Keskustelu: Ohjelmointikysymykset: C++: SDL timers

//focus on sdl

//timer demo

//fosdl7_1.cpp
//23MAY2002
//ernest pazera

//requires static linkage to:
//sdl.lib, sdlmain.lib

//requires dynamic linkage to:
//sdl.dll

//include SDL stuff
#include "sdl.h"

//include ability to exit program
#include <stdlib.h>

//screen dimensions
const int SCREEN_WIDTH=640;
const int SCREEN_HEIGHT=480;

//display surface
SDL_Surface* g_pDisplaySurface = NULL;

//event structure
SDL_Event g_Event;

//rectangle
SDL_Rect g_FillRect;

//timer id
SDL_TimerID g_TimerID;

//global boolean flag
bool g_bFlag=false;

//timer callback
Uint32 FOSDL_TimerCallback(Uint32 interval, void *param);

//main function
int main(int argc, char* argv[])
{
	//initialize SDL
	if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER)==-1)
	{
		//error initializing SDL

		//report the error
		fprintf(stderr,"Could not initialize SDL!\n");

		//end the program
		exit(1);
	}
	else
	{
		//SDL initialized

		//report success
		fprintf(stdout,"SDL initialized properly!\n");

		//set up to uninitialize SDL at exit
		atexit(SDL_Quit);
	}

	//create windowed environment
	g_pDisplaySurface = SDL_SetVideoMode(SCREEN_WIDTH,SCREEN_HEIGHT,0,SDL_ANYFORMAT);

	//error check
	if (g_pDisplaySurface == NULL)
	{
		//report error
		fprintf(stderr,"Could not set up display surface!\n");

		//exit the program
		exit(1);
	}

	//add the timer
	g_TimerID=SDL_AddTimer(1000,FOSDL_TimerCallback,NULL);

	//repeat forever
	for(;;)
	{
		//wait for an event
		if(SDL_PollEvent(&g_Event)==0)
		{
			//no event

			//check for the flag
			if(g_bFlag)
			{
				//set flag to false
				g_bFlag=false;

				//set up rectangle
				g_FillRect.x=g_FillRect.y=0;
				g_FillRect.w=SCREEN_WIDTH;
				g_FillRect.h=SCREEN_HEIGHT;
				SDL_FillRect(g_pDisplaySurface,&g_FillRect,SDL_MapRGB(g_pDisplaySurface->format,rand()%256,rand()%256,rand()%256));
			}

			//update the screen
			SDL_UpdateRect(g_pDisplaySurface,0,0,0,0);
		}
		else
		{
			//event occurred, check for quit
			if(g_Event.type==SDL_QUIT) break;
		}
	}

	//remove the timer
	SDL_RemoveTimer(g_TimerID);

	//normal termination
	fprintf(stdout,"Terminating normally.\n");

	//return 0
	return(0);
}

//timer callback
Uint32 FOSDL_TimerCallback(Uint32 interval, void *param)
{
	//set boolean flag to true
	g_bFlag=true;

	//return same interval
	return(interval)
}
[koodic]int main(void) {
    printf("Morjens!");
}