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impeller::SuperellipseGeometry Class Referencefinal

#include <superellipse_geometry.h>

Inheritance diagram for impeller::SuperellipseGeometry:
impeller::Geometry

Public Member Functions

 SuperellipseGeometry (const Point &center, Scalar radius, Scalar degree, Scalar alpha, Scalar beta)
 
 ~SuperellipseGeometry () override
 
bool CoversArea (const Matrix &transform, const IRect &rect) const override
 Determines if this geometry, transformed by the given transform, will completely cover all of the pixels within the given integer rect.
 
bool IsAxisAlignedRect () const override
 
- Public Member Functions inherited from impeller::Geometry
virtual ~Geometry ()
 
virtual GeometryResult::Mode GetResultMode () const
 
virtual bool CanApplyMaskFilter () const
 
virtual Scalar ComputeAlphaCoverage (const Matrix &transform) const
 

Additional Inherited Members

- Static Public Member Functions inherited from impeller::Geometry
static std::unique_ptr< GeometryMakeFillPath (const flutter::DlPath &path, std::optional< Rect > inner_rect=std::nullopt)
 
static std::unique_ptr< GeometryMakeStrokePath (const flutter::DlPath &path, const StrokeParameters &stroke={})
 
static std::unique_ptr< GeometryMakeCover ()
 
static std::unique_ptr< GeometryMakeRect (const Rect &rect)
 
static std::unique_ptr< GeometryMakeOval (const Rect &rect)
 
static std::unique_ptr< GeometryMakeLine (const Point &p0, const Point &p1, const StrokeParameters &stroke)
 
static std::unique_ptr< GeometryMakeCircle (const Point &center, Scalar radius)
 
static std::unique_ptr< GeometryMakeStrokedCircle (const Point &center, Scalar radius, Scalar stroke_width)
 
static std::unique_ptr< GeometryMakeFilledArc (const Rect &oval_bounds, Degrees start, Degrees sweep, bool include_center)
 
static std::unique_ptr< GeometryMakeStrokedArc (const Rect &oval_bounds, Degrees start, Degrees sweep, const StrokeParameters &stroke)
 
static std::unique_ptr< GeometryMakeRoundRect (const Rect &rect, const Size &radii)
 
static std::unique_ptr< GeometryMakeRoundSuperellipse (const Rect &rect, Scalar corner_radius)
 
static Scalar ComputeStrokeAlphaCoverage (const Matrix &entity, Scalar stroke_width)
 Compute an alpha value to simulate lower coverage of fractional pixel strokes.
 
static GeometryResult ComputePositionGeometry (const ContentContext &renderer, const Tessellator::VertexGenerator &generator, const Entity &entity, RenderPass &pass)
 

Detailed Description

Geometry class that can generate vertices for a superellipse.

A Superellipse is an ellipse-like shape that is defined by the parameters N, alpha, and beta:

1 = |x / b| ^n + |y / a| ^n

The radius and center apply a uniform scaling and offset that is separate from alpha or beta. When n = 4, the shape is referred to as a rectellipse.

See also: https://en.wikipedia.org/wiki/Superellipse

Definition at line 23 of file superellipse_geometry.h.

Constructor & Destructor Documentation

◆ SuperellipseGeometry()

impeller::SuperellipseGeometry::SuperellipseGeometry ( const Point center,
Scalar  radius,
Scalar  degree,
Scalar  alpha,
Scalar  beta 
)
explicit

Definition at line 13 of file superellipse_geometry.cc.

18 : center_(center),
19 degree_(degree),
20 radius_(radius),
21 alpha_(alpha),
22 beta_(beta) {}

◆ ~SuperellipseGeometry()

impeller::SuperellipseGeometry::~SuperellipseGeometry ( )
override

Definition at line 24 of file superellipse_geometry.cc.

24{}

Member Function Documentation

◆ CoversArea()

bool impeller::SuperellipseGeometry::CoversArea ( const Matrix transform,
const IRect rect 
) const
overridevirtual

Determines if this geometry, transformed by the given transform, will completely cover all of the pixels within the given integer rect.

The integer rect, by definition, will contain all of the area covered by any pixel within its boundary.

The return value can be a conservative estimate which will still be useful for certain optimizations. It may return false for obscure cases that might actually contain all of the pixels if it is too computationally costly to prove containment, but it should never return 'true' unless the implementation can prove that all pixels are fully covered (rendered) by the geometry.

Returns
true if the transformed geometry is guaranteed to cover the given rect. May return false in some cases where the transformed geometry does in fact cover the rect.

Reimplemented from impeller::Geometry.

Definition at line 104 of file superellipse_geometry.cc.

105 {
106 return false;
107}

◆ IsAxisAlignedRect()

bool impeller::SuperellipseGeometry::IsAxisAlignedRect ( ) const
overridevirtual

Reimplemented from impeller::Geometry.

Definition at line 109 of file superellipse_geometry.cc.

109 {
110 return false;
111}

The documentation for this class was generated from the following files: