The display functions provide an easy and fast way to display images. More...

Data Structures
struct	IC4_DISPLAY_STATS
	A structure containing display statistics. More...

struct	IC4_DISPLAY
	Represents a display that can be used to display images. More...

Macros
#define	IC4_WINDOW_HANDLE_NULL platform_specific
	An invalid window handle value.

Typedefs
typedef platform_specific	IC4_WINDOW_HANDLE
	A window handle to be used as parent.

typedef void(*	ic4_display_window_closed_handler) (struct IC4_DISPLAY pDisplay, void user_ptr)
	Function pointer for the window-closed handler.

typedef void(*	ic4_display_window_closed_deleter) (void *user_ptr)
	Function pointer for cleanup of the device-lost user data.

Enumerations
enum	IC4_DISPLAY_TYPE { IC4_DISPLAY_DEFAULT , IC4_DISPLAY_WIN32_OPENGL , IC4_DISPLAY_LINUX_GSTREAMER }
	Defines the possible display types. More...

enum	IC4_DISPLAY_RENDER_POSITION { IC4_DISPLAY_RENDER_POSITION_TOPLEFT , IC4_DISPLAY_RENDER_POSITION_CENTER , IC4_DISPLAY_RENDER_POSITION_STRETCH_TOPLEFT , IC4_DISPLAY_RENDER_POSITION_STRETCH_CENTER , IC4_DISPLAY_RENDER_POSITION_CUSTOM }
	Contains the possible display alignment and stretch modes. More...

Functions
bool	ic4_display_create (enum IC4_DISPLAY_TYPE type, IC4_WINDOW_HANDLE parent, struct IC4_DISPLAY **ppDisplay)
	Creates a new display.

struct IC4_DISPLAY *	ic4_display_ref (struct IC4_DISPLAY *pDisplay)
	Increases the display's internal reference count by one.

void	ic4_display_unref (struct IC4_DISPLAY *pDisplay)
	Decreases the display's internal reference count by one.

bool	ic4_display_display_buffer (struct IC4_DISPLAY pDisplay, const struct IC4_IMAGE_BUFFER buffer)
	Displays a specific image buffer.

bool	ic4_display_get_stats (struct IC4_DISPLAY pDisplay, struct IC4_DISPLAY_STATS stats)
	Queries statistics about a display.

bool	ic4_display_set_render_position (struct IC4_DISPLAY *pDisplay, enum IC4_DISPLAY_RENDER_POSITION pos, int left, int top, int width, int height)
	Configure the image scaling and alignment options for a display.

bool	ic4_display_event_add_window_closed (struct IC4_DISPLAY pDisplay, ic4_display_window_closed_handler handler, void user_ptr, ic4_display_window_closed_deleter deleter)
	Registers a callback to be called when the display is closed.

bool	ic4_display_event_remove_window_closed (struct IC4_DISPLAY pDisplay, ic4_display_window_closed_handler handler, void user_ptr)
	Unregisters a display-closed handler that was previously registered using ic4_display_event_add_window_closed().

Detailed Description

The display functions provide an easy and fast way to display images.

To create a display, call ic4_display_create().

Macro Definition Documentation

◆ IC4_WINDOW_HANDLE_NULL

#define IC4_WINDOW_HANDLE_NULL platform_specific

An invalid window handle value.

When passed to a function, this value specifies that no parent window is set.

The value of IC4_WINDOW_HANDLE_NULL is platform-specific.

Typedef Documentation

◆ ic4_display_window_closed_deleter

typedef void(* ic4_display_window_closed_deleter) (void *user_ptr)

Function pointer for cleanup of the device-lost user data.

Parameters

[in] user_ptr User data that was specified when calling ic4_grabber_event_add_device_lost()

◆ ic4_display_window_closed_handler

typedef void(* ic4_display_window_closed_handler) (struct IC4_DISPLAY *pDisplay, void *user_ptr)

Function pointer for the window-closed handler.

Parameters

[in]	pDisplay	Pointer to the display whose window was closed
[in]	user_ptr	User data that was specified when calling ic4_display_event_add_window_closed()

◆ IC4_WINDOW_HANDLE

typedef platform_specific IC4_WINDOW_HANDLE

A window handle to be used as parent.

The type of IC4_WINDOW_HANDLE is platform-specific.

Enumeration Type Documentation

◆ IC4_DISPLAY_RENDER_POSITION

enum IC4_DISPLAY_RENDER_POSITION

Contains the possible display alignment and stretch modes.

Enumerator
IC4_DISPLAY_RENDER_POSITION_TOPLEFT	Display images unscaled at the top left corner of the window.
IC4_DISPLAY_RENDER_POSITION_CENTER	Display images unscaled an the center of the window.
IC4_DISPLAY_RENDER_POSITION_STRETCH_TOPLEFT	Display images stretched at the top left corner of the window.
IC4_DISPLAY_RENDER_POSITION_STRETCH_CENTER	Display images stretched at the center of the window.
IC4_DISPLAY_RENDER_POSITION_CUSTOM	Display images at custom coordinates.

◆ IC4_DISPLAY_TYPE

enum IC4_DISPLAY_TYPE

Defines the possible display types.

Enumerator

IC4_DISPLAY_DEFAULT

Selects the platform's default display type.

For Windows, this is IC4_DISPLAY_WIN32_OPENGL.

For Linux, this is IC4_DISPLAY_LINUX_GSTREAMER.

IC4_DISPLAY_WIN32_OPENGL

Optimized OpenGL display for Windows platform.

IC4_DISPLAY_LINUX_GSTREAMER

Simple GStreamer-based display for Linux platform.

