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1 /* | |
2 * Copyright 2014 Google Inc. | |
3 * | |
4 * Use of this source code is governed by a BSD-style license that can be | |
5 * found in the LICENSE file. | |
6 */ | |
7 | |
8 #include "SkTextureCompressor_ASTC.h" | |
9 | |
10 #include "SkBlitter.h" | |
11 #include "SkEndian.h" | |
12 | |
13 // This table contains the weight values for each texel. This is used in determi ning | |
14 // how to convert a 12x12 grid of alpha values into a 6x5 grid of index values. Since | |
15 // we have a 6x5 grid, that gives 30 values that we have to compute. For each in dex, | |
16 // we store up to 20 different triplets of values. In order the triplets are: | |
17 // weight, texel-x, texel-y | |
18 // The weight value corresponds to the amount that this index contributes to the final | |
19 // index value of the given texel. Hence, we need to reconstruct the 6x5 index g rid | |
20 // from their relative contribution to the 12x12 texel grid. | |
21 // | |
22 // The algorithm is something like this: | |
23 // foreach index i: | |
24 // total-weight = 0; | |
25 // total-alpha = 0; | |
26 // for w = 1 to 20: | |
27 // weight = table[i][w*3]; | |
28 // texel-x = table[i][w*3 + 1]; | |
29 // texel-y = table[i][w*3 + 2]; | |
30 // if weight >= 0: | |
31 // total-weight += weight; | |
32 // total-alpha += weight * alphas[texel-x][texel-y]; | |
33 // | |
34 // total-alpha /= total-weight; | |
35 // index = top three bits of total-alpha | |
36 // | |
37 // If the associated index does not contribute to 20 different texels (e.g. it's in | |
38 // a corner), then the extra texels are stored with -1's in the table. | |
39 | |
40 static const int k6x5To12x12Table[30][60] = { | |
41 { 16, 0, 0, 9, 1, 0, 1, 2, 0, 10, 0, 1, 6, 1, 1, 1, 2, 1, 4, 0, 2, 2, | |
42 1, 2, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, | |
43 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
44 { 7, 1, 0, 15, 2, 0, 10, 3, 0, 3, 4, 0, 4, 1, 1, 9, 2, 1, 6, 3, 1, 2, | |
45 4, 1, 2, 1, 2, 4, 2, 2, 3, 3, 2, 1, 4, 2, -1, 0, 0, -1, 0, 0, -1, 0, | |
46 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
47 { 6, 3, 0, 13, 4, 0, 12, 5, 0, 4, 6, 0, 4, 3, 1, 8, 4, 1, 8, 5, 1, 3, | |
48 6, 1, 1, 3, 2, 3, 4, 2, 3, 5, 2, 1, 6, 2, -1, 0, 0, -1, 0, 0, -1, 0, | |
49 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
50 { 4, 5, 0, 12, 6, 0, 13, 7, 0, 6, 8, 0, 2, 5, 1, 7, 6, 1, 8, 7, 1, 4, | |
51 8, 1, 1, 5, 2, 3, 6, 2, 3, 7, 2, 2, 8, 2, -1, 0, 0, -1, 0, 0, -1, 0, | |
52 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
53 { 3, 7, 0, 10, 8, 0, 15, 9, 0, 7, 10, 0, 2, 7, 1, 6, 8, 1, 9, 9, 1, 4, | |
54 10, 1, 1, 7, 2, 2, 8, 2, 4, 9, 2, 2, 10, 2, -1, 0, 0, -1, 0, 0, -1, 0, | |
