1 /* 2 * Copyright 2015 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 #ifndef GrTextUtils_DEFINED 9 #define GrTextUtils_DEFINED 10 11 #include "GrColor.h" 12 #include "SkColorFilter.h" 13 #include "SkGr.h" 14 #include "SkPaint.h" 15 #include "SkScalar.h" 16 #include "SkTLazy.h" 17 18 class GrAtlasGlyphCache; 19 class GrAtlasTextBlob; 20 class GrAtlasTextStrike; 21 class GrClip; 22 class GrContext; 23 class GrPaint; 24 class GrRenderTargetContext; 25 class GrShaderCaps; 26 class SkDrawFilter; 27 class SkGlyph; 28 class SkMatrix; 29 struct SkIRect; 30 struct SkPoint; 31 class SkGlyphCache; 32 class SkTextBlobRunIterator; 33 class SkSurfaceProps; 34 35 /** 36 * A class to house a bunch of common text utilities. This class should *ONLY* have static 37 * functions. It is not a namespace only because we wish to friend SkPaint 38 */ 39 class GrTextUtils { 40 public: 41 /** 42 * This is used to wrap a SkPaint and its post-color filter color. It is also used by RunPaint 43 * (below). This keeps a pointer to the SkPaint it is initialized with and expects it to remain 44 * const. It is also used to transform to GrPaint. 45 */ 46 class Paint { 47 public: 48 explicit Paint(const SkPaint* paint) : fPaint(paint) { this->initFilteredColor(); } 49 50 // These expose the paint's color run through its color filter (if any). This is only valid 51 // when drawing grayscale/lcd glyph masks and not when drawing color glyphs. 52 SkColor filteredSkColor() const { return fFilteredSkColor; } 53 GrColor filteredPremulGrColor() const { return fFilteredGrColor; } 54 55 const SkPaint& skPaint() const { return *fPaint; } 56 operator const SkPaint&() const { return this->skPaint(); } 57 58 bool toGrPaint(GrMaskFormat, GrRenderTargetContext*, const SkMatrix& viewMatrix, 59 GrPaint*) const; 60 61 protected: 62 void initFilteredColor() { 63 fFilteredSkColor = fPaint->getColor(); 64 if (fPaint->getColorFilter()) { 65 fFilteredSkColor = fPaint->getColorFilter()->filterColor(fFilteredSkColor); 66 } 67 fFilteredGrColor = SkColorToPremulGrColor(fFilteredSkColor); 68 } 69 Paint() = default; 70 const SkPaint* fPaint; 71 // This is the paint's color run through its color filter, if present. This color should 72 // be used except when rendering bitmap text, in which case the bitmap must be filtered in 73 // the fragment shader. 74 SkColor fFilteredSkColor; 75 SkColor fFilteredGrColor; 76 }; 77 78 /** 79 * An extension of Paint that incorporated per-run modifications to the paint text settings and 80 * application of a draw filter. It expects its constructor arguments to remain alive and const 81 * during its lifetime. 82 */ 83 class RunPaint : public Paint { 84 public: 85 RunPaint(const Paint* paint, SkDrawFilter* filter, const SkSurfaceProps& props) 86 : fOriginalPaint(paint), fFilter(filter), fProps(props) { 87 // Initially we represent the original paint. 88 fPaint = &fOriginalPaint->skPaint(); 89 fFilteredSkColor = fOriginalPaint->filteredSkColor(); 90 fFilteredGrColor = fOriginalPaint->filteredPremulGrColor(); 91 } 92 93 bool modifyForRun(const SkTextBlobRunIterator&); 94 95 private: 96 SkTLazy<SkPaint> fModifiedPaint; 97 const Paint* fOriginalPaint; 98 SkDrawFilter* fFilter; 99 const SkSurfaceProps& fProps; 100 }; 101 102 // Functions for appending BMP text to GrAtlasTextBlob 103 static void DrawBmpText(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 104 const SkSurfaceProps&, const Paint& paint, uint32_t scalerContextFlags, 105 const SkMatrix& viewMatrix, const char text[], size_t byteLength, 106 SkScalar x, SkScalar y); 107 108 static void DrawBmpPosText(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 109 const SkSurfaceProps&, const Paint& paint, 110 uint32_t scalerContextFlags, const SkMatrix& viewMatrix, 111 const char text[], size_t byteLength, const SkScalar pos[], 112 int scalarsPerPosition, const SkPoint& offset); 113 114 // functions for appending distance field text 115 static bool CanDrawAsDistanceFields(const SkPaint& skPaint, const SkMatrix& viewMatrix, 116 const SkSurfaceProps& props, const GrShaderCaps& caps); 117 118 static void DrawDFText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache*, 119 const SkSurfaceProps&, const Paint& paint, uint32_t scalerContextFlags, 120 const SkMatrix& viewMatrix, const char text[], size_t byteLength, 121 SkScalar x, SkScalar y); 122 123 static void DrawDFPosText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache*, 124 const SkSurfaceProps&, const Paint& paint, 125 uint32_t scalerContextFlags, const SkMatrix& viewMatrix, 126 const char text[], size_t byteLength, const SkScalar pos[], 127 int scalarsPerPosition, const SkPoint& offset); 128 129 // Functions for drawing text as paths 130 static void DrawTextAsPath(GrContext*, GrRenderTargetContext*, const GrClip& clip, 131 const SkPaint& paint, const SkMatrix& viewMatrix, const char text[], 132 size_t byteLength, SkScalar x, SkScalar y, 133 const SkIRect& clipBounds); 134 135 static void DrawPosTextAsPath(GrContext* context, GrRenderTargetContext* rtc, 136 const SkSurfaceProps& props, const GrClip& clip, 137 const SkPaint& paint, const SkMatrix& viewMatrix, 138 const char text[], size_t byteLength, const SkScalar pos[], 139 int scalarsPerPosition, const SkPoint& offset, 140 const SkIRect& clipBounds); 141 142 static bool ShouldDisableLCD(const SkPaint& paint); 143 144 145 private: 146 static uint32_t FilterTextFlags(const SkSurfaceProps& surfaceProps, const SkPaint& paint); 147 148 static void InitDistanceFieldPaint(GrAtlasTextBlob* blob, 149 SkPaint* skPaint, 150 SkScalar* textRatio, 151 const SkMatrix& viewMatrix); 152 153 static void BmpAppendGlyph(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 154 GrAtlasTextStrike**, const SkGlyph&, int left, int top, 155 GrColor color, SkGlyphCache*); 156 157 static bool DfAppendGlyph(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 158 GrAtlasTextStrike**, const SkGlyph&, 159 SkScalar sx, SkScalar sy, GrColor color, 160 SkGlyphCache* cache, 161 SkScalar textRatio, const SkMatrix& viewMatrix); 162 }; 163 164 #endif 165
