gm/blurredclippedcircle.cpp

   1 /*
   2  * Copyright 2015 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 "gm.h"
   9 #include "sk_tool_utils.h"
  10 #include "SkBlurMaskFilter.h"
  11 #include "SkClipOpPriv.h"
  12 #include "SkColorFilter.h"
  13 #include "SkPaint.h"
  14 #include "SkRRect.h"
  15
  16 namespace skiagm {
  17
  18 // This GM reproduces the precision artifacts seen in crbug.com/560651.
  19 // It draws a largish blurred circle with its center clipped out.
  20 class BlurredClippedCircleGM : public GM {
  21 public:
  22     BlurredClippedCircleGM() {
  23         this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
  24     }
  25
  26 protected:
  27
  28     SkString onShortName() override {
  29         return SkString("blurredclippedcircle");
  30     }
  31
  32     SkISize onISize() override {
  33         return SkISize::Make(kWidth, kHeight);
  34     }
  35
  36     void onDraw(SkCanvas* canvas) override {
  37         SkPaint whitePaint;
  38         whitePaint.setColor(SK_ColorWHITE);
  39         whitePaint.setBlendMode(SkBlendMode::kSrc);
  40         whitePaint.setAntiAlias(true);
  41
  42         // This scale exercises precision limits in the circle blur effect (crbug.com/560651)
  43         constexpr float kScale = 2.0f;
  44         canvas->scale(kScale, kScale);
  45
  46         canvas->save();
  47             SkRect clipRect1 = SkRect::MakeLTRB(0, 0,
  48                                                 SkIntToScalar(kWidth), SkIntToScalar(kHeight));
  49
  50             canvas->clipRect(clipRect1);
  51
  52             canvas->save();
  53
  54                 canvas->clipRect(clipRect1);
  55                 canvas->drawRect(clipRect1, whitePaint);
  56
  57                 canvas->save();
  58
  59                     SkRect clipRect2 = SkRect::MakeLTRB(8, 8, 288, 288);
  60                     SkRRect clipRRect = SkRRect::MakeOval(clipRect2);
  61                     canvas->clipRRect(clipRRect, kDifference_SkClipOp, true);
  62
  63                     SkRect r = SkRect::MakeLTRB(4, 4, 292, 292);
  64                     SkRRect rr = SkRRect::MakeOval(r);
  65
  66                     SkPaint paint;
  67
  68                     paint.setMaskFilter(SkBlurMaskFilter::Make(
  69                                             kNormal_SkBlurStyle,
  70                                             1.366025f,
  71                                             SkBlurMaskFilter::kHighQuality_BlurFlag));
  72                     paint.setColorFilter(SkColorFilter::MakeModeFilter(
  73                                              SK_ColorRED,
  74                                              SkBlendMode::kSrcIn));
  75                     paint.setAntiAlias(true);
  76
  77                     canvas->drawRRect(rr, paint);
  78
  79                 canvas->restore();
  80             canvas->restore();
  81         canvas->restore();
  82     }
  83
  84 private:
  85     static constexpr int kWidth = 1164;
  86     static constexpr int kHeight = 802;
  87
  88     typedef GM INHERITED;
  89 };
  90
  91 //////////////////////////////////////////////////////////////////////////////
  92
  93 DEF_GM(return new BlurredClippedCircleGM;)
  94 }