diff options
Diffstat (limited to 'thirdparty/basis_universal/encoder/basisu_bc7enc.cpp')
| -rw-r--r-- | thirdparty/basis_universal/encoder/basisu_bc7enc.cpp | 1984 |
1 files changed, 1984 insertions, 0 deletions
diff --git a/thirdparty/basis_universal/encoder/basisu_bc7enc.cpp b/thirdparty/basis_universal/encoder/basisu_bc7enc.cpp new file mode 100644 index 0000000000..06aa7eb8b1 --- /dev/null +++ b/thirdparty/basis_universal/encoder/basisu_bc7enc.cpp @@ -0,0 +1,1984 @@ +// File: basisu_bc7enc.cpp +// Copyright (C) 2019-2021 Binomial LLC. All Rights Reserved. +// +// 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. +#include "basisu_bc7enc.h" + +#ifdef _DEBUG +#define BC7ENC_CHECK_OVERALL_ERROR 1 +#else +#define BC7ENC_CHECK_OVERALL_ERROR 0 +#endif + +using namespace basist; + +namespace basisu +{ + +// Helpers +static inline color_quad_u8 *color_quad_u8_set_clamped(color_quad_u8 *pRes, int32_t r, int32_t g, int32_t b, int32_t a) { pRes->m_c[0] = (uint8_t)clampi(r, 0, 255); pRes->m_c[1] = (uint8_t)clampi(g, 0, 255); pRes->m_c[2] = (uint8_t)clampi(b, 0, 255); pRes->m_c[3] = (uint8_t)clampi(a, 0, 255); return pRes; } +static inline color_quad_u8 *color_quad_u8_set(color_quad_u8 *pRes, int32_t r, int32_t g, int32_t b, int32_t a) { assert((uint32_t)(r | g | b | a) <= 255); pRes->m_c[0] = (uint8_t)r; pRes->m_c[1] = (uint8_t)g; pRes->m_c[2] = (uint8_t)b; pRes->m_c[3] = (uint8_t)a; return pRes; } +static inline bc7enc_bool color_quad_u8_notequals(const color_quad_u8 *pLHS, const color_quad_u8 *pRHS) { return (pLHS->m_c[0] != pRHS->m_c[0]) || (pLHS->m_c[1] != pRHS->m_c[1]) || (pLHS->m_c[2] != pRHS->m_c[2]) || (pLHS->m_c[3] != pRHS->m_c[3]); } +static inline bc7enc_vec4F*vec4F_set_scalar(bc7enc_vec4F*pV, float x) { pV->m_c[0] = x; pV->m_c[1] = x; pV->m_c[2] = x; pV->m_c[3] = x; return pV; } +static inline bc7enc_vec4F*vec4F_set(bc7enc_vec4F*pV, float x, float y, float z, float w) { pV->m_c[0] = x; pV->m_c[1] = y; pV->m_c[2] = z; pV->m_c[3] = w; return pV; } +static inline bc7enc_vec4F*vec4F_saturate_in_place(bc7enc_vec4F*pV) { pV->m_c[0] = saturate(pV->m_c[0]); pV->m_c[1] = saturate(pV->m_c[1]); pV->m_c[2] = saturate(pV->m_c[2]); pV->m_c[3] = saturate(pV->m_c[3]); return pV; } +static inline bc7enc_vec4F vec4F_saturate(const bc7enc_vec4F*pV) { bc7enc_vec4F res; res.m_c[0] = saturate(pV->m_c[0]); res.m_c[1] = saturate(pV->m_c[1]); res.m_c[2] = saturate(pV->m_c[2]); res.m_c[3] = saturate(pV->m_c[3]); return res; } +static inline bc7enc_vec4F vec4F_from_color(const color_quad_u8 *pC) { bc7enc_vec4F res; vec4F_set(&res, pC->m_c[0], pC->m_c[1], pC->m_c[2], pC->m_c[3]); return res; } +static inline bc7enc_vec4F vec4F_add(const bc7enc_vec4F*pLHS, const bc7enc_vec4F*pRHS) { bc7enc_vec4F res; vec4F_set(&res, pLHS->m_c[0] + pRHS->m_c[0], pLHS->m_c[1] + pRHS->m_c[1], pLHS->m_c[2] + pRHS->m_c[2], pLHS->m_c[3] + pRHS->m_c[3]); return res; } +static inline bc7enc_vec4F vec4F_sub(const bc7enc_vec4F*pLHS, const bc7enc_vec4F*pRHS) { bc7enc_vec4F res; vec4F_set(&res, pLHS->m_c[0] - pRHS->m_c[0], pLHS->m_c[1] - pRHS->m_c[1], pLHS->m_c[2] - pRHS->m_c[2], pLHS->m_c[3] - pRHS->m_c[3]); return res; } +static inline float vec4F_dot(const bc7enc_vec4F*pLHS, const bc7enc_vec4F*pRHS) { return pLHS->m_c[0] * pRHS->m_c[0] + pLHS->m_c[1] * pRHS->m_c[1] + pLHS->m_c[2] * pRHS->m_c[2] + pLHS->m_c[3] * pRHS->m_c[3]; } +static inline bc7enc_vec4F vec4F_mul(const bc7enc_vec4F*pLHS, float s) { bc7enc_vec4F res; vec4F_set(&res, pLHS->m_c[0] * s, pLHS->m_c[1] * s, pLHS->m_c[2] * s, pLHS->m_c[3] * s); return res; } +static inline bc7enc_vec4F* vec4F_normalize_in_place(bc7enc_vec4F*pV) { float s = pV->m_c[0] * pV->m_c[0] + pV->m_c[1] * pV->m_c[1] + pV->m_c[2] * pV->m_c[2] + pV->m_c[3] * pV->m_c[3]; if (s != 0.0f) { s = 1.0f / sqrtf(s); pV->m_c[0] *= s; pV->m_c[1] *= s; pV->m_c[2] *= s; pV->m_c[3] *= s; } return pV; } + +// Precomputed weight constants used during least fit determination. For each entry in g_bc7_weights[]: w * w, (1.0f - w) * w, (1.0f - w) * (1.0f - w), w +const float g_bc7_weights1x[2 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +const float g_bc7_weights2x[4 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.107666f, 0.220459f, 0.451416f, 0.328125f, 0.451416f, 0.220459f, 0.107666f, 0.671875f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +const float g_bc7_weights3x[8 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.019775f, 0.120850f, 0.738525f, 0.140625f, 0.079102f, 0.202148f, 0.516602f, 0.281250f, 0.177979f, 0.243896f, 0.334229f, 0.421875f, 0.334229f, 0.243896f, 0.177979f, 0.578125f, 0.516602f, 0.202148f, + 0.079102f, 0.718750f, 0.738525f, 0.120850f, 0.019775f, 0.859375f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +const float g_bc7_weights4x[16 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.003906f, 0.058594f, 0.878906f, 0.062500f, 0.019775f, 0.120850f, 0.738525f, 0.140625f, 0.041260f, 0.161865f, 0.635010f, 0.203125f, 0.070557f, 0.195068f, 0.539307f, 0.265625f, 0.107666f, 0.220459f, + 0.451416f, 0.328125f, 0.165039f, 0.241211f, 0.352539f, 0.406250f, 0.219727f, 0.249023f, 0.282227f, 0.468750f, 0.282227f, 0.249023f, 0.219727f, 0.531250f, 0.352539f, 0.241211f, 0.165039f, 0.593750f, 0.451416f, 0.220459f, 0.107666f, 0.671875f, 0.539307f, 0.195068f, 0.070557f, 0.734375f, + 0.635010f, 0.161865f, 0.041260f, 0.796875f, 0.738525f, 0.120850f, 0.019775f, 0.859375f, 0.878906f, 0.058594f, 0.003906f, 0.937500f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +const float g_astc_weights4x[16 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.003906f, 0.058594f, 0.878906f, 0.062500f, 0.015625f, 0.109375f, 0.765625f, 0.125000f, 0.035156f, 0.152344f, 0.660156f, 0.187500f, 0.070557f, 0.195068f, 0.539307f, 0.265625f, 0.107666f, 0.220459f, + 0.451416f, 0.328125f, 0.152588f, 0.238037f, 0.371338f, 0.390625f, 0.205322f, 0.247803f, 0.299072f, 0.453125f, 0.299072f, 0.247803f, 0.205322f, 0.546875f, 0.371338f, 0.238037f, 0.152588f, 0.609375f, 0.451416f, 0.220459f, 0.107666f, 0.671875f, 0.539307f, 0.195068f, 0.070557f, 0.734375f, + 0.660156f, 0.152344f, 0.035156f, 0.812500f, 0.765625f, 0.109375f, 0.015625f, 0.875000f, 0.878906f, 0.058594f, 0.003906f, 0.937500f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +const float g_astc_weights5x[32 * 4] = { 0.000000f, 0.000000f, 1.000000f, 0.000000f, 0.000977f, 0.030273f, 0.938477f, 0.031250f, 0.003906f, 0.058594f, 0.878906f, 0.062500f, 0.008789f, 0.084961f, 0.821289f, + 0.093750f, 0.015625f, 0.109375f, 0.765625f, 0.125000f, 0.024414f, 0.131836f, 0.711914f, 0.156250f, 0.035156f, 0.152344f, 0.660156f, 0.187500f, 0.047852f, 0.170898f, 0.610352f, 0.218750f, 0.062500f, 0.187500f, + 0.562500f, 0.250000f, 0.079102f, 0.202148f, 0.516602f, 0.281250f, 0.097656f, 0.214844f, 0.472656f, 0.312500f, 0.118164f, 0.225586f, 0.430664f, 0.343750f, 0.140625f, 0.234375f, 0.390625f, 0.375000f, 0.165039f, + 0.241211f, 0.352539f, 0.406250f, 0.191406f, 0.246094f, 0.316406f, 0.437500f, 0.219727f, 0.249023f, 0.282227f, 0.468750f, 0.282227f, 0.249023f, 0.219727f, 0.531250f, 0.316406f, 0.246094f, 0.191406f, 0.562500f, + 0.352539f, 0.241211f, 0.165039f, 0.593750f, 0.390625f, 0.234375f, 0.140625f, 0.625000f, 0.430664f, 0.225586f, 0.118164f, 0.656250f, 0.472656f, 0.214844f, 0.097656f, 0.687500f, 0.516602f, 0.202148f, 0.079102f, + 0.718750f, 0.562500f, 0.187500f, 0.062500f, 0.750000f, 0.610352f, 0.170898f, 0.047852f, 0.781250f, 0.660156f, 0.152344f, 0.035156f, 0.812500f, 0.711914f, 0.131836f, 0.024414f, 0.843750f, 0.765625f, 0.109375f, + 0.015625f, 0.875000f, 0.821289f, 0.084961f, 0.008789f, 0.906250f, 0.878906f, 0.058594f, 0.003906f, 0.937500f, 0.938477f, 0.030273f, 0.000977f, 0.968750f, 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +const float g_astc_weights_3levelsx[3 * 4] = { + 0.000000f, 0.000000f, 1.000000f, 0.000000f, + .5f * .5f, (1.0f - .5f) * .5f, (1.0f - .5f) * (1.0f - .5f), .5f, + 1.000000f, 0.000000f, 0.000000f, 1.000000f }; + +static endpoint_err g_bc7_mode_1_optimal_endpoints[256][2]; // [c][pbit] +static const uint32_t BC7ENC_MODE_1_OPTIMAL_INDEX = 2; + +static endpoint_err