58 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			58 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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|  * Copyright 2021 Google LLC
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|  *
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|  * Use of this source code is governed by a BSD-style license that can be
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|  * found in the LICENSE file.
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|  */
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| 
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| #include "gm/gm.h"
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| #include "include/core/SkCanvas.h"
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| #include "include/core/SkPaint.h"
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| #include "include/core/SkRect.h"
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| #include "include/effects/SkGradientShader.h"
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| #include "include/effects/SkImageFilters.h"
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| 
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| static void draw_bg_blur(SkCanvas* canvas, SkIRect rect, float sigma) {
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|     // First create an intermediate layer that has an opaque area that we blur with transparency
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|     // all around it. We want to make sure the transparency doesn't affect the blur of the opaque
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|     // content.
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|     auto outsetRect = SkRect::Make(rect).makeOutset(10, 10);
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|     canvas->saveLayer(outsetRect, nullptr);
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|     SkColor colors[] = {SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN};
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|     float cx = (rect.left() + rect.right() )/2.f;
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|     float cy = (rect.top()  + rect.bottom())/2.f;
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|     auto g = SkGradientShader::MakeSweep(cx,
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|                                          cy,
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|                                          colors,
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|                                          nullptr,
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|                                          3,
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|                                          SkTileMode::kMirror,
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|                                          0,
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|                                          45,
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|                                          0,
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|                                          nullptr);
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|     SkPaint paint;
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|     paint.setShader(std::move(g));
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|     canvas->drawRect(SkRect::Make(rect), paint);
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|     // Now do the bg-blur into another save-layer that should only read the opaque region.
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|     SkCanvas::SaveLayerRec rec;
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|     auto blur = SkImageFilters::Blur(sigma, sigma, SkTileMode::kClamp, nullptr, rect);
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|     rec.fBounds = &outsetRect;
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|     rec.fBackdrop = blur.get();
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|     canvas->saveLayer(rec);
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|     canvas->restore();
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|     canvas->restore();
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| }
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| 
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| DEF_SIMPLE_GM(crbug_1174354, canvas, 70, 250) {
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|     // The initial fix for crbug.com/1156805 had an issue where the border added to the downsampled
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|     // texture that was used as input to the blur could actually bring in transparency when there
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|     // wasn't any within the original src bounds. It was populated the border using a filtering draw
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|     // from the full res source that could read from outside the pixels surrounding the original src
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|     // bounds.
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|     draw_bg_blur(canvas, SkIRect::MakeXYWH(10,  10,  50, 50),  5);
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|     draw_bg_blur(canvas, SkIRect::MakeXYWH(10,  70,  50, 50), 15);
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|     draw_bg_blur(canvas, SkIRect::MakeXYWH(10, 130,  50, 50), 30);
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|     draw_bg_blur(canvas, SkIRect::MakeXYWH(10, 190, 50, 50),  70);
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| }
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