Function Documentation

◆ ic4_display_create()

bool ic4_display_create	(	enum IC4_DISPLAY_TYPE	type,
		IC4_WINDOW_HANDLE	parent,
		struct IC4_DISPLAY **	ppDisplay
	)

Creates a new display.

Parameters

[in]	type	The type of display to create
[in]	parent	Handle to the parent window to embed the display into.
[out]	ppDisplay	Pointer to receive the handle to the new display object. When the display is no longer required, release the object reference using ic4_display_unref().

Returns: true on success, otherwise false.
Use ic4_get_last_error() to query error information.

See also: ic4_display_unref

◆ ic4_display_display_buffer()

bool ic4_display_display_buffer	(	struct IC4_DISPLAY *	pDisplay,
		const struct IC4_IMAGE_BUFFER *	buffer
	)

Displays a specific image buffer.

Parameters

[in]	pDisplay	A display
[in]	buffer	The buffer to display

Remarks: It is not always necessary to call this function.
When a display is registered with a IC4_GRABBER using ic4_grabber_set_display(), images are displayed automatically.

Returns: true on success, otherwise false.
Use ic4_get_last_error() to query error information.

Remarks: When buffer is NULL, the display is cleared and will no longer display the previous buffer.

◆ ic4_display_event_add_window_closed()

bool ic4_display_event_add_window_closed	(	struct IC4_DISPLAY *	pDisplay,
		ic4_display_window_closed_handler	handler,
		void *	user_ptr,
		ic4_display_window_closed_deleter	deleter
	)

Registers a callback to be called when the display is closed.

Parameters

[in]	pDisplay	A display
[in]	handler	The function to be called when the display is closed
[in]	user_ptr	User data to be passed in calls to handler.
[in]	deleter	A function to be called when the handler was unregistered and the user_ptr will no longer be required. The deleter function can be used to release data associated with user_ptr. The deleter function will be called when the display-closed handler is unregistered, or the display object itself is destroyed.

Note: To unregister a display-closed handler, call ic4_display_event_remove_window_closed().

Returns: true on success, otherwise false.
Use ic4_get_last_error() to query error information.

◆ ic4_display_event_remove_window_closed()

bool ic4_display_event_remove_window_closed	(	struct IC4_DISPLAY *	pDisplay,
		ic4_display_window_closed_handler	handler,
		void *	user_ptr
	)

Unregisters a display-closed handler that was previously registered using ic4_display_event_add_window_closed().

Parameters

[in]	pDisplay	The display on which the callback is currently registered
[in]	handler	Pointer to the function to be unregistered
[in]	user_ptr	User data that the function was previously registered with

Note: The pair of handler and user_ptr has to be an exact match to the parameters used in the call to ic4_display_event_add_window_closed().

Returns: true on success, otherwise false.
Use ic4_get_last_error() to query error information.

◆ ic4_display_get_stats()

bool ic4_display_get_stats	(	struct IC4_DISPLAY *	pDisplay,
		struct IC4_DISPLAY_STATS *	stats
	)

Queries statistics about a display.

Parameters

[in]	pDisplay	A display
[out]	stats	Pointer to a IC4_DISPLAY_STATS structure receiving statistics about the display

Returns: true on success, otherwise false.
Use ic4_get_last_error() to query error information.

◆ ic4_display_ref()

struct IC4_DISPLAY * ic4_display_ref ( struct IC4_DISPLAY * pDisplay )

Increases the display's internal reference count by one.

Parameters

[in] pDisplay A pointer to a display

Returns: The pointer passed via pDisplay

Remarks: If pDisplay is NULL, the function returns NULL. An error value is not set.

See also: ic4_display_unref

◆ ic4_display_set_render_position()

bool ic4_display_set_render_position	(	struct IC4_DISPLAY *	pDisplay,
		enum IC4_DISPLAY_RENDER_POSITION	pos,
		int	left,
		int	top,
		int	width,
		int	height
	)

Configure the image scaling and alignment options for a display.

Parameters

[in]	pDisplay	A display
[in]	pos	The scaling and alignment mode to use
[in]	left	The left coordinate of the target rectangle inside the display window
[in]	top	The top coordinate of the target rectangle inside the display window
[in]	width	The width of the target rectangle inside the display window
[in]	height	The height of the target rectangle inside the display window

Remarks: The left, top, width and height parameters are ignored unless pos is IC4_DISPLAY_RENDER_POSITION_CUSTOM.

Returns: true on success, otherwise false.
Use ic4_get_last_error() to query error information.

◆ ic4_display_unref()

void ic4_display_unref ( struct IC4_DISPLAY * pDisplay )

Decreases the display's internal reference count by one.

If the reference count reaches zero, the object is destroyed.

Parameters

[in] pDisplay A pointer to a display

Remarks: If pDisplay is NULL, the function does nothing. An error value is not set.

See also: ic4_display_ref

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ IC4_WINDOW_HANDLE_NULL

Typedef Documentation

◆ ic4_display_window_closed_deleter

◆ ic4_display_window_closed_handler

◆ IC4_WINDOW_HANDLE

Enumeration Type Documentation

◆ IC4_DISPLAY_RENDER_POSITION

◆ IC4_DISPLAY_TYPE

Function Documentation

◆ ic4_display_create()

◆ ic4_display_display_buffer()

◆ ic4_display_event_add_window_closed()

◆ ic4_display_event_remove_window_closed()

◆ ic4_display_get_stats()

◆ ic4_display_ref()

◆ ic4_display_set_render_position()

◆ ic4_display_unref()