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