Container for a spline, which is a series of points connected by lines and curves. More...

#include "donner/svg/core/PathSpline.h"

Classes
struct	Command
	Metadata for a command, which describes how to connect the points. More...
struct	Vertex
	Vertex of the path, including the orientation. More...

Public Types
enum class	CommandType : uint8_t { MoveTo , LineTo , CurveTo , ClosePath }
	Type of command to connect the points. More...

Public Member Functions
	PathSpline ()=default
	Construct a new empty PathSpline.
bool	empty () const
	Returns true if the spline is empty.
const std::vector< Vector2d > &	points () const
	Returns the points in the spline.
const std::vector< Command > &	commands () const
	Returns the commands in the spline.
double	pathLength () const
	Returns the length of the spline.
Vector2d	currentPoint () const
	Get the end point of the path, where new draw commands will originate.
Boxd	bounds () const
	Returns the bounding box for this spline in local space.
Boxd	transformedBounds (const Transformd &pathFromTarget) const
	Returns the tight bounding box for this spline transformed to a target coordinate system.
Boxd	strokeMiterBounds (double strokeWidth, double miterLimit) const
	Get the bounds of critical points created by miter joints when applying a stroke to this path.
Vector2d	pointAt (size_t index, double t) const
	Get a point on the spline.
Vector2d	tangentAt (size_t index, double t) const
	Get the un-normalized tangent vector on the spline.
Vector2d	normalAt (size_t index, double t) const
	Get the normal vector on the spline.
std::vector< Vertex >	vertices () const
	Get the vertices of the path, including the orientation.
bool	isInside (const Vector2d &point, FillRule fillRule=FillRule::NonZero) const
	Returns true if this path contains the given point within its fill.
bool	isOnPath (const Vector2d &point, double strokeWidth) const
	Returns true if this path contains the given point within its stroke.
Modification
void	moveTo (const Vector2d &point)
	Move the starting point of the spline to a new point, creating a new subpath.
void	lineTo (const Vector2d &point)
	Draw a line from the current point to a new point.
void	curveTo (const Vector2d &control1, const Vector2d &control2, const Vector2d &endPoint)
	Draw a cubic Bézier curve from the current point to a new point.
void	arcTo (const Vector2d &radius, double rotationRadians, bool largeArcFlag, bool sweepFlag, const Vector2d &endPoint)
	Add an elliptical arc to the path.
void	closePath ()
	Close the path.
void	ellipse (const Vector2d &center, const Vector2d &radius)
	Draw an ellipse (uses multiple curve segments).
void	circle (const Vector2d &center, double radius)
	Draw a circle (uses multiple curve segments).
void	appendJoin (const PathSpline &spline, bool asInternalPath=false)
	Append an existing spline to this spline, joining the two splines together.

Friends
std::ostream &	operator<< (std::ostream &os, PathSpline::CommandType type)
	Ostream operator for CommandType, e.g.
std::ostream &	operator<< (std::ostream &os, const PathSpline &spline)
	Ostream output operator, outputs a human-readable representation of the spline.

Detailed Description

Container for a spline, which is a series of points connected by lines and curves.

This is used to represent the d attribute of the SVGPathElement ("<path>"), see https://www.w3.org/TR/SVG2/paths.html#PathData. To parse SVG path data into a PathSpline, use the donner::svg::parser::PathParser.

The spline is composed of a series of CommandType commands, which describe how to connect the points. The points are stored in a separate vector, and the commands reference the points by index.

Member Enumeration Documentation

◆ CommandType

enum class donner::svg::PathSpline::CommandType : uint8_t

strong

Type of command to connect the points.

Note that these may not map 1:1 to the SVG path commands, as the commands are decomposed into simpler curves.

Enumerator
MoveTo	Move the starting point of the spline to a new point, creating a new subpath. Consumes 1 point: 1: New starting point.
LineTo	Draw a line from the current point to a new point. Consumes 1 point: 1: End point of the line.
CurveTo	Draw a cubic Bézier curve from the current point to a new point. Consumes 3 points: 1: First control point. 2: Second control point. 3: End point of the curve.
ClosePath	Close the path. An automatic straight line is drawn from the current point back to the initial point of the current subpath. Consumes 0 points.

Member Function Documentation

◆ appendJoin()

void donner::svg::PathSpline::appendJoin	(	const PathSpline &	spline,
		bool	asInternalPath = false )

Append an existing spline to this spline, joining the two splines together.

This will ignore the moveTo comand at the start of spline.

Parameters

spline	Spline to append.
asInternalPath	True if the spline should be treated as an internal path, which means that markers will not be rendered onto its segments.

◆ arcTo()

void donner::svg::PathSpline::arcTo	(	const Vector2d &	radius,
		double	rotationRadians,
		bool	largeArcFlag,
		bool	sweepFlag,
		const Vector2d &	endPoint )

Add an elliptical arc to the path.

