122 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			122 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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|  * Copyright 2019 Google Inc.
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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/SkColor.h"
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| #include "include/core/SkImageFilter.h"
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| #include "include/core/SkPaint.h"
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| #include "include/core/SkPictureRecorder.h"
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| #include "include/core/SkRect.h"
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| #include "include/core/SkRefCnt.h"
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| #include "include/core/SkScalar.h"
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| #include "include/core/SkShader.h"
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| #include "include/core/SkTypes.h"
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| #include "include/effects/SkGradientShader.h"
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| #include "include/effects/SkImageFilters.h"
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| #include "src/core/SkCanvasPriv.h"
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| 
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| #include <initializer_list>
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| 
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| // Make a noisy (with hard-edges) background, so we can see the effect of the blur
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| //
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| static sk_sp<SkShader> make_shader(SkScalar cx, SkScalar cy, SkScalar rad) {
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|     const SkColor colors[] = {
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|         SK_ColorRED, SK_ColorRED, SK_ColorBLUE, SK_ColorBLUE, SK_ColorGREEN, SK_ColorGREEN,
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|         SK_ColorRED, SK_ColorRED, SK_ColorBLUE, SK_ColorBLUE, SK_ColorGREEN, SK_ColorGREEN,
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|     };
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|     constexpr int count = SK_ARRAY_COUNT(colors);
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|     SkScalar pos[count] = { 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6 };
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|     for (int i = 0; i < count; ++i) {
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|         pos[i] *= 1.0f/6;
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|     }
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|     return SkGradientShader::MakeSweep(cx, cy, colors, pos, count);
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| }
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| 
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| static void do_draw(SkCanvas* canvas, bool useClip, bool useHintRect, SkScalar scaleFactor) {
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|     SkAutoCanvasRestore acr(canvas, true);
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|     canvas->clipRect({0, 0, 256, 256});
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| 
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|     const SkScalar cx = 128, cy = 128, rad = 100;
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|     SkPaint p;
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|     p.setShader(make_shader(cx, cy, rad));
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|     p.setAntiAlias(true);
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|     canvas->drawCircle(cx, cy, rad, p);
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| 
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|     // now setup a saveLayer that will pull in the backdrop and blur it
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|     //
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|     const SkRect r = {cx-50, cy-50, cx+50, cy+50};
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|     const SkRect* drawrptr = useHintRect ? &r : nullptr;
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|     const SkScalar sigma = 10;
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|     if (useClip) {
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|         canvas->clipRect(r);
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|     }
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|     // Using kClamp because kDecal, the default, produces transparency near the edge of the canvas's
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|     // device.
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|     auto blur = SkImageFilters::Blur(sigma, sigma, SkTileMode::kClamp, nullptr);
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|     auto rec = SkCanvasPriv::ScaledBackdropLayer(drawrptr, nullptr, blur.get(), scaleFactor, 0);
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|     canvas->saveLayer(rec);
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|         // draw something inside, just to demonstrate that we don't blur the new contents,
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|         // just the backdrop.
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|         p.setColor(SK_ColorYELLOW);
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|         p.setShader(nullptr);
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|         canvas->drawCircle(cx, cy, 30, p);
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|     canvas->restore();
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| }
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| 
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| /*
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|  *  Draws a 2x4 grid of sweep circles.
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|  *  - for a given row, each col should be identical (canvas, picture)
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|  *  - row:0     no-hint-rect    no-clip-rect        expect big blur (except inner circle)
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|  *  - row:1     no-hint-rect    clip-rect           expect small blur (except inner circle)
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|  *  - row:2     hint-rect       no-clip-rect        expect big blur (except inner circle)
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|  *  - row:3     hint-rect       clip-rect           expect small blur (except inner circle)
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|  *
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|  *  The test is that backdrop effects should be independent of the hint-rect, but should
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|  *  respect the clip-rect.
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|  */
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| DEF_SIMPLE_GM(backdrop_hintrect_clipping, canvas, 512, 1024) {
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|     for (bool useHintRect : {false, true}) {
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|         for (bool useClip : {false, true}) {
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|             canvas->save();
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|                 do_draw(canvas, useClip, useHintRect, 1.0f);
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| 
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|                 SkPictureRecorder rec;
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|                 do_draw(rec.beginRecording(256, 256), useClip, useHintRect, 1.0f);
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|                 canvas->translate(256, 0);
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|                 canvas->drawPicture(rec.finishRecordingAsPicture());
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|             canvas->restore();
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| 
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|             canvas->translate(0, 256);
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|         }
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|     }
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| }
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| 
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| /*
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|  *  Draws a 3x4 grid of sweep circles.
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|  *  - for a given row, each col should be identical except that the intermediate scale factor used
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|  *    to evaluate the backdrop follows (1.0, 0.25, 0.1). Rows follow same pattern as above.
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|  *
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|  *  The test is that backdrop effects should be independent of the hint-rect, should respect the
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|  *  clip rect, and be logically consistent with the reduced intermediate scaling.
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|  */
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| DEF_SIMPLE_GM(backdrop_scalefactor, canvas, 768, 1024) {
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|     for (bool useHintRect : {false, true}) {
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|         for (bool useClip : {false, true}) {
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|             canvas->save();
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|                 do_draw(canvas, useClip, useHintRect, 1.0f);
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|                 canvas->translate(256, 0);
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|                 do_draw(canvas, useClip, useHintRect, 0.25f);
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|                 canvas->translate(256, 0);
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|                 do_draw(canvas, useClip, useHintRect, 0.1f);
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|             canvas->restore();
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| 
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|             canvas->translate(0, 256);
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|         }
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|     }
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| }
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