The area constrained manipulator. More...

#include <trackmode.h>

Inheritance diagram for vcg::AreaMode:

Public Member Functions
void	Apply (Trackball *trackball, Point3f new_point)
	Apply a translation, function of the user mouse drag action.
	AreaMode (const std::vector< Point3f > &pts)
	The constructor.
void	Draw (Trackball *trackball)
	Render this manipulator.
bool	isSticky ()
	The (non) avaibility to manipulator changes inside an action.
const char *	Name ()
	Return this manipulator's name.
void	Reset ()
	The reset function.
void	SetAction ()
	The begin action function.
Point3f	SetStartNear (Point3f p)
	Try to set the inital point.
void	Undo ()
	The undo function.
Private Member Functions
void	Init (const std::vector< Point3f > &pts)
	The data initializer.
bool	Inside (Point3f point)
	Point in Polygon test.
Point3f	Move (Point3f start, Point3f end)
	Try to move the object inside the polygon.
Private Attributes
bool	begin_action
	True in time inteval between a call to SetAction () and a call to Apply()
Point3f	delta_mouse
	The screen space differenve between the object and the cursor during an action.
int	first_coord_kept
	One of the two dimensions used during the point in polygon test.
Point3f	initial_status
	The initial status.
float	min_side_length
	The length of the shortest border.
Point3f	old_status
	The old status.
std::vector< Point3f >	path
	Current action's object trace.
Plane3f	plane
	The polygon plane.
std::vector< Point3f >	points
	The vertexes vector.
Point3f	rubberband_handle
	The rubberband handle (current destination in Move())
int	second_coord_kept
	One of the two dimensions used during the point in polygon test.
Point3f	status
	The current status.
bool	undo_begin_action
	begin_action after an Undo() call.
Point3f	undo_delta_mouse
	delta_mouse after an Undo() call.
Point3f	undo_old_status
	old_status after an Undo() call.
size_t	undo_path_index
	path endpoint after an Undo() call.
Point3f	undo_rubberband_handle
	rubberband_handle after an Undo() call.
Point3f	undo_status
	status after an Undo() call.

Detailed Description

The area constrained manipulator.

This manipulator moves the object inside a poligonal area.

The user can drag the object inside a planar area, defined by a polygon. The polygon can be non convex, and is specified with a vector of vertexes.

If the object's trajectory intersects some poligon side, it tries to slide around it, in a "rubber band flavoured" way.

The object is assumed to initially be on the same position of the first vertex.

This is a stateful manipulator, result of the Apply function is determined by the objects's position inside the area and by the mouse coordinates.

Definition at line 861 of file trackmode.h.

Constructor & Destructor Documentation

vcg::AreaMode::AreaMode ( const std::vector< Point3f > & pts ) [inline]

The constructor.

From the given vector, is calculated the plane of the polygon, then every point in the vector is projected on this plane.

The vector passed to build the polygon is copied locally.

Warning:: The vector is assumed to be formed of non collinear points.; The polygon is not assumed to have 0-length sides, so please do not add a copy of the first point on the end of the vector.

Parameters:

pts	the vertexes vector.

Definition at line 876 of file trackmode.h.

Member Function Documentation

void AreaMode::Apply	(	Trackball *	trackball,
		Point3f	new_point
	)		`[virtual]`

Apply a translation, function of the user mouse drag action.

The manipulated object is moved inside the poligon. This function implements an algorithm that makes the object try to slide around the polygon borders.

Parameters:

trackball	the manipulator manager.
new_point	the new mouse pointer coordinate.

Reimplemented from vcg::TrackMode.

Definition at line 520 of file trackmode.cpp.

void AreaMode::Draw ( Trackball * trackball ) [virtual]

Render this manipulator.

Parameters:

trackball the manipulator manager.

Reimplemented from vcg::TrackMode.

Definition at line 680 of file trackmode.cpp.

void AreaMode::Init ( const std::vector< Point3f > & pts ) [private]

The data initializer.

Initialize the internal state and checks params validity.

Parameters:

pts	The polygon vertexes.

Definition at line 466 of file trackmode.cpp.

bool AreaMode::Inside ( Point3f point ) [private]

Point in Polygon test.

Checks if a given point relies inside the poligon area, using the ray tracing algorithm, linear in the number of vertexes.

Parameters:

point The point to test.

Returns:: true if the point is inside the polygon, false otherwise.

Definition at line 619 of file trackmode.cpp.

bool AreaMode::isSticky ( ) [virtual]

The (non) avaibility to manipulator changes inside an action.

This manipulator has an internal state and does not allow a switch in the middle of a function.

Returns:: The costant boolean true.

Reimplemented from vcg::TrackMode.

Definition at line 666 of file trackmode.cpp.

Point3f AreaMode::Move	(	Point3f	start,
		Point3f	end
	)		`[private]`

Try to move the object inside the polygon.

Given a point inside the area and a destination in the poligon plane, try to move the point toward the destination, sliding on any evenual border of the polygon. The object can be imagined tied with a rubber attached to destination, so it won't go back from it to slide around a border.

The algorithm is quadratic in the number of vertexes (worst case, really really unlikely).

Parameters:

start	the starting point assumed inside.
end	the destination assumed in the plane.

Returns:: the final move vector.

Definition at line 555 of file trackmode.cpp.

const char* vcg::AreaMode::Name ( ) [inline, virtual]

Return this manipulator's name.

Returns:: the constant string "AreaMode"

Reimplemented from vcg::TrackMode.

Definition at line 886 of file trackmode.h.

void AreaMode::Reset ( ) [virtual]

The reset function.

This function reset the object position to the initial point.

Reimplemented from vcg::TrackMode.

Definition at line 514 of file trackmode.cpp.

void AreaMode::SetAction ( ) [virtual]

The begin action function.

This function is to be called at the begin of an user action.

Reimplemented from vcg::TrackMode.

Definition at line 545 of file trackmode.cpp.

Point3f AreaMode::SetStartNear ( Point3f p )

Try to set the inital point.

This function try to set the starting point in the point passed as parameter, if the point passed does not reside in the area, the start is put in the closest point on it.

Parameters: