view src/video/dga/SDL_dgaevents.c @ 4216:5b99971a27b4 SDL-1.2

Fixed bug #698 Hans de Goede 2009-02-13 01:10:52 PST Since the new "glitch free" version of pulseaudio (used in Fedora 10 amongst others), the sound of SDL using apps (like a simple playmus call) has been crackling. While looking in to fixing this I noticed that the current pulseaudio code in SDL uses pa_simple. However pa_simple uses a thread to pump pulseaudio events and ipc, given that SDL already has its own thread for audio handling this is clearly suboptimal, leading to unnecessary context switching IPC, etc. Also pa_simple does not allow one to implement the WaitAudio() callback for SDL audiodrivers properly. Given that my work is mostly a rewrite (although some original pieces remain) I'm attaching the new .c and .h file, as that is easier to review then the huge diff. Let me know if you also want the diff. This new version has the following features: -no longer use an additional thread next to the SDL sound thread -do not crackle with glitch free audio -when used with a newer pulse, which does glitch free audio, the total latency is the same as with the alsa driver -proper WaitAudio() implementation, saving another mixlen worth of latency -adds a WaitDone() implementation This patch has been written in consultancy with Lennart Poetering (the pulseaudio author) and has been reviewed by him for correct use of the pa API.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 21 Sep 2009 09:27:08 +0000
parents a1b03ba2fcd0
children f00e178dfc9e
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* Handle the event stream, converting DGA events into SDL events */

#include <stdio.h>
#include <X11/Xlib.h>
#include "../Xext/extensions/xf86dga.h"

#include "../SDL_sysvideo.h"
#include "../../events/SDL_events_c.h"
#include "SDL_dgavideo.h"
#include "SDL_dgaevents_c.h"

/* get function pointers... */
#include "../x11/SDL_x11dyn.h"

/* Heheh we're using X11 event code */
extern int X11_Pending(Display *display);
extern void X11_InitKeymap(void);
extern SDLKey X11_TranslateKeycode(Display *display, KeyCode kc);

static int DGA_DispatchEvent(_THIS)
{
	int posted;
	SDL_NAME(XDGAEvent) xevent;

	XNextEvent(DGA_Display, (XEvent *)&xevent);

	posted = 0;
	xevent.type -= DGA_event_base;
	switch (xevent.type) {

	    /* Mouse motion? */
	    case MotionNotify: {
		if ( SDL_VideoSurface ) {
			posted = SDL_PrivateMouseMotion(0, 1,
					xevent.xmotion.dx, xevent.xmotion.dy);
		}
	    }
	    break;

	    /* Mouse button press? */
	    case ButtonPress: {
		posted = SDL_PrivateMouseButton(SDL_PRESSED, 
					xevent.xbutton.button, 0, 0);
	    }
	    break;

	    /* Mouse button release? */
	    case ButtonRelease: {
		posted = SDL_PrivateMouseButton(SDL_RELEASED, 
					xevent.xbutton.button, 0, 0);
	    }
	    break;

	    /* Key press? */
	    case KeyPress: {
		SDL_keysym keysym;
		KeyCode keycode;
		XKeyEvent xkey;

		SDL_NAME(XDGAKeyEventToXKeyEvent)(&xevent.xkey, &xkey);
		keycode = xkey.keycode;
#ifdef DEBUG_XEVENTS
printf("KeyPress (X11 keycode = 0x%X)\n", xkey.keycode);
#endif
		/* Get the translated SDL virtual keysym */
		keysym.scancode = keycode;
		keysym.sym = X11_TranslateKeycode(DGA_Display, keycode);
		keysym.mod = KMOD_NONE;
		keysym.unicode = 0;

		/* Look up the translated value for the key event */
		if ( SDL_TranslateUNICODE ) {
			static XComposeStatus state;
			char keybuf[32];

			if ( XLookupString(&xkey, keybuf, sizeof(keybuf), NULL, &state) ) {
				/*
				* FIXME: XLookupString() may yield more than one
				* character, so we need a mechanism to allow for
				* this (perhaps null keypress events with a
				* unicode value)
				*/
				keysym.unicode = (Uint8)keybuf[0];
			}
		}
		posted = SDL_PrivateKeyboard(SDL_PRESSED, &keysym);
	    }
	    break;

	    /* Key release? */
	    case KeyRelease: {
		SDL_keysym keysym;
		KeyCode keycode;
		XKeyEvent xkey;

		SDL_NAME(XDGAKeyEventToXKeyEvent)(&xevent.xkey, &xkey);
		keycode = xkey.keycode;
#ifdef DEBUG_XEVENTS
printf("KeyRelease (X11 keycode = 0x%X)\n", xkey.keycode);
#endif
		/* Get the translated SDL virtual keysym */
		keysym.scancode = keycode;
		keysym.sym = X11_TranslateKeycode(DGA_Display, keycode);
		keysym.mod = KMOD_NONE;
		keysym.unicode = 0;
		posted = SDL_PrivateKeyboard(SDL_RELEASED, &keysym);
	    }
	    break;
	}
	return(posted);
}

void DGA_PumpEvents(_THIS)
{
	/* Keep processing pending events */
	LOCK_DISPLAY();

	/* Update activity every five seconds to prevent screensaver. --ryan. */
	if (!allow_screensaver) {
		static Uint32 screensaverTicks;
		Uint32 nowTicks = SDL_GetTicks();
		if ((nowTicks - screensaverTicks) > 5000) {
			XResetScreenSaver(DGA_Display);
			screensaverTicks = nowTicks;
		}
	}

	while ( X11_Pending(DGA_Display) ) {
		DGA_DispatchEvent(this);
	}

	UNLOCK_DISPLAY();
}

void DGA_InitOSKeymap(_THIS)
{
	X11_InitKeymap();
}