aboutsummaryrefslogtreecommitdiffhomepage
path: root/gm/atlastext.cpp
blob: 226b83fdd7ea970866adbfc85008cac7e50d36f4 (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
162
163
164
165
166
167
168
169
170
171
172
/*
 * Copyright 2017 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "gm.h"

#if SK_SUPPORT_ATLAS_TEXT

#include "SkAtlasTextContext.h"
#include "SkAtlasTextFont.h"
#include "SkAtlasTextTarget.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkTypeface.h"
#include "SkUtils.h"
#include "gpu/TestContext.h"
#include "gpu/atlastext/GLTestAtlasTextRenderer.h"
#include "gpu/atlastext/TestAtlasTextRenderer.h"
#include "sk_tool_utils.h"

// GM that draws text using the Atlas Text interface offscreen and then blits that to the canvas.

static SkScalar draw_string(SkAtlasTextTarget* target, const SkString& text, SkScalar x, SkScalar y,
                            uint32_t color, sk_sp<SkTypeface> typeface, float size) {
    if (!text.size()) {
        return x;
    }
    auto font = SkAtlasTextFont::Make(typeface, size);
    int cnt = SkUTF8_CountUnichars(text.c_str());
    std::unique_ptr<SkGlyphID[]> glyphs(new SkGlyphID[cnt]);
    typeface->charsToGlyphs(text.c_str(), SkTypeface::Encoding::kUTF8_Encoding, glyphs.get(), cnt);

    // Using a paint to get the positions for each glyph.
    SkPaint paint;
    paint.setTextSize(size);
    paint.setTypeface(std::move(typeface));
    paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    std::unique_ptr<SkScalar[]> widths(new SkScalar[cnt]);
    paint.getTextWidths(glyphs.get(), cnt * sizeof(SkGlyphID), widths.get(), nullptr);

    std::unique_ptr<SkPoint[]> positions(new SkPoint[cnt]);
    positions[0] = {x, y};
    for (int i = 1; i < cnt; ++i) {
        positions[i] = {positions[i - 1].fX + widths[i - 1], y};
    }

    target->drawText(glyphs.get(), positions.get(), cnt, color, *font);

    // Return the width of the of draw.
    return positions[cnt - 1].fX + widths[cnt - 1] - positions[0].fX;
}

class AtlasTextGM : public skiagm::GM {
public:
    AtlasTextGM() = default;

protected:
    SkString onShortName() override { return SkString("atlastext"); }

    SkISize onISize() override { return SkISize::Make(kSize, kSize); }

    void onOnceBeforeDraw() override {
        fRenderer = sk_gpu_test::MakeGLTestAtlasTextRenderer();
        if (!fRenderer) {
            return;
        }
        fContext = SkAtlasTextContext::Make(fRenderer);
        auto targetHandle = fRenderer->makeTargetHandle(kSize, kSize);
        if (!targetHandle) {
            return;
        }
        fTarget = SkAtlasTextTarget::Make(fContext, kSize, kSize, targetHandle);

        fTypefaces[0] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Italic());
        fTypefaces[1] =
                sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Italic());
        fTypefaces[2] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Normal());
        fTypefaces[3] =
                sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Normal());
        fTypefaces[4] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Bold());
        fTypefaces[5] = sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Bold());
    }

    void onDraw(SkCanvas* canvas) override {
        if (!fRenderer || !fTarget || !fTarget->handle()) {
            canvas->clear(SK_ColorRED);
            return;
        }
        fRenderer->clearTarget(fTarget->handle(), 0xFF808080);
        auto bmp = this->drawText();
        SkPaint paint;
        paint.setBlendMode(SkBlendMode::kSrc);
        canvas->drawBitmap(bmp, 0, 0);
    }

private:
    SkBitmap drawText() {
        static const int kSizes[] = {8, 13, 18, 23, 30};

        static const SkString kTexts[] = {SkString("ABCDEFGHIJKLMNOPQRSTUVWXYZ"),
                                          SkString("abcdefghijklmnopqrstuvwxyz"),
                                          SkString("0123456789"),
                                          SkString("!@#$%^&*()<>[]{}")};
        SkScalar x = 0;
        SkScalar y = 10;

        SkRandom random;
        do {
            for (auto s : kSizes) {
                auto size = 2 * s;
                for (const auto& typeface : fTypefaces) {
                    for (const auto& text : kTexts) {
                        // Choose a random color but don't let alpha be too small to see.
                        uint32_t color = random.nextU() | 0x40000000;
                        fTarget->save();
                        // Randomly add a little bit of perspective
                        if (random.nextBool()) {
                            SkMatrix persp;
                            persp.reset();
                            persp.setPerspY(0.0005f);
                            persp.preTranslate(-x, -y + s);
                            persp.postTranslate(x, y - s);
                            fTarget->concat(persp);
                        }
                        // Randomly switch between positioning with a matrix vs x, y passed to draw.
                        SkScalar drawX = x, drawY = y;
                        if (random.nextBool()) {
                            fTarget->translate(x, y);
                            drawX = drawY = 0;
                        }
                        x += size +
                             draw_string(fTarget.get(), text, drawX, drawY, color, typeface, size);
                        x = SkScalarCeilToScalar(x);
                        fTarget->restore();
                        // Flush periodically to test continued drawing after a flush.
                        if ((random.nextU() % 8) == 0) {
                            fTarget->flush();
                        }
                        if (x + 100 > kSize) {
                            x = 0;
                            y += SkScalarCeilToScalar(size + 3);
                            if (y > kSize) {
                                fTarget->flush();
                                return fRenderer->readTargetHandle(fTarget->handle());
                            }
                        }
                    }
                }
            }
        } while (true);
    }

    static constexpr int kSize = 1280;

    sk_sp<SkTypeface> fTypefaces[6];
    sk_sp<sk_gpu_test::TestAtlasTextRenderer> fRenderer;
    std::unique_ptr<SkAtlasTextTarget> fTarget;
    sk_sp<SkAtlasTextContext> fContext;

    typedef GM INHERITED;
};

constexpr int AtlasTextGM::kSize;

//////////////////////////////////////////////////////////////////////////////

DEF_GM(return new AtlasTextGM;)

#endif