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