impeller::LineGeometry Class Reference

#include <line_geometry.h>

Inheritance diagram for impeller::LineGeometry:

Public Member Functions
	LineGeometry (Point p0, Point p1, Scalar width, Cap cap)
	~LineGeometry () 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
Scalar	ComputeAlphaCoverage (const Matrix &transform) const override
Public Member Functions inherited from impeller::Geometry
virtual	~Geometry ()
virtual GeometryResult::Mode	GetResultMode () const
virtual bool	CanApplyMaskFilter () const

Static Public Member Functions
static Scalar	ComputePixelHalfWidth (const Matrix &transform, Scalar width)
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...

Additional Inherited Members
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

Definition at line 12 of file line_geometry.h.

Constructor & Destructor Documentation

LineGeometry()

impeller::LineGeometry::LineGeometry ( Point  p0, Point  p1, Scalar  width, Cap  cap  )

explicit

Definition at line 10 of file line_geometry.cc.

    : p0_(p0), p1_(p1), width_(width), cap_(cap) {
  FML_DCHECK(width >= 0);
}

~LineGeometry()

impeller::LineGeometry::~LineGeometry ( )

overridedefault

Member Function Documentation

ComputeAlphaCoverage()

Scalar impeller::LineGeometry::ComputeAlphaCoverage ( const Matrix &  transform ) const

overridevirtual

Reimplemented from impeller::Geometry.

Definition at line 70 of file line_geometry.cc.

                                                                    {
  return Geometry::ComputeStrokeAlphaCoverage(entity, width_);
}

References impeller::Geometry::ComputeStrokeAlphaCoverage().

ComputePixelHalfWidth()

Scalar impeller::LineGeometry::ComputePixelHalfWidth ( const Matrix &  transform, Scalar  width  )

static

Definition at line 17 of file line_geometry.cc.

                                                         {
  Scalar max_basis = transform.GetMaxBasisLengthXY();
  if (max_basis == 0) {
    return {};
  }
 
  Scalar min_size = kMinStrokeSize / max_basis;
  return std::max(width, min_size) * 0.5f;
}

References impeller::kMinStrokeSize, and transform.

CoversArea()

bool impeller::LineGeometry::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 131 of file line_geometry.cc.

                                                                             {
  if (!transform.IsTranslationScaleOnly() || !IsAxisAlignedRect()) {
    return false;
  }
  auto coverage = GetCoverage(transform);
  return coverage.has_value() ? coverage->Contains(rect) : false;
}

References IsAxisAlignedRect(), and transform.

IsAxisAlignedRect()

bool impeller::LineGeometry::IsAxisAlignedRect ( ) const

overridevirtual

Reimplemented from impeller::Geometry.

Definition at line 139 of file line_geometry.cc.

                                           {
  return cap_ != Cap::kRound && (p0_.x == p1_.x || p0_.y == p1_.y);
}

References impeller::kRound, impeller::TPoint< T >::x, and impeller::TPoint< T >::y.

Referenced by CoversArea().

---

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

• impeller/entity/geometry/line_geometry.h
• impeller/entity/geometry/line_geometry.cc