The basic structure used to hold the coordinates of an edge. More...

#include <libsswf.h>


Public Member Functions
	edge_t (const edge_t &edge)
	Copy an edge structure.
	edge_t (long x, long y, long ctrl_x, long ctrl_y)
	Constructs a curve edge structure.
	edge_t (long x, long y)
	Constructs a line edge structure.
	edge_t (void)
	Constructs a default edge structure.
bool	IsLine (void) const
	Check whether the edge represents a line (true) or a curve (false).
edge_t &	operator= (const edge_t &edge)
	Copy an edge structure.
Public Attributes
long	f_ctrl_x
	The control X coordinate or LONG_MIN.
long	f_ctrl_y
	The control Y coordinate or LONG_MIN.
long	f_x
	The X coordinate.
long	f_y
	The Y coordinate.

Detailed Description

This helper structure is used to hold edges internally. You can also use it to pass edges to an Edges object.

The points are all specified as two dimension coordinates in TWIPS (1/20^th of a pixel.)

Multiple points are specified as cumulative which means that the next point coordinates are added to the previous points coordinates. Thus a starting edge at (3, 7), followed by an edge at (9, 11) represents one point at (3, 7) and another at (12, 18).

Do not forget that this applies to control points as well. In an edge_t structure you first move to the (x, y) coordinate, and then to the (ctrl_x, ctrl_y) coordinates.

Note:: The fact that this structure is called Edges instead of Points is because of this fact. Edges coordinates are cumulative and not direct points. However, I most of the time will reference edges as points and vice versa.
For those of you who have played with a turtle under Logo, you can view this technique as if you were moving a turtle. It is very simiar (except that you do not have a direction since you move with relative coordinates.)

 ADVANCE [x1, y1]
 ADVANCE [ctrl_x1, ctrl_y1]
 ADVANCE [x2, y2]
 ADVANCE [ctrl_x2, ctrl_y2]
 ADVANCE [x3, y3]
 ADVANCE [ctrl_x3, ctrl_y3]
 ...

Warning:: This sub-structure is not currently accessible to the C library because it includes functions.

See also:: sswf::Edges

Constructor & Destructor Documentation

sswf::Edges::edge_t::edge_t ( void ) [inline]

The default constructor creates a line edge at coordinate (0, 0).

References f_ctrl_x, f_ctrl_y, f_x, and f_y.

sswf::Edges::edge_t::edge_t	(	long	x,
		long	y
	)			`[inline]`

This constructor creates a line edge at coordinate (x, y).

Parameters:

	x	The horizontal coordinate
	y	The vertical coordinate

References f_ctrl_x, f_ctrl_y, f_x, and f_y.

sswf::Edges::edge_t::edge_t	(	long	x,
		long	y,
		long	ctrl_x,
		long	ctrl_y
	)			`[inline]`

This constructor creates a curve edge at coordinate (x, y) and control point (ctrl_x, ctrl_y).

Parameters:

	x	The horizontal coordinate
	y	The vertical coordinate
	ctrl_x	The horizontal control coordinate
	ctrl_y	The vertical control coordinate

References f_ctrl_x, f_ctrl_y, f_x, and f_y.

sswf::Edges::edge_t::edge_t ( const edge_t & edge ) [inline]

The copy operator copies the input edge in 'this' edge.

Note:: It should not be necessary to make this copy operator explicit, but some older compilers have a hard time without it.

Parameters:

edge

The edge to copy in 'this' edge_t

References f_ctrl_x, f_ctrl_y, f_x, and f_y.

Member Function Documentation

sswf::Edges::edge_t::IsLine ( void ) const [inline]

This function returns true if one of the control point is set to LONG_MIN. You should use that function and not try to test yourself whether an edge represents a line or a curve.