xref: /third_party/skia/gm/textblobshader.cpp (revision cb93a386)
1/*
2 * Copyright 2014 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#include "gm/gm.h"
9#include "include/core/SkCanvas.h"
10#include "include/core/SkColor.h"
11#include "include/core/SkFont.h"
12#include "include/core/SkFontTypes.h"
13#include "include/core/SkPaint.h"
14#include "include/core/SkPoint.h"
15#include "include/core/SkRefCnt.h"
16#include "include/core/SkScalar.h"
17#include "include/core/SkShader.h"
18#include "include/core/SkSize.h"
19#include "include/core/SkString.h"
20#include "include/core/SkTextBlob.h"
21#include "include/core/SkTileMode.h"
22#include "include/core/SkTypeface.h"
23#include "include/core/SkTypes.h"
24#include "include/effects/SkGradientShader.h"
25#include "include/private/SkTDArray.h"
26#include "tools/ToolUtils.h"
27
28#include <math.h>
29#include <string.h>
30
31// This GM exercises drawTextBlob offset vs. shader space behavior.
32class TextBlobShaderGM : public skiagm::GM {
33public:
34    TextBlobShaderGM() {}
35
36private:
37    void onOnceBeforeDraw() override {
38        {
39            SkFont      font(ToolUtils::create_portable_typeface());
40            const char* txt = "Blobber";
41            size_t txtLen = strlen(txt);
42            fGlyphs.append(font.countText(txt, txtLen, SkTextEncoding::kUTF8));
43            font.textToGlyphs(txt, txtLen, SkTextEncoding::kUTF8, fGlyphs.begin(), fGlyphs.count());
44        }
45
46        SkFont font;
47        font.setSubpixel(true);
48        font.setEdging(SkFont::Edging::kAntiAlias);
49        font.setSize(30);
50        font.setTypeface(ToolUtils::create_portable_typeface());
51
52        SkTextBlobBuilder builder;
53        int glyphCount = fGlyphs.count();
54        const SkTextBlobBuilder::RunBuffer* run;
55
56        run = &builder.allocRun(font, glyphCount, 10, 10, nullptr);
57        memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
58
59        run = &builder.allocRunPosH(font, glyphCount,  80, nullptr);
60        memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
61        for (int i = 0; i < glyphCount; ++i) {
62            run->pos[i] = font.getSize() * i * .75f;
63        }
64
65        run = &builder.allocRunPos(font, glyphCount, nullptr);
66        memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
67        for (int i = 0; i < glyphCount; ++i) {
68            run->pos[i * 2] = font.getSize() * i * .75f;
69            run->pos[i * 2 + 1] = 150 + 5 * sinf((float)i * 8 / glyphCount);
70        }
71
72        fBlob = builder.make();
73
74        SkColor  colors[2];
75        colors[0] = SK_ColorRED;
76        colors[1] = SK_ColorGREEN;
77
78        SkScalar pos[SK_ARRAY_COUNT(colors)];
79        for (unsigned i = 0; i < SK_ARRAY_COUNT(pos); ++i) {
80            pos[i] = (float)i / (SK_ARRAY_COUNT(pos) - 1);
81        }
82
83        SkISize sz = this->onISize();
84        fShader = SkGradientShader::MakeRadial(SkPoint::Make(SkIntToScalar(sz.width() / 2),
85                                               SkIntToScalar(sz.height() / 2)),
86                                               sz.width() * .66f, colors, pos,
87                                               SK_ARRAY_COUNT(colors),
88                                               SkTileMode::kRepeat);
89    }
90
91    SkString onShortName() override {
92        return SkString("textblobshader");
93    }
94
95    SkISize onISize() override {
96        return SkISize::Make(640, 480);
97    }
98
99    void onDraw(SkCanvas* canvas) override {
100        SkPaint p;
101        p.setAntiAlias(true);
102        p.setStyle(SkPaint::kFill_Style);
103        p.setShader(fShader);
104
105        SkISize sz = this->onISize();
106        constexpr int kXCount = 4;
107        constexpr int kYCount = 3;
108        for (int i = 0; i < kXCount; ++i) {
109            for (int j = 0; j < kYCount; ++j) {
110                canvas->drawTextBlob(fBlob,
111                                     SkIntToScalar(i * sz.width() / kXCount),
112                                     SkIntToScalar(j * sz.height() / kYCount),
113                                     p);
114            }
115        }
116    }
117
118    SkTDArray<uint16_t> fGlyphs;
119    sk_sp<SkTextBlob>   fBlob;
120    sk_sp<SkShader>     fShader;
121
122    using INHERITED = skiagm::GM;
123};
124
125DEF_GM(return new TextBlobShaderGM;)
126