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.h"
9 #include "sk_tool_utils.h"
10 
11 #include "SkCanvas.h"
12 #include "SkGradientShader.h"
13 #include "SkPoint.h"
14 #include "SkShader.h"
15 #include "SkTextBlob.h"
16 #include "SkTDArray.h"
17 #include "SkTypeface.h"
18 
19 // This GM exercises drawTextBlob offset vs. shader space behavior.
20 class TextBlobShaderGM : public skiagm::GM {
21 public:
TextBlobShaderGM()22     TextBlobShaderGM() {}
23 
24 private:
onOnceBeforeDraw()25     void onOnceBeforeDraw() override {
26         {
27             SkFont font(sk_tool_utils::create_portable_typeface());
28             const char* txt = "Blobber";
29             size_t txtLen = strlen(txt);
30             fGlyphs.append(font.countText(txt, txtLen, kUTF8_SkTextEncoding));
31             font.textToGlyphs(txt, txtLen, kUTF8_SkTextEncoding, fGlyphs.begin(), fGlyphs.count());
32         }
33 
34         SkFont font;
35         font.setSubpixel(true);
36         font.setEdging(SkFont::Edging::kAntiAlias);
37         font.setSize(30);
38         font.setTypeface(sk_tool_utils::create_portable_typeface());
39 
40         SkTextBlobBuilder builder;
41         int glyphCount = fGlyphs.count();
42         const SkTextBlobBuilder::RunBuffer* run;
43 
44         run = &builder.allocRun(font, glyphCount, 10, 10, nullptr);
45         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
46 
47         run = &builder.allocRunPosH(font, glyphCount,  80, nullptr);
48         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
49         for (int i = 0; i < glyphCount; ++i) {
50             run->pos[i] = font.getSize() * i * .75f;
51         }
52 
53         run = &builder.allocRunPos(font, glyphCount, nullptr);
54         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
55         for (int i = 0; i < glyphCount; ++i) {
56             run->pos[i * 2] = font.getSize() * i * .75f;
57             run->pos[i * 2 + 1] = 150 + 5 * sinf((float)i * 8 / glyphCount);
58         }
59 
60         fBlob = builder.make();
61 
62         SkColor  colors[2];
63         colors[0] = SK_ColorRED;
64         colors[1] = SK_ColorGREEN;
65 
66         SkScalar pos[SK_ARRAY_COUNT(colors)];
67         for (unsigned i = 0; i < SK_ARRAY_COUNT(pos); ++i) {
68             pos[i] = (float)i / (SK_ARRAY_COUNT(pos) - 1);
69         }
70 
71         SkISize sz = this->onISize();
72         fShader = SkGradientShader::MakeRadial(SkPoint::Make(SkIntToScalar(sz.width() / 2),
73                                                SkIntToScalar(sz.height() / 2)),
74                                                sz.width() * .66f, colors, pos,
75                                                SK_ARRAY_COUNT(colors),
76                                                SkShader::kRepeat_TileMode);
77     }
78 
onShortName()79     SkString onShortName() override {
80         return SkString("textblobshader");
81     }
82 
onISize()83     SkISize onISize() override {
84         return SkISize::Make(640, 480);
85     }
86 
onDraw(SkCanvas * canvas)87     void onDraw(SkCanvas* canvas) override {
88         SkPaint p;
89         p.setAntiAlias(true);
90         p.setStyle(SkPaint::kFill_Style);
91         p.setShader(fShader);
92 
93         SkISize sz = this->onISize();
94         constexpr int kXCount = 4;
95         constexpr int kYCount = 3;
96         for (int i = 0; i < kXCount; ++i) {
97             for (int j = 0; j < kYCount; ++j) {
98                 canvas->drawTextBlob(fBlob,
99                                      SkIntToScalar(i * sz.width() / kXCount),
100                                      SkIntToScalar(j * sz.height() / kYCount),
101                                      p);
102             }
103         }
104     }
105 
106     SkTDArray<uint16_t> fGlyphs;
107     sk_sp<SkTextBlob>   fBlob;
108     sk_sp<SkShader>     fShader;
109 
110     typedef skiagm::GM INHERITED;
111 };
112 
113 DEF_GM(return new TextBlobShaderGM;)
114