vcg::Trackball Class Reference

The manipulator manager system. More...

#include <trackball.h>

Inheritance diagram for vcg::Trackball:

Public Types
enum	Button { BUTTON_NONE = 0x0000, BUTTON_LEFT = 0x0001, BUTTON_MIDDLE = 0x0002, BUTTON_RIGHT = 0x0004, WHEEL = 0x0008, KEY_SHIFT = 0x0010, KEY_CTRL = 0x0020, KEY_ALT = 0x0040, HANDLE = 0x0080, MODIFIER_MASK = 0x00FF, KEY_UP = 0x0100, KEY_DOWN = 0x0200, KEY_LEFT = 0x0400, KEY_RIGHT = 0x0800, KEY_PGUP = 0x1000, KEY_PGDOWN = 0x2000 }
	The componibile states of the manipulator system. More...
Public Member Functions
void	Animate (unsigned int msec=0)
void	Apply ()
	Old application of the transformation.
void	Apply (bool Draw)
	Apply the current transformation on the OpenGL modelview matrix.
void	ApplyInverse ()
	Apply the inverse of current transformation on the OpenGL modelview matrix.
void	Back ()
	Currently not in use.
void	ButtonDown (Button button, unsigned int msec=0)
	Interface function relative to key up event in QT/SDL.
void	ButtonUp (Button button)
	Interface function relative to key down event in QT/SDL.
void	ClearModes ()
	clear the modes map. Taking the right care of not doubledeleting anything.
void	DrawPostApply ()
	Draw the current manipulator.
void	Forward ()
	Currently not in use.
void	GetView ()
	Initialize the camera instance.
void	HistorySize (int lenght)
	Currently not in use.
void	Home ()
	Currently not in use.
Matrix44f	InverseMatrix () const
bool	IsAnimating (unsigned int msec=0)
bool	IsSpinnable ()
	Currently not in use.
bool	IsSpinning ()
	Currently not in use.
Matrix44f	Matrix () const
void	MouseDown (int x, int y, int button)
	Interface function relative to mouse down event in QT/SDL.
void	MouseDown (int button)
	Interface function relative to mouse down event in QT/SDL.
void	MouseMove (int x, int y)
	Interface function relative to mouse down event in QT/SDL.
void	MouseUp (int x, int y, int button)
	Interface function relative to mouse down event in QT/SDL.
void	MouseWheel (float notch, int button)
	Interface function relative to mouse down event in QT/SDL.
void	MouseWheel (float notch)
	Old interface function relative to mouse down event in QT/SDL.
void	Reset ()
	Reset the transformation and every mapped manipulator.
void	Scale (const float f)
	Apply a scaling on the current transformation.
void	SetCurrentAction ()
	Prepare Trackball and every mapped TrackMode for an user action.
void	setDefaultMapping ()
	Reset modes to default mapping.
void	SetFixedTimesteps (bool mode)
bool	SetFromAscii (const char *st)
	Loads current status from an ascii stings.
void	SetIdentity ()
	Reset the trackball.
void	SetPosition (const Point3f &c, int millisec=0)
	Set the position of the trackball.
void	SetScale (const float s)
	Currently not in use.
void	SetSensitivity (float s)
	Currently not in use.
void	SetSpinnable (bool on)
void	SetSpinning (Quaternionf &spin)
	Currently not in use.
void	SetTransform (const Transform &transform, int millisec=0)
	Currently not in use.
void	StopSpinning ()
	Currently not in use.
void	Store ()
	Currently not in use.
void	ToAscii (char *st)
	Stores current status into an ascii stings.
	Trackball ()
	The constructor.
void	Translate (Point3f tr)
	Apply a translation on the current transformation.
void	Undo ()
	Undo function for manipulator system.
	~Trackball ()
	The destructor.
Public Attributes
int	button_mask
	Currently not in use.
View< float >	camera
	The reference for point projection and unprojection from screen space to modelspace.
int	current_button
	Current state composition. Note: mask with MODIFIERS to get modifier buttons only.
TrackMode *	current_mode
	The selected manipulator.
bool	dragging
	Currently not in use.
std::list< Transform >	history
	Currently not in use.
int	history_size
	Currently not in use.
std::vector< Point3f >	Hits
	Currently not in use.
TrackMode *	idle_and_keys_mode
TrackMode *	inactive_mode
	The inactive manipulator. It is drawn when Trackball is inactive.
Point3f	last_point
	Mouse cursor coordinates before current action.
unsigned int	last_time
Similarityf	last_track
	Transformation before current user action.
Similarityf	last_view
	Currently not in use.
std::map< int, TrackMode * >	modes
	The manipulator mapping. Needs to be explicitally managed for custom mappings.
Quaternionf	spin
	Currently not in use.
bool	spinnable
	Currently not in use.
bool	spinning
	Currently not in use.
Similarityf	undo_track
	track after an Undo() call.
Private Member Functions
Trackball	operator= (const Trackball &)
void	Sync (unsigned int msec)
Private Attributes
bool	fixedTimestepMode
Friends
class	TrackMode
	Manipulators needs full access to this class.

Detailed Description

The manipulator manager system.

Short usage note:

Center specify the center of rotation and scaling of the trackball and usually is set by the program and do not interactively change
Radius specify the radius of the interactive ball shaped icon to specify rotation. It is in absolute unit.
Like the previous one it is not changed during interaction.

