text: /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
  
  #include "gm/gm.h"
  #include "include/core/SkBlurTypes.h"
  #include "include/core/SkCanvas.h"
  #include "include/core/SkColor.h"
  #include "include/core/SkMaskFilter.h"
  #include "include/core/SkPaint.h"
  #include "include/core/SkPath.h"
  #include "include/core/SkRect.h"
  #include "include/core/SkRefCnt.h"
  #include "include/core/SkScalar.h"
  #include "include/core/SkSize.h"
  #include "include/core/SkString.h"
  #include "include/utils/SkRandom.h"
  #include "src/core/SkBlurMask.h"
  #include "tools/timer/TimeUtils.h"
  
  /**
   * In GM mode this draws an array of circles with different radii and different blur radii. Below
   * each circle an almost-circle path is drawn with the same blur filter for comparison.
   *
   * In Sample mode this draws a single circle and almost-circle with animating radius and blur
   * radius.
   *
   * Bench mode draws the same as GM mode but without the comparison almost-circle paths. It also
   * slightly perturbs the blur and circle radii to stress caching of blurred profiles in GPU mode.
   */
  class BlurCircles2GM : public skiagm::GM {
  public:
      BlurCircles2GM() {
          fAnimRadius = TimeUtils::PingPong(
                  0, kRadiusPingPoingPeriod, kRadiusPingPoingShift, kMinRadius, kMaxRadius);
          fAnimBlurRadius = TimeUtils::PingPong(0,
                                                kBlurRadiusPingPoingPeriod,
                                                kBlurRadiusPingPoingShift,
                                                kMinBlurRadius,
                                                kMaxBlurRadius);
      }
  
  protected:
      bool runAsBench() const override { return true; }
  
      SkString onShortName() override { return SkString("blurcircles2"); }
  
      SkISize onISize() override {
          return SkISize::Make(730, 1350);
      }
  
      void onDraw(SkCanvas* canvas) override {
          constexpr SkScalar kMaxR = kMaxRadius + kMaxBlurRadius;
  
          auto almostCircleMaker = [] (SkScalar radius, SkPath* dst) {
              dst->reset();
              dst->addArc(SkRect::MakeXYWH(-radius, -radius, 2 * radius, 2 * radius), 0, 355);
              dst->setIsVolatile(true);
              dst->close();
          };
  
          auto blurMaker = [] (SkScalar radius) ->sk_sp<SkMaskFilter> {
              return SkMaskFilter::MakeBlur(kNormal_SkBlurStyle,
                                            SkBlurMask::ConvertRadiusToSigma(radius));
          };
  
          SkPaint paint;
          paint.setColor(SK_ColorBLACK);
  
          if (this->getMode() == kSample_Mode) {
              paint.setMaskFilter(blurMaker(fAnimBlurRadius));
              SkISize size = canvas->getBaseLayerSize();
              SkPath almostCircle;
              almostCircleMaker(fAnimRadius, &almostCircle);
              canvas->save();
                  canvas->translate(size.fWidth / 2.f, size.fHeight / 4.f);
                  canvas->drawCircle(0, 0, fAnimRadius, paint);
                  canvas->translate(0, 2 * kMaxR);
                  canvas->drawPath(almostCircle, paint);
              canvas->restore();
          } else {
              bool benchMode = this->getMode() == kBench_Mode;
              canvas->save();
              constexpr SkScalar kPad = 5;
              constexpr SkScalar kRadiusSteps = 5;
              constexpr SkScalar kBlurRadiusSteps = 5;
              canvas->translate(kPad + kMinRadius + kMaxBlurRadius,
                                kPad + kMinRadius + kMaxBlurRadius);
              constexpr SkScalar kDeltaRadius = (kMaxRadius - kMinRadius) / kRadiusSteps;
              constexpr SkScalar kDeltaBlurRadius = (kMaxBlurRadius - kMinBlurRadius) /
                                                           kBlurRadiusSteps;
              SkScalar lineWidth = 0;
              if (!benchMode) {
                  for (int r = 0; r < kRadiusSteps - 1; ++r) {
                      const SkScalar radius = r * kDeltaRadius + kMinRadius;
                      lineWidth += 2 * (radius + kMaxBlurRadius) + kPad;
                  }
              }
              for (int br = 0; br < kBlurRadiusSteps; ++br) {
                  SkScalar blurRadius = br * kDeltaBlurRadius + kMinBlurRadius;
                  if (benchMode) {
                      blurRadius += fRandom.nextSScalar1() * kDeltaBlurRadius;
                  }
                  const SkScalar maxRowR = blurRadius + kMaxRadius;
                  paint.setMaskFilter(blurMaker(blurRadius));
                  canvas->save();
                  for (int r = 0; r < kRadiusSteps; ++r) {
                      SkScalar radius = r * kDeltaRadius + kMinRadius;
                      if (benchMode) {
                          radius += fRandom.nextSScalar1() * kDeltaRadius;
                      }
                      SkPath almostCircle;
                      if (!benchMode) {
                          almostCircleMaker(radius, &almostCircle);
                      }
                      canvas->save();
                          canvas->drawCircle(0, 0, radius, paint);
                          canvas->translate(0, 2 * maxRowR + kPad);
                      if (!benchMode) {
                          canvas->drawPath(almostCircle, paint);
                      }
                      canvas->restore();
                      const SkScalar maxColR = radius + kMaxBlurRadius;
                      canvas->translate(maxColR * 2 + kPad, 0);
                  }
                  canvas->restore();
                  if (!benchMode) {
                      SkPaint blackPaint;
                      blackPaint.setColor(SK_ColorBLACK);
                      const SkScalar lineY = 3 * maxRowR + 1.5f * kPad;
                      if (br != kBlurRadiusSteps - 1) {
                          canvas->drawLine(0, lineY, lineWidth, lineY, blackPaint);
                      }
                  }
                  canvas->translate(0, maxRowR * 4 + 2 * kPad);
              }
              canvas->restore();
          }
      }
  
      bool onAnimate(double nanos) override {
          fAnimRadius = TimeUtils::PingPong(1e-9 * nanos, kRadiusPingPoingPeriod, kRadiusPingPoingShift, kMinRadius,
                                       kMaxRadius);
          fAnimBlurRadius = TimeUtils::PingPong(1e-9 * nanos, kBlurRadiusPingPoingPeriod, kBlurRadiusPingPoingShift,
                                           kMinBlurRadius, kMaxBlurRadius);
          return true;
      }
  
  private:
      static constexpr SkScalar kMinRadius = 15;
      static constexpr SkScalar kMaxRadius = 45;
      static constexpr SkScalar kRadiusPingPoingPeriod = 8;
      static constexpr SkScalar kRadiusPingPoingShift = 3;
  
      static constexpr SkScalar kMinBlurRadius = 5;
      static constexpr SkScalar kMaxBlurRadius = 45;
      static constexpr SkScalar kBlurRadiusPingPoingPeriod = 3;
      static constexpr SkScalar kBlurRadiusPingPoingShift = 1.5;
  
      SkScalar    fAnimRadius;
      SkScalar    fAnimBlurRadius;
  
      SkRandom    fRandom;
  
      typedef skiagm::GM INHERITED;
  };
  
  DEF_GM(return new BlurCircles2GM();)
  