An abstraction for display, keyboard and mouse. More...

#include <core/gp_types.h>
#include <core/gp_pixmap.h>
#include <utils/gp_timer.h>
#include <utils/gp_list.h>
#include <utils/gp_poll.h>
#include <input/gp_ev_queue.h>
#include <input/gp_task.h>
#include <backends/gp_types.h>

Data Structures
struct	gp_backend
	A backend. More...

Enumerations
enum	gp_backend_attr { GP_BACKEND_ATTR_SIZE , GP_BACKEND_ATTR_TITLE , GP_BACKEND_ATTR_FULLSCREEN , GP_BACKEND_ATTR_CURSOR , GP_BACKEND_ATTR_BACKLIGHT }
	Backend attributes. More...

enum	gp_backend_ret { GP_BACKEND_OK = 0 , GP_BACKEND_OFF = 0 , GP_BACKEND_ON = 1 , GP_BACKEND_NOTSUPP = -1 , GP_BACKEND_EINVAL = -2 , GP_BACKEND_CONNERR = -3 }
	A return value from the backend set_attr callback. More...

enum	gp_backend_fullscreen_req { GP_BACKEND_FULLSCREEN_OFF = 0 , GP_BACKEND_FULLSCREEN_ON = 1 , GP_BACKEND_FULLSCREEN_TOGGLE = 2 , GP_BACKEND_FULLSCREEN_QUERY = 3 }
	Fullscreen request type. More...

enum	gp_backend_cursor_req { GP_BACKEND_CURSOR_ARROW , GP_BACKEND_CURSOR_TEXT_EDIT , GP_BACKEND_CURSOR_CROSSHAIR , GP_BACKEND_CURSOR_HAND , GP_BACKEND_CURSOR_MAX , GP_BACKEND_CURSOR_SHOW = 0xc000 , GP_BACKEND_CURSOR_HIDE = 0x8000 }
	Cursor types. More...

enum	gp_backend_backlight_req { GP_BACKEND_BACKLIGHT_INC , GP_BACKEND_BACKLIGHT_DEC , GP_BACKEND_BACKLIGHT_GET }
	Backlight operations. More...

Functions
static gp_size	gp_backend_w (gp_backend *self)
	Returns backend width.

static gp_size	gp_backend_h (gp_backend *self)
	Returns backend height.

static gp_pixel_type	gp_backend_pixel_type (gp_backend *self)
	Returns backend pixel type.

void	gp_backend_update_rect_xyxy (gp_backend *self, gp_coord x0, gp_coord y0, gp_coord x1, gp_coord y1)
	Copies a rectangle from backend pixmap to a display.

static void	gp_backend_update_rect (gp_backend *self, gp_coord x0, gp_coord y0, gp_coord x1, gp_coord y1)
	Copies a rectangle from backend pixmap to a display.

static void	gp_backend_update_rect_xywh (gp_backend *self, gp_coord x, gp_coord y, gp_size w, gp_size h)
	Copies a rectangle from backend pixmap to a display.

static void	gp_backend_update (gp_backend *self)
	Copies data from backend buffer to display.

static void	gp_backend_flip (gp_backend *self)
	Flips backend and display buffers.

void	gp_backend_poll_add (gp_backend self, gp_fd fd)
	Add a file descriptor to the backend poll loop.

static void	gp_backend_poll_rem (gp_backend self, gp_fd fd)
	Removes a file descriptor to the backend poll loop.

static gp_fd *	gp_backend_poll_rem_by_fd (gp_backend *self, int fd)
	Removes a file descriptor to the backend poll loop.

static enum gp_backend_ret	gp_backend_cursor_set (gp_backend *self, enum gp_backend_cursor_req cursor)
	Sets backend cursor type.

static int	gp_backend_backlight_inc (gp_backend *self)
	Increases the backlight intensity.

static int	gp_backend_backlight_dec (gp_backend *self)
	Decreases the backlight intensity.

static int	gp_backend_backlight_get (gp_backend *self)
	Returns backlight intensity in percents.

