; z_weights = A + 2; break; case 1: x_weights = A + 2; y_weights = 6; z_weights = B + 2; break; case 2: x_weights = A + 2; y_weights = B + 2; z_weights = 6; break; case 3: x_weights = 2; y_weights = 2; z_weights = 2; switch ((block_mode >> 5) & 3) { case 0: x_weights = 6; break; case 1: y_weights = 6; break; case 2: z_weights = 6; break; case 3: return false; } break; } } unsigned int weight_count = x_weights * y_weights * z_weights * (D + 1); quant_mode = (base_quant_mode - 2) + 6 * H; is_dual_plane = D != 0; weight_bits = get_ise_sequence_bitcount(weight_count, static_cast<quant_method>(quant_mode)); return (weight_count <= BLOCK_MAX_WEIGHTS && weight_bits >= BLOCK_MIN_WEIGHT_BITS && weight_bits <= BLOCK_MAX_WEIGHT_BITS); } /** * @brief Create a 2D decimation entry for a block-size and weight-decimation pair. * * @param x_texels The number of texels in the X dimension. * @param y_texels The number of texels in the Y dimension. * @param x_weights The number of weights in the X dimension. * @param y_weights The number of weights in the Y dimension. * @param[out] di The decimation info structure to populate. * @param[out] wb The decimation table init scratch working buffers. */ static void init_decimation_info_2d( unsigned int x_texels, unsigned int y_texels, unsigned int x_weights, unsigned int y_weights, decimation_info& di, dt_init_working_buffers& wb ) { unsigned int texels_per_block = x_texels * y_texels; unsigned int weights_per_block = x_weights * y_weights; uint8_t max_texel_count_of_weight = 0; promise(weights_per_block > 0); promise(texels_per_block > 0); promise(x_texels > 0); promise(y_texels > 0); for (unsigned int i = 0; i < weights_per_block; i++) { wb.texel_count_of_weight[i] = 0; } for (unsigned int i = 0; i < texels_per_block; i++) { wb.weight_count_of_texel[i] = 0; } for (unsigned int y = 0; y < y_texels; y++) { for (unsigned int x = 0; x < x_texels; x++) { unsigned int texel = y * x_texels + x; unsigned int x_weight = (((1024 + x_texels / 2) / (x_texels - 1)) * x * (x_weights - 1) + 32) >> 6; unsigned int y_weight = (((1024 + y_texels / 2) / (y_texels - 1)) * y * (y_weights - 1) + 32) >> 6; unsigned int x_weight_frac = x_weight & 0xF; unsigned int y_weight_frac = y_weight & 0xF; unsigned int x_weight_int = x_weight >> 4; unsigned int y_weight_int = y_weight >> 4; unsigned int qweight[4]; qweight[0] = x_weight_int + y_weight_int * x_weights; qweight[1] = qweight[0] + 1; qweight[2] = qweight[0] + x_weights; qweight[3] = qweight[2] + 1; // Truncated-precision bilinear interpolation unsigned int prod = x_weight_frac * y_weight_frac; unsigned int weight[4]; weight[3] = (prod + 8) >> 4; weight[1] = x_weight_frac - weight[3]; weight[2] = y_weight_frac - weight[3]; weight[0] = 16 - x_weight_frac - y_weight_frac + weight[3]; for (unsigned int i = 0; i < 4; i++) { if (weight[i] != 0) { wb.grid_weights_of_texel[texel][wb.weight_count_of_texel[texel]] = static_cast<uint8_t>(qweight[i]); wb.weights_of_texel[texel][wb.weight_count_of_texel[texel]] = static_cast<uint8_t>(weight[i]); wb.weight_count_of_texel[texel]++; wb.texels_of_weight[qweight[i]][wb.texel_count_of_weight[qweight[i]]] = static_cast<uint8_t>(texel); wb.texel_weights_of_weight[qweight[i]][wb.texel_count_of_weight[qweight[i]]] = static_cast<uint8_t>(weight[i]); wb.texel_count_of_weight[qweight[i]]++; max_texel_count_of_weight = astc::max(max_texel_count_of_weight, wb.texel_count_of_weight[qweight[i]]); } } } } uint8_t max_texel_weight_count = 0; for (unsigned int i = 0; i < texels_per_block; i++) { di.texel_weight_count[i] = wb.weight_count_of_texel[i]; max_texel_weight_count = astc::max(max_texel_weight_count, di.texel_weight_count[i]); for (unsigned int j = 0; j < wb.weight_count_of_texel[i]; j++) { di.texel_weights_int_4t[j][i] = wb.weights_of_texel[i][j]; di.texel_weights_float_4t[j][i] = static_cast<float>(wb.weights_of_texel[i][j]) * (1.0f / WEIGHTS_TEXEL_SUM); di.texel_weights_4t[j][i] = wb.grid_weights_of_texel[i][j]; } // Init all 4 entries so we can rely on zeros for vectorization for (unsigned int j = wb.weight_count_of_texel[i]; j < 4; j++) { di.texel_weights_int_4t[j][i] = 0; di.texel_weights_float_4t[j][i] = 0.0f; di.texel_weights_4t[j][i] = 0; } } di.max_texel_weight_count = max_texel_weight_count; for (unsigned int i = 0; i < weights_per_block; i++) { unsigned int texel_count_wt = wb.texel_count_of_weight[i]; di.weight_texel_count[i] = static_cast<uint8_t>(texel_count_wt); for (unsigned int j = 0; j < texel_count_wt; j++) { uint8_t texel = wb.texels_of_weight[i][j]; // Create transposed versions of these for better vectorization di.weight_texel[j][i] = texel; di.weights_flt[j][i] = static_cast<float>(wb.texel_weights_of_weight[i][j]); // perform a layer of array unrolling. An aspect of this unrolling is that // one of the texel-weight indexes is an identity-mapped index; we will use this // fact to reorder the indexes so that the first one is the identity index. int swap_idx = -1; for (unsigned int k = 0; k < 4; k++) { uint8_t dttw = di.texel_weights_4t[k][texel]; float dttwf = di.texel_weights_float_4t[k][texel]; if (dttw == i && dttwf != 0.0f) { swap_idx = k; } di.texel_weights_texel[i][j][k] = dttw; di.texel_weights_float_texel[i][j][k] = dttwf; } if (swap_idx != 0) { uint8_t vi = di.texel_weights_texel[i][j][0]; float vf = di.texel_weights_float_texel[i][j][0]; di.texel_weights_texel[i][j][0] = di.texel_weights_texel[i][j][swap_idx]; di.texel_weights_float_texel[i][j][0] = di.texel_weights_float_texel[i][j][swap_idx]; di.texel_weights_texel[i][j][swap_idx] = vi; di.texel_weights_float_texel[i][j][swap_idx] = vf; } } // Initialize array tail so we can over-fetch with SIMD later to avoid loop tails // Match last texel in active lane in SIMD group, for better gathers uint8_t last_texel = di.weight_texel[texel_count_wt - 1][i]; for (unsigned int j = texel_count_wt; j < max_texel_count_of_weight; j++) { di.weight_texel[j][i] = last_texel; di.weights_flt[j][i] = 0.0f; } } // Initialize array tail so we can over-fetch with SIMD later to avoid loop tails unsigned int texels_per_block_simd = round_up_to_simd_multiple_vla(texels_per_block); for (unsigned int i = texels_per_block; i < texels_per_block_simd; i++) { di.texel_weight_count[i] = 0; for (unsigned int j = 0; j < 4; j++) { di.texel_weights_float_4t[j][i] = 0; di.texel_weights_4t[j][i] = 0; di.texel_weights_int_4t[j][i] = 0; } } // Initialize array tail so we can over-fetch with SIMD later to avoid loop tails // Match last texel in active lane in SIMD group, for better gathers unsigned int last_texel_count_wt = wb.texel_count_of_weight[weights_per_block - 1]; uint8_t last_texel = di.weight_texel[last_texel_count_wt - 1][weights_per_block - 1]; unsigned int weights_per_block_simd = round_up_to_simd_multiple_vla(weights_per_block); for (unsigned int i = weights_per_block; i < weights_per_block_simd; i++) { di.weight_texel_count[i] = 0; for (unsigned int j = 0; j < max_texel_count_of_weight; j++) { di.weight_texel[j][i] = last_texel; di.weights_flt[j][i] = 0.0f; } } di.texel_count = static_cast<uint8_t>(texels_per_block); di.weight_count = static_cast<uint8_t>(weights_per_block); di.weight_x = static_cast<uint8_t>(x_weights); di.weight_y = static_cast<uint8_t>(y_weights); di.weight_z = 1; } /** * @brief Create a 3D decimation entry for a block-size and weight-decimation pair. * * @param x_texels The number of texels in the X dimension. * @param y_texels The number of texels