#include "SDL_stdinc.h"#include "SDL_error.h"#include "begin_code.h"#include "close_code.h"Go to the source code of this file.
Defines | |
| #define | SDL_TIMESLICE 10 |
| #define | TIMER_RESOLUTION 10 |
Typedefs | |
| typedef Uint32(SDLCALL * | SDL_TimerCallback )(Uint32 interval) |
Functions | |
| DECLSPEC Uint32 SDLCALL | SDL_GetTicks (void) |
| DECLSPEC void SDLCALL | SDL_Delay (Uint32 ms) |
| DECLSPEC int SDLCALL | SDL_SetTimer (Uint32 interval, SDL_TimerCallback callback) |
New timer API | |
| New timer API, supports multiple timers Written by Stephane Peter <megastep@lokigames.com> | |
| typedef Uint32(SDLCALL * | SDL_NewTimerCallback )(Uint32 interval, void *param) |
| typedef struct _SDL_TimerID * | SDL_TimerID |
| DECLSPEC SDL_TimerID SDLCALL | SDL_AddTimer (Uint32 interval, SDL_NewTimerCallback callback, void *param) |
| DECLSPEC SDL_bool SDLCALL | SDL_RemoveTimer (SDL_TimerID t) |
| #define SDL_TIMESLICE 10 |
This is the OS scheduler timeslice, in milliseconds
| #define TIMER_RESOLUTION 10 |
This is the maximum resolution of the SDL timer on all platforms Experimentally determined
| typedef Uint32(SDLCALL * SDL_NewTimerCallback)(Uint32 interval, void *param) |
Function prototype for the new timer callback function. The callback function is passed the current timer interval and returns the next timer interval. If the returned value is the same as the one passed in, the periodic alarm continues, otherwise a new alarm is scheduled. If the callback returns 0, the periodic alarm is cancelled.
| typedef Uint32(SDLCALL * SDL_TimerCallback)(Uint32 interval) |
Function prototype for the timer callback function
| typedef struct _SDL_TimerID* SDL_TimerID |
Definition of the timer ID type
| DECLSPEC SDL_TimerID SDLCALL SDL_AddTimer | ( | Uint32 | interval, | |
| SDL_NewTimerCallback | callback, | |||
| void * | param | |||
| ) |
Add a new timer to the pool of timers already running. Returns a timer ID, or NULL when an error occurs.
| DECLSPEC void SDLCALL SDL_Delay | ( | Uint32 | ms | ) |
Wait a specified number of milliseconds before returning
| DECLSPEC Uint32 SDLCALL SDL_GetTicks | ( | void | ) |
Get the number of milliseconds since the SDL library initialization. Note that this value wraps if the program runs for more than ~49 days.
| DECLSPEC SDL_bool SDLCALL SDL_RemoveTimer | ( | SDL_TimerID | t | ) |
Remove one of the multiple timers knowing its ID. Returns a boolean value indicating success.
| DECLSPEC int SDLCALL SDL_SetTimer | ( | Uint32 | interval, | |
| SDL_TimerCallback | callback | |||
| ) |
Set a callback to run after the specified number of milliseconds has elapsed. The callback function is passed the current timer interval and returns the next timer interval. If the returned value is the same as the one passed in, the periodic alarm continues, otherwise a new alarm is scheduled. If the callback returns 0, the periodic alarm is cancelled.
To cancel a currently running timer, call SDL_SetTimer(0, NULL);
The timer callback function may run in a different thread than your main code, and so shouldn't call any functions from within itself.
The maximum resolution of this timer is 10 ms, which means that if you request a 16 ms timer, your callback will run approximately 20 ms later on an unloaded system. If you wanted to set a flag signaling a frame update at 30 frames per second (every 33 ms), you might set a timer for 30 ms:
SDL_SetTimer((33/10)*10, flag_update);
If you use this function, you need to pass SDL_INIT_TIMER to SDL_Init().
Under UNIX, you should not use raise or use SIGALRM and this function in the same program, as it is implemented using setitimer(). You also should not use this function in multi-threaded applications as signals to multi-threaded apps have undefined behavior in some implementations.
This function returns 0 if successful, or -1 if there was an error.
1.5.8