view src/video/ataricommon/SDL_xbiosinterrupt.S @ 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 0b9b4bf3c1e7
children d9f3b5bb7870
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  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
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

/*
 *	XBIOS mouse & joystick vectors
 *
 *	Patrice Mandin
 */

	.text

	.globl	_SDL_AtariXbios_Install
	.globl	_SDL_AtariXbios_Restore
	.globl	_SDL_AtariXbios_MouseVector
	.globl	_SDL_AtariXbios_JoystickVector

	.globl	_SDL_AtariXbios_mouseb
	.globl	_SDL_AtariXbios_mousex
	.globl	_SDL_AtariXbios_mousey
	.globl	_SDL_AtariXbios_joystick

/*--- Vector installer ---*/

_SDL_AtariXbios_Install:
	movel	sp@(4),a0

	/* Stop interrupts */

	movew	#0x2700,sr

	/* Save old mouse vector, set our routine */

	clrl	oldmousevector
	movel	sp@(8),d0
	beqs	no_new_mouse_vector
	movel	a0@(16),oldmousevector
	movel	d0,a0@(16)
no_new_mouse_vector:

	/* Save old joystick vector, set our routine */

	clrl	oldjoystickvector
	movel	sp@(12),d0
	beqs	no_new_joystick_vector
	movel	a0@(24),oldjoystickvector
	movel	d0,a0@(24)
no_new_joystick_vector:

	/* Restart interrupts */

	movew	#0x2300,sr

	rts

/*--- Vector restorer ---*/

_SDL_AtariXbios_Restore:
	movel	sp@(4),a0

	/* Stop interrupts */

	movew	#0x2700,sr

	/* Restore mouse vector */

	movel	oldmousevector,d0
	beqs	no_restore_mouse
	movel	d0,a0@(16)
no_restore_mouse:

	/* Restore joystick vector */

	movel	oldjoystickvector,d0
	beqs	no_restore_joystick
	movel	d0,a0@(24)
no_restore_joystick:

	/* Restart interrupts */

	movew	#0x2300,sr

	rts

/*--- Our mouse vector ---*/

	.text
	.even
	.ascii "XBRA"
	.ascii "LSDL"
	.comm	oldmousevector,4*1
_SDL_AtariXbios_MouseVector:
	moveml	d0/a1,sp@-

	/* Mouse buttons */
	moveb	(a0),d0
	andw	#3,d0
	movew	d0,_SDL_AtariXbios_mouseb

	/* X movement */
	moveb	a0@(1),d0
	extw	d0
	addw	d0,_SDL_AtariXbios_mousex

	/* Y movement */
	moveb	a0@(2),d0
	extw	d0
	addw	d0,_SDL_AtariXbios_mousey

	/* Jump through old vector */
	movel	oldmousevector,a1
	jsr	(a1)

	moveml	sp@+,d0/a1
	rts

	.data
	.even
	.comm	_SDL_AtariXbios_mousex,2*1
	.even
	.comm	_SDL_AtariXbios_mousey,2*1
	.even
	.comm	_SDL_AtariXbios_mouseb,2*1

/*--- Our joystick vector ---*/

	.text
	.even
	.ascii "XBRA"
	.ascii "LSDL"
	.comm	oldjoystickvector,4*1
_SDL_AtariXbios_JoystickVector:
	moveml	d0/a1,sp@-

	/* New joystick state */
	moveb	a0@(1),d0
	andw	#0x8f,d0
	movew	d0,_SDL_AtariXbios_joystick

	/* Jump through old vector */
	movel	oldjoystickvector,a1
	jsr	(a1)

	moveml	sp@+,d0/a1
	rts

	.data
	.even
	.comm	_SDL_AtariXbios_joystick,2*1