in the Y dimension. * @param z_texels The number of texels in the Z dimension. * @param x_weights The number of weights in the X dimension. * @param y_weights The number of weights in the Y dimension. * @param z_weights The number of weights in the Z dimension. * @param[out] di The decimation info structure to populate. @param[out] wb The decimation table init scratch working buffers. */ static void init_decimation_info_3d( unsigned int x_texels, unsigned int y_texels, unsigned int z_texels, unsigned int x_weights, unsigned int y_weights, unsigned int z_weights, decimation_info& di, dt_init_working_buffers& wb ) { unsigned int texels_per_block = x_texels * y_texels * z_texels; unsigned int weights_per_block = x_weights * y_weights * z_weights; uint8_t max_texel_count_of_weight = 0; promise(weights_per_block > 0); promise(texels_per_block > 0); for (unsigned int i = 0; i < weights_per_block; i++) { wb.texel_count_of_weight[i] = 0; } for (unsigned int i = 0; i < texels_per_block; i++) { wb.weight_count_of_texel[i] = 0; } for (unsigned int z = 0; z < z_texels; z++) { for (unsigned int y = 0; y < y_texels; y++) { for (unsigned int x = 0; x < x_texels; x++) { int texel = (z * y_texels + y) * x_texels + x; int x_weight = (((1024 + x_texels / 2) / (x_texels - 1)) * x * (x_weights - 1) + 32) >> 6; int y_weight = (((1024 + y_texels / 2) / (y_texels - 1)) * y * (y_weights - 1) + 32) >> 6; int z_weight = (((1024 + z_texels / 2) / (z_texels - 1)) * z * (z_weights - 1) + 32) >> 6; int x_weight_frac = x_weight & 0xF; int y_weight_frac = y_weight & 0xF; int z_weight_frac = z_weight & 0xF; int x_weight_int = x_weight >> 4; int y_weight_int = y_weight >> 4; int z_weight_int = z_weight >> 4; int qweight[4]; int weight[4]; qweight[0] = (z_weight_int * y_weights + y_weight_int) * x_weights + x_weight_int; qweight[3] = ((z_weight_int + 1) * y_weights + (y_weight_int + 1)) * x_weights + (x_weight_int + 1); // simplex interpolation int fs = x_weight_frac; int ft = y_weight_frac; int fp = z_weight_frac; int cas = ((fs > ft) << 2) + ((ft > fp) << 1) + ((fs > fp)); int N = x_weights; int NM = x_weights * y_weights; int s1, s2, w0, w1, w2, w3; switch (cas) { case 7: s1 = 1; s2 = N; w0 = 16 - fs; w1 = fs - ft; w2 = ft - fp; w3 = fp; break; case 3: s1 = N; s2 = 1; w0 = 16 - ft; w1 = ft - fs; w2 = fs - fp; w3 = fp; break; case 5: s1 = 1; s2 = NM; w0 = 16 - fs; w1 = fs - fp; w2 = fp - ft; w3 = ft; break; case 4: s1 = NM; s2 = 1; w0 = 16 - fp; w1 = fp - fs; w2 = fs - ft; w3 = ft; break; case 2: s1 = N; s2 = NM; w0 = 16 - ft; w1 = ft - fp; w2 = fp - fs; w3 = fs; break; case 0: s1 = NM; s2 = N; w0 = 16 - fp; w1 = fp - ft; w2 = ft - fs; w3 = fs; break; default: s1 = NM; s2 = N; w0 = 16 - fp; w1 = fp - ft; w2 = ft - fs; w3 = fs; break; } qweight[1] = qweight[0] + s1; qweight[2] = qweight[1] + s2; weight[0] = w0; weight[1] = w1; weight[2] = w2; weight[3] = w3; for (unsigned int i = 0; i < 4; i++) { if (weight[i] != 0) { wb.grid_weights_of_texel[texel][wb.weight_count_of_texel[texel]] = static_cast<uint8_t>(qweight[i]); wb.weights_of_texel[texel][wb.weight_count_of_texel[texel]] = static_cast<uint8_t>(weight[i]); wb.weight_count_of_texel[texel]++; wb.texels_of_weight[qweight[i]][wb.texel_count_of_weight[qweight[i]]] = static_cast<uint8_t>(texel); wb.texel_weights_of_weight[qweight[i]][wb.texel_count_of_weight[qweight[i]]] = static_cast<uint8_t>(weight[i]); wb.texel_count_of_weight[qweight[i]]++; max_texel_count_of_weight = astc::max(max_texel_count_of_weight, wb.texel_count_of_weight[qweight[i]]); } } } } } uint8_t max_texel_weight_count = 0; for (unsigned int i = 0; i < texels_per_block; i++) { di.texel_weight_count[i] = wb.weight_count_of_texel[i]; max_texel_weight_count = astc::max(max_texel_weight_count, di.texel_weight_count[i]); // Init all 4 entries so we can rely on zeros for vectorization for (unsigned int j = 0; j < 4; j++) { di.texel_weights_int_4t[j][i] = 0; di.texel_weights_float_4t[j][i] = 0.0f; di.texel_weights_4t[j][i] = 0; } for (unsigned int j = 0; j < wb.weight_count_of_texel[i]; j++) { di.texel_weights_int_4t[j][i] = wb.weights_of_texel[i][j]; di.texel_weights_float_4t[j][i] = static_cast<float>(wb.weights_of_texel[i][j]) * (1.0f / WEIGHTS_TEXEL_SUM); di.texel_weights_4t[j][i] = wb.grid_weights_of_texel[i][j]; } } di.max_texel_weight_count = max_texel_weight_count; for (unsigned int i = 0; i < weights_per_block; i++) { unsigned int texel_count_wt = wb.texel_count_of_weight[i]; di.weight_texel_count[i] = static_cast<uint8_t>(texel_count_wt); for (unsigned int j = 0; j < texel_count_wt; j++) { unsigned int texel = wb.texels_of_weight[i][j]; // Create transposed versions of these for better vectorization di.weight_texel[j][i] = static_cast<uint8_t>(texel); di.weights_flt[j][i] = static_cast<float>(wb.texel_weights_of_weight[i][j]); // perform a layer of array unrolling. An aspect of this unrolling is that // one of the texel-weight indexes is an identity-mapped index; we will use this // fact to reorder the indexes so that the first one is the identity index. int swap_idx = -1; for (unsigned int k = 0; k < 4; k++) { uint8_t dttw = di.texel_weights_4t[k][texel]; float dttwf = di.texel_weights_float_4t[k][texel]; if (dttw == i && dttwf != 0.0f) { swap_idx = k; } di.texel_weights_texel[i][j][k] = dttw; di.texel_weights_float_texel[i][j][k] = dttwf; } if (swap_idx != 0) { uint8_t vi = di.texel_weights_texel[i][j][0]; float vf = di.texel_weights_float_texel[i][j][0]; di.texel_weights_texel[i][j][0] = di.texel_weights_texel[i][j][swap_idx]; di.texel_weights_float_texel[i][j][0] = di.texel_weights_float_texel[i][j][swap_idx]; di.texel_weights_texel[i][j][swap_idx] = vi; di.texel_weights_float_texel[i][j][swap_idx] = vf; } } // Initialize array tail so we can over-fetch with SIMD later to avoid loop tails // Match last texel in active lane in SIMD group, for better gathers uint8_t last_texel = di.weight_texel[texel_count_wt - 1][i]; for (unsigned int j = texel_count_wt; j < max_texel_count_of_weight; j++) { di.weight_texel[j][i] = last_texel; di.weights_flt[j][i] = 0.0f; } } // Initialize array tail so we can over-fetch with SIMD later to avoid loop tails unsigned int texels_per_block_simd = round_up_to_simd_multiple_vla(texels_per_block); for (unsigned int i = texels_per_block; i < texels_per_block_simd; i++) { di.texel_weight_count[i] = 0; for (unsigned int j = 0; j < 4; j++) { di.texel_weights_float_4t[j][i] = 0; di.texel_weights_4t[j][i] = 0; di.texel_weights_int_4t[j][i] = 0; } } // Initialize array tail so we can over-fetch with SIMD later to avoid loop tails // Match last texel in active lane in SIMD group, for better gathers int last_texel_count_wt = wb.texel_count_of_weight[weights_per_block - 1]; uint8_t last_texel = di.weight_texel[last_texel_count_wt - 1][weights_per_block - 1]; unsigned int weights_per_block_simd = round_up_to_simd_multiple_vla(weights_per_block); for (unsigned int i = weights_per_block; i < weights_per_block_simd; i++) { di.weight_texel_count[i] = 0; for (int j = 0; j < max_texel_count_of_weight; j++) { di.weight_texel[j][i] = last_texel; di.weights_flt[j][i] = 0.0f; } } di.texel_count = static_cast<uint8_t>(texels_per_block); di.weight_count = static_cast<uint8_t>(weights_per_block); di.weight_x = static_cast<uint8_t>(x_weights); di.weight_y = static_cast<uint8_t>(y_weights); di.weight_z = static_cast<uint8_t>(z_weights); } /** * @brief Assign the texels to use for kmeans clustering. * * The max limit