aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/gpu/GrDistanceFieldTextContext.h
blob: 6fa2d6f173855b0debde9650bcc6259dea9fac5b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrDistanceFieldTextContext_DEFINED
#define GrDistanceFieldTextContext_DEFINED

#include "GrTextContext.h"

class GrGeometryProcessor;
class GrTextStrike;

/*
 * This class implements GrTextContext using distance field fonts
 */
class GrDistanceFieldTextContext : public GrTextContext {
public:
    static GrDistanceFieldTextContext* Create(GrContext*, const SkDeviceProperties&, bool enable);

    virtual ~GrDistanceFieldTextContext();

private:
    enum {
        kMinRequestedGlyphs      = 1,
        kDefaultRequestedGlyphs  = 64,
        kMinRequestedVerts       = kMinRequestedGlyphs * 4,
        kDefaultRequestedVerts   = kDefaultRequestedGlyphs * 4,
    };

    GrTextStrike*                      fStrike;
    SkScalar                           fTextRatio;
    bool                               fUseLCDText;
    bool                               fEnableDFRendering;
    SkAutoTUnref<GrGeometryProcessor>  fCachedGeometryProcessor;
    // Used to check whether fCachedEffect is still valid.
    uint32_t                           fEffectTextureUniqueID;
    SkColor                            fEffectColor;
    uint32_t                           fEffectFlags;
    GrTexture*                         fGammaTexture;
    void*                              fVertices;
    int32_t                            fMaxVertices;
    GrTexture*                         fCurrTexture;
    int                                fCurrVertex;
    SkRect                             fVertexBounds;

    GrDistanceFieldTextContext(GrContext*, const SkDeviceProperties&, bool enable);

    virtual bool canDraw(const SkPaint& paint) SK_OVERRIDE;

    virtual void onDrawText(const GrPaint&, const SkPaint&, const char text[], size_t byteLength,
                            SkScalar x, SkScalar y) SK_OVERRIDE;
    virtual void onDrawPosText(const GrPaint&, const SkPaint&,
                               const char text[], size_t byteLength,
                               const SkScalar pos[], int scalarsPerPosition,
                               const SkPoint& offset) SK_OVERRIDE;

    void init(const GrPaint&, const SkPaint&);
    void appendGlyph(GrGlyph::PackedID, SkFixed left, SkFixed top, GrFontScaler*);
    void setupCoverageEffect(const SkColor& filteredColor);
    void flush();                 // automatically called by destructor
    void finish();
};

#endif