1 /* 2 * Copyright 2013 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/gm.h" 9 #include "include/core/SkBlurTypes.h" 10 #include "include/core/SkCanvas.h" 11 #include "include/core/SkColor.h" 12 #include "include/core/SkMaskFilter.h" 13 #include "include/core/SkPaint.h" 14 #include "include/core/SkRect.h" 15 #include "include/core/SkScalar.h" 16 #include "include/core/SkSize.h" 17 #include "include/core/SkString.h" 18 #include "include/core/SkTypes.h" 19 #include "src/core/SkBlurMask.h" 20 21 // This GM tests out the quick reject bounds of the blur mask filter. It draws 22 // four blurred rects around a central clip. The blurred rect geometry outset 23 // by the blur radius does not overlap the clip rect so, if the blur clipping 24 // just uses the radius, they will be clipped out (and the result will differ 25 // from the result if quick reject were disabled. If the blur clipping uses 26 // the correct 3 sigma bound then the images with and without quick rejecting 27 // will be the same. 28 class BlurQuickRejectGM : public skiagm::GM { 29 public: BlurQuickRejectGM()30 BlurQuickRejectGM() {} 31 32 protected: getName() const33 SkString getName() const override { return SkString("blurquickreject"); } 34 getISize()35 SkISize getISize() override { return SkISize::Make(kWidth, kHeight); } 36 onDraw(SkCanvas * canvas)37 void onDraw(SkCanvas* canvas) override { 38 constexpr SkScalar kBlurRadius = SkIntToScalar(20); 39 constexpr SkScalar kBoxSize = SkIntToScalar(100); 40 41 SkRect clipRect = SkRect::MakeXYWH(0, 0, kBoxSize, kBoxSize); 42 SkRect blurRects[] = { 43 { -kBoxSize - (kBlurRadius+1), 0, -(kBlurRadius+1), kBoxSize }, 44 { 0, -kBoxSize - (kBlurRadius+1), kBoxSize, -(kBlurRadius+1) }, 45 { kBoxSize+kBlurRadius+1, 0, 2*kBoxSize+kBlurRadius+1, kBoxSize }, 46 { 0, kBoxSize+kBlurRadius+1, kBoxSize, 2*kBoxSize+kBlurRadius+1 } 47 }; 48 SkColor colors[] = { 49 SK_ColorRED, 50 SK_ColorGREEN, 51 SK_ColorBLUE, 52 SK_ColorYELLOW, 53 }; 54 SkASSERT(std::size(colors) == std::size(blurRects)); 55 56 SkPaint hairlinePaint; 57 hairlinePaint.setStyle(SkPaint::kStroke_Style); 58 hairlinePaint.setColor(SK_ColorWHITE); 59 hairlinePaint.setStrokeWidth(0); 60 61 SkPaint blurPaint; 62 blurPaint.setMaskFilter(SkMaskFilter::MakeBlur(kNormal_SkBlurStyle, 63 SkBlurMask::ConvertRadiusToSigma(kBlurRadius))); 64 65 canvas->clear(SK_ColorBLACK); 66 canvas->save(); 67 canvas->translate(kBoxSize, kBoxSize); 68 canvas->drawRect(clipRect, hairlinePaint); 69 canvas->clipRect(clipRect); 70 for (size_t i = 0; i < std::size(blurRects); ++i) { 71 blurPaint.setColor(colors[i]); 72 canvas->drawRect(blurRects[i], blurPaint); 73 canvas->drawRect(blurRects[i], hairlinePaint); 74 } 75 canvas->restore(); 76 } 77 78 private: 79 inline static constexpr int kWidth = 300; 80 inline static constexpr int kHeight = 300; 81 82 using INHERITED = GM; 83 }; 84 85 DEF_GM( return new BlurQuickRejectGM(); ) 86