is @c BLOCK_MAX_KMEANS_TEXELS; above this a random selection is used. * The @c bsd.texel_count is an input and must be populated beforehand. * * @param[in,out] bsd The block size descriptor to populate. */ static void assign_kmeans_texels( block_size_descriptor& bsd ) { // Use all texels for kmeans on a small block if (bsd.texel_count <= BLOCK_MAX_KMEANS_TEXELS) { for (uint8_t i = 0; i < bsd.texel_count; i++) { bsd.kmeans_texels[i] = i; } return; } // Select a random subset of BLOCK_MAX_KMEANS_TEXELS for kmeans on a large block uint64_t rng_state[2]; astc::rand_init(rng_state); // Initialize array used for tracking used indices bool seen[BLOCK_MAX_TEXELS]; for (uint8_t i = 0; i < bsd.texel_count; i++) { seen[i] = false; } // Assign 64 random indices, retrying if we see repeats unsigned int arr_elements_set = 0; while (arr_elements_set < BLOCK_MAX_KMEANS_TEXELS) { uint8_t texel = static_cast<uint8_t>(astc::rand(rng_state)); texel = texel % bsd.texel_count; if (!seen[texel]) { bsd.kmeans_texels[arr_elements_set++] = texel; seen[texel] = true; } } } /** * @brief Allocate a single 2D decimation table entry. * * @param x_texels The number of texels in the X dimension. * @param y_texels The number of texels in the Y dimension. * @param x_weights The number of weights in the X dimension. * @param y_weights The number of weights in the Y dimension. * @param bsd The block size descriptor we are populating. * @param wb The decimation table init scratch working buffers. * @param index The packed array index to populate. */ static void construct_dt_entry_2d( unsigned int x_texels, unsigned int y_texels, unsigned int x_weights, unsigned int y_weights, block_size_descriptor& bsd, dt_init_working_buffers& wb, unsigned int index ) { unsigned int weight_count = x_weights * y_weights; assert(weight_count <= BLOCK_MAX_WEIGHTS); bool try_2planes = (2 * weight_count) <= BLOCK_MAX_WEIGHTS; decimation_info& di = bsd.decimation_tables[index]; init_decimation_info_2d(x_texels, y_texels, x_weights, y_weights, di, wb); int maxprec_1plane = -1; int maxprec_2planes = -1; for (int i = 0; i < 12; i++) { unsigned int bits_1plane = get_ise_sequence_bitcount(weight_count, static_cast<quant_method>(i)); if (bits_1plane >= BLOCK_MIN_WEIGHT_BITS && bits_1plane <= BLOCK_MAX_WEIGHT_BITS) { maxprec_1plane = i; } if (try_2planes) { unsigned int bits_2planes = get_ise_sequence_bitcount(2 * weight_count, static_cast<quant_method>(i)); if (bits_2planes >= BLOCK_MIN_WEIGHT_BITS && bits_2planes <= BLOCK_MAX_WEIGHT_BITS) { maxprec_2planes = i; } } } // At least one of the two should be valid ... assert(maxprec_1plane >= 0 || maxprec_2planes >= 0); bsd.decimation_modes[index].maxprec_1plane = static_cast<int8_t>(maxprec_1plane); bsd.decimation_modes[index].maxprec_2planes = static_cast<int8_t>(maxprec_2planes); bsd.decimation_modes[index].refprec_1_plane = 0; bsd.decimation_modes[index].refprec_2_planes = 0; } /** * @brief Allocate block modes and decimation tables for a single 2D block size. * * @param x_texels The number of texels in the X dimension. * @param y_texels The number of texels in the Y dimension. * @param can_omit_modes Can we discard modes that astcenc won't use, even if legal? * @param mode_cutoff Percentile cutoff in range [0,1]. Low values more likely to be used. * @param[out] bsd The block size descriptor to populate. */ static void construct_block_size_descriptor_2d( unsigned int x_texels, unsigned int y_texels, bool can_omit_modes, float mode_cutoff, block_size_descriptor& bsd ) { // Store a remap table for storing packed decimation modes. // Indexing uses [Y * 16 + X] and max size for each axis is 12. static const unsigned int MAX_DMI = 12 * 16 + 12; int