xref: /aosp_15_r20/external/skia/src/gpu/graphite/geom/EdgeAAQuad.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2023 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 #ifndef skgpu_graphite_geom_EdgeAAQuad_DEFINED
9 #define skgpu_graphite_geom_EdgeAAQuad_DEFINED
10 
11 #include "include/core/SkPoint.h"
12 #include "include/core/SkRect.h"
13 #include "src/base/SkEnumBitMask.h"
14 #include "src/base/SkVx.h"
15 #include "src/gpu/graphite/geom/Rect.h"
16 
17 #include <cstdint>
18 
19 namespace skgpu::graphite {
20 
21 /**
22  * EdgeAAQuad contains (x,y) coordinates for the four corners of a quadrilateral, assumed to be
23  * convex and in a consistent winding (CW vs. CCW is fine). Locally, the vertices are ordered
24  * "top-left", "top-right", "bottom-right", "bottom-left". The edges are in order left (p0-p3),
25  * top (p1-p0), right (p2-p1), and bottom (p3-p2).
26  */
27 class EdgeAAQuad {
28 public:
29     // SkEnumBitMask<Flags> is a typesafe equivalent to SkCanvas::QuadAAFlags.
30     enum class Flags : uint8_t {
31         kLeft   = 0b0001,
32         kTop    = 0b0010,
33         kRight  = 0b0100,
34         kBottom = 0b1000,
35 
36         kNone   = 0b0000,
37         kAll    = 0b1111,
38     };
39 
40     EdgeAAQuad() = delete;
41 
EdgeAAQuad(const SkRect & rect,SkEnumBitMask<Flags> edgeFlags)42     EdgeAAQuad(const SkRect& rect, SkEnumBitMask<Flags> edgeFlags)
43             : fXs{rect.fLeft, rect.fRight, rect.fRight, rect.fLeft}
44             , fYs{rect.fTop, rect.fTop, rect.fBottom, rect.fBottom}
45             , fEdgeFlags(edgeFlags)
46             , fIsRect(true) {}
EdgeAAQuad(const Rect & rect,SkEnumBitMask<Flags> edgeFlags)47     EdgeAAQuad(const Rect& rect, SkEnumBitMask<Flags> edgeFlags)
48             : fXs{skvx::shuffle<0,2,2,0>(rect.ltrb())}
49             , fYs{skvx::shuffle<1,1,3,3>(rect.ltrb())}
50             , fEdgeFlags(edgeFlags)
51             , fIsRect(true) {}
EdgeAAQuad(const SkPoint points[4],SkEnumBitMask<Flags> edgeFlags)52     EdgeAAQuad(const SkPoint points[4], SkEnumBitMask<Flags> edgeFlags)
53             : fXs{points[0].fX, points[1].fX, points[2].fX, points[3].fX}
54             , fYs{points[0].fY, points[1].fY, points[2].fY, points[3].fY}
55             , fEdgeFlags(edgeFlags)
56             , fIsRect(false) {}
EdgeAAQuad(const skvx::float4 & xs,const skvx::float4 & ys,SkEnumBitMask<Flags> edgeFlags)57     EdgeAAQuad(const skvx::float4& xs, const skvx::float4& ys, SkEnumBitMask<Flags> edgeFlags)
58             : fXs(xs)
59             , fYs(ys)
60             , fEdgeFlags(edgeFlags)
61             , fIsRect(false) {}
62 
63     // The bounding box of the quadrilateral (not counting any outsetting for anti-aliasing).
bounds()64     Rect bounds() const {
65         if (fIsRect) {
66             return Rect({fXs[0], fYs[0]}, {fXs[2], fYs[2]});
67         }
68 
69         Rect p0p1 = Rect::LTRB(skvx::shuffle<0,2,1,3>(skvx::float4(fXs.lo, fYs.lo))).makeSorted();
70         Rect p2p3 = Rect::LTRB(skvx::shuffle<0,2,1,3>(skvx::float4(fXs.hi, fYs.hi))).makeSorted();
71         return p0p1.makeJoin(p2p3);
72     }
73 
74     // Access the individual elements of the quad data.
xs()75     const skvx::float4& xs() const { return fXs; }
ys()76     const skvx::float4& ys() const { return fYs; }
edgeFlags()77     SkEnumBitMask<Flags> edgeFlags() const { return fEdgeFlags; }
78 
isRect()79     bool isRect() const { return fIsRect; }
80 
81 private:
82     skvx::float4 fXs;
83     skvx::float4 fYs;
84     SkEnumBitMask<Flags> fEdgeFlags;
85     bool fIsRect;
86 };
87 
88 SK_MAKE_BITMASK_OPS(EdgeAAQuad::Flags)
89 
90 } // namespace skgpu::graphite
91 
92 #endif // skgpu_graphite_geom_EdgeAAQuad_DEFINED
93