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round_superellipse_geometry.h
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef FLUTTER_IMPELLER_ENTITY_GEOMETRY_ROUND_SUPERELLIPSE_GEOMETRY_H_
6 #define FLUTTER_IMPELLER_ENTITY_GEOMETRY_ROUND_SUPERELLIPSE_GEOMETRY_H_
7
8 #include "impeller/entity/geometry/geometry.h"
9 #include "impeller/geometry/rounding_radii.h"
10
11 namespace impeller {
12
13 /// Geometry class that can generate vertices for a rounded superellipse.
14 ///
15 /// A superellipse is an ellipse-like shape that is defined by the parameters N,
16 /// alpha, and beta:
17 ///
18 /// 1 = |x / b| ^n + |y / a| ^n
19 ///
20 /// A rounded superellipse is a square-like superellipse (a=b) with its four
21 /// corners replaced by circular arcs. It replicates the `RoundedRectangle`
22 /// shape in SwiftUI with corner style `.continuous`.
23 ///
24 /// The `bounds` defines the position and size of the shape. The `corner_radius`
25 /// corresponds to SwiftUI's `cornerRadius` parameter, which is close to, but
26 /// not exactly equals to, the radius of the corner circles.
27 class RoundSuperellipseGeometry final : public Geometry {
28 public:
29 RoundSuperellipseGeometry(const Rect& bounds, const RoundingRadii& radii);
30 RoundSuperellipseGeometry(const Rect& bounds, float corner_radius);
31
32 ~RoundSuperellipseGeometry() override;
33
34 // |Geometry|
35 bool CoversArea(const Matrix& transform, const Rect& rect) const override;
36
37 // |Geometry|
38 bool IsAxisAlignedRect() const override;
39
40 private:
41 // |Geometry|
42 GeometryResult GetPositionBuffer(const ContentContext& renderer,
43 const Entity& entity,
44 RenderPass& pass) const override;
45
46 // |Geometry|
47 std::optional<Rect> GetCoverage(const Matrix& transform) const override;
48
49 const Rect bounds_;
50 const RoundingRadii radii_;
51
52 RoundSuperellipseGeometry(const RoundSuperellipseGeometry&) = delete;
53
54 RoundSuperellipseGeometry& operator=(const RoundSuperellipseGeometry&) =
55 delete;
56 };
57
58 } // namespace impeller
59
60 #endif // FLUTTER_IMPELLER_ENTITY_GEOMETRY_ROUND_SUPERELLIPSE_GEOMETRY_H_
impeller::RoundingRadii
Definition: rounding_radii.h:14
geometry.h
impeller::Entity
Definition: entity.h:20
transform
Matrix transform
Definition: gaussian_blur_filter_contents.cc:214
rounding_radii.h
impeller::GeometryResult
Definition: geometry.h:21
impeller::RoundSuperellipseGeometry::IsAxisAlignedRect
bool IsAxisAlignedRect() const override
Definition: round_superellipse_geometry.cc:611
impeller::RenderPass
Render passes encode render commands directed as one specific render target into an underlying comman...
Definition: render_pass.h:30
impeller::Geometry
Definition: geometry.h:50
impeller::RoundSuperellipseGeometry::RoundSuperellipseGeometry
RoundSuperellipseGeometry(const Rect &bounds, const RoundingRadii &radii)
Definition: round_superellipse_geometry.cc:499
impeller::RoundSuperellipseGeometry
Definition: round_superellipse_geometry.h:27
impeller::RoundSuperellipseGeometry::CoversArea
bool CoversArea(const Matrix &transform, const Rect &rect) const override
Determines if this geometry, transformed by the given transform, will completely cover all surface ar...
Definition: round_superellipse_geometry.cc:592
impeller
Definition: allocation.cc:12
impeller::RoundSuperellipseGeometry::~RoundSuperellipseGeometry
~RoundSuperellipseGeometry() override
Definition: round_superellipse_geometry.cc:508
impeller::ContentContext
Definition: content_context.h:371
impeller::TRect< Scalar >
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37