55 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
56 { 1, 9, 0, 9, 10, 0, 16, 11, 0, 1, 9, 1, 6, 10, 1, 10, 11, 1, 2, 10, 2, 4, | |
57 11, 2, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, | |
58 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
59 { 6, 0, 1, 3, 1, 1, 12, 0, 2, 7, 1, 2, 1, 2, 2, 15, 0, 3, 8, 1, 3, 1, | |
60 2, 3, 9, 0, 4, 5, 1, 4, 1, 2, 4, 3, 0, 5, 2, 1, 5, -1, 0, 0, -1, 0, | |
61 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
62 { 3, 1, 1, 6, 2, 1, 4, 3, 1, 1, 4, 1, 5, 1, 2, 11, 2, 2, 7, 3, 2, 2, | |
63 4, 2, 7, 1, 3, 14, 2, 3, 9, 3, 3, 3, 4, 3, 4, 1, 4, 8, 2, 4, 6, 3, | |
64 4, 2, 4, 4, 1, 1, 5, 3, 2, 5, 2, 3, 5, 1, 4, 5}, // n = 20 | |
65 { 2, 3, 1, 5, 4, 1, 4, 5, 1, 1, 6, 1, 5, 3, 2, 10, 4, 2, 9, 5, 2, 3, | |
66 6, 2, 6, 3, 3, 12, 4, 3, 11, 5, 3, 4, 6, 3, 3, 3, 4, 7, 4, 4, 7, 5, | |
67 4, 2, 6, 4, 1, 3, 5, 2, 4, 5, 2, 5, 5, 1, 6, 5}, // n = 20 | |
68 { 2, 5, 1, 5, 6, 1, 5, 7, 1, 2, 8, 1, 3, 5, 2, 9, 6, 2, 10, 7, 2, 4, | |
69 8, 2, 4, 5, 3, 11, 6, 3, 12, 7, 3, 6, 8, 3, 2, 5, 4, 7, 6, 4, 7, 7, | |
70 4, 3, 8, 4, 1, 5, 5, 2, 6, 5, 2, 7, 5, 1, 8, 5}, // n = 20 | |
71 { 1, 7, 1, 4, 8, 1, 6, 9, 1, 3, 10, 1, 2, 7, 2, 8, 8, 2, 11, 9, 2, 5, | |
72 10, 2, 3, 7, 3, 9, 8, 3, 14, 9, 3, 7, 10, 3, 2, 7, 4, 6, 8, 4, 8, 9, | |
73 4, 4, 10, 4, 1, 7, 5, 2, 8, 5, 3, 9, 5, 1, 10, 5}, // n = 20 | |
74 { 3, 10, 1, 6, 11, 1, 1, 9, 2, 7, 10, 2, 12, 11, 2, 1, 9, 3, 8, 10, 3, 15, | |
75 11, 3, 1, 9, 4, 5, 10, 4, 9, 11, 4, 2, 10, 5, 3, 11, 5, -1, 0, 0, -1, 0, | |
76 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
77 { 1, 0, 3, 1, 1, 3, 7, 0, 4, 4, 1, 4, 13, 0, 5, 7, 1, 5, 1, 2, 5, 13, | |
78 0, 6, 7, 1, 6, 1, 2, 6, 7, 0, 7, 4, 1, 7, 1, 0, 8, 1, 1, 8, -1, 0, | |
79 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
80 { 1, 2, 3, 1, 3, 3, 3, 1, 4, 7, 2, 4, 4, 3, 4, 1, 4, 4, 6, 1, 5, 12, | |
81 2, 5, 8, 3, 5, 2, 4, 5, 6, 1, 6, 12, 2, 6, 8, 3, 6, 2, 4, 6, 3, 1, | |
82 7, 7, 2, 7, 4, 3, 7, 1, 4, 7, 1, 2, 8, 1, 3, 8}, // n = 20 | |
83 { 1, 4, 3, 1, 5, 3, 3, 3, 4, 6, 4, 4, 5, 5, 4, 2, 6, 4, 5, 3, 5, 11, | |
84 4, 5, 10, 5, 5, 3, 6, 5, 5, 3, 6, 11, 4, 6, 10, 5, 6, 3, 6, 6, 3, 3, | |
85 7, 6, 4, 7, 5, 5, 7, 2, 6, 7, 1, 4, 8, 1, 5, 8}, // n = 20 | |
86 { 1, 6, 3, 1, 7, 3, 2, 5, 4, 5, 6, 4, 6, 7, 4, 3, 8, 4, 3, 5, 5, 10, | |
87 6, 5, 11, 7, 5, 5, 8, 5, 3, 5, 6, 10, 6, 6, 11, 7, 6, 5, 8, 6, 2, 5, | |
88 7, 5, 6, 7, 6, 7, 7, 3, 8, 7, 1, 6, 8, 1, 7, 8}, // n = 20 | |
89 { 1, 8, 3, 1, 9, 3, 1, 7, 4, 4, 8, 4, 7, 9, 4, 3, 10, 4, 2, 7, 5, 8, | |
90 8, 5, 12, 9, 5, 6, 10, 5, 2, 7, 6, 8, 8, 6, 12, 9, 6, 6, 10, 6, 1, 7, | |
91 7, 4, 8, 7, 7, 9, 7, 3, 10, 7, 1, 8, 8, 1, 9, 8}, // n = 20 | |