g_astc_4bit_3bit_optimal_endpoints[256]; // [c] +static const uint32_t BC7ENC_ASTC_4BIT_3BIT_OPTIMAL_INDEX = 2; + +static endpoint_err g_astc_4bit_2bit_optimal_endpoints[256]; // [c] +static const uint32_t BC7ENC_ASTC_4BIT_2BIT_OPTIMAL_INDEX = 1; + +static endpoint_err g_astc_range7_2bit_optimal_endpoints[256]; // [c] +static const uint32_t BC7ENC_ASTC_RANGE7_2BIT_OPTIMAL_INDEX = 1; + +static endpoint_err g_astc_range13_4bit_optimal_endpoints[256]; // [c] +static const uint32_t BC7ENC_ASTC_RANGE13_4BIT_OPTIMAL_INDEX = 2; + +static endpoint_err g_astc_range13_2bit_optimal_endpoints[256]; // [c] +static const uint32_t BC7ENC_ASTC_RANGE13_2BIT_OPTIMAL_INDEX = 1; + +static endpoint_err g_astc_range11_5bit_optimal_endpoints[256]; // [c] +static const uint32_t BC7ENC_ASTC_RANGE11_5BIT_OPTIMAL_INDEX = 13; // not 1, which is optimal, because 26 losslessly maps to BC7 4-bit weights + +astc_quant_bin g_astc_sorted_order_unquant[BC7ENC_TOTAL_ASTC_RANGES][256]; // [sorted unquantized order] + +static uint8_t g_astc_nearest_sorted_index[BC7ENC_TOTAL_ASTC_RANGES][256]; + +static void astc_init() +{ + for (uint32_t range = 0; range < BC7ENC_TOTAL_ASTC_RANGES; range++) + { + if (!astc_is_valid_endpoint_range(range)) + continue; + + const uint32_t levels = astc_get_levels(range); + + uint32_t vals[256]; + // TODO + for (uint32_t i = 0; i < levels; i++) + vals[i] = (unquant_astc_endpoint_val(i, range) << 8) | i; + + std::sort(vals, vals + levels); + + for (uint32_t i = 0; i < levels; i++) + { + uint32_t order = vals[i] & 0xFF; + uint32_t unq = vals[i] >> 8; + + g_astc_sorted_order_unquant[range][i].m_unquant = (uint8_t)unq; + g_astc_sorted_order_unquant[range][i].m_index = (uint8_t)order; + + } // i + +#if 0 + if (g_astc_bise_range_table[range][1] || g_astc_bise_range_table[range][2]) + { + printf("// Range: %u, Levels: %u, Bits: %u, Trits: %u, Quints: %u\n", range, levels, g_astc_bise_range_table[range][0], g_astc_bise_range_table[range][1], g_astc_bise_range_table[range][2]); + + printf("{"); + for (uint32_t i = 0; i < levels; i++) + { + printf("{%u,%u}", g_astc_sorted_order_unquant[range][i].m_index, g_astc_sorted_order_unquant[range][i].m_unquant); + if (i != (levels - 1)) + printf(","); + } + printf("}\n"); + } +#endif + +#if 0 + if (g_astc_bise_range_table[range][1] || g_astc_bise_range_table[range][2]) + { + printf("// Range: %u, Levels: %u, Bits: %u, Trits: %u, Quints: %u\n", range, levels, g_astc_bise_range_table[range][0], g_astc_bise_range_table[range][1], g_astc_bise_range_table[range][2]); + + printf("{"); + for (uint32_t i = 0; i < levels; i++) + { + printf("{%u,%u}", g_astc_unquant[range][i].m_index, g_astc_unquant[range][i].m_unquant); + if (i != (levels - 1)) + printf(","); + } + printf("}\n"); + } +#endif + + for (uint32_t i = 0; i < 256; i++) + { + uint32_t best_index = 0; + int best_err = INT32_MAX; + + for (uint32_t j = 0; j < levels; j++) + { + int err = g_astc_sorted_order_unquant[range][j].m_unquant - i; + if (err < 0) + err = -err; + if (err < best_err) + { + best_err = err; + best_index = j; + } + } + + g_astc_nearest_sorted_index[range][i] = (uint8_t)best_index; + } // i + } // range +} + +static inline uint32_t astc_interpolate(uint32_t l, uint32_t h, uint32_t w) +{ + // This is for linear values, not sRGB. + l = (l << 8) | l; + h = (h << 8) | h; + uint32_t k = (l * (64 - w) + h * w + 32) >> 6; + return k >> 8; +} + +// Initialize the lookup table used for optimal single color compression in mode 1. Must be called before encoding. +void bc7enc_compress_block_init() +{ + astc_init(); + + // BC7 666.1 + for (int c = 0; c < 256; c++) + { + for (uint32_t lp = 0; lp < 2; lp++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 64; l++) + { + uint32_t low = ((l << 1) | lp) << 1; + low |= (low >> 7); + for (uint32_t h = 0; h < 64; h++) + { + uint32_t high = ((h << 1) | lp) << 1; + high |= (high >> 7); + const int k = (low * (64 - g_bc7_weights3[BC7ENC_MODE_1_OPTIMAL_INDEX]) + high * g_bc7_weights3[BC7ENC_MODE_1_OPTIMAL_INDEX] + 32) >> 6; + const int err = (k - c) * (k - c); + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + g_bc7_mode_1_optimal_endpoints[c][lp] = best; + } // lp + } // c + + // ASTC [0,15] 3-bit + for (int c = 0; c < 256; c++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 16; l++) + { + uint32_t low = (l << 4) | l; + + for (uint32_t h = 0; h < 16; h++) + { + uint32_t high = (h << 4) | h; + + const int k = astc_interpolate(low, high, g_bc7_weights3[BC7ENC_ASTC_4BIT_3BIT_OPTIMAL_INDEX]); + const int err = (k - c) * (k - c); + + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + + g_astc_4bit_3bit_optimal_endpoints[c] = best; + + } // c + + // ASTC [0,15] 2-bit + for (int c = 0; c < 256; c++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 16; l++) + { + uint32_t low = (l << 4) | l; + + for (uint32_t h = 0; h < 16; h++) + { + uint32_t high = (h << 4) | h; + + const int k = astc_interpolate(low, high, g_bc7_weights2[BC7ENC_ASTC_4BIT_2BIT_OPTIMAL_INDEX]); + const int err = (k - c) * (k - c); + + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + + g_astc_4bit_2bit_optimal_endpoints[c] = best; + + } // c + + // ASTC range 7 [0,11] 2-bit + for (int c = 0; c < 256; c++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 12; l++) + { + uint32_t low = g_astc_sorted_order_unquant[7][l].m_unquant; + + for (uint32_t h = 0; h < 12; h++) + { + uint32_t high = g_astc_sorted_order_unquant[7][h].m_unquant; + + const int k = astc_interpolate(low, high, g_bc7_weights2[BC7ENC_ASTC_RANGE7_2BIT_OPTIMAL_INDEX]); + const int err = (k - c) * (k - c); + + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + + g_astc_range7_2bit_optimal_endpoints[c] = best; + + } // c + + // ASTC range 13 [0,47] 4-bit + for (int c = 0; c < 256; c++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 48; l++) + { + uint32_t low = g_astc_sorted_order_unquant[13][l].m_unquant; + + for (uint32_t h = 0; h < 48; h++) + { + uint32_t high = g_astc_sorted_order_unquant[13][h].m_unquant; + + const int k = astc_interpolate(low, high, g_astc_weights4[BC7ENC_ASTC_RANGE13_4BIT_OPTIMAL_INDEX]); + const int err = (k - c) * (k - c); + + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + + g_astc_range13_4bit_optimal_endpoints[c] = best; + + } // c + + // ASTC range 13 [0,47] 2-bit + for (int c = 0; c < 256; c++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 48; l++) + { + uint32_t low = g_astc_sorted_order_unquant[13][l].m_unquant; + + for (uint32_t h = 0; h < 48; h++) + { + uint32_t high = g_astc_sorted_order_unquant[13][h].m_unquant; + + const int k = astc_interpolate(low, high, g_bc7_weights2[BC7ENC_ASTC_RANGE13_2BIT_OPTIMAL_INDEX]); + const int err = (k - c) * (k - c); + + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + + g_astc_range13_2bit_optimal_endpoints[c] = best; + + } // c + + // ASTC range 11 [0,31] 5-bit + for (int c = 0; c < 256; c++) + { + endpoint_err best; + best.m_error = (uint16_t)UINT16_MAX; + for (uint32_t l = 0; l < 32; l++) + { + uint32_t low = g_astc_sorted_order_unquant[11][l].m_unquant; + + for (uint32_t h = 0; h < 32; h++) + { + uint32_t high = g_astc_sorted_order_unquant[11][h].m_unquant; + + const int k = astc_interpolate(low, high, g_astc_weights5[BC7ENC_ASTC_RANGE11_5BIT_OPTIMAL_INDEX]); + const int err = (k - c) * (k - c); + + if (err < best.m_error) + { + best.m_error = (uint16_t)err; + best.m_lo = (uint8_t)l; + best.m_hi = (uint8_t)h; + } + } // h + } // l + + g_astc_range11_5bit_optimal_endpoints[c] = best; + + } // c +} + +static void compute_least_squares_endpoints_rgba(uint32_t N, const uint8_t *pSelectors, const bc7enc_vec4F* pSelector_weights, bc7enc_vec4F* pXl, bc7enc_vec4F* pXh, const color_quad_u8 *pColors) +{ + // Least squares using normal equations: http://www.cs.cornell.edu/~bindel/class/cs3220-s12/notes/lec10.pdf + // I did this in matrix form first, expanded out all the ops, then optimized it a bit. + double z00 = 0.0f, z01 = 0.0f, z10 = 0.0f, z11 = 0.0f; + double q00_r = 0.0f, q10_r = 0.0f, t_r = 0.0f; + double q00_g = 0.0f, q10_g = 0.0f, t_g = 0.0f; + double q00_b = 0.0f, q10_b = 0.0f, t_b = 0.0f; + double q00_a = 0.0f, q10_a = 0.0f, t_a = 0.0f; + + for (uint32_t i = 0; i < N; i++) + { + const uint32_t sel = pSelectors[i]; + z00 += pSelector_weights[sel].m_c[0]; + z10 += pSelector_weights[sel].m_c[1]; + z11 += pSelector_weights[sel].m_c[2]; + float w = pSelector_weights[sel].m_c[3]; + q00_r += w * pColors[i].m_c[0]; t_r += pColors[i].m_c[0]; + q00_g += w * pColors[i].m_c[1]; t_g += pColors[i].m_c[1]; + q00_b += w * pColors[i].m_c[2]; t_b += pColors[i].m_c[2]; + q00_a += w * pColors[i].m_c[3]; t_a += pColors[i].m_c[3]; + } + + q10_r = t_r - q00_r; + q10_g = t_g - q00_g; + q10_b = t_b - q00_b; + q10_a = t_a - q00_a; + + z01 = z10; + + double det = z00 * z11 - z01 * z10; + if (det != 0.0f) + det = 1.0f / det; + + double iz00, iz01, iz10, iz11; + iz00 = z11 * det; + iz01 = -z01 * det; + iz10 = -z10 * det; + iz11 = z00 * det; + + pXl->m_c[0] = (float)(iz00 * q00_r + iz01 * q10_r); pXh->m_c[0] = (float)(iz10 * q00_r + iz11 * q10_r); + pXl->m_c[1] = (float)(iz00 * q00_g + iz01 * q10_g); pXh->m_c[1] = (float)(iz10 * q00_g + iz11 * q10_g); + pXl->m_c[2] = (float)(iz00 * q00_b + iz01 * q10_b); pXh->m_c[2] = (float)(iz10 * q00_b + iz11 * q10_b); + pXl->m_c[3] = (float)(iz00 * q00_a + iz01 * q10_a); pXh->m_c[3] = (float)(iz10 * q00_a + iz11 * q10_a); + + for (uint32_t c = 0; c < 4; c++) + { + if ((pXl->m_c[c] < 0.0f) || (pXh->m_c[c] > 255.0f)) + { + uint32_t lo_v = UINT32_MAX, hi_v = 0; + for (uint32_t i = 0; i < N; i++) + { + lo_v = minimumu(lo_v, pColors[i].m_c[c]); + hi_v = maximumu(hi_v, pColors[i].m_c[c]); + } + + if (lo_v == hi_v) + { + pXl->m_c[c] = (float)lo_v; + pXh->m_c[c] = (float)hi_v; + } + } + } +} + +static void compute_least_squares_endpoints_rgb(uint32_t N, const uint8_t *pSelectors, const bc7enc_vec4F*pSelector_weights, bc7enc_vec4F*pXl, bc7enc_vec4F*pXh, const color_quad_u8 *pColors) +{ + double z00 = 0.0f, z01 = 0.0f, z10 = 0.0f, z11 = 0.0f; + double q00_r = 0.0f, q10_r = 0.0f, t_r = 0.0f; + double q00_g = 0.0f, q10_g = 0.0f, t_g = 0.0f; + double q00_b = 0.0f, q10_b = 0.0f, t_b = 0.0f; + + for (uint32_t i = 0; i < N; i++) + { + const uint32_t sel = pSelectors[i]; + z00 += pSelector_weights[sel].m_c[0]; + z10 += pSelector_weights[sel].m_c[1]; + z11 += pSelector_weights[sel].m_c[2]; + float w = pSelector_weights[sel].m_c[3]; + q00_r += w * pColors[i].m_c[0]; t_r += pColors[i].m_c[0]; + q00_g += w * pColors[i].m_c[1]; t_g += pColors[i].m_c[1]; + q00_b += w * pColors[i].m_c[2]; t_b += pColors[i].m_c[2]; + } + + q10_r = t_r - q00_r; + q10_g = t_g - q00_g; + q10_b = t_b - q00_b; + + z01 = z10; + + double det = z00 * z11 - z01 * z10; + if (det != 0.0f) + det = 1.0f / det; + + double iz00, iz01, iz10, iz11; + iz00 = z11 * det; + iz01 = -z01 * det; + iz10 = -z10 * det; + iz11 = z00 * det; + + pXl->m_c[0] = (float)(iz00 * q00_r + iz01 * q10_r); pXh->m_c[0] = (float)(iz10 * q00_r + iz11 * q10_r); + pXl->m_c[1] = (float)(iz00 * q00_g + iz01 * q10_g); pXh->m_c[1] = (float)(iz10 * q00_g + iz11 * q10_g); + pXl->m_c[2] = (float)(iz00 * q00_b + iz01 * q10_b); pXh->m_c[2] = (float)(iz10 * q00_b + iz11 * q10_b); + pXl->m_c[3] = 255.0f; pXh->m_c[3] = 255.0f; + + for (uint32_t c = 0; c < 3; c++) + { + if ((pXl->m_c[c] < 0.0f) || (pXh->m_c[c] > 255.0f)) + { + uint32_t lo_v = UINT32_MAX, hi_v = 0; + for (uint32_t i = 0; i < N; i++) + { + lo_v = minimumu(lo_v, pColors[i].m_c[c]); + hi_v = maximumu(hi_v, pColors[i].m_c[c]); + } + + if (lo_v == hi_v) + { + pXl->m_c[c] = (float)lo_v; + pXh->m_c[c] = (float)hi_v; + } + } + } +} + +static inline color_quad_u8 scale_color(const color_quad_u8* pC, const color_cell_compressor_params* pParams) +{ + color_quad_u8 results; + + if (pParams->m_astc_endpoint_range) + { + for (uint32_t i = 0; i < 4; i++) + { + results.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pC->m_c[i]].m_unquant; + } + } + else + { + const uint32_t n = pParams->m_comp_bits + (pParams->m_has_pbits ? 1 : 0); + assert((n >= 4) && (n <= 8)); + + for (uint32_t i = 0; i < 4; i++) + { + uint32_t v = pC->m_c[i] << (8 - n); + v |= (v >> n); + assert(v <= 255); + results.m_c[i] = (uint8_t)(v); + } + } + + return results; +} + +static inline uint64_t compute_color_distance_rgb(const color_quad_u8 *pE1, const color_quad_u8 *pE2, bc7enc_bool perceptual, const uint32_t weights[4]) +{ + int dr, dg, db; + + if (perceptual) + { + const int l1 = pE1->m_c[0] * 109 + pE1->m_c[1] * 366 + pE1->m_c[2] * 37; + const int cr1 = ((int)pE1->m_c[0] << 9) - l1; + const int cb1 = ((int)pE1->m_c[2] << 9) - l1; + const int l2 = pE2->m_c[0] * 109 + pE2->m_c[1] * 366 + pE2->m_c[2] * 37; + const int cr2 = ((int)pE2->m_c[0] << 9) - l2; + const int cb2 = ((int)pE2->m_c[2] << 9) - l2; + dr = (l1 - l2) >> 8; + dg = (cr1 - cr2) >> 8; + db = (cb1 - cb2) >> 8; + } + else + { + dr = (int)pE1->m_c[0] - (int)pE2->m_c[0]; + dg = (int)pE1->m_c[1] - (int)pE2->m_c[1]; + db = (int)pE1->m_c[2] - (int)pE2->m_c[2]; + } + + return weights[0] * (uint32_t)(dr * dr) + weights[1] * (uint32_t)(dg * dg) + weights[2] * (uint32_t)(db * db); +} + +static inline uint64_t compute_color_distance_rgba(const color_quad_u8 *pE1, const color_quad_u8 *pE2, bc7enc_bool perceptual, const uint32_t weights[4]) +{ + int da = (int)pE1->m_c[3] - (int)pE2->m_c[3]; + return compute_color_distance_rgb(pE1, pE2, perceptual, weights) + (weights[3] * (uint32_t)(da * da)); +} + +static uint64_t pack_mode1_to_one_color(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, uint32_t r, uint32_t g, uint32_t b, uint8_t *pSelectors) +{ + uint32_t best_err = UINT_MAX; + uint32_t best_p = 0; + + for (uint32_t p = 0; p < 2; p++) + { + uint32_t err = g_bc7_mode_1_optimal_endpoints[r][p].m_error + g_bc7_mode_1_optimal_endpoints[g][p].m_error + g_bc7_mode_1_optimal_endpoints[b][p].m_error; + if (err < best_err) + { + best_err = err; + best_p = p; + } + } + + const endpoint_err *pEr = &g_bc7_mode_1_optimal_endpoints[r][best_p]; + const endpoint_err *pEg = &g_bc7_mode_1_optimal_endpoints[g][best_p]; + const endpoint_err *pEb = &g_bc7_mode_1_optimal_endpoints[b][best_p]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, 0); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, 0); + pResults->m_pbits[0] = best_p; + pResults->m_pbits[1] = 0; + + memset(pSelectors, BC7ENC_MODE_1_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 3; i++) + { + uint32_t low = ((pResults->m_low_endpoint.m_c[i] << 1) | pResults->m_pbits[0]) << 1; + low |= (low >> 7); + + uint32_t high = ((pResults->m_high_endpoint.m_c[i] << 1) | pResults->m_pbits[0]) << 1; + high |= (high >> 7); + + p.m_c[i] = (uint8_t)((low * (64 - g_bc7_weights3[BC7ENC_MODE_1_OPTIMAL_INDEX]) + high * g_bc7_weights3[BC7ENC_MODE_1_OPTIMAL_INDEX] + 32) >> 6); + } + p.m_c[3] = 255; + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgb(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t pack_astc_4bit_3bit_to_one_color(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, uint32_t r, uint32_t g, uint32_t b, uint8_t *pSelectors) +{ + const endpoint_err *pEr = &g_astc_4bit_3bit_optimal_endpoints[r]; + const endpoint_err *pEg = &g_astc_4bit_3bit_optimal_endpoints[g]; + const endpoint_err *pEb = &g_astc_4bit_3bit_optimal_endpoints[b]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, 0); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, 0); + pResults->m_pbits[0] = 0; + pResults->m_pbits[1] = 0; + + for (uint32_t i = 0; i < 4; i++) + { + pResults->m_astc_low_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[i]].m_index; + pResults->m_astc_high_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[i]].m_index; + } + + memset(pSelectors, BC7ENC_ASTC_4BIT_3BIT_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 3; i++) + { + uint32_t low = (pResults->m_low_endpoint.m_c[i] << 4) | pResults->m_low_endpoint.m_c[i]; + uint32_t high = (pResults->m_high_endpoint.m_c[i] << 4) | pResults->m_high_endpoint.m_c[i]; + + p.m_c[i] = (uint8_t)astc_interpolate(low, high, g_bc7_weights3[BC7ENC_ASTC_4BIT_3BIT_OPTIMAL_INDEX]); + } + p.m_c[3] = 255; + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgb(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t