1 /* 2 * Copyright 2020 Google LLC 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/SkCanvas.h" 10 #include "include/core/SkMatrix.h" 11 #include "include/core/SkRect.h" 12 #include "src/base/SkFloatBits.h" 13 14 // This tests a scenario where when the 2D projection of a perspective quad is inset we degenerate 15 // the inset 2d geometry to a triangle because an inset vertex crosses the opposite edge. When we 16 // project back to 3D and try to move the original verts along the original edges so that they 17 // project to the 2D points. Whether an edge can be moved along depends on whether the adjacent edge 18 // at the vertex is AA. However, in the degenerate triangle case the 2D point may not fall along 19 // either of the edges. Thus, if we're constrained to moving along one edge and solve for X or Y the 20 // other value may go wildly away from projecting to the 2D value. The current approach is to force 21 // AA on at both edges that meet at a vertex whose inset point has been replaced by an off-edge 22 // point if either is AA originally. This gives us an additional vector to move along so that we can 23 // find a 3D point that projects to the 2D point in both X and Y. 24 DEF_SIMPLE_GM(crbug_1162942, canvas, 620, 200) { 25 // Matrix and quad values taken from Chrome repro scenario. 26 SkMatrix ctm = SkMatrix::MakeAll( 27 SkBits2Float(0x3FCC7F75), SkBits2Float(0x3D5784FC), SkBits2Float(0x44C48C99), 28 SkBits2Float(0x3F699F7F), SkBits2Float(0x3E0A0D37), SkBits2Float(0x43908518), 29 SkBits2Float(0x3AA17423), SkBits2Float(0x3A6CCDC3), SkBits2Float(0x3F2EFEEC)); 30 ctm.postTranslate(-1500.f, -325.f); 31 32 SkPoint pts[4] = {{SkBits2Float(0x3F39778B), SkBits2Float(0x43FF7FFC)}, 33 {SkBits2Float(0x0), SkBits2Float(0x43FF7FFA)}, 34 {SkBits2Float(0xB83B055E), SkBits2Float(0x42500003)}, 35 {SkBits2Float(0x3F39776F), SkBits2Float(0x4250000D)}}; 36 SkRect bounds; 37 bounds.setBounds(pts, 4); 38 39 canvas->clear(SK_ColorWHITE); 40 41 SkCanvas::QuadAAFlags flags[] = { 42 (SkCanvas::QuadAAFlags) (SkCanvas::kTop_QuadAAFlag | SkCanvas::kLeft_QuadAAFlag ), 43 (SkCanvas::QuadAAFlags) (SkCanvas::kBottom_QuadAAFlag | SkCanvas::kRight_QuadAAFlag), 44 (SkCanvas::QuadAAFlags) (SkCanvas::kBottom_QuadAAFlag), 45 (SkCanvas::QuadAAFlags) (SkCanvas::kRight_QuadAAFlag), 46 (SkCanvas::QuadAAFlags) (SkCanvas::kRight_QuadAAFlag | SkCanvas::kLeft_QuadAAFlag), 47 (SkCanvas::QuadAAFlags) (SkCanvas::kTop_QuadAAFlag | SkCanvas::kBottom_QuadAAFlag), 48 }; 49 50 SkColor color = SK_ColorGREEN; 51 for (auto aaFlags : flags) { 52 canvas->save(); 53 canvas->concat(ctm); 54 canvas->experimental_DrawEdgeAAQuad(bounds, pts, aaFlags, color, SkBlendMode::kSrcOver); 55 SkColor rgb = color & 0x00FFFFFF; 56 color = 0xFF000000 | (rgb << 4) | (rgb >> 20); 57 canvas->restore(); 58 canvas->translate(0, 25); 59 } 60 } 61 62