void	gp_backend_exit (gp_backend *self)
	Exits the backend.

void	gp_backend_poll (gp_backend *self)
	Polls a backend for events.

gp_event *	gp_backend_ev_poll (gp_backend *self)
	Returns an event from the queue, polls the backend for events if the queue is empty.

void	gp_backend_wait_timeout (gp_backend *self, int timeout_ms)
	Waits for a backend events with a timeout.

static void	gp_backend_wait (gp_backend *self)
	Waits for a backend events.

gp_event *	gp_backend_ev_wait_timeout (gp_backend *self, int timeout_ms)
	Returns an event from the queue, wait for the backend events until a timeout if the queue is empty.

static gp_event *	gp_backend_ev_wait (gp_backend *self)
	Returns an event from the queue, wait the backend for events if the queue is empty.

void	gp_backend_timer_start (gp_backend self, gp_timer timer)
	Adds a timer to a backend timer queue.

void	gp_backend_timer_reschedule (gp_backend self, gp_timer timer, uint32_t expires_ms)
	Reschedules a timer.

void	gp_backend_timer_stop (gp_backend self, gp_timer timer)
	Removes timer from backend timer queue.

static unsigned int	gp_backend_timers_queued (gp_backend *self)
	Returns number of timers scheduled in backend.

int	gp_backend_timer_timeout (gp_backend *self)
	Returns time to the closest timer timeout.

static enum gp_backend_ret	gp_backend_set_caption (gp_backend backend, const char caption)
	Sets backend caption, if supported.

int	gp_backend_resize (gp_backend *backend, uint32_t w, uint32_t h)
	Request backend resize.

static enum gp_backend_ret	gp_backend_fullscreen (gp_backend *backend, enum gp_backend_fullscreen_req req)
	Reuqests to change fullscreen mode.

int	gp_backend_resize_ack (gp_backend *self)
	Resize acknowledge.

void	gp_backend_task_ins (gp_backend self, gp_task task)
	Inserts a task into the task queue.

void	gp_backend_task_rem (gp_backend self, gp_task task)
	Removes a task from the task queue.

void	gp_backend_task_queue_set (gp_backend self, gp_task_queue task_queue)
	Sets the backend task_queue and starts task processing.

static void	gp_backend_ev_flush (gp_backend *self)
	Removes all events from the event queue.

static unsigned int	gp_backend_ev_queued (gp_backend *self)
	Returns a number of events in the backend event queue.

gp_event *	gp_backend_ev_get (gp_backend *self)
	Removes and returns a pointer to a first event in the queue.

static gp_event *	gp_backend_ev_peek (gp_backend *self)
	Returns a pointer to a first event in the queue.

static void	gp_backend_ev_put_back (gp_backend self, gp_event ev)
	Puts back an event that has been just removed from the queue.

Detailed Description

An abstraction for display, keyboard and mouse.

The gp_backend is unified API for managing xserver, framebuffer, waylaynd, drm, e-ink display, etc. along with support for input devices, e.g. mouse, keyboard and keymaps. It also implements timers and tasks so that work can be scheduled.

In contrast to other graphics libraries we do not try to create unified initalization interface that would match specialities for every possible backend. Rather than that we are trying to create API that is the same for all backends, once initalization is done. This is implemented by optional backend attributes that may or may not be supported by a backend.

Definition in file gp_backend.h.

Enumeration Type Documentation

◆ gp_backend_attr

enum gp_backend_attr

Backend attributes.

Enumerator
GP_BACKEND_ATTR_SIZE	Window change request. The attribute value is an array with two integers.
GP_BACKEND_ATTR_TITLE	Window title change request. The attribute value is an UTF8 string.
GP_BACKEND_ATTR_FULLSCREEN	Fullscreen mode change request. The attribute value is enum gp_backend_fullscreen_req.
GP_BACKEND_ATTR_CURSOR	Cursor modifications. The attribute value is enum gp_backend_cursor_req.
GP_BACKEND_ATTR_BACKLIGHT	Backlight support. Only a few backends need to support backlight, at the moment it's mostly Linux DRM.

