view test/threadwin.c @ 968:4675910b0b7b

Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST) From: Hannu Savolainen Subject: Re: SDL uses obsolete OSS features I did some work on getting OSS to work better with SDL. There have been some problems with select which should be fixed now. I'm having some problems in understanding what is the purpose of the DSP_WaitAudio() routine. I added a return to the very beginning of this routine and commendted out the define for USE_BLOCKING_WRITES. At least lbreakout2 seems to work as well as earlier. The latencies are the same. An ordinary blocking write does exactly the same thing than DSP_WaitAudio does. So I would recommend using the USE_BLOCKING_WRITES approach and removing everything from the DSP_WaitAudio routine. Also enabling USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because you don't need to handle the partial writes (the do-while loop). Attached is a patch against SDL-1.2.7. After these changes SDL will use OSS as it's designed to be used (make it as simple as possible). This code should work with all OSS implementations because it uses only the very fundamental features that have been there since the jurassic times.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 12 Nov 2004 21:39:04 +0000
parents cb40b26523a5
children be9c9c8f6d53
line wrap: on
line source


/* Test out the multi-threaded event handling functions */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "SDL.h"
#include "SDL_thread.h"

/* Are we done yet? */
static int done = 0;

/* Is the cursor visible? */
static int visible = 1;

SDL_Surface *LoadIconSurface(char *file, Uint8 **maskp)
{
	SDL_Surface *icon;
	Uint8       *pixels;
	Uint8       *mask;
	int          mlen, i;

	*maskp = NULL;

	/* Load the icon surface */
	icon = SDL_LoadBMP(file);
	if ( icon == NULL ) {
		fprintf(stderr, "Couldn't load %s: %s\n", file, SDL_GetError());
		return(NULL);
	}

	/* Check width and height */
	if ( (icon->w%8) != 0 ) {
		fprintf(stderr, "Icon width must be a multiple of 8!\n");
		SDL_FreeSurface(icon);
		return(NULL);
	}
	if ( icon->format->palette == NULL ) {
		fprintf(stderr, "Icon must have a palette!\n");
		SDL_FreeSurface(icon);
		return(NULL);
	}

	/* Set the colorkey */
	SDL_SetColorKey(icon, SDL_SRCCOLORKEY, *((Uint8 *)icon->pixels));

	/* Create the mask */
	pixels = (Uint8 *)icon->pixels;
	printf("Transparent pixel: (%d,%d,%d)\n",
				icon->format->palette->colors[*pixels].r,
				icon->format->palette->colors[*pixels].g,
				icon->format->palette->colors[*pixels].b);
	mlen = icon->w*icon->h;
	mask = (Uint8 *)malloc(mlen/8);
	if ( mask == NULL ) {
		fprintf(stderr, "Out of memory!\n");
		SDL_FreeSurface(icon);
		return(NULL);
	}
	memset(mask, 0, mlen/8);
	for ( i=0; i<mlen; ) {
		if ( pixels[i] != *pixels )
			mask[i/8] |= 0x01;
		++i;
		if ( (i%8) != 0 )
			mask[i/8] <<= 1;
	}
	*maskp = mask;
	return(icon);
}

int FilterEvents(const SDL_Event *event)
{
	static int reallyquit = 0;

	switch (event->type) {

		case SDL_ACTIVEEVENT:
			/* See what happened */
			printf("App %s ",
				event->active.gain ? "gained" : "lost");
			if ( event->active.state & SDL_APPACTIVE )
				printf("active ");
			if ( event->active.state & SDL_APPMOUSEFOCUS )
				printf("mouse ");
			if ( event->active.state & SDL_APPINPUTFOCUS )
				printf("input ");
			printf("focus\n");

			/* See if we are iconified or restored */
			if ( event->active.state & SDL_APPACTIVE ) {
				printf("App has been %s\n",
					event->active.gain ?
						 "restored" : "iconified");
			}
			return(0);