decimation_mode_index[MAX_DMI]; dt_init_working_buffers* wb = new dt_init_working_buffers; bsd.xdim = static_cast<uint8_t>(x_texels); bsd.ydim = static_cast<uint8_t>(y_texels); bsd.zdim = 1; bsd.texel_count = static_cast<uint8_t>(x_texels * y_texels); for (unsigned int i = 0; i < MAX_DMI; i++) { decimation_mode_index[i] = -1; } // Gather all the decimation grids that can be used with the current block #if !defined(ASTCENC_DECOMPRESS_ONLY) const float *percentiles = get_2d_percentile_table(x_texels, y_texels); float always_cutoff = 0.0f; #else // Unused in decompress-only builds (void)can_omit_modes; (void)mode_cutoff; #endif // Construct the list of block formats referencing the decimation tables unsigned int packed_bm_idx = 0; unsigned int packed_dm_idx = 0; // Trackers unsigned int bm_counts[4] { 0 }; unsigned int dm_counts[4] { 0 }; // Clear the list to a known-bad value for (unsigned int i = 0; i < WEIGHTS_MAX_BLOCK_MODES; i++) { bsd.block_mode_packed_index[i] = BLOCK_BAD_BLOCK_MODE; } // Iterate four times to build a usefully ordered list: // - Pass 0 - keep selected single plane "always" block modes // - Pass 1 - keep selected single plane "non-always" block modes // - Pass 2 - keep select dual plane block modes // - Pass 3 - keep everything else that's legal unsigned int limit = can_omit_modes ? 3 : 4; for (unsigned int j = 0; j < limit; j ++) { for (unsigned int i = 0; i < WEIGHTS_MAX_BLOCK_MODES; i++) { // Skip modes we've already included in a previous pass if (bsd.block_mode_packed_index[i] != BLOCK_BAD_BLOCK_MODE) { continue; } // Decode parameters unsigned int x_weights; unsigned int y_weights; bool is_dual_plane; unsigned int quant_mode; unsigned int weight_bits; bool valid = decode_block_mode_2d(i, x_weights, y_weights, is_dual_plane, quant_mode, weight_bits); // Always skip invalid encodings for the current block size if (!valid || (x_weights > x_texels) || (y_weights > y_texels)) { continue; } // Selectively skip dual plane encodings if (((j <= 1) && is_dual_plane) || (j == 2 && !is_dual_plane)) { continue; } // Always skip encodings we can't physically encode based on // generic encoding bit availability if (is_dual_plane) { // This is the only check we need as only support 1 partition if ((109 - weight_bits) <= 0) { continue; } } else { // This is conservative - fewer bits may be available for > 1 partition if ((111 - weight_bits) <= 0) { continue; } } // Selectively skip encodings based on percentile bool percentile_hit = false; #if !defined(ASTCENC_DECOMPRESS_ONLY) if (j == 0) { percentile_hit = percentiles[i] <= always_cutoff; } else { percentile_hit = percentiles[i] <= mode_cutoff; } #endif if (j != 3 && !percentile_hit) { continue; } // Allocate and initialize the decimation table entry if we've not used it yet int decimation_mode = decimation_mode_index[y_weights * 16 + x_weights]; if (decimation_mode < 0) { construct_dt_entry_2d(x_texels, y_texels, x_weights, y_weights, bsd, *wb, packed_dm_idx); decimation_mode_index[y_weights * 16 + x_weights] = packed_dm_idx; decimation_mode = packed_dm_idx; dm_counts[j]++; packed_dm_idx++; } auto& bm = bsd.block_modes[packed_bm_idx]; bm.decimation_mode = static_cast<uint8_t>(decimation_mode); bm.quant_mode = static_cast<uint8_t>(quant_mode); bm.is_dual_plane = static_cast<uint8_t>(is_dual_plane); bm.weight_bits = static_cast<uint8_t>(weight_bits); bm.mode_index = static_cast<uint16_t>(i); auto& dm = bsd.decimation_modes[decimation_mode]; if (is_dual_plane) { dm.set_ref_2_plane(bm.get_weight_quant_mode()); } else { dm.set_ref_1_plane(bm.get_weight_quant_mode()); } bsd.block_mode_packed_index[i] = static_cast<uint16_t>(packed_bm_idx); packed_bm_idx++; bm_counts[j]++; } } bsd.block_mode_count_1plane_always = bm_counts[0]; bsd.block_mode_count_1plane_selected = bm_counts[0] + bm_counts[1]; bsd.block_mode_count_1plane_2plane_selected = bm_counts[0] + bm_counts[1] + bm_counts[2]; bsd.block_mode_count_all = bm_counts[0] + bm_counts[1] + bm_counts[2] + bm_counts[3]; bsd.decimation_mode_count_always = dm_counts[0]; bsd.decimation_mode_count_selected = dm_counts[0] + dm_counts[1] + dm_counts[2]; bsd.decimation_mode_count_all = dm_counts[0] + dm_counts[1] + dm_counts[2] + dm_counts[3]; #if !defined(ASTCENC_DECOMPRESS_ONLY) assert(bsd.block_mode_count_1plane_always > 0); assert(bsd.decimation_mode_count_always > 0); delete[] percentiles; #endif // Ensure the end of the array contains valid data (should never get read) for (unsigned int i = bsd.decimation_mode_count_all; i < WEIGHTS_MAX_DECIMATION_MODES; i++) { bsd.decimation_modes[i].maxprec_1plane = -1; bsd.decimation_modes[i].maxprec_2planes = -1; bsd.decimation_modes[i].refprec_1_plane = 0; bsd.decimation_modes[i].refprec_2_planes = 0; } // Determine the texels to use for kmeans clustering. assign_kmeans_texels(bsd); delete wb; } /** * @brief Allocate block modes and decimation tables for a single £D block size. * * TODO: This function doesn't include all of the heuristics that we use for 2D block sizes such as * the percentile mode cutoffs. If 3D becomes more widely used we should look at this. * * @param x_texels The number of texels in the X dimension. * @param y_texels The number of texels in the Y dimension. * @param z_texels The number of texels in the Z dimension. * @param[out] bsd The block size descriptor to populate. */ static void construct_block_size_descriptor_3d( unsigned int x_texels, unsigned int y_texels, unsigned int z_texels, block_size_descriptor& bsd ) { // Store a remap table for storing packed decimation modes. // Indexing uses [Z * 64 + Y * 8 + X] and max size for each axis is 6. static constexpr unsigned int MAX_DMI = 6 * 64 + 6 * 8 + 6; int decimation_mode_index[MAX_DMI]; unsigned int decimation_mode_count = 0; dt_init_working_buffers* wb = new dt_init_working_buffers; bsd.xdim = static_cast<uint8_t>(x_texels); bsd.ydim = static_cast<uint8_t>(y_texels); bsd.zdim = static_cast<uint8_t>(z_texels); bsd.texel_count = static_cast<uint8_t>(x_texels * y_texels * z_texels); for (unsigned int i = 0; i < MAX_DMI; i++) { decimation_mode_index[i] = -1; } // gather all the infill-modes that can be used with the current block size for (unsigned int x_weights = 2; x_weights <= x_texels; x_weights++) { for (unsigned int y_weights = 2; y_weights <= y_texels; y_weights++) { for (unsigned int z_weights = 2; z_weights <= z_texels; z_weights++) { unsigned int weight_count = x_weights * y_weights * z_weights; if (weight_count > BLOCK_MAX_WEIGHTS) { continue; } decimation_info& di = bsd.decimation_tables[decimation_mode_count]; decimation_mode_index[z_weights * 64 + y_weights * 8 + x_weights] = decimation_mode_count; init_decimation_info_3d(x_texels, y_texels, z_texels, x_weights, y_weights, z_weights, di, *wb); int maxprec_1plane = -1; int maxprec_2planes = -1; for (unsigned int i = 0; i < 12; i++) { unsigned int bits_1plane = get_ise_sequence_bitcount(weight_count, static_cast<quant_method>(i)); if (bits_1plane >= BLOCK_MIN_WEIGHT_BITS && bits_1plane <= BLOCK_MAX_WEIGHT_BITS) { maxprec_1plane = i; } unsigned int bits_2planes = get_ise_sequence_bitcount(2 * weight_count, static_cast<quant_method>(i)); if (bits_2planes >= BLOCK_MIN_WEIGHT_BITS && bits_2planes <= BLOCK_MAX_WEIGHT_BITS) { maxprec_2planes = i; } } if ((2 * weight_count) > BLOCK_MAX_WEIGHTS) { maxprec_2planes = -1; } bsd.decimation_modes[decimation_mode_count].maxprec_1plane = static_cast<int8_t>(maxprec_1plane); bsd.decimation_modes[decimation_mode_count].maxprec_2planes = static_cast<int8_t>(maxprec_2planes); bsd.decimation_modes[decimation_mode_count].refprec_1_plane = maxprec_1plane == -1 ? 