impeller::StrokePathGeometry Class Reference

A geometry that is created from a stroked path object. More...

#include <stroke_path_geometry.h>

Inheritance diagram for impeller::StrokePathGeometry:

Public Member Functions
	StrokePathGeometry (const Path &path, Scalar stroke_width, Scalar miter_limit, Cap stroke_cap, Join stroke_join)
	~StrokePathGeometry ()
Scalar	GetStrokeWidth () const
Scalar	GetMiterLimit () const
Cap	GetStrokeCap () const
Join	GetStrokeJoin () const
Public Member Functions inherited from impeller::Geometry
virtual bool	CoversArea (const Matrix &transform, const Rect &rect) const
	Determines if this geometry, transformed by the given transform, will completely cover all surface area of the given rect.
virtual bool	IsAxisAlignedRect () const
virtual bool	CanApplyMaskFilter () const

Private Member Functions
GeometryResult	GetPositionBuffer (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
GeometryResult::Mode	GetResultMode () const override
std::optional< Rect >	GetCoverage (const Matrix &transform) const override

Friends
class	ImpellerBenchmarkAccessor
class	ImpellerEntityUnitTestAccessor

Additional Inherited Members
Static Public Member Functions inherited from impeller::Geometry
static std::shared_ptr< Geometry >	MakeFillPath (const Path &path, std::optional< Rect > inner_rect=std::nullopt)
static std::shared_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::shared_ptr< Geometry >	MakeCover ()
static std::shared_ptr< Geometry >	MakeRect (const Rect &rect)
static std::shared_ptr< Geometry >	MakeOval (const Rect &rect)
static std::shared_ptr< Geometry >	MakeLine (const Point &p0, const Point &p1, Scalar width, Cap cap)
static std::shared_ptr< Geometry >	MakeCircle (const Point &center, Scalar radius)
static std::shared_ptr< Geometry >	MakeStrokedCircle (const Point &center, Scalar radius, Scalar stroke_width)
static std::shared_ptr< Geometry >	MakeRoundRect (const Rect &rect, const Size &radii)
static std::shared_ptr< Geometry >	MakePointField (std::vector< Point > points, Scalar radius, bool round)
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

A geometry that is created from a stroked path object.

Definition at line 13 of file stroke_path_geometry.h.

Constructor & Destructor Documentation

StrokePathGeometry()

impeller::StrokePathGeometry::StrokePathGeometry	(	const Path &	path,
		Scalar	stroke_width,
		Scalar	miter_limit,
		Cap	stroke_cap,
		Join	stroke_join
	)

Definition at line 484 of file stroke_path_geometry.cc.

    : path_(path),
      stroke_width_(stroke_width),
      miter_limit_(miter_limit),
      stroke_cap_(stroke_cap),
      stroke_join_(stroke_join) {}

~StrokePathGeometry()

impeller::StrokePathGeometry::~StrokePathGeometry ( )

default

Member Function Documentation

GetCoverage()

std::optional< Rect > impeller::StrokePathGeometry::GetCoverage ( const Matrix &  transform ) const

overrideprivatevirtual

Implements impeller::Geometry.

Definition at line 561 of file stroke_path_geometry.cc.

                                   {
  auto path_bounds = path_.GetBoundingBox();
  if (!path_bounds.has_value()) {
    return std::nullopt;
  }
 
  Scalar max_radius = 0.5;
  if (stroke_cap_ == Cap::kSquare) {
    max_radius = max_radius * kSqrt2;
  }
  if (stroke_join_ == Join::kMiter) {
    max_radius = std::max(max_radius, miter_limit_ * 0.5f);
  }
  Scalar determinant = transform.GetDeterminant();
  if (determinant == 0) {
    return std::nullopt;
  }
  Scalar min_size = 1.0f / sqrt(std::abs(determinant));
  max_radius *= std::max(stroke_width_, min_size);
  return path_bounds->Expand(max_radius).TransformBounds(transform);
}

GetMiterLimit()

Scalar impeller::StrokePathGeometry::GetMiterLimit

(

)

const

Definition at line 501 of file stroke_path_geometry.cc.

                                               {
  return miter_limit_;
}

GetPositionBuffer()

GeometryResult impeller::StrokePathGeometry::GetPositionBuffer ( const ContentContext &  renderer, const Entity &  entity, RenderPass &  pass  ) const

overrideprivatevirtual

Implements impeller::Geometry.

Definition at line 513 of file stroke_path_geometry.cc.

                            {
  if (stroke_width_ < 0.0) {
    return {};
  }
  auto determinant = entity.GetTransform().GetDeterminant();
  if (determinant == 0) {
    return {};
  }
 
  Scalar min_size = 1.0f / sqrt(std::abs(determinant));
  Scalar stroke_width = std::max(stroke_width_, min_size);
 
  auto& host_buffer = renderer.GetTransientsBuffer();
  auto scale = entity.GetTransform().GetMaxBasisLength();
 
  PositionWriter position_writer;
  auto polyline = renderer.GetTessellator()->CreateTempPolyline(path_, scale);
  CreateSolidStrokeVertices(position_writer, polyline, stroke_width,
                            miter_limit_ * stroke_width_ * 0.5f,
                            GetJoinProc<PositionWriter>(stroke_join_),
                            GetCapProc<PositionWriter>(stroke_cap_), scale);
 
  BufferView buffer_view =
      host_buffer.Emplace(position_writer.GetData().data(),
                          position_writer.GetData().size() *
                              sizeof(SolidFillVertexShader::PerVertexData),
                          alignof(SolidFillVertexShader::PerVertexData));
 
  return GeometryResult{
      .type = PrimitiveType::kTriangleStrip,
      .vertex_buffer =
          {
              .vertex_buffer = buffer_view,
              .vertex_count = position_writer.GetData().size(),
              .index_type = IndexType::kNone,
          },
      .transform = entity.GetShaderTransform(pass),
      .mode = GeometryResult::Mode::kPreventOverdraw,
  };
}

GetResultMode()

GeometryResult::Mode impeller::StrokePathGeometry::GetResultMode ( ) const

overrideprivatevirtual

Reimplemented from impeller::Geometry.

Definition at line 557 of file stroke_path_geometry.cc.

                                                           {
  return GeometryResult::Mode::kPreventOverdraw;
}

GetStrokeCap()

Cap impeller::StrokePathGeometry::GetStrokeCap

(

)

const

Definition at line 505 of file stroke_path_geometry.cc.

                                           {
  return stroke_cap_;
}

GetStrokeJoin()

Join impeller::StrokePathGeometry::GetStrokeJoin

(

)

const

Definition at line 509 of file stroke_path_geometry.cc.

                                             {
  return stroke_join_;
}

GetStrokeWidth()

Scalar impeller::StrokePathGeometry::GetStrokeWidth

(

)

const

Definition at line 497 of file stroke_path_geometry.cc.

                                                {
  return stroke_width_;
}

Friends And Related Symbol Documentation

ImpellerBenchmarkAccessor

friend class ImpellerBenchmarkAccessor

friend

Definition at line 52 of file stroke_path_geometry.h.

ImpellerEntityUnitTestAccessor

friend class ImpellerEntityUnitTestAccessor

friend

Definition at line 53 of file stroke_path_geometry.h.

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

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