88 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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|  * Copyright 2013 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/SkPaint.h"
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| #include "include/core/SkPoint.h"
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| #include "include/core/SkRect.h"
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| #include "include/core/SkShader.h"
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| #include "include/core/SkSize.h"
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| #include "include/core/SkString.h"
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| #include "include/core/SkTileMode.h"
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| #include "include/core/SkTypes.h"
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| #include "include/effects/SkGradientShader.h"
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| 
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| class AlphaGradientsGM : public skiagm::GM {
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| public:
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|     AlphaGradientsGM() {}
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| 
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| protected:
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|     SkString onShortName() override {
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|         return SkString("alphagradients");
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|     }
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| 
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|     SkISize onISize() override {
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|         return SkISize::Make(640, 480);
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|     }
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| 
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|     static void draw_grad(SkCanvas* canvas, const SkRect& r,
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|                           SkColor c0, SkColor c1, bool doPreMul) {
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|         SkColor colors[] = { c0, c1 };
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|         SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fBottom } };
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|         SkPaint paint;
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|         uint32_t flags = doPreMul ? SkGradientShader::kInterpolateColorsInPremul_Flag : 0;
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|         paint.setShader(SkGradientShader::MakeLinear(pts, colors, nullptr, 2,
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|                                                      SkTileMode::kClamp, flags, nullptr));
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|         canvas->drawRect(r, paint);
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| 
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|         paint.setShader(nullptr);
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|         paint.setStyle(SkPaint::kStroke_Style);
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|         canvas->drawRect(r, paint);
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|     }
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| 
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|     void onDraw(SkCanvas* canvas) override {
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|         constexpr struct {
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|             SkColor fColor0;
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|             SkColor fColor1;
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|         } gRec[] = {
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|             { 0xFFFFFFFF, 0x00000000 },
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|             { 0xFFFFFFFF, 0x00FF0000 },
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|             { 0xFFFFFFFF, 0x00FFFF00 },
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|             { 0xFFFFFFFF, 0x00FFFFFF },
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|             { 0xFFFF0000, 0x00000000 },
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|             { 0xFFFF0000, 0x00FF0000 },
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|             { 0xFFFF0000, 0x00FFFF00 },
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|             { 0xFFFF0000, 0x00FFFFFF },
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|             { 0xFF0000FF, 0x00000000 },
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|             { 0xFF0000FF, 0x00FF0000 },
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|             { 0xFF0000FF, 0x00FFFF00 },
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|             { 0xFF0000FF, 0x00FFFFFF },
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|         };
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| 
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|         SkRect r = SkRect::MakeWH(300, 30);
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| 
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|         canvas->translate(10, 10);
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| 
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|         for (int doPreMul = 0; doPreMul <= 1; ++doPreMul) {
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|             canvas->save();
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|             for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
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|                 draw_grad(canvas, r, gRec[i].fColor0, gRec[i].fColor1, SkToBool(doPreMul));
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|                 canvas->translate(0, r.height() + 8);
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|             }
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|             canvas->restore();
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|             canvas->translate(r.width() + 10, 0);
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|         }
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|     }
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| 
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| private:
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|     using INHERITED = skiagm::GM;
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| };
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| 
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| DEF_GM(return new AlphaGradientsGM;)
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