		/* This is important!  Queue it if we want to quit. */
		case SDL_QUIT:
			if ( ! reallyquit ) {
				reallyquit = 1;
				printf("Quit requested\n");
				return(0);
			}
			printf("Quit demanded\n");
			return(1);

		/* Mouse and keyboard events go to threads */
		case SDL_MOUSEMOTION:
		case SDL_MOUSEBUTTONDOWN:
		case SDL_MOUSEBUTTONUP:
		case SDL_KEYDOWN:
		case SDL_KEYUP:
			return(1);

		/* Drop all other events */
		default:
			return(0);
	}
}

int HandleMouse(void *unused)
{
	SDL_Event events[10];
	int i, found;
	Uint32 mask;

	/* Handle mouse events here */
	mask = (SDL_MOUSEMOTIONMASK|SDL_MOUSEBUTTONDOWNMASK|SDL_MOUSEBUTTONUPMASK);
	while ( ! done ) {
		found = SDL_PeepEvents(events, 10, SDL_GETEVENT, mask);
		for ( i=0; i<found; ++i ) {
			switch(events[i].type) {
				/* We want to toggle visibility on buttonpress */
				case SDL_MOUSEBUTTONDOWN:
				case SDL_MOUSEBUTTONUP:
					if ( events[i].button.state == SDL_PRESSED ) {
						visible = !visible;
						SDL_ShowCursor(visible);
					}
					printf("Mouse button %d has been %s\n",
						events[i].button.button,
						(events[i].button.state == SDL_PRESSED) ?
						"pressed" : "released");
					break;
				/* Show relative mouse motion */
				case SDL_MOUSEMOTION:
					printf("Mouse relative motion: {%d,%d}\n",
							events[i].motion.xrel, events[i].motion.yrel);
					break;
			}
		}
		/* Give up some CPU to allow events to arrive */
		SDL_Delay(20);
	}
	return(0);
}

int HandleKeyboard(void *unused)
{
	SDL_Event events[10];
	int i, found;
	Uint32 mask;

	/* Handle mouse events here */
	mask = (SDL_KEYDOWNMASK|SDL_KEYUPMASK);
	while ( ! done ) {
		found = SDL_PeepEvents(events, 10, SDL_GETEVENT, mask);
		for ( i=0; i<found; ++i ) {
			switch(events[i].type) {
			    /* We want to toggle visibility on buttonpress */
			    case SDL_KEYDOWN:
			    case SDL_KEYUP:
			    	printf("Key '%c' has been %s\n",
						events[i].key.keysym.unicode,
					(events[i].key.state == SDL_PRESSED) ?
						"pressed" : "released");

			    	/* Allow hitting <ESC> to quit the app */
			    	if ( events[i].key.keysym.sym == SDLK_ESCAPE ) {
			    		done = 1;
			    	}

					/* skip events now that aren't KEYUPs... */
					if (events[i].key.state == SDL_PRESSED)
						break;

			    	if ( events[i].key.keysym.sym == SDLK_f ) {
						int rc = 0;
						printf("attempting to toggle fullscreen...\n");
						rc = SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
                        printf("SDL_WM_ToggleFullScreen returned %d.\n", rc);
			    	}

			    	if ( events[i].key.keysym.sym == SDLK_g ) {
						SDL_GrabMode m;
						m = SDL_WM_GrabInput(SDL_GRAB_QUERY) == SDL_GRAB_ON ?
								SDL_GRAB_OFF : SDL_GRAB_ON;
						printf("attempting to toggle input grab to %s...\n",
                                m == SDL_GRAB_ON ? "ON" : "OFF");
                        SDL_WM_GrabInput(m);
						printf("attempt finished.\n");
			    	}

			    	break;
			}
		}
		/* Give up some CPU to allow events to arrive */
		SDL_Delay(20);
	}
	return(0);
}

int main(int argc, char *argv[])
{
	SDL_Surface *screen;
	SDL_Surface *icon;
	Uint8 *icon_mask;
	int i, parsed;
	Uint8 *buffer;
	SDL_Color palette[256];
	Uint32 init_flags;
	Uint8  video_bpp;
	Uint32 video_flags;
	SDL_Thread *mouse_thread;
	SDL_Thread *keybd_thread;

