Line data Source code
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 0 : 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 0 : SkColor filteredSkColor() const { return fFilteredSkColor; }
53 0 : GrColor filteredPremulGrColor() const { return fFilteredGrColor; }
54 :
55 0 : const SkPaint& skPaint() const { return *fPaint; }
56 0 : operator const SkPaint&() const { return this->skPaint(); }
57 :
58 : bool toGrPaint(GrMaskFormat, GrRenderTargetContext*, const SkMatrix& viewMatrix,
59 : GrPaint*) const;
60 :
61 : protected:
62 0 : void initFilteredColor() {
63 0 : fFilteredSkColor = fPaint->getColor();
64 0 : if (fPaint->getColorFilter()) {
65 0 : fFilteredSkColor = fPaint->getColorFilter()->filterColor(fFilteredSkColor);
66 : }
67 0 : fFilteredGrColor = SkColorToPremulGrColor(fFilteredSkColor);
68 0 : }
69 0 : 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 0 : class RunPaint : public Paint {
84 : public:
85 0 : RunPaint(const Paint* paint, SkDrawFilter* filter, const SkSurfaceProps& props)
86 0 : : fOriginalPaint(paint), fFilter(filter), fProps(props) {
87 : // Initially we represent the original paint.
88 0 : fPaint = &fOriginalPaint->skPaint();
89 0 : fFilteredSkColor = fOriginalPaint->filteredSkColor();
90 0 : fFilteredGrColor = fOriginalPaint->filteredPremulGrColor();
91 0 : }
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
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