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comparison: gfx/skia/trunk/src/core/SkDither.cpp
gfx/skia/trunk/src/core/SkDither.cpp
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:a0dcd7d1af93 |
|---|---|
| 1 | |
| 2 /* | |
| 3 * Copyright 2011 Google Inc. | |
| 4 * | |
| 5 * Use of this source code is governed by a BSD-style license that can be | |
| 6 * found in the LICENSE file. | |
| 7 */ | |
| 8 #include "SkDither.h" | |
| 9 | |
| 10 /* The base dither matrix we use to derive optimized ones for 565 and 4444 | |
| 11 | |
| 12 { 0, 32, 8, 40, 2, 34, 10, 42 }, | |
| 13 { 48, 16, 56, 24, 50, 18, 58, 26 }, | |
| 14 { 12, 44, 4, 36, 14, 46, 6, 38 }, | |
| 15 { 60, 28, 52, 20, 62, 30, 54, 22 }, | |
| 16 { 3, 35, 11, 43, 1, 33, 9, 41 }, | |
| 17 { 51, 19, 59, 27, 49, 17, 57, 25 }, | |
| 18 { 15, 47, 7, 39, 13, 45, 5, 37 }, | |
| 19 { 63, 31, 55, 23, 61, 29, 53, 21 } | |
| 20 | |
| 21 The 4444 version only needs 4 bits, and given that we can reduce its size | |
| 22 since the other 4x4 sub pieces all look the same once we truncate the bits. | |
| 23 | |
| 24 The 565 version only needs 3 bits for red/blue, and only 2 bits for green. | |
| 25 For simplicity, we store 3 bits, and have the dither macros for green know | |
| 26 this, and they shift the dither value down by 1 to make it 2 bits. | |
| 27 */ | |
| 28 | |
| 29 #ifdef ENABLE_DITHER_MATRIX_4X4 | |
| 30 | |
| 31 const uint8_t gDitherMatrix_4Bit_4X4[4][4] = { | |
| 32 { 0, 8, 2, 10 }, | |
| 33 { 12, 4, 14, 6 }, | |
| 34 { 3, 11, 1, 9 }, | |
| 35 { 15, 7, 13, 5 } | |
| 36 }; | |
| 37 | |
| 38 const uint8_t gDitherMatrix_3Bit_4X4[4][4] = { | |
| 39 { 0, 4, 1, 5 }, | |
| 40 { 6, 2, 7, 3 }, | |
| 41 { 1, 5, 0, 4 }, | |
| 42 { 7, 3, 6, 2 } | |
| 43 }; | |
| 44 | |
| 45 #else // used packed shorts for a scanlines worth of dither values | |
| 46 | |
| 47 const uint16_t gDitherMatrix_4Bit_16[4] = { | |
| 48 0xA280, 0x6E4C, 0x91B3, 0x5D7F | |
| 49 }; | |
| 50 | |
| 51 const uint16_t gDitherMatrix_3Bit_16[4] = { | |
| 52 0x5140, 0x3726, 0x4051, 0x2637 | |
| 53 }; | |
| 54 | |
| 55 #endif |