	/* Set the options, based on command line arguments */
	init_flags = SDL_INIT_VIDEO;
	video_bpp = 8;
	video_flags = SDL_SWSURFACE;
	parsed = 1;
	while ( parsed ) {
		/* If the threaded option is enabled, and the SDL library hasn't
		   been compiled with threaded events enabled, then the mouse and
		   keyboard won't respond.
		 */
		if ( (argc >= 2) && (strcmp(argv[1], "-threaded") == 0) ) {
			init_flags |= SDL_INIT_EVENTTHREAD;
			argc -= 1;
			argv += 1;
			printf("Running with threaded events\n");
		} else
		if ( (argc >= 2) && (strcmp(argv[1], "-fullscreen") == 0) ) {
			video_flags |= SDL_FULLSCREEN;
			argc -= 1;
			argv += 1;
		} else
		if ( (argc >= 3) && (strcmp(argv[1], "-bpp") == 0) ) {
			video_bpp = atoi(argv[2]);
			argc -= 2;
			argv += 2;
		} else {
			parsed = 0;
		}
	}

	/* Initialize SDL with the requested flags */
	if ( SDL_Init(init_flags) < 0 ) {
		fprintf(stderr,
			"Couldn't initialize SDL: %s\n", SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit);

	/* Set the icon -- this must be done before the first mode set */
	icon = LoadIconSurface("icon.bmp", &icon_mask);
	if ( icon != NULL ) {
		SDL_WM_SetIcon(icon, icon_mask);
	}
	if ( icon_mask != NULL )
		free(icon_mask);

	/* Initialize the display */
	screen = SDL_SetVideoMode(640, 480, video_bpp, video_flags);
	if (  screen == NULL ) {
		fprintf(stderr, "Couldn't set 640x480x%d video mode: %s\n",
						video_bpp, SDL_GetError());
		exit(1);
	}
	printf("Running in %s mode\n", screen->flags & SDL_FULLSCREEN ?
						"fullscreen" : "windowed");

	/* Enable printable characters */
	SDL_EnableUNICODE(1);

	/* Set an event filter that discards everything but QUIT */
	SDL_SetEventFilter(FilterEvents);

	/* Create the event handling threads */
	mouse_thread = SDL_CreateThread(HandleMouse, NULL);
	keybd_thread = SDL_CreateThread(HandleKeyboard, NULL);

	/* Set the surface pixels and refresh! */
	for ( i=0; i<256; ++i ) {
		palette[i].r = 255-i;
		palette[i].g = 255-i;
		palette[i].b = 255-i;
	}
	SDL_SetColors(screen, palette, 0, 256);
	if ( SDL_LockSurface(screen) < 0 ) {
		fprintf(stderr, "Couldn't lock display surface: %s\n",
							SDL_GetError());
		exit(2);
	}
	buffer = (Uint8 *)screen->pixels;
	for ( i=0; i<screen->h; ++i ) {
		memset(buffer,(i*255)/screen->h,
				screen->w*screen->format->BytesPerPixel);
		buffer += screen->pitch;
	}
	SDL_UnlockSurface(screen);
	SDL_UpdateRect(screen, 0, 0, 0, 0);

	/* Loop, waiting for QUIT */
	while ( ! done ) {
		if ( ! (init_flags & SDL_INIT_EVENTTHREAD) ) {
			SDL_PumpEvents(); /* Needed when event thread is off */
		}
		if ( SDL_PeepEvents(NULL, 0, SDL_PEEKEVENT, SDL_QUITMASK) ) {
			done = 1;
		}
		/* Give up some CPU so the events can accumulate */
		SDL_Delay(20);
	}
	SDL_WaitThread(mouse_thread, NULL);
	SDL_WaitThread(keybd_thread, NULL);
	return(0);
}