61 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			61 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C++
		
	
	
	
| /*
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|  * Copyright 2020 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/SkMatrix.h"
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| #include "include/core/SkRect.h"
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| 
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| // This tests a scenario where when the 2D projection of a perspective quad is inset we degenerate
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| // the inset 2d geometry to a triangle because an inset vertex crosses the opposite edge. When we
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| // project back to 3D and try to move the original verts along the original edges so that they
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| // project to the 2D points. Whether an edge can be moved along depends on whether the adjacent edge
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| // at the vertex is AA. However, in the degenerate triangle case the 2D point may not fall along
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| // either of the edges. Thus, if we're constrained to moving along one edge and solve for X or Y the
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| // other value may go wildly away from projecting to the 2D value. The current approach is to force
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| // AA on at both edges that meet at a vertex whose inset point has been replaced by an off-edge
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| // point if either is AA originally. This gives us an additional vector to move along so that we can
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| // find a 3D point that projects to the 2D point in both X and Y.
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| DEF_SIMPLE_GM(crbug_1162942, canvas, 620, 200) {
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|     // Matrix and quad values taken from Chrome repro scenario.
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|     SkMatrix ctm = SkMatrix::MakeAll(
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|             SkBits2Float(0x3FCC7F75), SkBits2Float(0x3D5784FC), SkBits2Float(0x44C48C99),
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|             SkBits2Float(0x3F699F7F), SkBits2Float(0x3E0A0D37), SkBits2Float(0x43908518),
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|             SkBits2Float(0x3AA17423), SkBits2Float(0x3A6CCDC3), SkBits2Float(0x3F2EFEEC));
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|     ctm.postTranslate(-1500.f, -325.f);
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| 
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|     SkPoint pts[4] = {{SkBits2Float(0x3F39778B), SkBits2Float(0x43FF7FFC)},
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|                       {SkBits2Float(0x0), SkBits2Float(0x43FF7FFA)},
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|                       {SkBits2Float(0xB83B055E), SkBits2Float(0x42500003)},
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|                       {SkBits2Float(0x3F39776F), SkBits2Float(0x4250000D)}};
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|     SkRect bounds;
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|     bounds.setBounds(pts, 4);
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| 
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|     canvas->clear(SK_ColorWHITE);
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| 
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|     SkCanvas::QuadAAFlags flags[] = {
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|             (SkCanvas::QuadAAFlags) (SkCanvas::kTop_QuadAAFlag    | SkCanvas::kLeft_QuadAAFlag ),
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|             (SkCanvas::QuadAAFlags) (SkCanvas::kBottom_QuadAAFlag | SkCanvas::kRight_QuadAAFlag),
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|             (SkCanvas::QuadAAFlags) (SkCanvas::kBottom_QuadAAFlag),
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|             (SkCanvas::QuadAAFlags) (SkCanvas::kRight_QuadAAFlag),
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|             (SkCanvas::QuadAAFlags) (SkCanvas::kRight_QuadAAFlag  | SkCanvas::kLeft_QuadAAFlag),
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|             (SkCanvas::QuadAAFlags) (SkCanvas::kTop_QuadAAFlag    | SkCanvas::kBottom_QuadAAFlag),
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|     };
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| 
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|     SkColor color = SK_ColorGREEN;
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|     for (auto aaFlags : flags) {
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|         canvas->save();
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|         canvas->concat(ctm);
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|         canvas->experimental_DrawEdgeAAQuad(bounds, pts, aaFlags, color, SkBlendMode::kSrcOver);
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|         SkColor rgb = color & 0x00FFFFFF;
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|         color = 0xFF000000 | (rgb << 4) | (rgb >> 20);
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|         canvas->restore();
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|         canvas->translate(0, 25);
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|     }
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| }
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| 
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