Extended structure used set and get callback functions. More...

Data Fields
int	major

int	minor

void *	userData

INT16(*	setup_cal_display_hook )(void *userData)

INT16(*	exit_cal_display_hook )(void *userData)

INT16(*	setup_image_display_hook )(void *userData, INT16 width, INT16 height)

INT16(*	image_title_hook )(void userData, char title)

INT16(*	draw_image )(void userData, INT16 width, INT16 height, byte pixels)

INT16(*	exit_image_display_hook )(void *userData)

INT16(*	clear_cal_display_hook )(void *userData)

INT16(*	erase_cal_target_hook )(void *userData)

INT16(*	draw_cal_target_hook )(void *userData, float x, float y)

INT16(*	play_target_beep_hook )(void *userData, EL_CAL_BEEP beep_type)

INT16(*	get_input_key_hook )(void userData, InputEvent event)

INT16(*	alert_printf_hook )(void userData, const char msg)

Detailed Description

Extended structure used set and get callback functions.

Structure used set and get callback functions so that the calibration graphics can be drawn.

/sa setup_graphic_hook_functions( )

Field Documentation

INT16( * alert_printf_hook) (void *userData, const char *msg)

Called by alert_printf( ). Defaults to the MessageBox( ) function, in Windows. Prints to standard error in macOS and Linux.

Parameters

userData	User context data set on userData field of HOOKFCNS2.
msg	The message that is displayed.

Returns: 0 upon success.

INT16( * clear_cal_display_hook) (void *userData)

Called to clear the calibration display.

Parameters

userData User context data set on userData field of HOOKFCNS2.

Returns: 0 upon success.

INT16( * draw_cal_target_hook) (void *userData, float x, float y)

Call to draw a gaze target for calibration, validation or drift correction.

Parameters

userData	User context data set on userData field of HOOKFCNS2.
x	x-axis coordinate of the target.
y	y-axis coordinate of the target.

Returns: 0 upon success.

Remarks: The x and y values are relative to those that were sent to the tracker by the 'screen_pixel_coords' command.

INT16( * draw_image) (void *userData, INT16 width, INT16 height, byte *pixels)

Called to supply the image.

Parameters

userData	User context data set on userData field of HOOKFCNS2.
width	width of the picture.
height	height of the picture.
pixels	pixels pointer to the pixel data. The size of the pixel data can be calculate by widthheight4. The image comes in RGBA(network order) format.

Returns: 0 upon success.

INT16( * erase_cal_target_hook) (void *userData)

Erases the target that was drawn by the last call to draw_cal_target.

Parameters

userData User context data set on userData field of HOOKFCNS2.

Returns: 0 upon success.

INT16( * exit_cal_display_hook) (void *userData)

Called to release the resources that are not used after calibration.

Parameters

userData User context data set on userData field of HOOKFCNS2.

Returns: 0 upon success.

INT16( * exit_image_display_hook) (void *userData)

Called to notify when the camera setup is complete. Any resources that are allocated in setup_image_display( ) may be released by this function.

Parameters

userData User context data set on userData field of HOOKFCNS2.

Returns: 0 upon success.

INT16( * get_input_key_hook) (void *userData, InputEvent *event)

Called to check for keyboard input.

Parameters

[in]	userData	User context data set on userData field of HOOKFCNS2.
[out]	event	Returns the new state of the keyboard.

Returns: 1 when a key changed state, otherwise 0. -1 on error.

Remarks: Special keys and modifiers should match the following code.

Special keys:

#define F1_KEY    0x3B00
#define F2_KEY    0x3C00
#define F3_KEY    0x3D00
#define F4_KEY    0x3E00
#define F5_KEY    0x3F00
#define F6_KEY    0x4000
#define F7_KEY    0x4100
#define F8_KEY    0x4200
#define F9_KEY    0x4300
#define F10_KEY   0x4400
#define PAGE_UP    0x4900
#define PAGE_DOWN  0x5100
#define CURS_UP    0x4800
#define CURS_DOWN  0x5000
#define CURS_LEFT  0x4B00
#define CURS_RIGHT 0x4D00
#define ESC_KEY   0x001B
#define ENTER_KEY 0x000D

One needn't change the modifier value when using SDL, as it will already match the desired value.

#define ELKMOD_NONE   0x0000
#define ELKMOD_LSHIFT 0x0001
#define ELKMOD_RSHIFT 0x0002
#define ELKMOD_LCTRL  0x0040
#define ELKMOD_RCTRL  0x0080
#define ELKMOD_LALT   0x0100
#define ELKMOD_RALT   0x0200
#define ELKMOD_LMETA  0x0400
#define ELKMOD_RMETA  0x0800
#define ELKMOD_NUM    0x1000
#define ELKMOD_CAPS   0x2000
#define ELKMOD_MODE   0x4000

INT16( * image_title_hook) (void *userData, char *title)

Called to update the image title.

Parameters

userData	User context data set on userData field of HOOKFCNS2.
title	The text that will be rendered and printed by the image.

Returns: 0 upon success.

int major

Major version. At the moment the version number must be set to 1.

int minor

Minor version. At the moment the version number must be set to 0.

INT16( * play_target_beep_hook) (void *userData, EL_CAL_BEEP beep_type)

Called to signal audibly that a new target has been presented.

Parameters

userData	User context data set on userData field of HOOKFCNS2.
beep_type	Specifies what sound to play, from the EL_CAL_BEEP enumeration.

Returns: 0 upon success.

INT16( * setup_cal_display_hook) (void *userData)

Called before any calibration routine is started to set up the calibration/validation display.

Parameters

userData User context data set on userData field of HOOKFCNS2.

Returns: 0 upon success.

INT16( * setup_image_display_hook) (void *userData, INT16 width, INT16 height)

Initialises the resources that are required for camera setup.

Parameters

userData	User context data set on userData field of HOOKFCNS2.
width	width of the source image to expect.
height	height of the source image to expect.

Returns: -1 on failure
0 success with support for drawing single size camera images
1 success with support for drawing variable size camera images, for high resolution global camera images from newer EyeLink models.

void* userData

The value set here will be passed to every single call back functions.

Data Fields

Detailed Description

Field Documentation