Parameters

radius	Radius before rotation.
rotationRadians	Rotation of the x-axis of the ellipse.
largeArcFlag	False for arc length ≤ 180°, true for arc length ≥ 180°.
sweepFlag	False for negative angle, true for positive angle.
endPoint	End point of the arc.

◆ circle()

void donner::svg::PathSpline::circle	(	const Vector2d &	center,
		double	radius )

Draw a circle (uses multiple curve segments).

Parameters

center	Center of the circle.
radius	Radius.

◆ closePath()

void donner::svg::PathSpline::closePath ( )

Close the path.

An automatic straight line is drawn from the current point back to the initial point of the current subpath.

◆ curveTo()

void donner::svg::PathSpline::curveTo	(	const Vector2d &	control1,
		const Vector2d &	control2,
		const Vector2d &	endPoint )

Draw a cubic Bézier curve from the current point to a new point.

Parameters

control1	First control point.
control2	Second control point.
endPoint	End point of the curve.

◆ ellipse()

void donner::svg::PathSpline::ellipse	(	const Vector2d &	center,
		const Vector2d &	radius )

Draw an ellipse (uses multiple curve segments).

Parameters

center	Center of the ellipse.
radius	Ellipse radius, for both the x and y axis.

◆ isInside()

bool donner::svg::PathSpline::isInside	(	const Vector2d &	point,
		FillRule	fillRule = FillRule::NonZero ) const

Returns true if this path contains the given point within its fill.

Parameters

point	Point to check.
fillRule	Fill rule to use, defaults to FillRule::NonZero.

◆ isOnPath()

bool donner::svg::PathSpline::isOnPath	(	const Vector2d &	point,
		double	strokeWidth ) const

Returns true if this path contains the given point within its stroke.

Parameters

point	Point to check.
strokeWidth	Width of the stroke.

◆ lineTo()

void donner::svg::PathSpline::lineTo ( const Vector2d & point )

Draw a line from the current point to a new point.

Parameters

point End point of the line.

◆ moveTo()

void donner::svg::PathSpline::moveTo ( const Vector2d & point )

Move the starting point of the spline to a new point, creating a new subpath.

If this is called multiple times in a row, subsequent calls will replace the previous.

Parameters

point Point to move to.

◆ normalAt()

Vector2d donner::svg::PathSpline::normalAt	(	size_t	index,
		double	t ) const

Get the normal vector on the spline.

Parameters

index	Index of the command in the spline.
t	Position on the segment, between 0.0 and 1.0.

Returns: Vector2d Normal vector at the specified position.

◆ pointAt()

Vector2d donner::svg::PathSpline::pointAt	(	size_t	index,
		double	t ) const

Get a point on the spline.

Parameters

index	Index of the command in the spline.
t	Position on the segment, between 0.0 and 1.0.

Returns: Vector2d Point at the specified position.

◆ strokeMiterBounds()

Boxd donner::svg::PathSpline::strokeMiterBounds	(	double	strokeWidth,
		double	miterLimit ) const

Get the bounds of critical points created by miter joints when applying a stroke to this path.

Parameters

strokeWidth	Width of stroke.
miterLimit	Miter limit of the stroke.

◆ tangentAt()

Vector2d donner::svg::PathSpline::tangentAt	(	size_t	index,
		double	t ) const

Get the un-normalized tangent vector on the spline.

Parameters

index	Index of the command in the spline.
t	Position on the segment, between 0.0 and 1.0.

Returns: Vector2d Tangent vector at the specified position.

◆ transformedBounds()

Boxd donner::svg::PathSpline::transformedBounds ( const Transformd & pathFromTarget ) const

Returns the tight bounding box for this spline transformed to a target coordinate system.

Parameters

pathFromTarget Transform to transform the path to the target coordinate system.

◆ vertices()

std::vector< PathSpline::Vertex > donner::svg::PathSpline::vertices ( ) const

Get the vertices of the path, including the orientation.

Used to place markers for "<marker>".

◆ operator<< [1/2]

std::ostream & operator<<	(	std::ostream &	os,
		const PathSpline &	spline )

friend

Ostream output operator, outputs a human-readable representation of the spline.

Parameters

os	Output stream.
spline	Spline to output.

◆ operator<< [2/2]

std::ostream & operator<<	(	std::ostream &	os,
		PathSpline::CommandType	type )

friend

Ostream operator for CommandType, e.g.

CommandType::MoveTo.

Parameters

os	Output stream.
type	Command type.

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

donner/svg/core/PathSpline.h
donner/svg/core/PathSpline.cc

Classes

Public Types

Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ CommandType

Member Function Documentation

◆ appendJoin()

◆ arcTo()

◆ circle()

◆ closePath()

◆ curveTo()

◆ ellipse()

◆ isInside()

◆ isOnPath()

◆ lineTo()

◆ moveTo()

◆ normalAt()

◆ pointAt()

◆ strokeMiterBounds()

◆ tangentAt()

◆ transformedBounds()

◆ vertices()

Friends And Related Symbol Documentation

◆ operator<< [1/2]

◆ operator<< [2/2]