jcgregorio | eb9a84a | 2016-07-18 08:18:50 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2006 The Android Open Source Project |
| 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 | #ifndef SkTableMaskFilter_DEFINED |
| 9 | #define SkTableMaskFilter_DEFINED |
| 10 | |
| 11 | #include "SkMaskFilter.h" |
| 12 | #include "SkScalar.h" |
| 13 | |
| 14 | /** \class SkTableMaskFilter |
| 15 | |
| 16 | Applies a table lookup on each of the alpha values in the mask. |
| 17 | Helper methods create some common tables (e.g. gamma, clipping) |
| 18 | */ |
| 19 | class SK_API SkTableMaskFilter : public SkMaskFilter { |
| 20 | public: |
| 21 | /** Utility that sets the gamma table |
| 22 | */ |
| 23 | static void MakeGammaTable(uint8_t table[256], SkScalar gamma); |
| 24 | |
| 25 | /** Utility that creates a clipping table: clamps values below min to 0 |
| 26 | and above max to 255, and rescales the remaining into 0..255 |
| 27 | */ |
| 28 | static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max); |
| 29 | |
| 30 | static SkMaskFilter* Create(const uint8_t table[256]) { |
| 31 | return new SkTableMaskFilter(table); |
| 32 | } |
| 33 | |
| 34 | static SkMaskFilter* CreateGamma(SkScalar gamma) { |
| 35 | uint8_t table[256]; |
| 36 | MakeGammaTable(table, gamma); |
| 37 | return new SkTableMaskFilter(table); |
| 38 | } |
| 39 | |
| 40 | static SkMaskFilter* CreateClip(uint8_t min, uint8_t max) { |
| 41 | uint8_t table[256]; |
| 42 | MakeClipTable(table, min, max); |
| 43 | return new SkTableMaskFilter(table); |
| 44 | } |
| 45 | |
| 46 | SkMask::Format getFormat() const override; |
| 47 | bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*) const override; |
| 48 | |
| 49 | SK_TO_STRING_OVERRIDE() |
| 50 | SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTableMaskFilter) |
| 51 | |
| 52 | protected: |
| 53 | virtual ~SkTableMaskFilter(); |
| 54 | |
| 55 | void flatten(SkWriteBuffer&) const override; |
| 56 | |
| 57 | private: |
| 58 | SkTableMaskFilter(); |
| 59 | explicit SkTableMaskFilter(const uint8_t table[256]); |
| 60 | |
| 61 | uint8_t fTable[256]; |
| 62 | |
| 63 | typedef SkMaskFilter INHERITED; |
| 64 | }; |
| 65 | |
| 66 | #endif |