92 { 1, 10, 3, 1, 11, 3, 4, 10, 4, 7, 11, 4, 1, 9, 5, 7, 10, 5, 13, 11, 5, 1, | |
93 9, 6, 7, 10, 6, 13, 11, 6, 4, 10, 7, 7, 11, 7, 1, 10, 8, 1, 11, 8, -1, 0, | |
94 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
95 { 3, 0, 6, 2, 1, 6, 9, 0, 7, 5, 1, 7, 1, 2, 7, 15, 0, 8, 8, 1, 8, 1, | |
96 2, 8, 12, 0, 9, 7, 1, 9, 1, 2, 9, 6, 0, 10, 3, 1, 10, -1, 0, 0, -1, 0, | |
97 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
98 { 1, 1, 6, 3, 2, 6, 2, 3, 6, 1, 4, 6, 4, 1, 7, 8, 2, 7, 6, 3, 7, 2, | |
99 4, 7, 7, 1, 8, 14, 2, 8, 9, 3, 8, 3, 4, 8, 5, 1, 9, 11, 2, 9, 8, 3, | |
100 9, 2, 4, 9, 3, 1, 10, 6, 2, 10, 4, 3, 10, 1, 4, 10}, // n = 20 | |
101 { 1, 3, 6, 2, 4, 6, 2, 5, 6, 1, 6, 6, 3, 3, 7, 7, 4, 7, 7, 5, 7, 2, | |
102 6, 7, 6, 3, 8, 12, 4, 8, 11, 5, 8, 4, 6, 8, 4, 3, 9, 10, 4, 9, 9, 5, | |
103 9, 3, 6, 9, 2, 3, 10, 5, 4, 10, 5, 5, 10, 2, 6, 10}, // n = 20 | |
104 { 1, 5, 6, 2, 6, 6, 2, 7, 6, 1, 8, 6, 2, 5, 7, 7, 6, 7, 7, 7, 7, 3, | |
105 8, 7, 4, 5, 8, 11, 6, 8, 12, 7, 8, 6, 8, 8, 3, 5, 9, 9, 6, 9, 10, 7, | |
106 9, 5, 8, 9, 1, 5, 10, 4, 6, 10, 5, 7, 10, 2, 8, 10}, // n = 20 | |
107 { 1, 7, 6, 2, 8, 6, 3, 9, 6, 1, 10, 6, 2, 7, 7, 6, 8, 7, 8, 9, 7, 4, | |
108 10, 7, 3, 7, 8, 9, 8, 8, 14, 9, 8, 7, 10, 8, 2, 7, 9, 7, 8, 9, 11, 9, | |
109 9, 5, 10, 9, 1, 7, 10, 4, 8, 10, 6, 9, 10, 3, 10, 10}, // n = 20 | |
110 { 2, 10, 6, 3, 11, 6, 1, 9, 7, 5, 10, 7, 9, 11, 7, 1, 9, 8, 8, 10, 8, 15, | |
111 11, 8, 1, 9, 9, 7, 10, 9, 12, 11, 9, 3, 10, 10, 6, 11, 10, -1, 0, 0, -1, 0, | |
112 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
113 { 4, 0, 9, 2, 1, 9, 10, 0, 10, 6, 1, 10, 1, 2, 10, 16, 0, 11, 9, 1, 11, 1, | |
114 2, 11, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, | |
115 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
116 { 2, 1, 9, 4, 2, 9, 2, 3, 9, 1, 4, 9, 4, 1, 10, 9, 2, 10, 6, 3, 10, 2, | |
117 4, 10, 7, 1, 11, 15, 2, 11, 10, 3, 11, 3, 4, 11, -1, 0, 0, -1, 0, 0, -1, 0, | |
118 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
119 { 2, 3, 9, 3, 4, 9, 3, 5, 9, 1, 6, 9, 4, 3, 10, 8, 4, 10, 7, 5, 10, 2, | |
120 6, 10, 6, 3, 11, 13, 4, 11, 12, 5, 11, 4, 6, 11, -1, 0, 0, -1, 0, 0, -1, 0, | |
121 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
122 { 1, 5, 9, 3, 6, 9, 3, 7, 9, 1, 8, 9, 3, 5, 10, 8, 6, 10, 8, 7, 10, 4, | |
123 8, 10, 4, 5, 11, 12, 6, 11, 13, 7, 11, 6, 8, 11, -1, 0, 0, -1, 0, 0, -1, 0, | |
124 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
125 { 1, 7, 9, 3, 8, 9, 4, 9, 9, 2, 10, 9, 2, 7, 10, 6, 8, 10, 9, 9, 10, 4, | |
126 10, 10, 3, 7, 11, 10, 8, 11, 15, 9, 11, 7, 10, 11, -1, 0, 0, -1, 0, 0, -1, 0, | |
127 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0}, // n = 20 | |
