sdl_systimer.cpp

SDL库 在进行视频显示程序spcaview安装时必须的库文件

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    [e-mail]
*/

/*
    SDL_systimer.cpp

    Epoc version by Hannu Viitala ([e-mail]) 
    Markus Mertama
*/

#include <e32std.h>
#include <e32hal.h>

extern "C" {
#include "SDL_error.h"
#include "SDL_thread.h"
#include "SDL_timer.h"
#include "SDL_timer_c.h"

static TUint start = 0;
static TInt tickPeriodMilliSeconds;


void SDL_StartTicks(void)
	{
	/* Set first ticks value */
    start = User::TickCount();

    TTimeIntervalMicroSeconds32 period;
	TInt tmp = UserHal::TickPeriod(period);
    tickPeriodMilliSeconds = period.Int() / 1000;
	}

Uint32 SDL_GetTicks(void)
	{
    TUint deltaTics = User::TickCount() - start;
	return(deltaTics * tickPeriodMilliSeconds); 
	}

void SDL_Delay(Uint32 ms)
	{     
    User::After(TTimeIntervalMicroSeconds32(ms*1000));
	}

/* Data to handle a single periodic alarm */
static int timer_alive = 0;
static SDL_Thread *timer = NULL;

static int RunTimer(void *unused)
	{
	while ( timer_alive )
		{
		if (SDL_timer_running)
			{
			SDL_ThreadedTimerCheck();
			}
		SDL_Delay(10);
		}
	return(0);
	}

/* This is only called if the event thread is not running */
int SDL_SYS_TimerInit(void)
	{
	if(timer != NULL)
		return (-1);
	timer_alive = 1;
	timer = SDL_CreateThread(RunTimer, NULL);
	if ( timer == NULL )
		return(-1);
	return(SDL_SetTimerThreaded(1));
	}

void SDL_SYS_TimerQuit(void)
	{
	timer_alive = 0;
	if ( timer ) 
		{
		SDL_WaitThread(timer, NULL);
		timer = NULL;
		}
	}

int SDL_SYS_StartTimer(void)
	{
	SDL_SetError("Internal logic error: Epoc uses threaded timer");
	return(-1);
	}

void SDL_SYS_StopTimer(void)
	{
	return;
	}

} // extern "C"