gsCurveLoop< T > Class Template Reference

Detailed Description

template<class T>
class gismo::gsCurveLoop< T >

A closed loop given by a collection of curves.

The loop may be oriented clockwise (CW) or counterclockwise (CCW).

Template Parameters

T	coefficient type

Public Types
typedef memory::shared_ptr< gsCurveLoop >	Ptr
	Shared pointer for gsCurveLoop.
typedef memory::unique_ptr< gsCurveLoop >	uPtr
	Unique pointer for gsCurveLoop.

Public Member Functions
	gsCurveLoop ()
	Default empty constructor.
	gsCurveLoop (const std::vector< gsVector3d< T > * > points3D, const std::vector< bool > isConvex, T margin, gsVector3d< T > *outNormal)
	gsCurveLoop (const std::vector< T > angles3D, const std::vector< T > lengths3D, const std::vector< bool > isConvex, T margin, const bool unitSquare=false)
	gsCurveLoop (gsCurve< T > *cc)
	Constructor by one curve.
	gsCurveLoop (std::vector< gsCurve< T > * > const &curves)
	Constructor by a list of curves forming a loop.
isOn
returns true if the points in Parameters u are ON the curve ideally it should store in paramResult the parametric values associated to those points.
is_ccw
returns true if the curve is oriented counterclockwise

reverse
changes the orientation of the curve
gsCurve< T >::uPtr	singleCurve () const
	Return the curve-loop as a single new B-Spline curve.
std::ostream &	print (std::ostream &os) const
	Prints the object as a string.
gsMatrix< T >	normal (int const &c, gsMatrix< T > const &u)
uPtr	split (int startIndex, int endIndex, gsCurve< T > *newCurveThisFace, gsCurve< T > *newCurveNewFace)
std::vector< T >	lineIntersections (int const &direction, T const &abscissa)
int	numCurves () const
	get Number of curves
gsMatrix< T >	sample (int npoints=50, int numEndPoints=2) const
	Sample npoints uniformly distributed (in parameter domain) points on the loop.
std::vector< T >	domainSizes () const
	return a vector containing whose nth entry is the length of the domin of the nth curve.
gsMatrix< T >	splitCurve (size_t curveId, T lengthRatio=.5)
gsVector3d< T >	initFrom3DPlaneFit (const std::vector< gsVector3d< T > * > points3D, T margin)
	Initialize a curve loop from some 3d vertices by projecting them onto the plane of best fit and constructing a polygon.
bool	initFrom3DByAngles (const std::vector< gsVector3d< T > * > points3D, const std::vector< bool > isConvex, T margin)
void	initFromIsConvex (const std::vector< bool > isConvex, T margin)
	Initialize a curve loop from a list of bools indicating whether the corners are convex or not.
void	flip1 (T minu=0, T maxu=1)
	flip a curve loop in the u direction
static bool	approximatingPolygon (const std::vector< T > &signedAngles, const std::vector< T > &lengths, T margin, gsMatrix< T > &result)
static void	adjustPolygonToUnitSquare (gsMatrix< T > &corners, T const margin)

Constructor & Destructor Documentation

gsCurveLoop() [1/2]

template<class T >

gsCurveLoop	(	const std::vector< gsVector3d< T > * >	points3D,
		const std::vector< bool >	isConvex,
		T	margin,
		gsVector3d< T > *	outNormal
	)

Constructor from a sequence of points in 3D. Produces a polygon in 2D whose angles are in proportion to the corresponding angles in space. You need to pass in a sequence of bools indicating which angles are convex.

gsCurveLoop() [2/2]

template<class T >

gsCurveLoop	(	const std::vector< T >	angles3D,
		const std::vector< T >	lengths3D,
		const std::vector< bool >	isConvex,
		T	margin,
		const bool	unitSquare = false
	)

Constructor from a sequence of angles and lengths (measured in 3D). If unitSquare==true, when there are four vertices and isConvex are all true, then return the spline curve loop of degree 1 of the unit square with each edge being one spline curve.

Member Function Documentation

adjustPolygonToUnitSquare()

template<class T >

void adjustPolygonToUnitSquare ( gsMatrix< T > &  corners, T const  margin  )

static

Scale and shift a polygon (represented by a matrix whose rows are its corners so that it will be contained in the square [0, 1]x[0, 1]. Modifies the polygon in place. Specifying margin > 0 will make the polygon fit in the interior of the square.

approximatingPolygon()

template<class T >

bool approximatingPolygon ( const std::vector< T > &  signedAngles, const std::vector< T > &  lengths, T  margin, gsMatrix< T > &  result  )

static

Computes the corners of a polygon that matches the specified angles and relative side lengths as well as possible. Fits the resulting polygon inside the square [0, 1] x [0, 1]. Fills a gsmatrix whose rows are the corners of the polygon. Returns true on success.

initFrom3DByAngles()

template<class T >

bool initFrom3DByAngles	(	const std::vector< gsVector3d< T > * >	points3D,
		const std::vector< bool >	isConvex,
		T	margin
	)

Initialize a curve loop from some 3d vertices by trying to match the angles as well as possible. Return true on success.

lineIntersections()

template<class T >

std::vector< T > lineIntersections	(	int const &	direction,
		T const &	abscissa
	)

Computes the intersections with the axis-aligned line with constant value abscissa in direction.

normal()

template<class T >

gsMatrix< T > normal	(	int const &	c,
		gsMatrix< T > const &	u
	)

Computes the normal vector of curve i at parameter u (is outer in case of CCW orientation)

split()

template<class T >

gsCurveLoop< T >::uPtr split	(	int	startIndex,
		int	endIndex,
		gsCurve< T > *	newCurveThisFace,
		gsCurve< T > *	newCurveNewFace
	)

Split a second curve loop off from this one by inserting two new curves. Curve startIndex will be included in the new loop, while curve endIndex will be kept in the original loop.

splitCurve()

template<class T >

gsMatrix< T > splitCurve	(	size_t	curveId,
		T	lengthRatio = .5
	)

split the curveId^th curve in the loop into two curves. Return the point where it splits.

Parameters

curveId
lengthRatio	the ratio between the lengths of the first new curve and that of the original curve