pack_astc_4bit_2bit_to_one_color_rgba(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, uint32_t r, uint32_t g, uint32_t b, uint32_t a, uint8_t *pSelectors) +{ + const endpoint_err *pEr = &g_astc_4bit_2bit_optimal_endpoints[r]; + const endpoint_err *pEg = &g_astc_4bit_2bit_optimal_endpoints[g]; + const endpoint_err *pEb = &g_astc_4bit_2bit_optimal_endpoints[b]; + const endpoint_err *pEa = &g_astc_4bit_2bit_optimal_endpoints[a]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, pEa->m_lo); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, pEa->m_hi); + pResults->m_pbits[0] = 0; + pResults->m_pbits[1] = 0; + + for (uint32_t i = 0; i < 4; i++) + { + pResults->m_astc_low_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[i]].m_index; + pResults->m_astc_high_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[i]].m_index; + } + + memset(pSelectors, BC7ENC_ASTC_4BIT_2BIT_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 4; i++) + { + uint32_t low = (pResults->m_low_endpoint.m_c[i] << 4) | pResults->m_low_endpoint.m_c[i]; + uint32_t high = (pResults->m_high_endpoint.m_c[i] << 4) | pResults->m_high_endpoint.m_c[i]; + + p.m_c[i] = (uint8_t)astc_interpolate(low, high, g_bc7_weights2[BC7ENC_ASTC_4BIT_2BIT_OPTIMAL_INDEX]); + } + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgba(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t pack_astc_range7_2bit_to_one_color(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, uint32_t r, uint32_t g, uint32_t b, uint8_t *pSelectors) +{ + assert(pParams->m_astc_endpoint_range == 7 && pParams->m_num_selector_weights == 4); + + const endpoint_err *pEr = &g_astc_range7_2bit_optimal_endpoints[r]; + const endpoint_err *pEg = &g_astc_range7_2bit_optimal_endpoints[g]; + const endpoint_err *pEb = &g_astc_range7_2bit_optimal_endpoints[b]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, 0); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, 0); + pResults->m_pbits[0] = 0; + pResults->m_pbits[1] = 0; + + for (uint32_t i = 0; i < 4; i++) + { + pResults->m_astc_low_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[i]].m_index; + pResults->m_astc_high_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[i]].m_index; + } + + memset(pSelectors, BC7ENC_ASTC_RANGE7_2BIT_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 3; i++) + { + uint32_t low = g_astc_sorted_order_unquant[7][pResults->m_low_endpoint.m_c[i]].m_unquant; + uint32_t high = g_astc_sorted_order_unquant[7][pResults->m_high_endpoint.m_c[i]].m_unquant; + + p.m_c[i] = (uint8_t)astc_interpolate(low, high, g_bc7_weights2[BC7ENC_ASTC_RANGE7_2BIT_OPTIMAL_INDEX]); + } + p.m_c[3] = 255; + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgb(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t pack_astc_range13_2bit_to_one_color(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, uint32_t r, uint32_t g, uint32_t b, uint8_t *pSelectors) +{ + assert(pParams->m_astc_endpoint_range == 13 && pParams->m_num_selector_weights == 4 && !pParams->m_has_alpha); + + const endpoint_err *pEr = &g_astc_range13_2bit_optimal_endpoints[r]; + const endpoint_err *pEg = &g_astc_range13_2bit_optimal_endpoints[g]; + const endpoint_err *pEb = &g_astc_range13_2bit_optimal_endpoints[b]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, 47); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, 47); + pResults->m_pbits[0] = 0; + pResults->m_pbits[1] = 0; + + for (uint32_t i = 0; i < 4; i++) + { + pResults->m_astc_low_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[i]].m_index; + pResults->m_astc_high_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[i]].m_index; + } + + memset(pSelectors, BC7ENC_ASTC_RANGE13_2BIT_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 4; i++) + { + uint32_t low = g_astc_sorted_order_unquant[13][pResults->m_low_endpoint.m_c[i]].m_unquant; + uint32_t high = g_astc_sorted_order_unquant[13][pResults->m_high_endpoint.m_c[i]].m_unquant; + + p.m_c[i] = (uint8_t)astc_interpolate(low, high, g_bc7_weights2[BC7ENC_ASTC_RANGE13_2BIT_OPTIMAL_INDEX]); + } + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgb(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t pack_astc_range11_5bit_to_one_color(const color_cell_compressor_params* pParams, color_cell_compressor_results* pResults, uint32_t r, uint32_t g, uint32_t b, uint8_t* pSelectors) +{ + assert(pParams->m_astc_endpoint_range == 11 && pParams->m_num_selector_weights == 32 && !pParams->m_has_alpha); + + const endpoint_err* pEr = &g_astc_range11_5bit_optimal_endpoints[r]; + const endpoint_err* pEg = &g_astc_range11_5bit_optimal_endpoints[g]; + const endpoint_err* pEb = &g_astc_range11_5bit_optimal_endpoints[b]; + + color_quad_u8_set(&pResults->m_low_endpoint, pEr->m_lo, pEg->m_lo, pEb->m_lo, 31); + color_quad_u8_set(&pResults->m_high_endpoint, pEr->m_hi, pEg->m_hi, pEb->m_hi, 31); + pResults->m_pbits[0] = 0; + pResults->m_pbits[1] = 0; + + for (uint32_t i = 0; i < 4; i++) + { + pResults->m_astc_low_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[i]].m_index; + pResults->m_astc_high_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[i]].m_index; + } + + memset(pSelectors, BC7ENC_ASTC_RANGE11_5BIT_OPTIMAL_INDEX, pParams->m_num_pixels); + + color_quad_u8 p; + for (uint32_t i = 0; i < 4; i++) + { + uint32_t low = g_astc_sorted_order_unquant[11][pResults->m_low_endpoint.m_c[i]].m_unquant; + uint32_t high = g_astc_sorted_order_unquant[11][pResults->m_high_endpoint.m_c[i]].m_unquant; + + p.m_c[i] = (uint8_t)astc_interpolate(low, high, g_astc_weights5[BC7ENC_ASTC_RANGE11_5BIT_OPTIMAL_INDEX]); + } + + uint64_t total_err = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + total_err += compute_color_distance_rgb(&p, &pParams->m_pPixels[i], pParams->m_perceptual, pParams->m_weights); + + pResults->m_best_overall_err = total_err; + + return total_err; +} + +static uint64_t evaluate_solution(const color_quad_u8 *pLow, const color_quad_u8 *pHigh, const uint32_t pbits[2], const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults) +{ + color_quad_u8 quantMinColor = *pLow; + color_quad_u8 quantMaxColor = *pHigh; + + if (pParams->m_has_pbits) + { + uint32_t minPBit, maxPBit; + + if (pParams->m_endpoints_share_pbit) + maxPBit = minPBit = pbits[0]; + else + { + minPBit = pbits[0]; + maxPBit = pbits[1]; + } + + quantMinColor.m_c[0] = (uint8_t)((pLow->m_c[0] << 1) | minPBit); + quantMinColor.m_c[1] = (uint8_t)((pLow->m_c[1] << 1) | minPBit); + quantMinColor.m_c[2] = (uint8_t)((pLow->m_c[2] << 1) | minPBit); + quantMinColor.m_c[3] = (uint8_t)((pLow->m_c[3] << 1) | minPBit); + + quantMaxColor.m_c[0] = (uint8_t)((pHigh->m_c[0] << 1) | maxPBit); + quantMaxColor.m_c[1] = (uint8_t)((pHigh->m_c[1] << 1) | maxPBit); + quantMaxColor.m_c[2] = (uint8_t)((pHigh->m_c[2] << 1) | maxPBit); + quantMaxColor.m_c[3] = (uint8_t)((pHigh->m_c[3] << 1) | maxPBit); + } + + color_quad_u8 actualMinColor = scale_color(&quantMinColor, pParams); + color_quad_u8 actualMaxColor = scale_color(&quantMaxColor, pParams); + + const uint32_t N = pParams->m_num_selector_weights; + assert(N >= 1 && N <= 32); + + color_quad_u8 weightedColors[32]; + weightedColors[0] = actualMinColor; + weightedColors[N - 1] = actualMaxColor; + + const uint32_t nc = pParams->m_has_alpha ? 