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

#include <videodisplay.h>

Public Member Functions
Display *	display ()
	What is my display?
void	display_to_video (int dx, int dy, double &vx, double &vy)
void	flush ()
	Flushes the output buffer by calling XFlush.
void	get_event (XEvent *event)
int	get_fd ()
	Returns the connection number for this display.
void	locate_display_pointer (int &x, int &y)
void	locate_video_pointer (double &x, double &y)
void	make_current ()
int	pending ()
	How many events are waiting the queue?
void	select_events (long event_mask)
void	set_title (const std::string &s)
void	set_zoom (double left, double top, double right, double bottom, double scale)
void	swap_buffers ()
double	video_height () const
	What is the height of the local GL co-ordinates displayed?
void	video_to_display (double dx, double dy, int &vx, int &vy)
double	video_width () const
	What is the width of the local GL co-ordinates displayed?
	VideoDisplay (ImageRef size, double scale=1, int *visualAttr=defAttr)
	VideoDisplay (double left, double top, double right, double bottom, double scale=1, int *visualAttr=defAttr)
Window	window ()
	Which is my window?
void	zoom_in (double cx, double cy, double factor=2)
void	zoom_out (double cx, double cy, double factor=2)
void	zoom_reset ()
	Reset the image mapping to that when the VideoDisplay was created.
	~VideoDisplay ()
	Destructor. This also removes the window from the display.
Private Member Functions
void	init (double, double, double, double, double, int *visualAttr)
int	operator= (VideoDisplay &copyof)
	VideoDisplay (VideoDisplay &copyof)
Private Attributes
double	my_bottom
Colormap	my_cmap
Display *	my_display
GLXContext	my_glx_context
double	my_left
double	my_orig_bottom
double	my_orig_left
double	my_orig_right
double	my_orig_scale
double	my_orig_top
bool	my_positive_down
bool	my_positive_right
double	my_right
double	my_scale
double	my_top
XVisualInfo *	my_visual
Window	my_window
Related Functions
(Note that these are not member functions.)
int	defAttr []

Detailed Description

A cheap and cheerful GL display window using X and the GLX library. 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.

Definition at line 87 of file videodisplay.h.

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.

CVD::VideoDisplay::VideoDisplay ( VideoDisplay & copyof ) [private]

Member Function Documentation

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

What is my display?

Definition at line 185 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::flush ( )

Flushes the output buffer by calling XFlush.

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

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

Returns the connection number for this display.

Definition at line 115 of file videodisplay.h.

void CVD::VideoDisplay::init	(	double	,
		double	,
		double	,
		double	,
		double	,
		int *	visualAttr
	)			`[private]`

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::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.

int CVD::VideoDisplay::operator= ( VideoDisplay & copyof ) [private]

int CVD::VideoDisplay::pending ( )

How many events are waiting the queue?

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::set_title ( const std::string & s )

Set the window title.

Parameters:

s

The new title

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