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.
21class FlutterAnimateView : public Sample {
22public:
23    FlutterAnimateView() : fCurrTime(0), fResetTime(0) {}
24
25protected:
26    void onOnceBeforeDraw() override {
27        fTypeface = SkTypeface::MakeFromFile("/skimages/samplefont.ttf");
28        initChars();
29    }
30
31    SkString name() override { return SkString("FlutterAnimate"); }
32
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
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
65private:
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
97DEF_SAMPLE( return new FlutterAnimateView(); )
98