#include <round_superellipse_geometry.h>

Inheritance diagram for impeller::RoundSuperellipseGeometry:

Public Member Functions
	RoundSuperellipseGeometry (const Rect &bounds, const RoundingRadii &radii)

	RoundSuperellipseGeometry (const Rect &bounds, float corner_radius)

	~RoundSuperellipseGeometry () override

bool	CoversArea (const Matrix &transform, const Rect &rect) const override
	Determines if this geometry, transformed by the given `transform`, will completely cover all surface area of the given `rect`. More...

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< Geometry >	MakeFillPath (const Path &path, std::optional< Rect > inner_rect=std::nullopt)

static std::unique_ptr< Geometry >	MakeStrokePath (const Path &path, Scalar stroke_width=0.0, Scalar miter_limit=4.0, Cap stroke_cap=Cap::kButt, Join stroke_join=Join::kMiter)

static std::unique_ptr< Geometry >	MakeCover ()

static std::unique_ptr< Geometry >	MakeRect (const Rect &rect)

static std::unique_ptr< Geometry >	MakeOval (const Rect &rect)

static std::unique_ptr< Geometry >	MakeLine (const Point &p0, const Point &p1, Scalar width, Cap cap)

static std::unique_ptr< Geometry >	MakeCircle (const Point &center, Scalar radius)

static std::unique_ptr< Geometry >	MakeStrokedCircle (const Point &center, Scalar radius, Scalar stroke_width)

static std::unique_ptr< Geometry >	MakeRoundRect (const Rect &rect, const Size &radii)

static Scalar	ComputeStrokeAlphaCoverage (const Matrix &entity, Scalar stroke_width)
	Compute an alpha value to simulate lower coverage of fractional pixel strokes. More...

Static Protected Member Functions inherited from impeller::Geometry
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 rounded 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

A rounded superellipse is a square-like superellipse (a=b) with its four corners replaced by circular arcs. It replicates the RoundedRectangle shape in SwiftUI with corner style .continuous.

The bounds defines the position and size of the shape. The corner_radius corresponds to SwiftUI's cornerRadius parameter, which is close to, but not exactly equals to, the radius of the corner circles.

Definition at line 27 of file round_superellipse_geometry.h.

Constructor & Destructor Documentation

◆ RoundSuperellipseGeometry() [1/2]

impeller::RoundSuperellipseGeometry::RoundSuperellipseGeometry	(	const Rect &	bounds,
		const RoundingRadii &	radii
	)

Definition at line 499 of file round_superellipse_geometry.cc.

501 : bounds_(bounds.GetPositive()), radii_(radii.Scaled(bounds_)) {}

◆ RoundSuperellipseGeometry() [2/2]

impeller::RoundSuperellipseGeometry::RoundSuperellipseGeometry	(	const Rect &	bounds,
		float	corner_radius
	)

Definition at line 503 of file round_superellipse_geometry.cc.

505 : RoundSuperellipseGeometry(bounds,

506 RoundingRadii::MakeRadius(corner_radius)) {}

impeller::RoundSuperellipseGeometry::RoundSuperellipseGeometry

RoundSuperellipseGeometry(const Rect &bounds, const RoundingRadii &radii)

Definition: round_superellipse_geometry.cc:499

impeller::RoundingRadii::MakeRadius

constexpr static RoundingRadii MakeRadius(Scalar radius)

Definition: rounding_radii.h:20

◆ ~RoundSuperellipseGeometry()

impeller::RoundSuperellipseGeometry::~RoundSuperellipseGeometry ( )

override

Definition at line 508 of file round_superellipse_geometry.cc.

508 {}

Member Function Documentation

◆ CoversArea()

bool impeller::RoundSuperellipseGeometry::CoversArea	(	const Matrix &	transform,
		const Rect &	rect
	)		const

overridevirtual

Determines if this geometry, transformed by the given transform, will completely cover all surface area of the given rect.

This is a conservative estimate useful for certain optimizations.

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

Reimplemented from impeller::Geometry.

Definition at line 592 of file round_superellipse_geometry.cc.

                                                                    {
   if (!transform.IsTranslationScaleOnly()) {
     return false;
   }
   Scalar left_inset = std::max(radii_.top_left.width, radii_.bottom_left.width);
   Scalar right_inset =
       std::max(radii_.top_right.width, radii_.bottom_right.width);
   Scalar top_inset = std::max(radii_.top_left.height, radii_.top_right.height);
   Scalar bottom_inset =
       std::max(radii_.bottom_left.height, radii_.bottom_right.height);
   Rect coverage =
       Rect::MakeLTRB(bounds_.GetLeft() + left_inset * kGapFactor,
                      bounds_.GetTop() + top_inset * kGapFactor,
                      bounds_.GetRight() - right_inset * kGapFactor,
                      bounds_.GetBottom() - bottom_inset * kGapFactor);
   return coverage.TransformBounds(transform).Contains(rect);
 }

References impeller::RoundingRadii::bottom_left, impeller::RoundingRadii::bottom_right, impeller::TRect< T >::Contains(), impeller::TRect< T >::GetBottom(), impeller::TRect< T >::GetLeft(), impeller::TRect< T >::GetRight(), impeller::TRect< T >::GetTop(), impeller::TSize< T >::height, impeller::TRect< Scalar >::MakeLTRB(), impeller::RoundingRadii::top_left, impeller::RoundingRadii::top_right, transform, impeller::TRect< T >::TransformBounds(), and impeller::TSize< T >::width.

◆ IsAxisAlignedRect()

bool impeller::RoundSuperellipseGeometry::IsAxisAlignedRect ( ) const