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comparison: gfx/skia/trunk/src/core/SkBlitter.h
gfx/skia/trunk/src/core/SkBlitter.h
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- TOR_BUG_3246
- changeset 6
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| -1:000000000000 | 0:e0f4eeb8ca94 |
|---|---|
| 1 | |
| 2 /* | |
| 3 * Copyright 2006 The Android Open Source Project | |
| 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 | |
| 9 | |
| 10 #ifndef SkBlitter_DEFINED | |
| 11 #define SkBlitter_DEFINED | |
| 12 | |
| 13 #include "SkBitmap.h" | |
| 14 #include "SkBitmapProcShader.h" | |
| 15 #include "SkMask.h" | |
| 16 #include "SkMatrix.h" | |
| 17 #include "SkPaint.h" | |
| 18 #include "SkRefCnt.h" | |
| 19 #include "SkRegion.h" | |
| 20 #include "SkShader.h" | |
| 21 #include "SkSmallAllocator.h" | |
| 22 | |
| 23 /** SkBlitter and its subclasses are responsible for actually writing pixels | |
| 24 into memory. Besides efficiency, they handle clipping and antialiasing. | |
| 25 */ | |
| 26 class SkBlitter { | |
| 27 public: | |
| 28 virtual ~SkBlitter(); | |
| 29 | |
| 30 /// Blit a horizontal run of one or more pixels. | |
| 31 virtual void blitH(int x, int y, int width); | |
| 32 /// Blit a horizontal run of antialiased pixels; runs[] is a *sparse* | |
| 33 /// zero-terminated run-length encoding of spans of constant alpha values. | |
| 34 virtual void blitAntiH(int x, int y, const SkAlpha antialias[], | |
| 35 const int16_t runs[]); | |
| 36 /// Blit a vertical run of pixels with a constant alpha value. | |
| 37 virtual void blitV(int x, int y, int height, SkAlpha alpha); | |
| 38 /// Blit a solid rectangle one or more pixels wide. | |
| 39 virtual void blitRect(int x, int y, int width, int height); | |
| 40 /** Blit a rectangle with one alpha-blended column on the left, | |
| 41 width (zero or more) opaque pixels, and one alpha-blended column | |
| 42 on the right. | |
| 43 The result will always be at least two pixels wide. | |
| 44 */ | |
| 45 virtual void blitAntiRect(int x, int y, int width, int height, | |
| 46 SkAlpha leftAlpha, SkAlpha rightAlpha); | |
| 47 /// Blit a pattern of pixels defined by a rectangle-clipped mask; | |
| 48 /// typically used for text. | |
| 49 virtual void blitMask(const SkMask&, const SkIRect& clip); | |
| 50 | |
| 51 /** If the blitter just sets a single value for each pixel, return the | |
| 52 bitmap it draws into, and assign value. If not, return NULL and ignore | |
| 53 the value parameter. | |
| 54 */ | |
| 55 virtual const SkBitmap* justAnOpaqueColor(uint32_t* value); | |
| 56 | |
| 57 /** | |
| 58 * Special method just to identify the null blitter, which is returned | |
| 59 * from Choose() if the request cannot be fulfilled. Default impl | |
| 60 * returns false. | |
| 61 */ | |
| 62 virtual bool isNullBlitter() const; | |
| 63 | |
| 64 ///@name non-virtual helpers | |
| 65 void blitMaskRegion(const SkMask& mask, const SkRegion& clip); | |
| 66 void blitRectRegion(const SkIRect& rect, const SkRegion& clip); | |
| 67 void blitRegion(const SkRegion& clip); | |
| 68 ///@} | |
| 69 | |
| 70 /** @name Factories | |
| 71 Return the correct blitter to use given the specified context. | |
| 72 */ | |
| 73 static SkBlitter* Choose(const SkBitmap& device, | |
| 74 const SkMatrix& matrix, | |
| 75 const SkPaint& paint, | |
| 76 SkTBlitterAllocator*, | |
| 77 bool drawCoverage = false); | |
| 78 | |
| 79 static SkBlitter* ChooseSprite(const SkBitmap& device, | |
| 80 const SkPaint&, | |
| 81 const SkBitmap& src, | |
| 82 int left, int top, | |
| 83 SkTBlitterAllocator*); | |
| 84 ///@} | |
| 85 | |
| 86 private: | |
| 87 }; | |
| 88 | |
| 89 /** This blitter silently never draws anything. | |
| 90 */ | |
| 91 class SkNullBlitter : public SkBlitter { | |
| 92 public: | |
| 93 virtual void blitH(int x, int y, int width) SK_OVERRIDE; | |
| 94 virtual void blitAntiH(int x, int y, const SkAlpha[], | |
| 95 const int16_t runs[]) SK_OVERRIDE; | |
| 96 virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE; | |
| 97 virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE; | |
| 98 virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE; | |
| 99 virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE; | |
| 100 virtual bool isNullBlitter() const SK_OVERRIDE; | |
| 101 }; | |
| 102 | |
| 103 /** Wraps another (real) blitter, and ensures that the real blitter is only | |
| 104 called with coordinates that have been clipped by the specified clipRect. | |
| 105 This means the caller need not perform the clipping ahead of time. | |
| 106 */ | |
| 107 class SkRectClipBlitter : public SkBlitter { | |
| 108 public: | |
| 109 void init(SkBlitter* blitter, const SkIRect& clipRect) { | |
| 110 SkASSERT(!clipRect.isEmpty()); | |
| 111 fBlitter = blitter; | |
| 112 fClipRect = clipRect; | |
| 113 } | |
| 114 | |
| 115 virtual void blitH(int x, int y, int width) SK_OVERRIDE; | |
| 116 virtual void blitAntiH(int x, int y, const SkAlpha[], | |
| 117 const int16_t runs[]) SK_OVERRIDE; | |
| 118 virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE; | |
| 119 virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE; | |
| 120 virtual void blitAntiRect(int x, int y, int width, int height, | |
| 121 SkAlpha leftAlpha, SkAlpha rightAlpha) SK_OVERRIDE; | |
| 122 virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE; | |
| 123 virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE; | |
| 124 | |
| 125 private: | |
| 126 SkBlitter* fBlitter; | |
| 127 SkIRect fClipRect; | |
| 128 }; | |
| 129 | |
| 130 /** Wraps another (real) blitter, and ensures that the real blitter is only | |
| 131 called with coordinates that have been clipped by the specified clipRgn. | |
| 132 This means the caller need not perform the clipping ahead of time. | |
| 133 */ | |
| 134 class SkRgnClipBlitter : public SkBlitter { | |
| 135 public: | |
| 136 void init(SkBlitter* blitter, const SkRegion* clipRgn) { | |
| 137 SkASSERT(clipRgn && !clipRgn->isEmpty()); | |
| 138 fBlitter = blitter; | |
| 139 fRgn = clipRgn; | |
| 140 } | |
| 141 | |
| 142 virtual void blitH(int x, int y, int width) SK_OVERRIDE; | |
| 143 virtual void blitAntiH(int x, int y, const SkAlpha[], | |
| 144 const int16_t runs[]) SK_OVERRIDE; | |
| 145 virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE; | |
| 146 virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE; | |
| 147 virtual void blitAntiRect(int x, int y, int width, int height, | |
| 148 SkAlpha leftAlpha, SkAlpha rightAlpha) SK_OVERRIDE; | |
| 149 virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE; | |
| 150 virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE; | |
| 151 | |
| 152 private: | |
| 153 SkBlitter* fBlitter; | |
| 154 const SkRegion* fRgn; | |
| 155 }; | |
| 156 | |
| 157 /** Factory to set up the appropriate most-efficient wrapper blitter | |
| 158 to apply a clip. Returns a pointer to a member, so lifetime must | |
| 159 be managed carefully. | |
| 160 */ | |
| 161 class SkBlitterClipper { | |
| 162 public: | |
| 163 SkBlitter* apply(SkBlitter* blitter, const SkRegion* clip, | |
| 164 const SkIRect* bounds = NULL); | |
| 165 | |
| 166 private: | |
| 167 SkNullBlitter fNullBlitter; | |
| 168 SkRectClipBlitter fRectBlitter; | |
| 169 SkRgnClipBlitter fRgnBlitter; | |
| 170 }; | |
| 171 | |
| 172 #endif |
