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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 "SampleCode.h"
      9 #include "SkAnimTimer.h"
     10 #include "SkView.h"
     11 #include "SkCanvas.h"
     12 #include "SkUtils.h"
     13 #include "SkColorPriv.h"
     14 #include "SkColorFilter.h"
     15 #include "SkImage.h"
     16 #include "SkRandom.h"
     17 #include "SkTime.h"
     18 #include "SkTypeface.h"
     19 #include "Timer.h"
     20 
     21 #if SK_SUPPORT_GPU
     22 #include "GrContext.h"
     23 #endif
     24 
     25 // Create an animation of a bunch of letters that rotate in place. This is intended to stress
     26 // the glyph atlas and test that we don't see corruption or bad slowdowns.
     27 class FlutterAnimateView : public SampleView {
     28 public:
     29     FlutterAnimateView() : fCurrTime(0), fResetTime(0) {}
     30 
     31 protected:
     32     void onOnceBeforeDraw() override {
     33         fTypeface = SkTypeface::MakeFromFile("/skimages/samplefont.ttf");
     34         initChars();
     35     }
     36 
     37     // overrides from SkEventSink
     38     bool onQuery(SkEvent* evt) override {
     39         if (SampleCode::TitleQ(*evt)) {
     40             SampleCode::TitleR(evt, "FlutterAnimate");
     41             return true;
     42         }
     43 
     44         return this->INHERITED::onQuery(evt);
     45     }
     46 
     47     void onDrawContent(SkCanvas* canvas) override {
     48         SkPaint paint;
     49         paint.setTypeface(fTypeface);
     50         paint.setAntiAlias(true);
     51         paint.setFilterQuality(kMedium_SkFilterQuality);
     52         paint.setTextSize(50);
     53 
     54         // rough center of each glyph
     55         static constexpr auto kMidX = 35;
     56         static constexpr auto kMidY = 50;
     57 
     58         canvas->clear(SK_ColorWHITE);
     59         for (int i = 0; i < kNumChars; ++i) {
     60             canvas->save();
     61             double rot = SkScalarInterp(fChars[i].fStartRotation, fChars[i].fEndRotation,
     62                                         fCurrTime/kDuration);
     63             canvas->translate(fChars[i].fPosition.fX + kMidX, fChars[i].fPosition.fY - kMidY);
     64             canvas->rotate(SkRadiansToDegrees(rot));
     65             canvas->translate(-35,+50);
     66             canvas->drawString(fChars[i].fChar, 0, 0, paint);
     67             canvas->restore();
     68         }
     69     }
     70 
     71     bool onAnimate(const SkAnimTimer& timer) override {
     72         fCurrTime = timer.secs() - fResetTime;
     73         if (fCurrTime > kDuration) {
     74             this->initChars();
     75             fResetTime = timer.secs();
     76             fCurrTime = 0;
     77         }
     78 
     79         return true;
     80     }
     81 
     82 private:
     83     void initChars() {
     84         for (int i = 0; i < kNumChars; ++i) {
     85             char c = fRand.nextULessThan(26) + 65;
     86             fChars[i].fChar[0] = c;
     87             fChars[i].fChar[1] = '\0';
     88             fChars[i].fPosition = SkPoint::Make(fRand.nextF()*748 + 10, fRand.nextF()*1004 + 10);
     89             fChars[i].fStartRotation = fRand.nextF();
     90             fChars[i].fEndRotation = fRand.nextF() * 20 - 10;
     91         }
     92     }
     93 
     94     static constexpr double kDuration = 5.0;
     95     double fCurrTime;
     96     double fResetTime;
     97     SkRandom fRand;
     98 
     99     struct AnimatedChar {
    100         char fChar[2];
    101         SkPoint  fPosition;
    102         SkScalar fStartRotation;
    103         SkScalar fEndRotation;
    104     };
    105     sk_sp<SkTypeface> fTypeface;
    106     static constexpr int kNumChars = 40;
    107     AnimatedChar fChars[kNumChars];
    108 
    109     typedef SampleView INHERITED;
    110 };
    111 
    112 //////////////////////////////////////////////////////////////////////////////
    113 
    114 static SkView* MyFactory() { return new FlutterAnimateView; }
    115 static SkViewRegister reg(MyFactory);
    116