samplecode/SampleAnimBlur.cpp

   1 /*
   2  * Copyright 2012 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 "SkBlurMaskFilter.h"
  11 #include "SkColorPriv.h"
  12 #include "SkCanvas.h"
  13 #include "SkRandom.h"
  14
  15 SkScalar get_anim_sin(double secs, SkScalar amplitude, SkScalar periodInSec, SkScalar phaseInSec) {
  16     if (!periodInSec) {
  17         return 0;
  18     }
  19     double t = secs + phaseInSec;
  20     t *= SkScalarToFloat(2 * SK_ScalarPI) / periodInSec;
  21     amplitude = SK_ScalarHalf * amplitude;
  22     return amplitude * SkDoubleToScalar(sin(t)) + amplitude;
  23 }
  24
  25 class AnimBlurView : public SampleView {
  26 public:
  27     AnimBlurView() : fBlurSigma(0), fCircleRadius(100) {}
  28
  29 protected:
  30     // overrides from SkEventSink
  31     bool onQuery(SkEvent* evt) SK_OVERRIDE {
  32         if (SampleCode::TitleQ(*evt)) {
  33             SampleCode::TitleR(evt, "AnimBlur");
  34             return true;
  35         }
  36         return this->INHERITED::onQuery(evt);
  37     }
  38
  39     void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
  40         static const SkBlurStyle gStyles[] = {
  41             kNormal_SkBlurStyle,
  42             kInner_SkBlurStyle,
  43             kSolid_SkBlurStyle,
  44             kOuter_SkBlurStyle,
  45         };
  46         SkRandom random;
  47
  48         for (size_t i = 0; i < SK_ARRAY_COUNT(gStyles); ++i) {
  49             SkMaskFilter* mf = SkBlurMaskFilter::Create(
  50                                        gStyles[i],
  51                                        fBlurSigma,
  52                                        SkBlurMaskFilter::kHighQuality_BlurFlag);
  53             SkPaint paint;
  54             SkSafeUnref(paint.setMaskFilter(mf));
  55             paint.setColor(random.nextU() | 0xff000000);
  56             canvas->drawCircle(200 * SK_Scalar1 + 400 * (i % 2) * SK_Scalar1,
  57                                200 * SK_Scalar1 + i / 2 * 400 * SK_Scalar1,
  58                                fCircleRadius, paint);
  59         }
  60     }
  61
  62     bool onAnimate(const SkAnimTimer& timer) SK_OVERRIDE {
  63         fBlurSigma = get_anim_sin(timer.secs(), 100, 4, 5);
  64         fCircleRadius = 3 + get_anim_sin(timer.secs(), 150, 25, 3);
  65         return true;
  66     }
  67
  68 private:
  69     SkScalar fBlurSigma, fCircleRadius;
  70
  71     typedef SampleView INHERITED;
  72 };
  73
  74 //////////////////////////////////////////////////////////////////////////////
  75
  76 static SkView* MyFactory() { return new AnimBlurView; }
  77 static SkViewRegister reg(MyFactory);