Definition at line 43 of file gp_backend.h.

◆ gp_backend_backlight_req

enum gp_backend_backlight_req

Backlight operations.

Enumerator

GP_BACKEND_BACKLIGHT_INC

Increases the backlight brightness.

Returns current backlight intensity in percents.

GP_BACKEND_BACKLIGHT_DEC

Decreases the backlight brightness.

Returns current backlight intensity in percents.

GP_BACKEND_BACKLIGHT_GET

Returns current backlight intensity in percents.

Definition at line 151 of file gp_backend.h.

◆ gp_backend_cursor_req

enum gp_backend_cursor_req

Cursor types.

Enumerator
GP_BACKEND_CURSOR_ARROW	Arrow default cursor type.
GP_BACKEND_CURSOR_TEXT_EDIT	Text edit cursor.
GP_BACKEND_CURSOR_CROSSHAIR	Crosshair.
GP_BACKEND_CURSOR_HAND	Used typicaly while howering over links.
GP_BACKEND_CURSOR_MAX	Last cursor + 1.
GP_BACKEND_CURSOR_SHOW	Shows cursor.
GP_BACKEND_CURSOR_HIDE	Hides cursor.

Definition at line 130 of file gp_backend.h.

◆ gp_backend_fullscreen_req

enum gp_backend_fullscreen_req

Fullscreen request type.

Enumerator
GP_BACKEND_FULLSCREEN_OFF	Request fullscreen to be turned off.
GP_BACKEND_FULLSCREEN_ON	Request fullscreen to be turned on.
GP_BACKEND_FULLSCREEN_TOGGLE	Toggle fullscreen state.
GP_BACKEND_FULLSCREEN_QUERY	Query fullscreen state. Returns the fullscreen state one of GP_BACKEND_ON, GP_BACKEND_OFF or an error e.g. GP_BACKEND_NOTSUPP if fullscreen is not supported.

Definition at line 111 of file gp_backend.h.

◆ gp_backend_ret

enum gp_backend_ret

A return value from the backend set_attr callback.

All error states are negative, for fucntions that sets attribute success is 0 and for functions that query an attribute the return is either >= 0 for success, or negative for errors.

Enumerator
GP_BACKEND_OK	Atrribute set succesfully.
GP_BACKEND_OFF	Attribute is disabled.
GP_BACKEND_ON	Attribute is enabled.
GP_BACKEND_NOTSUPP	Unsupported attribute. Not all backends support all attributes.
GP_BACKEND_EINVAL	Invalid value. E.g. an attempt to set windows size to 0x0 pixels or resize window in a fullscreen mode.
GP_BACKEND_CONNERR	Connection error.

Definition at line 84 of file gp_backend.h.

Function Documentation

◆ gp_backend_backlight_dec()

static int gp_backend_backlight_dec ( gp_backend * self )

inlinestatic

Decreases the backlight intensity.

There are a few backends that can modify the backlight intensity, e.g. Linux DRM. For these backends the backlight can be decreased in several steps.

Parameters

self	A backend.

Returns: A new backlight intensity in percents or GP_BACKEND_NOTSUPP if backlight is not supported by the backend.

Definition at line 571 of file gp_backend.h.

References GP_BACKEND_ATTR_BACKLIGHT, GP_BACKEND_BACKLIGHT_DEC, GP_BACKEND_NOTSUPP, and gp_backend::set_attr.

◆ gp_backend_backlight_get()

static int gp_backend_backlight_get ( gp_backend * self )

inlinestatic

Returns backlight intensity in percents.

There are a few backends that can modify the backlight intensity, e.g. Linux DRM.

Parameters

self	A backend.

Returns: A backlight intensity in percents or GP_BACKEND_NOTSUPP if backlight is not supported by the backend.

Definition at line 591 of file gp_backend.h.

References GP_BACKEND_ATTR_BACKLIGHT, GP_BACKEND_BACKLIGHT_GET, GP_BACKEND_NOTSUPP, and gp_backend::set_attr.