128 { 2, 10, 9, 4, 11, 9, 1, 9, 10, 6, 10, 10, 10, 11, 10, 1, 9, 11, 9, 10, 11, 16, | |
129 11, 11, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, | |
130 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0} // n = 20 | |
131 }; | |
132 | |
133 // Returns the alpha value of a texel at position (x, y) from src. | |
134 // (x, y) are assumed to be in the range [0, 12). | |
135 uint8_t get_alpha(const uint8_t *src, int rowBytes, int x, int y) { | |
136 SkASSERT(x >= 0 && x < 12); | |
137 SkASSERT(y >= 0 && y < 12); | |
138 SkASSERT(rowBytes >= 12); | |
139 return *(src + y*rowBytes + x); | |
140 } | |
141 | |
142 // Output the 16 bytes stored in top and bottom and advance the pointer. The byt es | |
143 // are stored as the integers are represented in memory, so they should be swapp ed | |
144 // if necessary. | |
145 static inline void send_packing(uint8_t** dst, const uint64_t top, const uint64_ t bottom) { | |
146 uint64_t* dst64 = reinterpret_cast<uint64_t*>(*dst); | |
147 dst64[0] = top; | |
148 dst64[1] = bottom; | |
149 *dst += 16; | |
150 } | |
151 | |
152 // Compresses an ASTC block, by looking up the proper contributions from | |
153 // k6x5To12x12Table and computing an index from the associated values. | |
154 static void compress_a8_astc_block(uint8_t** dst, const uint8_t* src, int rowByt es) { | |
155 // Check for single color | |
156 bool constant = true; | |
157 const uint32_t firstInt = *(reinterpret_cast<const uint32_t*>(src)); | |
158 for (int i = 0; i < 12; ++i) { | |
159 const uint32_t *rowInt = reinterpret_cast<const uint32_t *>(src + i*rowB ytes); | |
160 constant = constant && (rowInt[0] == firstInt); | |
161 constant = constant && (rowInt[1] == firstInt); | |
162 constant = constant && (rowInt[2] == firstInt); | |
163 } | |
164 | |
165 if (constant) { | |
166 if (0 == firstInt) { | |
167 // All of the indices are set to zero, and the colors are | |
168 // v0 = 0, v1 = 255, so everything will be transparent. | |
169 send_packing(dst, SkTEndian_SwapLE64(0x0000000001FE000173ULL), 0); | |
170 return; | |
171 } else if (0xFFFFFFFF == firstInt) { | |
172 // All of the indices are set to zero, and the colors are | |
173 // v0 = 255, v1 = 0, so everything will be opaque. | |
174 send_packing(dst, SkTEndian_SwapLE64(0x000000000001FE0173ULL), 0); | |
175 return; | |
176 } | |
177 } | |
178 | |
179 uint8_t indices[30]; // 6x5 index grid | |
180 for (int idx = 0; idx < 30; ++idx) { | |
181 int weightTot = 0; | |
182 int alphaTot = 0; | |
183 for (int w = 0; w < 20; ++w) { | |
184 const int weight = k6x5To12x12Table[idx][w*3]; | |
robertphillips
2014/07/25 13:06:58
Can we move the x & y lookups inside the "if (weig
krajcevski
2014/07/25 14:20:14
Done.
