CVD: CVD::VideoDisplay Class Reference

VideoDisplay maintains for you the mapping between your choice of local GL co-ordinates, and image co-ordinates and provides functions for converting between the two. It does not, however, manage any X events, for example resize or redraw events. To develop a more sophisticated display window, you must select which XEvents to monitor using select_events() and then poll using pending() and use get_event() to handle events.

Constructor & Destructor Documentation

CVD::VideoDisplay::VideoDisplay	(	double	left,
		double	top,
		double	right,
		double	bottom,
		double	scale = `1`,
		int *	visualAttr = `defAttr`
	)

Construct (and display) a display window.

Parameters:

	left	The local GL co-ordinate of the left of the window
	top	The local GL co-ordinate of the top of the window
	right	The local GL co-ordinate of the right of the window
	bottom	The local GL co-ordinate of bottom of the window
	scale	The number of image pixels per GL unit (default 1:1)
	visualAttr	The attributes passed to glXChooseVisual

CVD::VideoDisplay::VideoDisplay	(	ImageRef	size,
		double	scale = `1`,
		int *	visualAttr = `defAttr`
	)

Construct (and display) a display window.

Parameters:

	size	The GL co-ordinate window goes from (0,0) to (size.x, size.y)
	scale	The number of image pixels per GL unit (default 1:1)
	visualAttr	The attributes passed to glXChooseVisual

CVD::VideoDisplay::~VideoDisplay ( )

Destructor. This also removes the window from the display.

Member Function Documentation

void CVD::VideoDisplay::set_title ( const std::string & s )

Set the window title.

Parameters:

The new title

int CVD::VideoDisplay::get_fd ( ) [inline]

Returns the connection number for this display.

Definition at line 115 of file videodisplay.h.

void CVD::VideoDisplay::select_events ( long event_mask )

Select which X events to handle (by default, nothing is handled).

Parameters:

event_mask

ORed list of XEvents to handle

void CVD::VideoDisplay::get_event ( XEvent * event )

Get the next X event from the queue by calling XNextEvent.

If the queue is empty, this function blocks until the next event

Parameters:

event

The next event

void CVD::VideoDisplay::locate_display_pointer	(	int &	x,
		int &	y
	)

Where is the mouse pointer in the window?

Parameters:

	x	The x co-ordinate
	y	The y co-ordinate

void CVD::VideoDisplay::locate_video_pointer	(	double &	x,
		double &	y
	)

Where is the mouse pointer in local GL co-ordinates?

Parameters:

	x	The x co-ordinate
	y	The y co-ordinate

void CVD::VideoDisplay::flush ( )

Flushes the output buffer by calling XFlush.

int CVD::VideoDisplay::pending ( )

How many events are waiting the queue?

void CVD::VideoDisplay::set_zoom	(	double	left,
		double	top,
		double	right,
		double	bottom,
		double	scale
	)

Set the desired mapping between local GL and image co-ordinates.

Parameters:

	left	The local GL co-ordinate of the left of the window
	top	The local GL co-ordinate of the top of the window
	right	The local GL co-ordinate of the right of the window
	bottom	The local GL co-ordinate of bottom of the window
	scale	The number if image pixels per GL unit

Referenced by zoom_reset().

void CVD::VideoDisplay::zoom_in	(	double	cx,
		double	cy,
		double	factor = `2`
	)

Change the image mapping to zoom in around the specified point.

Parameters:

	cx	The x co-ordinate of the zoom centre
	cy	The y co-ordinate of the zoom centre
	factor	The zoom factor (default 2)

Referenced by zoom_out().

void CVD::VideoDisplay::zoom_out	(	double	cx,
		double	cy,
		double	factor = `2`
	)			`[inline]`

Change the image mapping to zoom out around the specified point.

Parameters:

	cx	The x co-ordinate of the zoom centre
	cy	The y co-ordinate of the zoom centre
	factor	The zoom factor (default 2)

Definition at line 152 of file videodisplay.h.

References zoom_in().

void CVD::VideoDisplay::zoom_reset ( ) [inline]

Reset the image mapping to that when the VideoDisplay was created.

Definition at line 155 of file videodisplay.h.

References set_zoom().

double CVD::VideoDisplay::video_width ( ) const [inline]

What is the width of the local GL co-ordinates displayed?

Definition at line 159 of file videodisplay.h.

double CVD::VideoDisplay::video_height ( ) const [inline]

What is the height of the local GL co-ordinates displayed?

Definition at line 161 of file videodisplay.h.

void CVD::VideoDisplay::display_to_video	(	int	dx,
		int	dy,
		double &	vx,
		double &	vy
	)

Convert image co-ordinates into local GL co-ordinates.

Parameters:

	dx	The image x co-ordinate to convert
	dy	The image y co-ordinate to convert
	vx	The returned local GL x co-ordinate
	vy	The returned local GL y co-ordinate

void CVD::VideoDisplay::video_to_display	(	double	dx,
		double	dy,
		int &	vx,
		int &	vy
	)

Convert local GL co-ordinates into image co-ordinates.

Parameters:

	dx	The local GL x co-ordinate to convert
	dy	The local GL y co-ordinate to convert
	vx	The returned image x co-ordinate
	vy	The returned image y co-ordinate

void CVD::VideoDisplay::make_current ( )

Make this window the current GL context.

If there is more than one GL window being used in your program, this function should be called before drawing to ensure you draw to the correct window.

void CVD::VideoDisplay::swap_buffers ( )

Swap the front and back GL buffers.

This calls glXSwapBuffers for the current context.

Display* CVD::VideoDisplay::display ( ) [inline]

What is my display?

Definition at line 185 of file videodisplay.h.

Window CVD::VideoDisplay::window ( ) [inline]

Which is my window?

Definition at line 187 of file videodisplay.h.

Friends And Related Function Documentation

int defAttr[] [related]

The default GLX display request, corresponding to the minimum specification Gl display visual (8-bit colour).

Definition at line 76 of file videodisplay.h.


Public Member Functions
	VideoDisplay (double left, double top, double right, double bottom, double scale=1, int *visualAttr=defAttr)
	VideoDisplay (ImageRef size, double scale=1, int *visualAttr=defAttr)
	~VideoDisplay ()
void	set_title (const std::string &s)
int	get_fd ()
void	select_events (long event_mask)
void	get_event (XEvent *event)
void	locate_display_pointer (int &x, int &y)
void	locate_video_pointer (double &x, double &y)
void	flush ()
int	pending ()
void	set_zoom (double left, double top, double right, double bottom, double scale)
void	zoom_in (double cx, double cy, double factor=2)
void	zoom_out (double cx, double cy, double factor=2)
void	zoom_reset ()
double	video_width () const
double	video_height () const
void	display_to_video (int dx, int dy, double &vx, double &vy)
void	video_to_display (double dx, double dy, int &vx, int &vy)
void	make_current ()
void	swap_buffers ()
Display *	display ()
Window	window ()
Related Functions
(Note that these are not member functions.)
int	defAttr []

CVD::VideoDisplay Class Reference
[GL helper functions and classes.]

Detailed Description

Public Member Functions

Related Functions

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

CVD::VideoDisplay Class Reference [GL helper functions and classes.]

Detailed Description

Public Member Functions

Related Functions

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

CVD::VideoDisplay Class Reference
[GL helper functions and classes.]