Agar


Note: The Agar manual pages follow certain conventions, notably concerning function return values. Please read AG_Intro(3) first.

SYNOPSIS

#include <agar/core.h>
#include <agar/gui.h>

DESCRIPTION

The event loop of an Agar application typically waits for events, invokes GUI rendering routines and processes timer events. Applications can either use the stock event loop routine, AG_EventLoop(), or a custom event loop.

GENERIC EVENT LOOP


void AG_EventLoop (void)

void AG_EventLoop_FixedFPS (void)

void AG_EventLoop_Drv (AG_Driver *drv)



The AG_EventLoop() routine enters a generic Agar event loop, which performs the following tasks:
  1. Render GUI elements to the graphics system as necessary.
  2. Process incoming events from the system.
  3. Invoke timed callback functions (see AG_Timeout(3)).
  4. Let the application idle if possible.

AG_EventLoop() is a general-purpose event loop suitable for most common applications. The AG_EventLoop_FixedFPS() variant tries to guarantee a constant display refresh rate (at the potential cost of reduced accuracy of time-sensitive events).

Both AG_EventLoop() and AG_EventLoop_FixedFPS() assume that the application is using a single Agar driver, as it is the case for most applications. The AG_EventLoop_Drv() variant allows applications which may want to use different Agar drivers concurrently, to specify a driver instance via the drv argument.

CUSTOM EVENT LOOPS

As of Agar-1.4.0, it is possible to write custom event loops in a driver-independent fashion, using the functions AG_PendingEvents(), AG_GetNextEvent() and AG_ProcessEvent(). Low-level driver events are represented by the AG_DriverEvent structure. See AG_Driver(3) for more information.

EXAMPLES

See AG_Driver(3). Also see demos/customeventloop in the Agar distribution for an example of an application using a custom event loop.

SEE ALSO

AG_Intro(3), AG_Event(3), AG_Driver(3)

HISTORY

The AG_EventLoop routine first appeared in Agar 1.0. While custom event loops were possible with Agar 1.3, an official API for low-level event processing only appeared in Agar 1.4.0.