aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/SkGlyphRun.h
blob: affc044f76be53207ebec18f24bcb478fc62f167 (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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/*
 * Copyright 2018 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkGlyphRunInfo_DEFINED
#define SkGlyphRunInfo_DEFINED

#include <functional>
#include <memory>
#include <vector>

#include "SkDescriptor.h"
#include "SkMask.h"
#include "SkPath.h"
#include "SkPoint.h"
#include "SkTypes.h"

class SkBaseDevice;

template <typename T>
class SkSpan {
public:
    SkSpan() : fPtr{nullptr}, fSize{0} {}
    SkSpan(T* ptr, size_t size) : fPtr{ptr}, fSize{size} { }
    template <typename U>
    explicit SkSpan(std::vector<U>& v) : fPtr{v.data()}, fSize{v.size()} {}
    SkSpan(const SkSpan<T>& o) = default;
    SkSpan& operator=( const SkSpan& other ) = default;
    T& operator [] (size_t i) const { return fPtr[i]; }
    T* begin() const { return fPtr; }
    T* end() const { return fPtr + fSize; }
    const T* cbegin() const { return fPtr; }
    const T* cend() const { return fPtr + fSize; }
    T* data() const { return fPtr; }
    size_t size() const { return fSize; }
    bool empty() const { return fSize == 0; }

private:
    T* fPtr;
    size_t fSize;
};

class SkGlyphRun {
public:
    SkGlyphRun() = default;
    SkGlyphRun(SkPaint&& runPaint,
               SkSpan<const uint16_t> denseIndices,
               SkSpan<const SkPoint> positions,
               SkSpan<const SkGlyphID> glyphIDs,
               SkSpan<const SkGlyphID> uniqueGlyphIDs,
               SkSpan<const char> text,
               SkSpan<const uint32_t> clusters);

    // The temporaryShunt calls are to allow inter-operating with existing code while glyph runs
    // are developed.
    void temporaryShuntToDrawPosText(SkBaseDevice* device);
    using TemporaryShuntCallback = std::function<void(size_t, const char*, const SkScalar*)>;
    void temporaryShuntToCallback(TemporaryShuntCallback callback);

    size_t runSize() const { return fUniqueGlyphIDIndices.size(); }
    uint16_t uniqueSize() const { return fUniqueGlyphIDs.size(); }
    SkSpan<const SkPoint> positions() const { return fPositions; }
    SkSpan<const SkGlyphID> uniqueGlyphIDs() const { return fUniqueGlyphIDs; }
    SkSpan<const SkGlyphID> shuntGlyphsIDs() const { return fTemporaryShuntGlyphIDs; }

private:
    //
    const SkSpan<const uint16_t> fUniqueGlyphIDIndices;
    //
    const SkSpan<const SkPoint> fPositions;
    // This is temporary while converting from the old per glyph code to the bulk code.
    const SkSpan<const SkGlyphID> fTemporaryShuntGlyphIDs;
    // The unique glyphs from fTemporaryShuntGlyphIDs.
    const SkSpan<const SkGlyphID> fUniqueGlyphIDs;
    // Original text from SkTextBlob if present. Will be empty of not present.
    const SkSpan<const char> fText;
    // Original clusters from SkTextBlob if present. Will be empty if not present.
    const SkSpan<const uint32_t>   fClusters;
    // Paint for this run modified to have glyph encoding and left alignment.
    const SkPaint fRunPaint;
};

class SkGlyphIDSet {
public:
    SkSpan<const SkGlyphID> uniquifyGlyphIDs(
            uint32_t universeSize, SkSpan<const SkGlyphID> glyphIDs,
            SkGlyphID* uniqueGlyphIDs, uint16_t* denseindices);
private:
    size_t fUniverseToUniqueSize{0};
    SkAutoTMalloc<uint16_t> fUniverseToUnique;
};

class SkGlyphRunBuilder {
public:
    SkGlyphRunBuilder() = default;
    void prepareDrawText(
            const SkPaint& paint, const void* bytes, size_t byteLength, SkPoint origin);
    void prepareDrawPosTextH(
            const SkPaint& paint, const void* bytes, size_t byteLength,
            const SkScalar xpos[], SkScalar constY);
    void prepareDrawPosText(
            const SkPaint& paint, const void* bytes, size_t byteLength, const SkPoint pos[]);

    SkGlyphRun* useGlyphRun();

private:
    void initialize(size_t totalRunSize);
    SkSpan<const SkGlyphID> textToGlyphIDs(
            const SkPaint& paint, const void* bytes, size_t byteLength);

    // Returns the span of unique glyph IDs.
    SkSpan<const SkGlyphID> addDenseAndUnique(
            const SkPaint& paint,
            SkSpan<const SkGlyphID> glyphIDs);

    void makeGlyphRun(
            const SkPaint& runPaint,
            SkSpan<const SkGlyphID> glyphIDs,
            SkSpan<const SkPoint> positions,
            SkSpan<const uint16_t> uniqueGlyphIDIndices,
            SkSpan<const SkGlyphID> uniqueGlyphIDs,
            SkSpan<const char> text,
            SkSpan<const uint32_t> clusters);

    void drawText(
            const SkPaint& paint, SkSpan<const SkGlyphID> glyphIDs, SkPoint origin,
            SkSpan<const char> text, SkSpan<const uint32_t> clusters);
    void drawPosTextH(
            const SkPaint& paint, SkSpan<const SkGlyphID> glyphIDs,
            const SkScalar* xpos, SkScalar constY,
            SkSpan<const char> text, SkSpan<const uint32_t> clusters);
    void drawPosText(
            const SkPaint& paint, SkSpan<const SkGlyphID> glyphIDs, const SkPoint* pos,
            SkSpan<const char> text, SkSpan<const uint32_t> clusters);

    uint64_t fUniqueID{0};

    size_t fMaxTotalRunSize{0};
    SkAutoTMalloc<uint16_t> fUniqueGlyphIDIndices;
    SkAutoTMalloc<SkPoint> fPositions;
    SkAutoTMalloc<SkGlyphID> fUniqueGlyphIDs;

    // Used as a temporary for preparing using utfN text. This implies that only one run of
    // glyph ids will ever be needed because blobs are already glyph based.
    std::vector<SkGlyphID> fScratchGlyphIDs;

    // Used as temporary storage for calculating positions for drawText.
    std::vector<SkPoint> fScratchAdvances;


    // Used as temporary glyph run for the rest of the Text stack.
    SkGlyphRun fScratchGlyphRun;

    // Used for collecting the set of unique glyphs.
    SkGlyphIDSet fGlyphIDSet;
};

#endif  // SkGlyphRunInfo_DEFINED