4 : 3; + if (pParams->m_astc_endpoint_range) + { + for (uint32_t i = 1; i < (N - 1); i++) + { + for (uint32_t j = 0; j < nc; j++) + weightedColors[i].m_c[j] = (uint8_t)(astc_interpolate(actualMinColor.m_c[j], actualMaxColor.m_c[j], pParams->m_pSelector_weights[i])); + } + } + else + { + for (uint32_t i = 1; i < (N - 1); i++) + for (uint32_t j = 0; j < nc; j++) + weightedColors[i].m_c[j] = (uint8_t)((actualMinColor.m_c[j] * (64 - pParams->m_pSelector_weights[i]) + actualMaxColor.m_c[j] * pParams->m_pSelector_weights[i] + 32) >> 6); + } + + const int lr = actualMinColor.m_c[0]; + const int lg = actualMinColor.m_c[1]; + const int lb = actualMinColor.m_c[2]; + const int dr = actualMaxColor.m_c[0] - lr; + const int dg = actualMaxColor.m_c[1] - lg; + const int db = actualMaxColor.m_c[2] - lb; + + uint64_t total_err = 0; + + if (pParams->m_pForce_selectors) + { + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8* pC = &pParams->m_pPixels[i]; + + const uint8_t sel = pParams->m_pForce_selectors[i]; + assert(sel < N); + + total_err += (pParams->m_has_alpha ? compute_color_distance_rgba : compute_color_distance_rgb)(&weightedColors[sel], pC, pParams->m_perceptual, pParams->m_weights); + + pResults->m_pSelectors_temp[i] = sel; + } + } + else if (!pParams->m_perceptual) + { + if (pParams->m_has_alpha) + { + const int la = actualMinColor.m_c[3]; + const int da = actualMaxColor.m_c[3] - la; + + const float f = N / (float)(squarei(dr) + squarei(dg) + squarei(db) + squarei(da) + .00000125f); + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8 *pC = &pParams->m_pPixels[i]; + int r = pC->m_c[0]; + int g = pC->m_c[1]; + int b = pC->m_c[2]; + int a = pC->m_c[3]; + + int best_sel = (int)((float)((r - lr) * dr + (g - lg) * dg + (b - lb) * db + (a - la) * da) * f + .5f); + best_sel = clampi(best_sel, 1, N - 1); + + uint64_t err0 = compute_color_distance_rgba(&weightedColors[best_sel - 1], pC, BC7ENC_FALSE, pParams->m_weights); + uint64_t err1 = compute_color_distance_rgba(&weightedColors[best_sel], pC, BC7ENC_FALSE, pParams->m_weights); + + if (err0 == err1) + { + // Prefer non-interpolation + if ((best_sel - 1) == 0) + best_sel = 0; + } + else if (err1 > err0) + { + err1 = err0; + --best_sel; + } + total_err += err1; + + pResults->m_pSelectors_temp[i] = (uint8_t)best_sel; + } + } + else + { + const float f = N / (float)(squarei(dr) + squarei(dg) + squarei(db) + .00000125f); + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8 *pC = &pParams->m_pPixels[i]; + int r = pC->m_c[0]; + int g = pC->m_c[1]; + int b = pC->m_c[2]; + + int sel = (int)((float)((r - lr) * dr + (g - lg) * dg + (b - lb) * db) * f + .5f); + sel = clampi(sel, 1, N - 1); + + uint64_t err0 = compute_color_distance_rgb(&weightedColors[sel - 1], pC, BC7ENC_FALSE, pParams->m_weights); + uint64_t err1 = compute_color_distance_rgb(&weightedColors[sel], pC, BC7ENC_FALSE, pParams->m_weights); + + int best_sel = sel; + uint64_t best_err = err1; + if (err0 == err1) + { + // Prefer non-interpolation + if ((best_sel - 1) == 0) + best_sel = 0; + } + else if (err0 < best_err) + { + best_err = err0; + best_sel = sel - 1; + } + + total_err += best_err; + + pResults->m_pSelectors_temp[i] = (uint8_t)best_sel; + } + } + } + else + { + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint64_t best_err = UINT64_MAX; + uint32_t best_sel = 0; + + if (pParams->m_has_alpha) + { + for (uint32_t j = 0; j < N; j++) + { + uint64_t err = compute_color_distance_rgba(&weightedColors[j], &pParams->m_pPixels[i], BC7ENC_TRUE, pParams->m_weights); + if (err < best_err) + { + best_err = err; + best_sel = j; + } + // Prefer non-interpolation + else if ((err == best_err) && (j == (N - 1))) + best_sel = j; + } + } + else + { + for (uint32_t j = 0; j < N; j++) + { + uint64_t err = compute_color_distance_rgb(&weightedColors[j], &pParams->m_pPixels[i], BC7ENC_TRUE, pParams->m_weights); + if (err < best_err) + { + best_err = err; + best_sel = j; + } + // Prefer non-interpolation + else if ((err == best_err) && (j == (N - 1))) + best_sel = j; + } + } + + total_err += best_err; + + pResults->m_pSelectors_temp[i] = (uint8_t)best_sel; + } + } + + if (total_err < pResults->m_best_overall_err) + { + pResults->m_best_overall_err = total_err; + + pResults->m_low_endpoint = *pLow; + pResults->m_high_endpoint = *pHigh; + + pResults->m_pbits[0] = pbits[0]; + pResults->m_pbits[1] = pbits[1]; + + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + } + + return total_err; +} + +static bool areDegenerateEndpoints(color_quad_u8* pTrialMinColor, color_quad_u8* pTrialMaxColor, const bc7enc_vec4F* pXl, const bc7enc_vec4F* pXh) +{ + for (uint32_t i = 0; i < 3; i++) + { + if (pTrialMinColor->m_c[i] == pTrialMaxColor->m_c[i]) + { + if (fabs(pXl->m_c[i] - pXh->m_c[i]) > 0.0f) + return true; + } + } + + return false; +} + +static void fixDegenerateEndpoints(uint32_t mode, color_quad_u8 *pTrialMinColor, color_quad_u8 *pTrialMaxColor, const bc7enc_vec4F*pXl, const bc7enc_vec4F*pXh, uint32_t iscale, int flags) +{ + if (mode == 255) + { + for (uint32_t i = 0; i < 3; i++) + { + if (pTrialMinColor->m_c[i] == pTrialMaxColor->m_c[i]) + { + if (fabs(pXl->m_c[i] - pXh->m_c[i]) > 0.000125f) + { + if (flags & 1) + { + if (pTrialMinColor->m_c[i] > 0) + pTrialMinColor->m_c[i]--; + } + if (flags & 2) + { + if (pTrialMaxColor->m_c[i] < iscale) + pTrialMaxColor->m_c[i]++; + } + } + } + } + } + else if (mode == 1) + { + // fix degenerate case where the input collapses to a single colorspace voxel, and we loose all freedom (test with grayscale ramps) + for (uint32_t i = 0; i < 3; i++) + { + if (pTrialMinColor->m_c[i] == pTrialMaxColor->m_c[i]) + { + if (fabs(pXl->m_c[i] - pXh->m_c[i]) > 0.000125f) + { + if (pTrialMinColor->m_c[i] > (iscale >> 1)) + { + if (pTrialMinColor->m_c[i] > 0) + pTrialMinColor->m_c[i]--; + else + if (pTrialMaxColor->m_c[i] < iscale) + pTrialMaxColor->m_c[i]++; + } + else + { + if (pTrialMaxColor->m_c[i] < iscale) + pTrialMaxColor->m_c[i]++; + else if (pTrialMinColor->m_c[i] > 0) + pTrialMinColor->m_c[i]--; + } + } + } + } + } +} + +static uint64_t find_optimal_solution(uint32_t mode, bc7enc_vec4F xl, bc7enc_vec4F xh, const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults) +{ + vec4F_saturate_in_place(&xl); vec4F_saturate_in_place(&xh); + + if (pParams->m_astc_endpoint_range) + { + const uint32_t levels = astc_get_levels(pParams->m_astc_endpoint_range); + + const float scale = 255.0f; + + color_quad_u8 trialMinColor8Bit, trialMaxColor8Bit; + color_quad_u8_set_clamped(&trialMinColor8Bit, (int)(xl.m_c[0] * scale + .5f), (int)(xl.m_c[1] * scale + .5f), (int)(xl.m_c[2] * scale + .5f), (int)(xl.m_c[3] * scale + .5f)); + color_quad_u8_set_clamped(&trialMaxColor8Bit, (int)(xh.m_c[0] * scale + .5f), (int)(xh.m_c[1] * scale + .5f), (int)(xh.m_c[2] * scale + .5f), (int)(xh.m_c[3] * scale + .5f)); + + color_quad_u8 trialMinColor, trialMaxColor; + for (uint32_t i = 0; i < 4; i++) + { + trialMinColor.m_c[i] = g_astc_nearest_sorted_index[pParams->m_astc_endpoint_range][trialMinColor8Bit.m_c[i]]; + trialMaxColor.m_c[i] = g_astc_nearest_sorted_index[pParams->m_astc_endpoint_range][trialMaxColor8Bit.m_c[i]]; + } + + if (areDegenerateEndpoints(&trialMinColor, &trialMaxColor, &xl, &xh)) + { + color_quad_u8 trialMinColorOrig(trialMinColor), trialMaxColorOrig(trialMaxColor); + + fixDegenerateEndpoints(mode, &trialMinColor, &trialMaxColor, &xl, &xh, levels - 1, 1); + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + + trialMinColor = trialMinColorOrig; + trialMaxColor = trialMaxColorOrig; + fixDegenerateEndpoints(mode, &trialMinColor, &trialMaxColor, &xl, &xh, levels - 1, 0); + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + + trialMinColor = trialMinColorOrig; + trialMaxColor = trialMaxColorOrig; + fixDegenerateEndpoints(mode, &trialMinColor, &trialMaxColor, &xl, &xh, levels - 1, 2); + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + + trialMinColor = trialMinColorOrig; + trialMaxColor = trialMaxColorOrig; + fixDegenerateEndpoints(mode, &trialMinColor, &trialMaxColor, &xl, &xh, levels - 1, 3); + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + } + else + { + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + { + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + } + } + + for (uint32_t i = 0; i < 4; i++) + { + pResults->m_astc_low_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[i]].m_index; + pResults->m_astc_high_endpoint.m_c[i] = g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[i]].m_index; + } + } + else if (pParams->m_has_pbits) + { + const int iscalep = (1 << (pParams->m_comp_bits + 1)) - 1; + const float scalep = (float)iscalep; + + const int32_t totalComps = pParams->m_has_alpha ? 