2 * Copyright 2006 The Android Open Source Project
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
8 #ifndef SkTableMaskFilter_DEFINED
9 #define SkTableMaskFilter_DEFINED
11 #include "SkMaskFilter.h"
14 /** \class SkTableMaskFilter
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)
19 class SK_API SkTableMaskFilter : public SkMaskFilter {
21 virtual ~SkTableMaskFilter();
23 /** Utility that sets the gamma table
25 static void MakeGammaTable(uint8_t table[256], SkScalar gamma);
27 /** Utility that creates a clipping table: clamps values below min to 0
28 and above max to 255, and rescales the remaining into 0..255
30 static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max);
32 static SkTableMaskFilter* Create(const uint8_t table[256]) {
33 return SkNEW_ARGS(SkTableMaskFilter, (table));
36 static SkTableMaskFilter* CreateGamma(SkScalar gamma) {
38 MakeGammaTable(table, gamma);
39 return SkNEW_ARGS(SkTableMaskFilter, (table));
42 static SkTableMaskFilter* CreateClip(uint8_t min, uint8_t max) {
44 MakeClipTable(table, min, max);
45 return SkNEW_ARGS(SkTableMaskFilter, (table));
48 virtual SkMask::Format getFormat() const SK_OVERRIDE;
49 virtual bool filterMask(SkMask*, const SkMask&, const SkMatrix&,
50 SkIPoint*) const SK_OVERRIDE;
52 SK_TO_STRING_OVERRIDE()
53 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTableMaskFilter)
57 explicit SkTableMaskFilter(const uint8_t table[256]);
58 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
59 explicit SkTableMaskFilter(SkReadBuffer& rb);
61 virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
66 typedef SkMaskFilter INHERITED;