/* | |

* Copyright 2020 Google LLC | |

* | |

* Use of this source code is governed by a BSD-style license that can be | |

* found in the LICENSE file. | |

*/ | |

#include "gm/gm.h" | |

#include "include/core/SkCanvas.h" | |

#include "include/core/SkMatrix.h" | |

#include "include/core/SkRect.h" | |

// This tests a scenario where when the 2D projection of a perspective quad is inset we degenerate | |

// the inset 2d geometry to a triangle because an inset vertex crosses the opposite edge. When we | |

// project back to 3D and try to move the original verts along the original edges so that they | |

// project to the 2D points. Whether an edge can be moved along depends on whether the adjacent edge | |

// at the vertex is AA. However, in the degenerate triangle case the 2D point may not fall along | |

// either of the edges. Thus, if we're constrained to moving along one edge and solve for X or Y the | |

// other value may go wildly away from projecting to the 2D value. The current approach is to force | |

// AA on at both edges that meet at a vertex whose inset point has been replaced by an off-edge | |

// point if either is AA originally. This gives us an additional vector to move along so that we can | |

// find a 3D point that projects to the 2D point in both X and Y. | |

DEF_SIMPLE_GM(crbug_1162942, canvas, 620, 200) { | |

// Matrix and quad values taken from Chrome repro scenario. | |

SkMatrix ctm = SkMatrix::MakeAll( | |

SkBits2Float(0x3FCC7F75), SkBits2Float(0x3D5784FC), SkBits2Float(0x44C48C99), | |

SkBits2Float(0x3F699F7F), SkBits2Float(0x3E0A0D37), SkBits2Float(0x43908518), | |

SkBits2Float(0x3AA17423), SkBits2Float(0x3A6CCDC3), SkBits2Float(0x3F2EFEEC)); | |

ctm.postTranslate(-1500.f, -325.f); | |

SkPoint pts[4] = {{SkBits2Float(0x3F39778B), SkBits2Float(0x43FF7FFC)}, | |

{SkBits2Float(0x0), SkBits2Float(0x43FF7FFA)}, | |

{SkBits2Float(0xB83B055E), SkBits2Float(0x42500003)}, | |

{SkBits2Float(0x3F39776F), SkBits2Float(0x4250000D)}}; | |

SkRect bounds; | |

bounds.setBounds(pts, 4); | |

canvas->clear(SK_ColorWHITE); | |

SkCanvas::QuadAAFlags flags[] = { | |

(SkCanvas::QuadAAFlags) (SkCanvas::kTop_QuadAAFlag | SkCanvas::kLeft_QuadAAFlag ), | |

(SkCanvas::QuadAAFlags) (SkCanvas::kBottom_QuadAAFlag | SkCanvas::kRight_QuadAAFlag), | |

(SkCanvas::QuadAAFlags) (SkCanvas::kBottom_QuadAAFlag), | |

(SkCanvas::QuadAAFlags) (SkCanvas::kRight_QuadAAFlag), | |

(SkCanvas::QuadAAFlags) (SkCanvas::kRight_QuadAAFlag | SkCanvas::kLeft_QuadAAFlag), | |

(SkCanvas::QuadAAFlags) (SkCanvas::kTop_QuadAAFlag | SkCanvas::kBottom_QuadAAFlag), | |

}; | |

SkColor color = SK_ColorGREEN; | |

for (auto aaFlags : flags) { | |

canvas->save(); | |

canvas->concat(ctm); | |

canvas->experimental_DrawEdgeAAQuad(bounds, pts, aaFlags, color, SkBlendMode::kSrcOver); | |

SkColor rgb = color & 0x00FFFFFF; | |

color = 0xFF000000 | (rgb << 4) | (rgb >> 20); | |

canvas->restore(); | |

canvas->translate(0, 25); | |

} | |

} | |