4 : 3; + + uint32_t best_pbits[2]; + color_quad_u8 bestMinColor, bestMaxColor; + + if (!pParams->m_endpoints_share_pbit) + { + float best_err0 = 1e+9; + float best_err1 = 1e+9; + + for (int p = 0; p < 2; p++) + { + color_quad_u8 xMinColor, xMaxColor; + + // Notes: The pbit controls which quantization intervals are selected. + // total_levels=2^(comp_bits+1), where comp_bits=4 for mode 0, etc. + // pbit 0: v=(b*2)/(total_levels-1), pbit 1: v=(b*2+1)/(total_levels-1) where b is the component bin from [0,total_levels/2-1] and v is the [0,1] component value + // rearranging you get for pbit 0: b=floor(v*(total_levels-1)/2+.5) + // rearranging you get for pbit 1: b=floor((v*(total_levels-1)-1)/2+.5) + for (uint32_t c = 0; c < 4; c++) + { + xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + } + + color_quad_u8 scaledLow = scale_color(&xMinColor, pParams); + color_quad_u8 scaledHigh = scale_color(&xMaxColor, pParams); + + float err0 = 0, err1 = 0; + for (int i = 0; i < totalComps; i++) + { + err0 += squaref(scaledLow.m_c[i] - xl.m_c[i] * 255.0f); + err1 += squaref(scaledHigh.m_c[i] - xh.m_c[i] * 255.0f); + } + + if (err0 < best_err0) + { + best_err0 = err0; + best_pbits[0] = p; + + bestMinColor.m_c[0] = xMinColor.m_c[0] >> 1; + bestMinColor.m_c[1] = xMinColor.m_c[1] >> 1; + bestMinColor.m_c[2] = xMinColor.m_c[2] >> 1; + bestMinColor.m_c[3] = xMinColor.m_c[3] >> 1; + } + + if (err1 < best_err1) + { + best_err1 = err1; + best_pbits[1] = p; + + bestMaxColor.m_c[0] = xMaxColor.m_c[0] >> 1; + bestMaxColor.m_c[1] = xMaxColor.m_c[1] >> 1; + bestMaxColor.m_c[2] = xMaxColor.m_c[2] >> 1; + bestMaxColor.m_c[3] = xMaxColor.m_c[3] >> 1; + } + } + } + else + { + // Endpoints share pbits + float best_err = 1e+9; + + for (int p = 0; p < 2; p++) + { + color_quad_u8 xMinColor, xMaxColor; + for (uint32_t c = 0; c < 4; c++) + { + xMinColor.m_c[c] = (uint8_t)(clampi(((int)((xl.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + xMaxColor.m_c[c] = (uint8_t)(clampi(((int)((xh.m_c[c] * scalep - p) / 2.0f + .5f)) * 2 + p, p, iscalep - 1 + p)); + } + + color_quad_u8 scaledLow = scale_color(&xMinColor, pParams); + color_quad_u8 scaledHigh = scale_color(&xMaxColor, pParams); + + float err = 0; + for (int i = 0; i < totalComps; i++) + err += squaref((scaledLow.m_c[i] / 255.0f) - xl.m_c[i]) + squaref((scaledHigh.m_c[i] / 255.0f) - xh.m_c[i]); + + if (err < best_err) + { + best_err = err; + best_pbits[0] = p; + best_pbits[1] = p; + for (uint32_t j = 0; j < 4; j++) + { + bestMinColor.m_c[j] = xMinColor.m_c[j] >> 1; + bestMaxColor.m_c[j] = xMaxColor.m_c[j] >> 1; + } + } + } + } + + fixDegenerateEndpoints(mode, &bestMinColor, &bestMaxColor, &xl, &xh, iscalep >> 1, 0); + + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&bestMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&bestMaxColor, &pResults->m_high_endpoint) || (best_pbits[0] != pResults->m_pbits[0]) || (best_pbits[1] != pResults->m_pbits[1])) + evaluate_solution(&bestMinColor, &bestMaxColor, best_pbits, pParams, pResults); + } + else + { + const int iscale = (1 << pParams->m_comp_bits) - 1; + const float scale = (float)iscale; + + color_quad_u8 trialMinColor, trialMaxColor; + color_quad_u8_set_clamped(&trialMinColor, (int)(xl.m_c[0] * scale + .5f), (int)(xl.m_c[1] * scale + .5f), (int)(xl.m_c[2] * scale + .5f), (int)(xl.m_c[3] * scale + .5f)); + color_quad_u8_set_clamped(&trialMaxColor, (int)(xh.m_c[0] * scale + .5f), (int)(xh.m_c[1] * scale + .5f), (int)(xh.m_c[2] * scale + .5f), (int)(xh.m_c[3] * scale + .5f)); + + fixDegenerateEndpoints(mode, &trialMinColor, &trialMaxColor, &xl, &xh, iscale, 0); + + if ((pResults->m_best_overall_err == UINT64_MAX) || color_quad_u8_notequals(&trialMinColor, &pResults->m_low_endpoint) || color_quad_u8_notequals(&trialMaxColor, &pResults->m_high_endpoint)) + evaluate_solution(&trialMinColor, &trialMaxColor, pResults->m_pbits, pParams, pResults); + } + + return pResults->m_best_overall_err; +} + +void check_best_overall_error(const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults) +{ + const uint32_t n = pParams->m_num_selector_weights; + + assert(n <= 32); + + color_quad_u8 colors[32]; + for (uint32_t c = 0; c < 4; c++) + { + colors[0].m_c[c] = g_astc_unquant[pParams->m_astc_endpoint_range][pResults->m_astc_low_endpoint.m_c[c]].m_unquant; + assert(colors[0].m_c[c] == g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_low_endpoint.m_c[c]].m_unquant); + + colors[n-1].m_c[c] = g_astc_unquant[pParams->m_astc_endpoint_range][pResults->m_astc_high_endpoint.m_c[c]].m_unquant; + assert(colors[n-1].m_c[c] == g_astc_sorted_order_unquant[pParams->m_astc_endpoint_range][pResults->m_high_endpoint.m_c[c]].m_unquant); + } + + for (uint32_t i = 1; i < pParams->m_num_selector_weights - 1; i++) + for (uint32_t c = 0; c < 4; c++) + colors[i].m_c[c] = (uint8_t)astc_interpolate(colors[0].m_c[c], colors[n - 1].m_c[c], pParams->m_pSelector_weights[i]); + + uint64_t total_err = 0; + for (uint32_t p = 0; p < pParams->m_num_pixels; p++) + { + const color_quad_u8 &orig = pParams->m_pPixels[p]; + const color_quad_u8 &packed = colors[pResults->m_pSelectors[p]]; + + if (pParams->m_has_alpha) + total_err += compute_color_distance_rgba(&orig, &packed, pParams->m_perceptual, pParams->m_weights); + else + total_err += compute_color_distance_rgb(&orig, &packed, pParams->m_perceptual, pParams->m_weights); + } + assert(total_err == pResults->m_best_overall_err); + + // HACK HACK + //if (total_err != pResults->m_best_overall_err) + // printf("X"); +} + +static bool is_solid_rgb(const color_cell_compressor_params *pParams, uint32_t &r, uint32_t &g, uint32_t &b) +{ + r = pParams->m_pPixels[0].m_c[0]; + g = pParams->m_pPixels[0].m_c[1]; + b = pParams->m_pPixels[0].m_c[2]; + + bool allSame = true; + for (uint32_t i = 1; i < pParams->m_num_pixels; i++) + { + if ((r != pParams->m_pPixels[i].m_c[0]) || (g != pParams->m_pPixels[i].m_c[1]) || (b != pParams->m_pPixels[i].m_c[2])) + { + allSame = false; + break; + } + } + + return allSame; +} + +static bool is_solid_rgba(const color_cell_compressor_params *pParams, uint32_t &r, uint32_t &g, uint32_t &b, uint32_t &a) +{ + r = pParams->m_pPixels[0].m_c[0]; + g = pParams->m_pPixels[0].m_c[1]; + b = pParams->m_pPixels[0].m_c[2]; + a = pParams->m_pPixels[0].m_c[3]; + + bool allSame = true; + for (uint32_t i = 1; i < pParams->m_num_pixels; i++) + { + if ((r != pParams->m_pPixels[i].m_c[0]) || (g != pParams->m_pPixels[i].m_c[1]) || (b != pParams->m_pPixels[i].m_c[2]) || (a != pParams->m_pPixels[i].m_c[3])) + { + allSame = false; + break; + } + } + + return allSame; +} + +uint64_t color_cell_compression(uint32_t mode, const color_cell_compressor_params *pParams, color_cell_compressor_results *pResults, const bc7enc_compress_block_params *pComp_params) +{ + if (!pParams->m_astc_endpoint_range) + { + assert((mode == 6) || (!pParams->m_has_alpha)); + } + assert(pParams->m_num_selector_weights >= 1 && pParams->m_num_selector_weights <= 32); + assert(pParams->m_pSelector_weights[0] == 0); + assert(pParams->m_pSelector_weights[pParams->m_num_selector_weights - 1] == 64); + + pResults->m_best_overall_err = UINT64_MAX; + + uint32_t cr, cg, cb, ca; + + // If the partition's colors are all the same, then just pack them as a single color. + if (!pParams->m_pForce_selectors) + { + if (mode == 1) + { + if (is_solid_rgb(pParams, cr, cg, cb)) + return pack_mode1_to_one_color(pParams, pResults, cr, cg, cb, pResults->m_pSelectors); + } + else if ((pParams->m_astc_endpoint_range == 8) && (pParams->m_num_selector_weights == 8) && (!pParams->m_has_alpha)) + { + if (is_solid_rgb(pParams, cr, cg, cb)) + return pack_astc_4bit_3bit_to_one_color(pParams, pResults, cr, cg, cb, pResults->m_pSelectors); + } + else if ((pParams->m_astc_endpoint_range == 7) && (pParams->m_num_selector_weights == 4) && (!pParams->m_has_alpha)) + { + if (is_solid_rgb(pParams, cr, cg, cb)) + return pack_astc_range7_2bit_to_one_color(pParams, pResults, cr, cg, cb, pResults->m_pSelectors); + } + else if ((pParams->m_astc_endpoint_range == 8) && (pParams->m_num_selector_weights == 4) && (pParams->m_has_alpha)) + { + if (is_solid_rgba(pParams, cr, cg, cb, ca)) + return pack_astc_4bit_2bit_to_one_color_rgba(pParams, pResults, cr, cg, cb, ca, pResults->m_pSelectors); + } + else if ((pParams->m_astc_endpoint_range == 13) && (pParams->m_num_selector_weights == 4) && (!pParams->m_has_alpha)) + { + if (is_solid_rgb(pParams, cr, cg, cb)) + return pack_astc_range13_2bit_to_one_color(pParams, pResults, cr, cg, cb, pResults->m_pSelectors); + } + else if ((pParams->m_astc_endpoint_range == 11) && (pParams->m_num_selector_weights == 32) && (!pParams->m_has_alpha)) + { + if (is_solid_rgb(pParams, cr, cg, cb)) + return pack_astc_range11_5bit_to_one_color(pParams, pResults, cr, cg, cb, pResults->m_pSelectors); + } + } + + // Compute partition's mean color and principle axis. + bc7enc_vec4F meanColor, axis; + vec4F_set_scalar(&meanColor, 0.0f); + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + bc7enc_vec4F color = vec4F_from_color(&pParams->m_pPixels[i]); + meanColor = vec4F_add(&meanColor, &color); + } + + bc7enc_vec4F meanColorScaled = vec4F_mul(&meanColor, 1.0f / (float)(pParams->m_num_pixels)); + + meanColor = vec4F_mul(&meanColor, 1.0f / (float)(pParams->m_num_pixels * 255.0f)); + vec4F_saturate_in_place(&meanColor); + + if (pParams->m_has_alpha) + { + // Use incremental PCA for RGBA PCA, because it's simple. + vec4F_set_scalar(&axis, 0.0f); + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + bc7enc_vec4F color = vec4F_from_color(&pParams->m_pPixels[i]); + color = vec4F_sub(&color, &meanColorScaled); + bc7enc_vec4F a = vec4F_mul(&color, color.m_c[0]); + bc7enc_vec4F b = vec4F_mul(&color, color.m_c[1]); + bc7enc_vec4F c = vec4F_mul(&color, color.m_c[2]); + bc7enc_vec4F d = vec4F_mul(&color, color.m_c[3]); + bc7enc_vec4F n = i ? axis : color; + vec4F_normalize_in_place(&n); + axis.m_c[0] += vec4F_dot(&a, &n); + axis.m_c[1] += vec4F_dot(&b, &n); + axis.m_c[2] += vec4F_dot(&c, &n); + axis.m_c[3] += vec4F_dot(&d, &n); + } + vec4F_normalize_in_place(&axis); + } + else + { + // Use covar technique for RGB PCA, because it doesn't require per-pixel normalization. + float cov[6] = { 0, 0, 0, 0, 0, 0 }; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + const color_quad_u8 *pV = &pParams->m_pPixels[i]; + float r = pV->m_c[0] - meanColorScaled.m_c[0]; + float g = pV->m_c[1] - meanColorScaled.m_c[1]; + float b = pV->m_c[2] - meanColorScaled.m_c[2]; + cov[0] += r*r; cov[1] += r*g; cov[2] += r*b; cov[3] += g*g; cov[4] += g*b; cov[5] += b*b; + } + + float xr = .9f, xg = 1.0f, xb = .7f; + for (uint32_t iter = 0; iter < 3; iter++) + { + float r = xr * cov[0] + xg * cov[1] + xb * cov[2]; + float g = xr * cov[1] + xg * cov[3] + xb * cov[4]; + float b = xr * cov[2] + xg * cov[4] + xb * cov[5]; + + float m = maximumf(maximumf(fabsf(r), fabsf(g)), fabsf(b)); + if (m > 1e-10f) + { + m = 1.0f / m; + r *= m; g *= m; b *= m; + } + + xr = r; xg = g; xb = b; + } + + float len = xr * xr + xg * xg + xb * xb; + if (len < 1e-10f) + vec4F_set_scalar(&axis, 0.0f); + else + { + len = 1.0f / sqrtf(len); + xr *= len; xg *= len; xb *= len; + vec4F_set(&axis, xr, xg, xb, 0); + } + } + + if (vec4F_dot(&axis, &axis) < .5f) + { + if (pParams->m_perceptual) + vec4F_set(&axis, .213f, .715f, .072f, pParams->m_has_alpha ? .715f : 0); + else + vec4F_set(&axis, 1.0f, 1.0f, 1.0f, pParams->m_has_alpha ? 1.0f : 0); + vec4F_normalize_in_place(&axis); + } + + bc7enc_vec4F minColor, maxColor; + + float l = 1e+9f, h = -1e+9f; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + bc7enc_vec4F color = vec4F_from_color(&pParams->m_pPixels[i]); + + bc7enc_vec4F q = vec4F_sub(&color, &meanColorScaled); + float d = vec4F_dot(&q, &axis); + + l = minimumf(l, d); + h = maximumf(h, d); + } + + l *= (1.0f / 255.0f); + h *= (1.0f / 255.0f); + + bc7enc_vec4F b0 = vec4F_mul(&axis, l); + bc7enc_vec4F b1 = vec4F_mul(&axis, h); + bc7enc_vec4F c0 = vec4F_add(&meanColor, &b0); + bc7enc_vec4F c1 = vec4F_add(&meanColor, &b1); + minColor = vec4F_saturate(&c0); + maxColor = vec4F_saturate(&c1); + + bc7enc_vec4F whiteVec; + vec4F_set_scalar(&whiteVec, 1.0f); + if (vec4F_dot(&minColor, &whiteVec) > vec4F_dot(&maxColor, &whiteVec)) + { +#if 1 + std::swap(minColor.m_c[0], maxColor.m_c[0]); + std::swap(minColor.m_c[1], maxColor.m_c[1]); + std::swap(minColor.m_c[2], maxColor.m_c[2]); + std::swap(minColor.m_c[3], maxColor.m_c[3]); +#elif 0 + // Fails to compile correctly with MSVC 2019 (code generation bug) + std::swap(minColor, maxColor); +#else + // Fails with MSVC 2019 + bc7enc_vec4F temp = minColor; + minColor = maxColor; + maxColor = temp; +#endif + } + + // First find a solution using the block's PCA. + if (!find_optimal_solution(mode, minColor, maxColor, pParams, pResults)) + return 0; + + for (uint32_t i = 0; i < pComp_params->m_least_squares_passes; i++) + { + // Now try to refine the solution using least squares by computing the optimal endpoints from the current selectors. + bc7enc_vec4F xl, xh; + vec4F_set_scalar(&xl, 0.0f); + vec4F_set_scalar(&xh, 0.0f); + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, pResults->m_pSelectors, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, pResults->m_pSelectors, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + } + + if ((!pParams->m_pForce_selectors) && (pComp_params->m_uber_level > 0)) + { + // In uber level 1, try varying the selectors a little, somewhat like cluster fit would. First try incrementing the minimum selectors, + // then try decrementing the selectrors, then try both. + uint8_t selectors_temp[16], selectors_temp1[16]; + memcpy(selectors_temp, pResults->m_pSelectors, pParams->m_num_pixels); + + const int max_selector = pParams->m_num_selector_weights - 1; + + uint32_t min_sel = 256; + uint32_t max_sel = 0; + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + min_sel = minimumu(min_sel, sel); + max_sel = maximumu(max_sel, sel); + } + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + if ((sel == min_sel) && (sel < (pParams->m_num_selector_weights - 1))) + sel++; + selectors_temp1[i] = (uint8_t)sel; + } + + bc7enc_vec4F xl, xh; + vec4F_set_scalar(&xl, 0.0f); + vec4F_set_scalar(&xh, 0.0f); + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + if ((sel == max_sel) && (sel > 0)) + sel--; + selectors_temp1[i] = (uint8_t)sel; + } + + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + { + uint32_t sel = selectors_temp[i]; + if ((sel == min_sel) && (sel < (pParams->m_num_selector_weights - 1))) + sel++; + else if ((sel == max_sel) && (sel > 0)) + sel--; + selectors_temp1[i] = (uint8_t)sel; + } + + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + + // In uber levels 2+, try taking more advantage of endpoint extrapolation by scaling the selectors in one direction or another. + const uint32_t uber_err_thresh = (pParams->m_num_pixels * 56) >> 4; + if ((pComp_params->m_uber_level >= 2) && (pResults->m_best_overall_err > uber_err_thresh)) + { + const int Q = (pComp_params->m_uber_level >= 4) ? (pComp_params->m_uber_level - 2) : 1; + for (int ly = -Q; ly <= 1; ly++) + { + for (int hy = max_selector - 1; hy <= (max_selector + Q); hy++) + { + if ((ly == 0) && (hy == max_selector)) + continue; + + for (uint32_t i = 0; i < pParams->m_num_pixels; i++) + selectors_temp1[i] = (uint8_t)clampf(floorf((float)max_selector * ((float)selectors_temp[i] - (float)ly) / ((float)hy - (float)ly) + .5f), 0, (float)max_selector); + + //bc7enc_vec4F xl, xh; + vec4F_set_scalar(&xl, 0.0f); + vec4F_set_scalar(&xh, 0.0f); + if (pParams->m_has_alpha) + compute_least_squares_endpoints_rgba(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + else + compute_least_squares_endpoints_rgb(pParams->m_num_pixels, selectors_temp1, pParams->m_pSelector_weightsx, &xl, &xh, pParams->m_pPixels); + + xl = vec4F_mul(&xl, (1.0f / 255.0f)); + xh = vec4F_mul(&xh, (1.0f / 255.0f)); + + if (!find_optimal_solution(mode, xl, xh, pParams, pResults)) + return 0; + } + } + } + } + + if (!pParams->m_pForce_selectors) + { + // Try encoding the partition as a single color by using the optimal single colors tables to encode the block to its mean. + if (mode == 1) + { + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f); + uint64_t avg_err = pack_mode1_to_one_color(pParams, &avg_results, r, g, b, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + else if ((pParams->m_astc_endpoint_range == 8) && (pParams->m_num_selector_weights == 8) && (!pParams->m_has_alpha)) + { + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f); + uint64_t avg_err = pack_astc_4bit_3bit_to_one_color(pParams, &avg_results, r, g, b, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + else if ((pParams->m_astc_endpoint_range == 7) && (pParams->m_num_selector_weights == 4) && (!pParams->m_has_alpha)) + { + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f); + uint64_t avg_err = pack_astc_range7_2bit_to_one_color(pParams, &avg_results, r, g, b, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + else if ((pParams->m_astc_endpoint_range == 8) && (pParams->m_num_selector_weights == 4) && (pParams->m_has_alpha)) + { + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f), a = (int)(.5f + meanColor.m_c[3] * 255.0f); + uint64_t avg_err = pack_astc_4bit_2bit_to_one_color_rgba(pParams, &avg_results, r, g, b, a, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + else if ((pParams->m_astc_endpoint_range == 13) && (pParams->m_num_selector_weights == 4) && (!pParams->m_has_alpha)) + { + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f); + uint64_t avg_err = pack_astc_range13_2bit_to_one_color(pParams, &avg_results, r, g, b, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + else if ((pParams->m_astc_endpoint_range == 11) && (pParams->m_num_selector_weights == 32) && (!pParams->m_has_alpha)) + { + color_cell_compressor_results avg_results = *pResults; + const uint32_t r = (int)(.5f + meanColor.m_c[0] * 255.0f), g = (int)(.5f + meanColor.m_c[1] * 255.0f), b = (int)(.5f + meanColor.m_c[2] * 255.0f); + uint64_t avg_err = pack_astc_range11_5bit_to_one_color(pParams, &avg_results, r, g, b, pResults->m_pSelectors_temp); + if (avg_err < pResults->m_best_overall_err) + { + *pResults = avg_results; + memcpy(pResults->m_pSelectors, pResults->m_pSelectors_temp, sizeof(pResults->m_pSelectors[0]) * pParams->m_num_pixels); + pResults->m_best_overall_err = avg_err; + } + } + } + +#if BC7ENC_CHECK_OVERALL_ERROR + check_best_overall_error(pParams, pResults); +#endif + + return pResults->m_best_overall_err; +} + +uint64_t color_cell_compression_est_astc( + uint32_t num_weights, uint32_t num_comps, const uint32_t *pWeight_table, + uint32_t num_pixels, const color_quad_u8* pPixels, + uint64_t best_err_so_far, const uint32_t weights[4]) +{ + assert(num_comps == 3 || num_comps == 4); + assert(num_weights >= 1 && num_weights <= 32); + assert(pWeight_table[0] == 0 && pWeight_table[num_weights - 1] == 64); + + // Find RGB bounds as an approximation of the block's principle axis + uint32_t lr = 255, lg = 255, lb = 255, la = 255; + uint32_t hr = 0, hg = 0, hb = 0, ha = 0; + if (num_comps == 4) + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8* pC = &pPixels[i]; + if (pC->m_c[0] < lr) lr = pC->m_c[0]; + if (pC->m_c[1] < lg) lg = pC->m_c[1]; + if (pC->m_c[2] < lb) lb = pC->m_c[2]; + if (pC->m_c[3] < la) la = pC->m_c[3]; + + if (pC->m_c[0] > hr) hr = pC->m_c[0]; + if (pC->m_c[1] > hg) hg = pC->m_c[1]; + if (pC->m_c[2] > hb) hb = pC->m_c[2]; + if (pC->m_c[3] > ha) ha = pC->m_c[3]; + } + } + else + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8* pC = &pPixels[i]; + if (pC->m_c[0] < lr) lr = pC->m_c[0]; + if (pC->m_c[1] < lg) lg = pC->m_c[1]; + if (pC->m_c[2] < lb) lb = pC->m_c[2]; + + if (pC->m_c[0] > hr) hr = pC->m_c[0]; + if (pC->m_c[1] > hg) hg = pC->m_c[1]; + if (pC->m_c[2] > hb) hb = pC->m_c[2]; + } + la = 255; + ha = 255; + } + + color_quad_u8 lowColor, highColor; + color_quad_u8_set(&lowColor, lr, lg, lb, la); + color_quad_u8_set(&highColor, hr, hg, hb, ha); + + // Place endpoints at bbox diagonals and compute interpolated colors + color_quad_u8 weightedColors[32]; + + weightedColors[0] = lowColor; + weightedColors[num_weights - 1] = highColor; + for (uint32_t i = 1; i < (num_weights - 1); i++) + { + weightedColors[i].m_c[0] = (uint8_t)astc_interpolate(lowColor.m_c[0], highColor.m_c[0], pWeight_table[i]); + weightedColors[i].m_c[1] = (uint8_t)astc_interpolate(lowColor.m_c[1], highColor.m_c[1], pWeight_table[i]); + weightedColors[i].m_c[2] = (uint8_t)astc_interpolate(lowColor.m_c[2], highColor.m_c[2], pWeight_table[i]); + weightedColors[i].m_c[3] = (num_comps == 4) ? (uint8_t)astc_interpolate(lowColor.m_c[3], highColor.m_c[3], pWeight_table[i]) : 255; + } + + // Compute dots and thresholds + const int ar = highColor.m_c[0] - lowColor.m_c[0]; + const int ag = highColor.m_c[1] - lowColor.m_c[1]; + const int ab = highColor.m_c[2] - lowColor.m_c[2]; + const int aa = highColor.m_c[3] - lowColor.m_c[3]; + + int dots[32]; + if (num_comps == 4) + { + for (uint32_t i = 0; i < num_weights; i++) + dots[i] = weightedColors[i].m_c[0] * ar + weightedColors[i].m_c[1] * ag + weightedColors[i].m_c[2] * ab + weightedColors[i].m_c[3] * aa; + } + else + { + assert(aa == 0); + for (uint32_t i = 0; i < num_weights; i++) + dots[i] = weightedColors[i].m_c[0] * ar + weightedColors[i].m_c[1] * ag + weightedColors[i].m_c[2] * ab; + } + + int thresh[32 - 1]; + for (uint32_t i = 0; i < (num_weights - 1); i++) + thresh[i] = (dots[i] + dots[i + 1] + 1) >> 1; + + uint64_t total_err = 0; + if ((weights[0] | weights[1] | weights[2] | weights[3]) == 1) + { + if (num_comps == 4) + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8* pC = &pPixels[i]; + + int d = ar * pC->m_c[0] + ag * pC->m_c[1] + ab * pC->m_c[2] + aa * pC->m_c[3]; + + // Find approximate selector + uint32_t s = 0; + for (int j = num_weights - 2; j >= 0; j--) + { + if (d >= thresh[j]) + { + s = j + 1; + break; + } + } + + // Compute error + const color_quad_u8* pE1 = &weightedColors[s]; + + int dr = (int)pE1->m_c[0] - (int)pC->m_c[0]; + int dg = (int)pE1->m_c[1] - (int)pC->m_c[1]; + int db = (int)pE1->m_c[2] - (int)pC->m_c[2]; + int da = (int)pE1->m_c[3] - (int)pC->m_c[3]; + + total_err += (dr * dr) + (dg * dg) + (db * db) + (da * da); + if (total_err > best_err_so_far) + break; + } + } + else + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8* pC = &pPixels[i]; + + int d = ar * pC->m_c[0] + ag * pC->m_c[1] + ab * pC->m_c[2]; + + // Find approximate selector + uint32_t s = 0; + for (int j = num_weights - 2; j >= 0; j--) + { + if (d >= thresh[j]) + { + s = j + 1; + break; + } + } + + // Compute error + const color_quad_u8* pE1 = &weightedColors[s]; + + int dr = (int)pE1->m_c[0] - (int)pC->m_c[0]; + int dg = (int)pE1->m_c[1] - (int)pC->m_c[1]; + int db = (int)pE1->m_c[2] - (int)pC->m_c[2]; + + total_err += (dr * dr) + (dg * dg) + (db * db); + if (total_err > best_err_so_far) + break; + } + } + } + else + { + if (num_comps == 4) + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8* pC = &pPixels[i]; + + int d = ar * pC->m_c[0] + ag * pC->m_c[1] + ab * pC->m_c[2] + aa * pC->m_c[3]; + + // Find approximate selector + uint32_t s = 0; + for (int j = num_weights - 2; j >= 0; j--) + { + if (d >= thresh[j]) + { + s = j + 1; + break; + } + } + + // Compute error + const color_quad_u8* pE1 = &weightedColors[s]; + + int dr = (int)pE1->m_c[0] - (int)pC->m_c[0]; + int dg = (int)pE1->m_c[1] - (int)pC->m_c[1]; + int db = (int)pE1->m_c[2] - (int)pC->m_c[2]; + int da = (int)pE1->m_c[3] - (int)pC->m_c[3]; + + total_err += weights[0] * (dr * dr) + weights[1] * (dg * dg) + weights[2] * (db * db) + weights[3] * (da * da); + if (total_err > best_err_so_far) + break; + } + } + else + { + for (uint32_t i = 0; i < num_pixels; i++) + { + const color_quad_u8* pC = &pPixels[i]; + + int d = ar * pC->m_c[0] + ag * pC->m_c[1] + ab * pC->m_c[2]; + + // Find approximate selector + uint32_t s = 0; + for (int j = num_weights - 2; j >= 0; j--) + { + if (d >= thresh[j]) + { + s = j + 1; + break; + } + } + + // Compute error + const color_quad_u8* pE1 = &weightedColors[s]; + + int dr = (int)pE1->m_c[0] - (int)pC->m_c[0]; + int dg = (int)pE1->m_c[1] - (int)pC->m_c[1]; + int db = (int)pE1->m_c[2] - (int)pC->m_c[2]; + + total_err += weights[0] * (dr * dr) + weights[1] * (dg * dg) + weights[2] * (db * db); + if (total_err > best_err_so_far) + break; + } + } + } + + return total_err; +} + +} // namespace basisu |