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1 /*
2  * Copyright 2018 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 "include/core/SkCanvas.h"
9 #include "include/core/SkColorFilter.h"
10 #include "include/core/SkColorPriv.h"
11 #include "include/core/SkFont.h"
12 #include "include/core/SkImage.h"
13 #include "include/core/SkTime.h"
14 #include "include/core/SkTypeface.h"
15 #include "include/utils/SkRandom.h"
16 #include "samplecode/Sample.h"
17 #include "tools/timer/Timer.h"
18 
19 #if SK_SUPPORT_GPU
20 #include "include/gpu/GrContext.h"
21 #endif
22 
23 // Create an animation of a bunch of letters that rotate in place. This is intended to stress
24 // the glyph atlas and test that we don't see corruption or bad slowdowns.
25 class FlutterAnimateView : public Sample {
26 public:
FlutterAnimateView()27     FlutterAnimateView() : fCurrTime(0), fResetTime(0) {}
28 
29 protected:
onOnceBeforeDraw()30     void onOnceBeforeDraw() override {
31         fTypeface = SkTypeface::MakeFromFile("/skimages/samplefont.ttf");
32         initChars();
33     }
34 
name()35     SkString name() override { return SkString("FlutterAnimate"); }
36 
onDrawContent(SkCanvas * canvas)37     void onDrawContent(SkCanvas* canvas) override {
38         SkFont font(fTypeface, 50);
39         SkPaint paint;
40         paint.setFilterQuality(kMedium_SkFilterQuality);
41 
42         // rough center of each glyph
43         static constexpr auto kMidX = 35;
44         static constexpr auto kMidY = 50;
45 
46         canvas->clear(SK_ColorWHITE);
47         for (int i = 0; i < kNumChars; ++i) {
48             canvas->save();
49             double rot = SkScalarInterp(fChars[i].fStartRotation, fChars[i].fEndRotation,
50                                         fCurrTime/kDuration);
51             canvas->translate(fChars[i].fPosition.fX + kMidX, fChars[i].fPosition.fY - kMidY);
52             canvas->rotate(SkRadiansToDegrees(rot));
53             canvas->translate(-35,+50);
54             canvas->drawString(fChars[i].fChar, 0, 0, font, paint);
55             canvas->restore();
56         }
57     }
58 
onAnimate(double nanos)59     bool onAnimate(double nanos) override {
60         fCurrTime = 1e-9 * nanos - fResetTime;
61         if (fCurrTime > kDuration) {
62             this->initChars();
63             fResetTime = 1e-9 * nanos;
64             fCurrTime = 0;
65         }
66 
67         return true;
68     }
69 
70 private:
initChars()71     void initChars() {
72         for (int i = 0; i < kNumChars; ++i) {
73             char c = fRand.nextULessThan(26) + 65;
74             fChars[i].fChar[0] = c;
75             fChars[i].fChar[1] = '\0';
76             fChars[i].fPosition = SkPoint::Make(fRand.nextF()*748 + 10, fRand.nextF()*1004 + 10);
77             fChars[i].fStartRotation = fRand.nextF();
78             fChars[i].fEndRotation = fRand.nextF() * 20 - 10;
79         }
80     }
81 
82     static constexpr double kDuration = 5.0;
83     double fCurrTime;
84     double fResetTime;
85     SkRandom fRand;
86 
87     struct AnimatedChar {
88         char fChar[2];
89         SkPoint  fPosition;
90         SkScalar fStartRotation;
91         SkScalar fEndRotation;
92     };
93     sk_sp<SkTypeface> fTypeface;
94     static constexpr int kNumChars = 40;
95     AnimatedChar fChars[kNumChars];
96 
97     typedef Sample INHERITED;
98 };
99 
100 //////////////////////////////////////////////////////////////////////////////
101 
102 DEF_SAMPLE( return new FlutterAnimateView(); )
103