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 GrAtlasTextContext_DEFINED 9 #define GrAtlasTextContext_DEFINED 10 11 #include "GrAtlasTextBlob.h" 12 #include "GrDistanceFieldAdjustTable.h" 13 #include "GrGeometryProcessor.h" 14 #include "GrTextUtils.h" 15 #include "SkTextBlobRunIterator.h" 16 17 #if GR_TEST_UTILS 18 #include "GrDrawOpTest.h" 19 #endif 20 21 class GrDrawOp; 22 class GrTextBlobCache; 23 class SkGlyph; 24 25 /* 26 * Renders text using some kind of an atlas, ie BitmapText or DistanceField text 27 */ 28 class GrAtlasTextContext { 29 public: 30 struct Options { 31 /** 32 * Below this size (in device space) distance field text will not be used. Negative means 33 * use a default value. 34 */ 35 SkScalar fMinDistanceFieldFontSize = -1.f; 36 /** 37 * Above this size (in device space) distance field text will not be used and glyphs will 38 * be rendered from outline as individual paths. Negative means use a default value. 39 */ 40 SkScalar fMaxDistanceFieldFontSize = -1.f; 41 /** Forces all distance field vertices to use 3 components, not just when in perspective. */ 42 bool fDistanceFieldVerticesAlwaysHaveW = false; 43 }; 44 45 static std::unique_ptr<GrAtlasTextContext> Make(const Options& options); 46 47 bool canDraw(const GrAtlasGlyphCache* fontCache, const SkPaint&, const SkMatrix& viewMatrix, 48 const SkSurfaceProps&, const GrShaderCaps&); 49 50 void drawText(GrContext*, GrTextUtils::Target*, const GrClip&, const SkPaint&, 51 const SkMatrix& viewMatrix, const SkSurfaceProps&, const char text[], 52 size_t byteLength, SkScalar x, SkScalar y, const SkIRect& regionClipBounds); 53 void drawPosText(GrContext*, GrTextUtils::Target*, const GrClip&, const SkPaint&, 54 const SkMatrix& viewMatrix, const SkSurfaceProps&, const char text[], 55 size_t byteLength, const SkScalar pos[], int scalarsPerPosition, 56 const SkPoint& offset, const SkIRect& regionClipBounds); 57 void drawTextBlob(GrContext*, GrTextUtils::Target*, const GrClip&, const SkPaint&, 58 const SkMatrix& viewMatrix, const SkSurfaceProps&, const SkTextBlob*, 59 SkScalar x, SkScalar y, SkDrawFilter*, const SkIRect& clipBounds); 60 61 private: 62 GrAtlasTextContext(const Options& options); 63 64 // sets up the descriptor on the blob and returns a detached cache. Client must attach 65 static SkColor ComputeCanonicalColor(const SkPaint&, bool lcd); 66 // Determines if we need to use fake gamma (and contrast boost): 67 static SkScalerContextFlags ComputeScalerContextFlags(const GrColorSpaceInfo&); 68 void regenerateTextBlob(GrAtlasTextBlob* bmp, 69 GrAtlasGlyphCache*, 70 const GrShaderCaps&, 71 const GrTextUtils::Paint&, 72 SkScalerContextFlags scalerContextFlags, 73 const SkMatrix& viewMatrix, 74 const SkSurfaceProps&, 75 const SkTextBlob* blob, SkScalar x, SkScalar y, 76 SkDrawFilter* drawFilter) const; 77 78 static bool HasLCD(const SkTextBlob*); 79 80 sk_sp<GrAtlasTextBlob> makeDrawTextBlob(GrTextBlobCache*, GrAtlasGlyphCache*, 81 const GrShaderCaps&, 82 const GrTextUtils::Paint&, 83 SkScalerContextFlags scalerContextFlags, 84 const SkMatrix& viewMatrix, 85 const SkSurfaceProps&, 86 const char text[], size_t byteLength, 87 SkScalar x, SkScalar y) const; 88 89 sk_sp<GrAtlasTextBlob> makeDrawPosTextBlob(GrTextBlobCache*, GrAtlasGlyphCache*, 90 const GrShaderCaps&, 91 const GrTextUtils::Paint&, 92 SkScalerContextFlags scalerContextFlags, 93 const SkMatrix& viewMatrix, 94 const SkSurfaceProps&, 95 const char text[], size_t byteLength, 96 const SkScalar pos[], 97 int scalarsPerPosition, 98 const SkPoint& offset) const; 99 100 // Functions for appending BMP text to GrAtlasTextBlob 101 static void DrawBmpText(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 102 const SkSurfaceProps&, const GrTextUtils::Paint& paint, 103 SkScalerContextFlags scalerContextFlags, const SkMatrix& viewMatrix, 104 const char text[], size_t byteLength, SkScalar x, SkScalar y); 105 106 static void DrawBmpPosText(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 107 const SkSurfaceProps&, const GrTextUtils::Paint& paint, 108 SkScalerContextFlags scalerContextFlags, const SkMatrix& viewMatrix, 109 const char text[], size_t byteLength, const SkScalar pos[], 110 int scalarsPerPosition, const SkPoint& offset, 111 SkScalar textRatio); 112 113 // functions for appending distance field text 114 bool canDrawAsDistanceFields(const SkPaint& skPaint, const SkMatrix& viewMatrix, 115 const SkSurfaceProps& props, const GrShaderCaps& caps) const; 116 117 void drawDFText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache*, const SkSurfaceProps&, 118 const GrTextUtils::Paint& paint, SkScalerContextFlags scalerContextFlags, 119 const SkMatrix& viewMatrix, const char text[], size_t byteLength, SkScalar x, 120 SkScalar y) const; 121 122 void drawDFPosText(GrAtlasTextBlob* blob, int runIndex, GrAtlasGlyphCache*, 123 const SkSurfaceProps&, const GrTextUtils::Paint& paint, 124 SkScalerContextFlags scalerContextFlags, 125 const SkMatrix& viewMatrix, const char text[], 126 size_t byteLength, const SkScalar pos[], int scalarsPerPosition, 127 const SkPoint& offset) const; 128 129 void initDistanceFieldPaint(GrAtlasTextBlob* blob, 130 SkPaint* skPaint, 131 SkScalar* textRatio, 132 const SkMatrix& viewMatrix) const; 133 134 static void BmpAppendGlyph(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 135 GrAtlasTextStrike**, const SkGlyph&, SkScalar sx, SkScalar sy, 136 GrColor color, SkGlyphCache*, SkScalar textRatio); 137 138 static void DfAppendGlyph(GrAtlasTextBlob*, int runIndex, GrAtlasGlyphCache*, 139 GrAtlasTextStrike**, const SkGlyph&, SkScalar sx, SkScalar sy, 140 GrColor color, SkGlyphCache* cache, SkScalar textRatio); 141 dfAdjustTable()142 const GrDistanceFieldAdjustTable* dfAdjustTable() const { return fDistanceAdjustTable.get(); } 143 144 sk_sp<const GrDistanceFieldAdjustTable> fDistanceAdjustTable; 145 146 SkScalar fMinDistanceFieldFontSize; 147 SkScalar fMaxDistanceFieldFontSize; 148 bool fDistanceFieldVerticesAlwaysHaveW; 149 150 #if GR_TEST_UTILS 151 static const SkScalerContextFlags kTextBlobOpScalerContextFlags = 152 SkScalerContextFlags::kFakeGammaAndBoostContrast; 153 GR_DRAW_OP_TEST_FRIEND(GrAtlasTextOp); 154 #endif 155 }; 156 157 #endif 158