A Geometry class that generates fillable vertices (with or without texture coordinates) directly from a round superellipse object regardless of radii uniformity. More...

#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`.

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 flutter::DlPath &path, std::optional< Rect > inner_rect=std::nullopt)

static std::unique_ptr< Geometry >	MakeStrokePath (const flutter::DlPath &path, const StrokeParameters &stroke={})

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, const StrokeParameters &stroke)

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 >	MakeFilledArc (const Rect &oval_bounds, Degrees start, Degrees sweep, bool include_center)

static std::unique_ptr< Geometry >	MakeStrokedArc (const Rect &oval_bounds, Degrees start, Degrees sweep, const StrokeParameters &stroke)

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

static std::unique_ptr< Geometry >	MakeRoundSuperellipse (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

A Geometry class that generates fillable vertices (with or without texture coordinates) directly from a round superellipse object regardless of radii uniformity.

A rounded superellipse is a shape similar to a typical rounded rectangle (RoundSuperellipse), but with smoother transitions between the straight sides and the rounded corners. It resembles the RoundedRectangle shape in SwiftUI with the .continuous corner style. Technically, it is created by replacing the four corners of a superellipse (also known as a Lamé curve) with circular arcs.

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.

See also: |StrokeRoundSuperellipseGeometry|

Definition at line 30 of file round_superellipse_geometry.h.

Constructor & Destructor Documentation

◆ RoundSuperellipseGeometry() [1/2]

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

Definition at line 366 of file round_superellipse_geometry.cc.

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

◆ RoundSuperellipseGeometry() [2/2]

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

Definition at line 370 of file round_superellipse_geometry.cc.

372 : RoundSuperellipseGeometry(bounds,

373 RoundingRadii::MakeRadius(corner_radius)) {}

impeller::RoundSuperellipseGeometry::RoundSuperellipseGeometry

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

Definition round_superellipse_geometry.cc:366

impeller::RoundingRadii::MakeRadius

static constexpr RoundingRadii MakeRadius(Scalar radius)

Definition rounding_radii.h:20

◆ ~RoundSuperellipseGeometry()

impeller::RoundSuperellipseGeometry::~RoundSuperellipseGeometry ( )

override

Definition at line 375 of file round_superellipse_geometry.cc.

375{}

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 443 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