Geometry class that defined strokes entered by a user. The creation and usage of this class must be followed after certain steps. Here's an example of how to create a new stroke when user is drawing right away: More...

#include <Stroke.h>

Inheritance diagram for entity::Stroke:

Public Member Functions
	Stroke ()

	Stroke (const Stroke &copy, const osg::CopyOp &copyop=osg::CopyOp::SHALLOW_COPY)

	META_Node (entity, Stroke) void setIsCurved(bool curved)

bool	getIsCurved () const

virtual bool	copyFrom (const entity::ShaderedEntity2D *copy)

virtual bool	redefineToShape (osg::MatrixTransform *t=0)

osg::Node *	getMeshRepresentation () const

float	getLength () const

bool	isLengthy () const

cher::ENTITY_TYPE	getEntityType () const

virtual ProgramStroke *	getProgram () const

virtual void	appendPoint (const float u, const float v)

Public Member Functions inherited from entity::ShaderedEntity2D
	ShaderedEntity2D (unsigned int drawing, osg::Geometry::AttributeBinding binding, const std::string &name, const osg::Vec4f &color)

	ShaderedEntity2D (const entity::ShaderedEntity2D &copy, const osg::CopyOp &copyop)

virtual void	initializeProgram (ProgramEntity2D *p, unsigned int mode=GL_LINE_STRIP)

virtual void	appendPoint (const float u, const float v, osg::Vec4f color)

virtual osg::Vec2f	getPoint (unsigned int i) const

virtual osg::Vec3f	getPoint3 (unsigned int i) const

int	getNumPoints () const

virtual void	moveDelta (double du, double dv)

virtual void	scale (double scaleX, double scaleY, osg::Vec3f center)

virtual void	scale (double scale, osg::Vec3f center)

virtual void	rotate (double theta, osg::Vec3f center)

void	setLines (osg::DrawArrays *lines)

const osg::DrawArrays *	getLines () const

void	setColor (const osg::Vec4f &color)

const osg::Vec4f &	getColor () const

void	setSelected (float alpha)

void	setUnselected (float alpha)

void	setIsShadered (bool shadered)

bool	getIsShadered () const

virtual void	setProgram (ProgramEntity2D *p)

Public Member Functions inherited from entity::Entity2D
	Entity2D (const Entity2D &copy, const osg::CopyOp &copyop=osg::CopyOp::SHALLOW_COPY)

Protected Member Functions
virtual bool	redefineToShader (osg::MatrixTransform *t)

osg::Vec3Array *	getCurvePoints (const osg::Vec3Array *bezierPts) const

double	normalize (osg::Vec3Array *path, const osg::Vec3f &center)

void	denormalize (osg::Vec3Array *path, const osg::Vec3f &center, double scale)

Additional Inherited Members
Protected Attributes inherited from entity::ShaderedEntity2D
osg::ref_ptr< osg::DrawArrays >	m_lines

osg::observer_ptr< ProgramEntity2D >	m_program

bool	m_isShadered

osg::Vec4f	m_colorNormal

osg::Vec4f	m_colorSelected

Detailed Description

Geometry class that defined strokes entered by a user. The creation and usage of this class must be followed after certain steps. Here's an example of how to create a new stroke when user is drawing right away:

// create an empty stroke
entity::Stroke* original = new entity::Stroke;
// initialize the shader program
original->initializeProgram(p); // e.g. Canvas::getProgramStroke()
// as user draws, add mouse coordinates, in an event loop:
original->addPoint(u,v);
\\ after user is finished drawing, re-define the look (shaderize as well)
original->redefineToShape();

The below example provides details on how to copy/clone a stroke that is already present on the scene graph:

// create an empty stroke
entity::Stroke* copy = new entity::Stroke;
// copy data points from the stroke that is already on the scene (which means it is shadered)
// it also copies shader data
copy->copyFrom(original);
// as before, we re-define the stroke to be shadered
copy->redefineToShape();

Constructor & Destructor Documentation

§ Stroke() [1/2]

entity::Stroke::Stroke ( )

Constructor that creates an empty stroke.

