1// File: basisu_bc7enc.h
2// Copyright (C) 2019-2021 Binomial LLC. All Rights Reserved.
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8// http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15#pragma once
16#include "basisu_enc.h"
17#include "../transcoder/basisu_transcoder_uastc.h"
18
19namespace basisu
20{
21
22#define BC7ENC_MAX_PARTITIONS1 (64)
23#define BC7ENC_MAX_UBER_LEVEL (4)
24
25 typedef uint8_t bc7enc_bool;
26
27#define BC7ENC_TRUE (1)
28#define BC7ENC_FALSE (0)
29
30 typedef struct { float m_c[4]; } bc7enc_vec4F;
31
32 extern const float g_bc7_weights1x[2 * 4];
33 extern const float g_bc7_weights2x[4 * 4];
34 extern const float g_bc7_weights3x[8 * 4];
35 extern const float g_bc7_weights4x[16 * 4];
36 extern const float g_astc_weights4x[16 * 4];
37 extern const float g_astc_weights5x[32 * 4];
38 extern const float g_astc_weights_3levelsx[3 * 4];
39
40 extern basist::astc_quant_bin g_astc_sorted_order_unquant[basist::BC7ENC_TOTAL_ASTC_RANGES][256]; // [sorted unquantized order]
41
42 struct color_cell_compressor_params
43 {
44 uint32_t m_num_pixels;
45 const basist::color_quad_u8* m_pPixels;
46
47 uint32_t m_num_selector_weights;
48 const uint32_t* m_pSelector_weights;
49
50 const bc7enc_vec4F* m_pSelector_weightsx;
51 uint32_t m_comp_bits;
52
53 const uint8_t *m_pForce_selectors;
54
55 // Non-zero m_astc_endpoint_range enables ASTC mode. m_comp_bits and m_has_pbits are always false. We only support 2, 3, or 4 bit weight encodings.
56 uint32_t m_astc_endpoint_range;
57
58 uint32_t m_weights[4];
59 bc7enc_bool m_has_alpha;
60 bc7enc_bool m_has_pbits;
61 bc7enc_bool m_endpoints_share_pbit;
62 bc7enc_bool m_perceptual;
63 };
64
65 struct color_cell_compressor_results
66 {
67 uint64_t m_best_overall_err;
68 basist::color_quad_u8 m_low_endpoint;
69 basist::color_quad_u8 m_high_endpoint;
70 uint32_t m_pbits[2];
71 uint8_t* m_pSelectors;
72 uint8_t* m_pSelectors_temp;
73
74 // Encoded ASTC indices, if ASTC mode is enabled
75 basist::color_quad_u8 m_astc_low_endpoint;
76 basist::color_quad_u8 m_astc_high_endpoint;
77 };
78
79 struct bc7enc_compress_block_params
80 {
81 // m_max_partitions_mode1 may range from 0 (disables mode 1) to BC7ENC_MAX_PARTITIONS1. The higher this value, the slower the compressor, but the higher the quality.
82 uint32_t m_max_partitions_mode1;
83
84 // Relative RGBA or YCbCrA weights.
85 uint32_t m_weights[4];
86
87 // m_uber_level may range from 0 to BC7ENC_MAX_UBER_LEVEL. The higher this value, the slower the compressor, but the higher the quality.
88 uint32_t m_uber_level;
89
90 // If m_perceptual is true, colorspace error is computed in YCbCr space, otherwise RGB.
91 bc7enc_bool m_perceptual;
92
93 uint32_t m_least_squares_passes;
94 };
95
96 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);
97
98 uint64_t color_cell_compression_est_astc(
99 uint32_t num_weights, uint32_t num_comps, const uint32_t* pWeight_table,
100 uint32_t num_pixels, const basist::color_quad_u8* pPixels,
101 uint64_t best_err_so_far, const uint32_t weights[4]);
102
103 inline void bc7enc_compress_block_params_init_linear_weights(bc7enc_compress_block_params* p)
104 {
105 p->m_perceptual = BC7ENC_FALSE;
106 p->m_weights[0] = 1;
107 p->m_weights[1] = 1;
108 p->m_weights[2] = 1;
109 p->m_weights[3] = 1;
110 }
111
112 inline void bc7enc_compress_block_params_init_perceptual_weights(bc7enc_compress_block_params* p)
113 {
114 p->m_perceptual = BC7ENC_TRUE;
115 p->m_weights[0] = 128;
116 p->m_weights[1] = 64;
117 p->m_weights[2] = 16;
118 p->m_weights[3] = 32;
119 }
120
121 inline void bc7enc_compress_block_params_init(bc7enc_compress_block_params* p)
122 {
123 p->m_max_partitions_mode1 = BC7ENC_MAX_PARTITIONS1;
124 p->m_least_squares_passes = 1;
125 p->m_uber_level = 0;
126 bc7enc_compress_block_params_init_perceptual_weights(p);
127 }
128
129 // bc7enc_compress_block_init() MUST be called before calling bc7enc_compress_block() (or you'll get artifacts).
130 void bc7enc_compress_block_init();
131
132} // namespace basisu
133