◆ gp_backend_backlight_inc()

static int gp_backend_backlight_inc ( gp_backend * self )

inlinestatic

Increases the backlight intensity.

There are a few backends that can modify the backlight intensity, e.g. Linux DRM. For these backends the backlight can be increased in several steps.

Parameters

self	A backend.

Returns: A new backlight intensity in percents or GP_BACKEND_NOTSUPP if backlight is not supported by the backend.

Definition at line 551 of file gp_backend.h.

References GP_BACKEND_ATTR_BACKLIGHT, GP_BACKEND_BACKLIGHT_INC, GP_BACKEND_NOTSUPP, and gp_backend::set_attr.

◆ gp_backend_cursor_set()

static enum gp_backend_ret gp_backend_cursor_set	(	gp_backend *	self,
		enum gp_backend_cursor_req	cursor )

inlinestatic

Sets backend cursor type.

If supported changes backend cursor to the requested type, disables or enables a cursor.

Parameters

self	A backend.
cursor	A cursor type.

Returns: A GP_BACKEND_OK if cursor was modified, GP_BACKEND_NOTSUPP if backend cursor cannot be set.

Definition at line 532 of file gp_backend.h.

References GP_BACKEND_ATTR_CURSOR, GP_BACKEND_NOTSUPP, and gp_backend::set_attr.

◆ gp_backend_ev_flush()

static void gp_backend_ev_flush ( gp_backend * self )

inlinestatic

Removes all events from the event queue.

Parameters

self	A backend.

Definition at line 924 of file gp_backend.h.

References gp_backend::event_queue, and gp_ev_queue_flush().

◆ gp_backend_ev_get()

gp_event * gp_backend_ev_get ( gp_backend * self )

Removes and returns a pointer to a first event in the queue.

Warning: The pointer to the event is valid only until the next call to a function that modifies the queue. That includes the functions that fill in the queue e.g. gp_backend_wait().

Parameters

self	A backend.

Returns: A pointer to an event or NULL if queue is empty.

◆ gp_backend_ev_peek()

static gp_event * gp_backend_ev_peek ( gp_backend * self )

inlinestatic

Returns a pointer to a first event in the queue.

Unlike the gp_backend_ev_get() the event is not removed from the queue.

Warning: The pointer to the event is valid only until the next call to a function that modifies the queue. That includes the functions that fill in the queue e.g. gp_backend_wait().

Parameters

self	A backend.

Returns: A pointer to an event or NULL if queue is empty.

Definition at line 965 of file gp_backend.h.

References gp_backend::event_queue, and gp_ev_queue_peek().

◆ gp_backend_ev_poll()

gp_event * gp_backend_ev_poll ( gp_backend * self )

Returns an event from the queue, polls the backend for events if the queue is empty.

This combines a gp_backend_poll() and gp_backend_ev_get() into a one function. The call to gp_backend_poll() may generate more than one event so the function tries to return events from the queue first and only if the queue is empty it reaches to the backend to try to fill the queue.

The function is supposed to be called in a loop:

gp_event *ev;
 
while ((ev = gp_backend_ev_poll(backend)) {
     // Event processing has to be done here
 
     // To avoid bussy loop we have to sleep here
     usleep(100);
}

Parameters

self	A backend.

Returns: An event or NULL if queue was empty and no events were generated by by backend.

◆ gp_backend_ev_put_back()

static void gp_backend_ev_put_back	(	gp_backend *	self,
		gp_event *	ev )

inlinestatic

Puts back an event that has been just removed from the queue.

This can undo a last call to gp_backend_ev_get() by putting the event that has been just removed back into the queue.

Warning: An attempt to put back more than one evevent or an event that wasn't removed from the top of the queue is not supported.

Parameters

self	A backend.
ev	An event to be put back into the queue.

Definition at line 982 of file gp_backend.h.

References gp_backend::event_queue, and gp_ev_queue_put_back().

◆ gp_backend_ev_queued()

static unsigned int gp_backend_ev_queued ( gp_backend * self )

inlinestatic

Returns a number of events in the backend event queue.