§ Stroke() [2/2]

entity::Stroke::Stroke	(	const Stroke &	copy,
		const osg::CopyOp &	copyop = `osg::CopyOp::SHALLOW_COPY`
	)

Copy constructor, only used for serialization; not to be used otherwise.

Member Function Documentation

§ appendPoint()

void entity::Stroke::appendPoint	(	const float	u,
		const float	v
	)

virtual

A method to add a point to the end of the entity. It is normally used when constructing an emtity in-motion while sketching.

Parameters

u	is local U coordinate,
v	is local V coordinate.

§ copyFrom()

bool entity::Stroke::copyFrom ( const entity::ShaderedEntity2D * copy )

virtual

A method to be used to copy the input geometry data. It is assumed *this is empty.

Parameters

copy	is the source geometry to copy from.

Reimplemented from entity::ShaderedEntity2D.

§ denormalize()

void entity::Stroke::denormalize	(	osg::Vec3Array *	path,
		const osg::Vec3f &	center,
		double	scale
	)

protected

A method to denormalize the curve coordinates. Should be used after the curve fitting algorithm.

See also: normalize().

§ getCurvePoints()

osg::Vec3Array * entity::Stroke::getCurvePoints ( const osg::Vec3Array * bezierPts ) const

protected

Returns: Sampled points from provided set of bezier control points.

§ getEntityType()

cher::ENTITY_TYPE entity::Stroke::getEntityType ( ) const

virtual

A re-defined method of entity::Entity2D to obtain entity type.

Returns: entity type

Implements entity::ShaderedEntity2D.

§ getLength()

float entity::Stroke::getLength ( ) const

Returns: length of the stroke, which is measured as a largest dimention of the bounding box around the stroke.

§ getMeshRepresentation()

osg::Node * entity::Stroke::getMeshRepresentation ( ) const

A method that generates mesh representation of the stroke using Parallel Transport Algorithm.

Returns: pointer on the cretated mesh structure. The structure is not attached to the scene graph.

§ isLengthy()

bool entity::Stroke::isLengthy ( ) const

Returns: true if the stroke is longer than allowed threshold, false otherwise.

§ normalize()

double entity::Stroke::normalize	(	osg::Vec3Array *	path,
		const osg::Vec3f &	center
	)

protected

A method to make sure the curve is not too small, neither too large for a fitter tolerance level. Nomalization should be applied before the fitting algorithm, and then the result coordinates must get denrmalized back to their true size. The nornalization algorithm is as follows:

Find center of the points.
For each curve coordinate, substract a center coordinate from it.
The scale factor equals to all the squared point deviations devided by total number of the points.
Scale each coordinate by scale factor.
Parameters

path is the point array to normalize,

center is local 2d center (e.g., bounding box center).

Returns
scaling factor.

§ redefineToShader()

bool entity::Stroke::redefineToShader ( osg::MatrixTransform * t )

protectedvirtual

A method to tune the look of the stroke with smoother connections and thicker linewidth. So that to avoid broken and thin look of the default OpenGL functionality when using GL_LINE_STRIP_ADJACENCY and such.

Implements entity::ShaderedEntity2D.

§ redefineToShape()

bool entity::Stroke::redefineToShape ( osg::MatrixTransform * t = 0 )

virtual

A method that fits the stroke's points to a set of curve using Schneider's algorithm.

Parameters

t	is the Canvas matrix transform. If none is provided, the transform of the current canvas is taken.
tolerance	is the threshold fitting.

Returns: true upon success.

Implements entity::ShaderedEntity2D.

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

src/libSGEntities/Stroke.h
src/libSGEntities/Stroke.cpp

path	is the point array to normalize,
center	is local 2d center (e.g., bounding box center).

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

§ Stroke() [1/2]

§ Stroke() [2/2]

Member Function Documentation

§ appendPoint()

§ copyFrom()

§ denormalize()

§ getCurvePoints()

§ getEntityType()

§ getLength()

§ getMeshRepresentation()

§ isLengthy()

§ normalize()

§ redefineToShader()

§ redefineToShape()