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From Bug #36: There are a couple of issues with the selection of Altivec alpha-blitting routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c. 1) There's no check for the presence of Altivec when checking if the Blit32to565PixelAlphaAltivec() routine can be selected. 2) Altivec cannot be used in video memory, and there's no check if the destination surface is a hardware surface. (Alpha-blitting to a hardware surface with GPU support is a bad idea, but somebody's bound to do it anyway.) Patch to fix these attached.
author Ryan C. Gordon <icculus@icculus.org>
date Sun, 08 Jan 2006 21:18:15 +0000
parents f6ffac90895c
children c9b51268668f
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

/*
 *	VBL queue routine
 *
 *	Patrice Mandin
 */

#define _vbl_queue 0x456

	.text

	.globl	_SDL_AtariVblInstall
	.globl	_SDL_AtariVblUninstall

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

_SDL_AtariVblInstall:
	movel	sp@(4),my_vector
	lea		_my_vbl,a0

	clrw	vbl_mutex

	/* Stop interrupts */

	movew	#0x2700,sr

	/* Read vbl_queue pointer */
	movel	_vbl_queue.w,a1

	/* Search a free place */
	moveq	#7,d0
bcl_search_place:
	movel	(a1),d1
	beqs	place_found
	addql	#4,a1
	dbra	d0,bcl_search_place

	/* Not found */
	moveq	#1,d0
	bras	exit_vbl_queue

	/* Then install ourselves */
place_found:
	movel	a0,(a1)
	moveq	#0,d0	

exit_vbl_queue:
	/* Restart interrupts */
	movew	#0x2300,sr

	rts

/*--- Vector uninstaller ---*/

_SDL_AtariVblUninstall:
	movel	sp@(4),d0
	cmpl	my_vector,d0
	bnes	badvector
	
	movel	#_my_vbl,d0

	/* Stop interrupts */

	movew	#0x2700,sr

	/* Read vbl_queue pointer */
	movel	_vbl_queue.w,a1

	/* Search where we are */
	moveq	#7,d1
bcl2_search_place:
	cmpl	(a1),d0
	bnes	next_place
	clrl	(a1)
	moveq	#0,d1
next_place:
	addql	#4,a1
	dbra	d1,bcl2_search_place

	/* Restart interrupts */
	movew	#0x2300,sr
badvector:
	rts

/*--- Our vbl ---*/

_my_vbl:
	/* Verify if this is not already running */

	tstw	vbl_mutex
	bnes	vbl_end
	notw	vbl_mutex

	moveml	d0-d7/a0-a6,sp@-
	movel	my_vector,a0
	jsr		a0@
	moveml	sp@+,d0-d7/a0-a6

	clrw	vbl_mutex
vbl_end:
	rts

	.data
	.even
	.comm	vbl_mutex,2*1
	.even
	.comm	my_vector,4*1