Parameters

self	A backend.

Returns: A number of events queued.

Definition at line 936 of file gp_backend.h.

References gp_backend::event_queue, and gp_ev_queue_events().

◆ gp_backend_ev_wait()

static gp_event * gp_backend_ev_wait ( gp_backend * self )

inlinestatic

Returns an event from the queue, wait the backend for events if the queue is empty.

This combines a gp_backend_wait() and gp_backend_ev_get() into a one function. The call to gp_backend_wait() may generate more than one event so the function tries to return events from the queue first and only if the queue is empty it reaches to the backend to try to fill the queue.

The function is supposed to be called in a loop:

for (;;) {
     gp_event *ev = gp_backend_ev_wait(backend));
 
     // Event processing has to be done here
}

Parameters

self	A backend.

Returns: An event.

Definition at line 754 of file gp_backend.h.

References gp_backend_ev_wait_timeout().

◆ gp_backend_ev_wait_timeout()

gp_event * gp_backend_ev_wait_timeout	(	gp_backend *	self,
		int	timeout_ms )

Returns an event from the queue, wait for the backend events until a timeout if the queue is empty.

This combines a gp_backend_wait_timeout() and gp_backend_ev_get() into a one function. The call to gp_backend_wait_timeout() may generate more than one event so the function tries to return events from the queue first and only if the queue is empty it reaches to the backend to try to fill the queue.

The function is supposed to be called in a loop:

for (;;) {
     gp_event *ev = gp_backend_ev_wait_timeout(backend, 10);
 
     // Event processing has to be done here
}

Parameters

self	A backend.
timeout_ms	A timeout in miliseconds. Passing -1 means no timeout.

Returns: An event.

Referenced by gp_backend_ev_wait().

◆ gp_backend_exit()

void gp_backend_exit ( gp_backend * self )

Exits the backend.

This functions deinitializes the backend. E.g. closes all file descriptors, frees memory, etc.

Warning: It's important to call this before the application exits since some backends, e.g. framebuffer, cannot be recovered unless we return the underlying facility to the original state.

Parameters

self	A backend.

◆ gp_backend_flip()

static void gp_backend_flip ( gp_backend * self )

inlinestatic

Flips backend and display buffers.

Important: This call should be used when application generates each frame from a scratch and send them to a display e.g. video player.

In most cases this function swaps buffers between the gp_backend::pixmap and display. If flipping buffers is not supported, e.g. for displays connected over SPI the gp_backend::flip pointer is NULL and the operation falls back to gp_backend_update().

Warning: After this call the content of the gp_backend::pixmap or the location of its memory may change.

This call is no-op for backends that write directly into the display DMA buffer.

Parameters

self	A backend.

Definition at line 479 of file gp_backend.h.

References gp_backend::flip, and gp_backend_update().

◆ gp_backend_fullscreen()

static enum gp_backend_ret gp_backend_fullscreen	(	gp_backend *	backend,
		enum gp_backend_fullscreen_req	req )

inlinestatic

Reuqests to change fullscreen mode.

Parameters

backend	A backend.
req	A fullscreen request.

Returns: GP_BACKEND_OK on success, negative on failure. In the case of GP_BACKEND_FULLSCREEN_QUERY it's either GP_BACKEND_ON, GP_BACKEND_OFF or an error, most commonly GP_BACKEND_NOTSUPP.

Definition at line 854 of file gp_backend.h.

References GP_BACKEND_ATTR_FULLSCREEN, GP_BACKEND_NOTSUPP, and gp_backend::set_attr.

◆ gp_backend_h()

static gp_size gp_backend_h ( gp_backend * self )

inlinestatic

Returns backend height.

Parameters

self	A backend.

Returns: A backend pixmap height.

Definition at line 360 of file gp_backend.h.

References gp_pixmap_h(), and gp_backend::pixmap.

◆ gp_backend_pixel_type()

static gp_pixel_type gp_backend_pixel_type ( gp_backend * self )

inlinestatic

Returns backend pixel type.

Parameters

self	A backend.

Returns: A backend pixel type.

