cogl_poll_renderer_get_info ()

int
cogl_poll_renderer_get_info (CoglRenderer *renderer,
                             CoglPollFD **poll_fds,
                             int *n_poll_fds,
                             int64_t *timeout);

Is used to integrate Cogl with an application mainloop that is based on the unix poll(2) api (or select() or something equivalent). This api should be called whenever an application is about to go idle so that Cogl has a chance to describe what file descriptor events it needs to be woken up for.

After the function is called *poll_fds will contain a pointer to an array of CoglPollFD structs describing the file descriptors that Cogl expects. The fd and events members will be updated accordingly. After the application has completed its idle it is expected to either update the revents members directly in this array or to create a copy of the array and update them there.

When the application mainloop returns from calling poll(2) (or its equivalent) then it should call cogl_poll_renderer_dispatch() passing a pointer the array of CoglPollFDs with updated revent values.

When using the COGL_WINSYS_ID_WGL winsys (where file descriptors don't make any sense) or COGL_WINSYS_ID_SDL (where the event handling functions of SDL don't allow blocking on a file descriptor) *n_poll_fds is guaranteed to be zero.

timeout will contain a maximum amount of time to wait in microseconds before the application should wake up or -1 if the application should wait indefinitely. This can also be 0 if Cogl needs to be woken up immediately.

Since: 1.16

Stability Level: Unstable

cogl_poll_renderer_dispatch ()

void
cogl_poll_renderer_dispatch (CoglRenderer *renderer,
                             const CoglPollFD *poll_fds,
                             int n_poll_fds);

This should be called whenever an application is woken up from going idle in its main loop. The poll_fds array should contain a list of file descriptors matched with the events that occurred in revents. The events field is ignored. It is safe to pass in extra file descriptors that Cogl didn't request when calling cogl_poll_renderer_get_info() or a shorter array missing some file descriptors that Cogl requested.

Since: 1.16

Stability Level: Unstable

cogl_glib_source_new ()

GSource *
cogl_glib_source_new (CoglContext *context,
                      int priority);

Creates a GSource which handles Cogl's internal system event processing. This can be used as a convenience instead of cogl_poll_renderer_get_info() and cogl_poll_renderer_dispatch() in applications that are already using the GLib main loop. After this is called the GSource should be attached to the main loop using g_source_attach().

Applications that manually connect to a CoglRenderer before they create a CoglContext should instead use cogl_glib_renderer_source_new() so that events may be dispatched before a context has been created. In that case you don't need to use this api in addition later, it is simply enough to use cogl_glib_renderer_source_new() instead.

Since: 1.10

Stability Level: Unstable

cogl_glib_renderer_source_new ()

GSource *
cogl_glib_renderer_source_new (CoglRenderer *renderer,
                               int priority);

Creates a GSource which handles Cogl's internal system event processing. This can be used as a convenience instead of cogl_poll_renderer_get_info() and cogl_poll_renderer_dispatch() in applications that are already using the GLib main loop. After this is called the GSource should be attached to the main loop using g_source_attach().

Since: 1.16

Stability Level: Unstable

enum CoglPollFDEvent

A bitmask of events that Cogl may need to wake on for a file descriptor. Note that these all have the same values as the corresponding defines for the poll function call on Unix so they may be directly passed to poll.

Since: 1.10

Stability Level: Unstable

CoglPollFD

typedef struct {
  int fd;
  short int events;
  short int revents;
} CoglPollFD;

A struct for describing the state of a file descriptor that Cogl needs to block on. The events field contains a bitmask of CoglPollFDEvents that should cause the application to wake up. After the application is woken up from idle it should pass back an array of CoglPollFDs to Cogl and update the revents mask to the actual events that occurred on the file descriptor.

Note that CoglPollFD is deliberately exactly the same as struct pollfd on Unix so that it can simply be cast when calling poll.

Since: 1.10

Stability Level: Unstable