0 : 0xFFFF; bsd.decimation_modes[decimation_mode_count].refprec_2_planes = maxprec_2planes == -1 ? 0 : 0xFFFF; decimation_mode_count++; } } } // Ensure the end of the array contains valid data (should never get read) for (unsigned int i = decimation_mode_count; i < WEIGHTS_MAX_DECIMATION_MODES; i++) { bsd.decimation_modes[i].maxprec_1plane = -1; bsd.decimation_modes[i].maxprec_2planes = -1; bsd.decimation_modes[i].refprec_1_plane = 0; bsd.decimation_modes[i].refprec_2_planes = 0; } bsd.decimation_mode_count_always = 0; // Skipped for 3D modes bsd.decimation_mode_count_selected = decimation_mode_count; bsd.decimation_mode_count_all = decimation_mode_count; // Construct the list of block formats referencing the decimation tables // Clear the list to a known-bad value for (unsigned int i = 0; i < WEIGHTS_MAX_BLOCK_MODES; i++) { bsd.block_mode_packed_index[i] = BLOCK_BAD_BLOCK_MODE; } unsigned int packed_idx = 0; unsigned int bm_counts[2] { 0 }; // Iterate two times to build a usefully ordered list: // - Pass 0 - keep valid single plane block modes // - Pass 1 - keep valid dual plane block modes for (unsigned int j = 0; j < 2; j++) { for (unsigned int i = 0; i < WEIGHTS_MAX_BLOCK_MODES; i++) { // Skip modes we've already included in a previous pass if (bsd.block_mode_packed_index[i] != BLOCK_BAD_BLOCK_MODE) { continue; } unsigned int x_weights; unsigned int y_weights; unsigned int z_weights; bool is_dual_plane; unsigned int quant_mode; unsigned int weight_bits; bool valid = decode_block_mode_3d(i, x_weights, y_weights, z_weights, is_dual_plane, quant_mode, weight_bits); // Skip invalid encodings if (!valid || x_weights > x_texels || y_weights > y_texels || z_weights > z_texels) { continue; } // Skip encodings in the wrong iteration if ((j == 0 && is_dual_plane) || (j == 1 && !is_dual_plane)) { continue; } // Always skip encodings we can't physically encode based on bit availability if (is_dual_plane) { // This is the only check we need as only support 1 partition if ((109 - weight_bits) <= 0) { continue; } } else { // This is conservative - fewer bits may be available for > 1 partition if ((111 - weight_bits) <= 0) { continue; } } int decimation_mode = decimation_mode_index[z_weights * 64 + y_weights * 8 + x_weights]; bsd.block_modes[packed_idx].decimation_mode = static_cast<uint8_t>(decimation_mode); bsd.block_modes[packed_idx].quant_mode = static_cast<uint8_t>(quant_mode); bsd.block_modes[packed_idx].weight_bits = static_cast<uint8_t>(weight_bits); bsd.block_modes[packed_idx].is_dual_plane = static_cast<uint8_t>(is_dual_plane); bsd.block_modes[packed_idx].mode_index = static_cast<uint16_t>(i); bsd.block_mode_packed_index[i] = static_cast<uint16_t>(packed_idx); bm_counts[j]++; packed_idx++; } } bsd.block_mode_count_1plane_always = 0; // Skipped for 3D modes bsd.block_mode_count_1plane_selected = bm_counts[0]; bsd.block_mode_count_1plane_2plane_selected = bm_counts[0] + bm_counts[1]; bsd.block_mode_count_all = bm_counts[0] + bm_counts[1]; // Determine the texels to use for kmeans clustering. assign_kmeans_texels(bsd); delete wb; } /* See header for documentation. */ void init_block_size_descriptor( unsigned int x_texels, unsigned int y_texels, unsigned int z_texels, bool can_omit_modes, unsigned int partition_count_cutoff, float mode_cutoff, block_size_descriptor& bsd ) { if (z_texels > 1) { construct_block_size_descriptor_3d(x_texels, y_texels, z_texels, bsd); } else { construct_block_size_descriptor_2d(x_texels, y_texels, can_omit_modes, mode_cutoff, bsd); } init_partition_tables(bsd, can_omit_modes, partition_count_cutoff); }