| |
185 const int x = k6x5To12x12Table[idx][w*3 + 1]; | |
186 const int y = k6x5To12x12Table[idx][w*3 + 2]; | |
187 if (weight > 0) { | |
188 weightTot += weight; | |
189 alphaTot += weight * get_alpha(src, rowBytes, x, y); | |
190 } | |
191 } | |
192 | |
193 indices[idx] = (alphaTot + (weightTot/2)) / weightTot; | |
194 } | |
195 | |
196 // Pack indices... The ASTC block layout is fairly complicated. An extensive | |
197 // description can be found here: | |
198 // https://www.opengl.org/registry/specs/KHR/texture_compression_astc_hdr.tx t | |
199 // | |
200 // Here is a summary of the options that we've chosen: | |
201 // 1. Block mode: 0b00101110011 | |
202 // - 6x5 texel grid | |
203 // - Single plane | |
204 // - Low-precision index values | |
205 // - Index range 0-7 (three bits per index) | |
206 // 2. Partitions: 0b00 | |
207 // - One partition | |
208 // 3. Color Endpoint Mode: 0b0000 | |
209 // - Direct luminance -- e0=(v0,v0,v0,0xFF); e1=(v1,v1,v1,0xFF); | |
210 // 4. 8-bit endpoints: | |
211 // v0 = 0, v1 = 255 | |
212 // | |
213 // The rest of the block contains the 30 index values from before, which | |
214 // are currently stored in the indices variable. | |
215 | |
216 uint64_t top = 0x0000000001FE000173ULL; | |
217 uint64_t bottom = 0; | |
218 | |
219 for (int idx = 0; idx <= 20; ++idx) { | |
220 const uint8_t index = (indices[idx] & 0xE0) >> 5; | |
221 bottom |= static_cast<uint64_t>(index) << (61-(idx*3)); | |
222 } | |
223 | |
224 // index 21 straddles top and bottom | |
225 { | |
226 const uint8_t index = (indices[21] & 0xE0) >> 5; | |
227 bottom |= index & 1; | |
228 top |= static_cast<uint64_t>((index >> 2) | (index & 2)) << 62; | |
229 } | |
230 | |
231 for (int idx = 22; idx < 30; ++idx) { | |
232 const uint8_t index = (indices[idx] & 0xE0) >> 5; | |
233 top |= static_cast<uint64_t>(index) << (59-(idx-22)*3); | |
234 } | |
235 | |
236 // Reverse each 3-bit index since indices are read in reverse order... | |
237 uint64_t t = (bottom ^ (bottom >> 2)) & 0x2492492492492492ULL; | |
238 bottom = bottom ^ t ^ (t << 2); | |
239 | |
240 t = (top ^ (top >> 2)) & 0x0924924000000000ULL; | |
241 top = top ^ t ^ (t << 2); | |
242 | |
243 send_packing(dst, SkEndian_SwapLE64(top), SkEndian_SwapLE64(bottom)); | |
244 } | |
245 | |
246 //////////////////////////////////////////////////////////////////////////////// | |
247 | |
248 namespace SkTextureCompressor { | |
249 | |
250 bool CompressA8To12x12ASTC(uint8_t* dst, const uint8_t* src, int width, int heig ht, int rowBytes) { | |
251 if (width < 0 || ((width % 12) != 0) || height < 0 || ((height % 12) != 0)) { | |
252 return false; | |
253 } | |
254 | |
255 uint8_t** dstPtr = &dst; | |
robertphillips
2014/07/25 13:06:58
j,i -> y,x ?
krajcevski
2014/07/25 14:20:14
Done.
| |
256 for (int j = 0; j < height; j+=12) { | |
257 for (int i = 0; i < width; i+=12) { | |
258 compress_a8_astc_block(dstPtr, src + j*rowBytes + i, rowBytes); | |
259 } | |
260 } | |
261 | |
262 return true; | |
263 } | |
264 | |
265 SkBlitter* CreateASTCBlitter(int width, int height, void* outputBuffer) { | |
266 // TODO (krajcevski) | |
267 return NULL; | |
268 } | |
269 | |
270 } // SkTextureCompressor | |
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