When you specify a translation with the trackball the trackball center remain unchanged, in other words it means that the object move out of the trackball icon. Similarly when you apply a scaling the size of the manipulator icon do not change.

Typical use:

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60, float(width())/float(height()), 1, 100);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0,0,3,   0,0,0,   0,1,0)

trackball.center=Point3f(0, 0, 0);
trackball.radius= 1;

trackball.GetView();
trackball.Apply(true); //false if you want an invisible trackball

float d=1.0f/mesh.bbox.Diag();
glScale(d);
glTranslate(-mesh.bbox.Center());
mesh->Render();

Note on the typical use:

Perspective and glulookat are choosed to frame the origin centered 1-radius trackball.
The final scale and translate are just to fit a generic mesh to the 1sized origin centered where the trackball stays box.
The trackball works also on Orthographic projections but that are not centered around origin (just move it back along the Z)

Definition at line 167 of file gui/trackball.h.

Member Enumeration Documentation

enum vcg::Trackball::Button

The componibile states of the manipulator system.

Enumerator:

BUTTON_NONE	No button or key pressed.
BUTTON_LEFT	Left mouse button pressed.
BUTTON_MIDDLE	Middle mouse button pressed.
BUTTON_RIGHT	Right mouse button pressed.
WHEEL	Mouse wheel activated.
KEY_SHIFT	Shift key pressed.
KEY_CTRL	Ctrl key pressed.
KEY_ALT	Alt key pressed.
HANDLE	Application-defined state activated.
MODIFIER_MASK	(mask to get modifiers only)
KEY_UP	Up directional key.
KEY_DOWN	Down directional key.
KEY_LEFT	Left directional key.
KEY_RIGHT	Right directional key.
KEY_PGUP	PageUp directional key.
KEY_PGDOWN	PageDown directional key.

Definition at line 171 of file gui/trackball.h.

Constructor & Destructor Documentation

Trackball::Trackball ( )

The constructor.

Initialize the internal state with default values and call setDefaultMapping().

Definition at line 127 of file trackball.cpp.

Trackball::~Trackball ( )

The destructor.

Warning:: The destructor does not deallocate the memory allocated by setDefaultMapping(), because the application can change the modes map. This can lead to small memory leaks, so please explicitally delete any manipulator in the modes map if you are going to repeatly allocate and deallocate Trackball instances.

Definition at line 133 of file trackball.cpp.

Member Function Documentation

void Trackball::Animate ( unsigned int msec = 0 )

Definition at line 414 of file trackball.cpp.

void Trackball::Apply ( )

Old application of the transformation.

Warning:: This function does not call DrawPostApply() after the application.

Definition at line 197 of file trackball.cpp.

void Trackball::Apply ( bool Draw )

Apply the current transformation on the OpenGL modelview matrix.

Parameters:

Draw

true if has to call DrawPostApply() after the application.

Definition at line 203 of file trackball.cpp.

void Trackball::ApplyInverse ( )

Apply the inverse of current transformation on the OpenGL modelview matrix.

Definition at line 211 of file trackball.cpp.

void Trackball::Back ( )

Currently not in use.

Definition at line 517 of file trackball.cpp.

void Trackball::ButtonDown	(	Trackball::Button	button,
		unsigned int	msec = `0`
	)

Interface function relative to key up event in QT/SDL.

Parameters:

button

the new state.

Definition at line 468 of file trackball.cpp.

void Trackball::ButtonUp ( Trackball::Button button )

Interface function relative to key down event in QT/SDL.

Parameters:

button

the new state.

Definition at line 484 of file trackball.cpp.

void Trackball::ClearModes ( )

clear the modes map. Taking the right care of not doubledeleting anything.

Definition at line 139 of file trackball.cpp.

void Trackball::DrawPostApply ( )

Draw the current manipulator.

Call the draw function of the current manipulator. If no manipulator is selected call the draw function of the manipulator associated to inactive_mode.

Warning:: This function assumes that the OpenGL modelview matrix has been initialized with Apply ().

Definition at line 189 of file trackball.cpp.

void Trackball::Forward ( )

Currently not in use.

Definition at line 518 of file trackball.cpp.

void Trackball::GetView ( )

Initialize the camera instance.

Definition at line 184 of file trackball.cpp.

void Trackball::HistorySize ( int lenght )

Currently not in use.

Definition at line 520 of file trackball.cpp.

void Trackball::Home ( )

Currently not in use.

Definition at line 519 of file trackball.cpp.

Matrix44f Trackball::InverseMatrix ( ) const

Definition at line 233 of file trackball.cpp.

bool Trackball::IsAnimating ( unsigned int msec = 0 )

Definition at line 397 of file trackball.cpp.

bool Trackball::IsSpinnable ( )

Currently not in use.

Returns:: A meaningless boolean value.

Definition at line 507 of file trackball.cpp.

bool Trackball::IsSpinning ( )

Currently not in use.

Returns:: A meaningless boolean value.

Definition at line 512 of file trackball.cpp.

Matrix44f Trackball::Matrix ( ) const

Definition at line 218 of file trackball.cpp.

void Trackball::MouseDown	(	int	x,
		int	y,
		int	button
	)