Definition at line 371 of file gp_backend.h.

References gp_pixmap::pixel_type, and gp_backend::pixmap.

◆ gp_backend_poll()

void gp_backend_poll ( gp_backend * self )

Polls a backend for events.

This is a non-blocking function that fills the events into the backend event queue.

Parameters

self	A backend.

◆ gp_backend_poll_add()

void gp_backend_poll_add	(	gp_backend *	self,
		gp_fd *	fd )

Add a file descriptor to the backend poll loop.

If fd gp_fd::event callback is NULL a gp_event with GP_EV_FD type is pushed into the backend event queue once events are returned from poll.

Parameters

self	A backend.
fd	A file descriptor with a callback.

◆ gp_backend_poll_rem()

static void gp_backend_poll_rem	(	gp_backend *	self,
		gp_fd *	fd )

inlinestatic

Removes a file descriptor to the backend poll loop.

Parameters

self	A backend.
fd	A file descriptor with a callback.

Definition at line 504 of file gp_backend.h.

References gp_backend::fds, and gp_poll_rem().

◆ gp_backend_poll_rem_by_fd()

static gp_fd * gp_backend_poll_rem_by_fd	(	gp_backend *	self,
		int	fd )

inlinestatic

Removes a file descriptor to the backend poll loop.

Parameters

self	A backend.
fd	A file descriptor used to look up the gp_fd structure.

Definition at line 515 of file gp_backend.h.

References gp_backend::fds, and gp_poll_rem_by_fd().

◆ gp_backend_resize()

int gp_backend_resize	(	gp_backend *	backend,
		uint32_t	w,
		uint32_t	h )

Request backend resize.

When the backend size matches the requested width and height no action is done.

If a resize request is granted the backend sends GP_EV_SYS event type with GP_EV_SYS_RESIZE code and the new width and height in the struct gp_ev_sys. Upon receiving this event the application must stop any access to the gp_backend::pixmap and call gp_backend_resize_ack() to signal to the backend that it's safe to resize the buffers. Once that is done the application can start drawing to the new and resized gp_backend::pixmap.

Returns: When resizing is not possible or not implemented non zero is returned.

◆ gp_backend_resize_ack()

int gp_backend_resize_ack ( gp_backend * self )

Resize acknowledge.

You must call this right after you application has received resize event. For a multithreaded application all threads that operate on the backend pixmap must be stopped first.

After this call returns the backend pixmap has been resized, that means that at least the width, height, and pixels of gp_backend::pixmap are different and the content of the gp_pixmap::pixels is undefined.

This call also resizes the window, display, screen size in the backend gp_ev_queue.

If the function fails the best action to take is to save application data and exit as the backend may be in undefined state.

Parameters

self	A backend.

Returns: Zero on success, non-zero otherwise.

◆ gp_backend_set_caption()

static enum gp_backend_ret gp_backend_set_caption	(	gp_backend *	backend,
		const char *	caption )

inlinestatic

Sets backend caption, if supported.

Caption is an UTF8 string that is usually shown in the window title.

Returns: On success GP_BACKEND_OK is returned. When setting caption is not possible or implemented GP_BACKEND_NOTSUPP is returned.

Definition at line 818 of file gp_backend.h.

References GP_BACKEND_ATTR_TITLE, GP_BACKEND_NOTSUPP, and gp_backend::set_attr.

◆ gp_backend_task_ins()

void gp_backend_task_ins	(	gp_backend *	self,
		gp_task *	task )

Inserts a task into the task queue.

Tasks are executed sequentionally and input processing is blocked during task execution.

Warning: When backend is created there is no task queue, to be able to schedule tasks user has to allocate and set the task queue first.

Parameters

self	A backend.
task	A task to be inserted into the task queue.

◆ gp_backend_task_queue_set()

void gp_backend_task_queue_set	(	gp_backend *	self,
		gp_task_queue *	task_queue )

Sets the backend task_queue and starts task processing.

By default backends does not have a task queue populated. Applications that require a task queue have to allocate and initialize the queue then pass it to the backend with this function.

Parameters

self	A backend.
task_queue	A pointer to initialized task_queue.

◆ gp_backend_task_rem()

void gp_backend_task_rem	(	gp_backend *	self,
		gp_task *	task )

Removes a task from the task queue.

Parameters

self	A backend.
task	A task to be removed from the task queue.

◆ gp_backend_timer_reschedule()

void gp_backend_timer_reschedule	(	gp_backend *	self,
		gp_timer *	timer,
		uint32_t	expires_ms )

Reschedules a timer.

If a timer is running (inserted into the timer queue) it's stopped before it's started again.

Parameters

self	A backend.
timer	A timer.
expires_ms	A new timeout for the timer in miliseconds.

◆ gp_backend_timer_start()

void gp_backend_timer_start	(	gp_backend *	self,
		gp_timer *	timer )

Adds a timer to a backend timer queue.

If timer callback is NULL a gp_event with GP_EV_TMR type is pushed into the backend event queue once timer expires.

Parameters

self	A backend.
timer	A timer.

◆ gp_backend_timer_stop()

void gp_backend_timer_stop	(	gp_backend *	self,
		gp_timer *	timer )

Removes timer from backend timer queue.

Parameters

self	A backend.
timer	A timer.

◆ gp_backend_timer_timeout()

int gp_backend_timer_timeout ( gp_backend * self )

Returns time to the closest timer timeout.

Parameters

self	A backend.

Returns: Returns a timeout to a closest timer in ms or -1. Can be passed directly to poll(2).

◆ gp_backend_timers_queued()

static unsigned int gp_backend_timers_queued ( gp_backend * self )

inlinestatic

Returns number of timers scheduled in backend.

Parameters

self	A backend.

Definition at line 795 of file gp_backend.h.

References gp_timer_queue_size(), and gp_backend::timers.

◆ gp_backend_update()

static void gp_backend_update ( gp_backend * self )

inlinestatic

Copies data from backend buffer to display.

This function copies the data from the backend pixmap to the displayed buffer. Unlike the gp_backend_flip() the pixmap data are kept after the operation. For some backends, e.g. Linux DRM this means that this function does memcpy() of the buffer we are about to display. For SPI display backends this sends the whole gp_backend::pixmap pixels buffer to the display over SPI.

This call is no-op for backends that write directly into the display DMA buffer.

Parameters

self	A backend.

Definition at line 454 of file gp_backend.h.

References gp_backend::update.

Referenced by gp_backend_flip().

◆ gp_backend_update_rect()

static void gp_backend_update_rect	(	gp_backend *	self,
		gp_coord	x0,
		gp_coord	y0,
		gp_coord	x1,
		gp_coord	y1 )

inlinestatic

Copies a rectangle from backend pixmap to a display.

This is an alias for gp_backend_update_rect_xyxy().

Parameters

self	A backend.
x0	First x coordinate of the rectangle.
y0	First y coordinate of the rectangle.
x1	Last x coordinate of the rectangle.
y1	Last y coordinate of the rectangle.

Definition at line 414 of file gp_backend.h.

References gp_backend_update_rect_xyxy().

◆ gp_backend_update_rect_xywh()

static void gp_backend_update_rect_xywh	(	gp_backend *	self,
		gp_coord	x,
		gp_coord	y,
		gp_size	w,
		gp_size	h )

inlinestatic

Copies a rectangle from backend pixmap to a display.

This is a version of gp_backend_update_rect_xyxy() with width and height.

Parameters

self	A backend.
x	Left x coordinate of the rectangle.
y	Top y coordinate of the rectangle.
w	Rectangle width.
h	Rectangle height.

Definition at line 432 of file gp_backend.h.

References gp_backend_update_rect_xyxy().

◆ gp_backend_update_rect_xyxy()

void gp_backend_update_rect_xyxy	(	gp_backend *	self,
		gp_coord	x0,
		gp_coord	y0,
		gp_coord	x1,
		gp_coord	y1 )

Copies a rectangle from backend pixmap to a display.

Important: This function should be used when application draws small partial updates of the display, e.g. appending letters into a textbox.

Updates a rectangle from a gp_pixmap::pixels buffer on the display.

Warning: Some backends does not support partial update (e.g. Linux DRM) and always do a full display update. Other backends needs to round the coordinates to a byte boundary (e.g. E-Ink display). That means that the whole gp_pixmap::pixels buffer must contain a valid data even if we do partial update.

This call is no-op for backends that write directly into the display DMA buffer.

Parameters

self	A backend.
x0	First x coordinate of the rectangle.
y0	First y coordinate of the rectangle.
x1	Last x coordinate of the rectangle.
y1	Last y coordinate of the rectangle.

Referenced by gp_backend_update_rect(), and gp_backend_update_rect_xywh().

◆ gp_backend_w()

static gp_size gp_backend_w ( gp_backend * self )

inlinestatic

Returns backend width.

Parameters

self	A backend.

Returns: A backend pixmap width.

Definition at line 349 of file gp_backend.h.

References gp_pixmap_w(), and gp_backend::pixmap.

◆ gp_backend_wait()

static void gp_backend_wait ( gp_backend * self )

inlinestatic

Waits for a backend events.

This is a blocking call that fills the events into the backend event queue.

Once this call returns the events from the event queue must be processed.

The event processing may look like:

for (;;) {
     gp_event *ev;
 
     gp_backend_wait(backend);
 
     while ((ev = gp_backend_ev_get(backend)) {
     // Event processing has to be done here
     }
}

Parameters

self	A backend.

Definition at line 702 of file gp_backend.h.

References gp_backend_wait_timeout().

◆ gp_backend_wait_timeout()

void gp_backend_wait_timeout	(	gp_backend *	self,
		int	timeout_ms )

Waits for a backend events with a timeout.

This is a blocking call that fills the events into the backend event queue until timeout.

Once this call returns the events from the event queue must be processed.

The event processing may look like:

for (;;) {
     gp_event *ev;
 
     gp_backend_wait_timeout(backend, 10);
 
     while ((ev = gp_backend_ev_get(backend)) {
     // Event processing has to be done here
     }
}

Parameters

self	A backend.
timeout_ms	A timeout in miliseconds. Passing -1 means no timeout.

Referenced by gp_backend_wait().

Data Structures

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

◆ gp_backend_attr

◆ gp_backend_backlight_req

◆ gp_backend_cursor_req

◆ gp_backend_fullscreen_req

◆ gp_backend_ret

Function Documentation

◆ gp_backend_backlight_dec()

◆ gp_backend_backlight_get()

◆ gp_backend_backlight_inc()

◆ gp_backend_cursor_set()

◆ gp_backend_ev_flush()

◆ gp_backend_ev_get()

◆ gp_backend_ev_peek()

◆ gp_backend_ev_poll()

◆ gp_backend_ev_put_back()

◆ gp_backend_ev_queued()

◆ gp_backend_ev_wait()

◆ gp_backend_ev_wait_timeout()

◆ gp_backend_exit()

◆ gp_backend_flip()

◆ gp_backend_fullscreen()

◆ gp_backend_h()

◆ gp_backend_pixel_type()

◆ gp_backend_poll()

◆ gp_backend_poll_add()

◆ gp_backend_poll_rem()

◆ gp_backend_poll_rem_by_fd()

◆ gp_backend_resize()

◆ gp_backend_resize_ack()

◆ gp_backend_set_caption()

◆ gp_backend_task_ins()

◆ gp_backend_task_queue_set()

◆ gp_backend_task_rem()

◆ gp_backend_timer_reschedule()

◆ gp_backend_timer_start()

◆ gp_backend_timer_stop()

◆ gp_backend_timer_timeout()

◆ gp_backend_timers_queued()

◆ gp_backend_update()

◆ gp_backend_update_rect()

◆ gp_backend_update_rect_xywh()

◆ gp_backend_update_rect_xyxy()

◆ gp_backend_w()

◆ gp_backend_wait()

◆ gp_backend_wait_timeout()