Mercurial > sdl-ios-xcode
view src/timer/mint/SDL_vbltimer.S @ 1554:0ca607a5d173
Fixed bug #84
Date: Sun, 23 Oct 2005 16:39:03 +0200
From: "A. Schmid" <sahib@phreaker.net>
Subject: [SDL] no software surfaces with svgalib driver?
Hi,
I noticed that the SDL (1.2.9) svgalib driver only makes use of linear
addressable (framebuffer) video modes. On older systems (like one of
mine), linear addressable modes are often not available.
Especially for cards with VESA VBE < 2.0 the svgalib vesa driver is
unusable, since VESA only supports framebuffering for VBE 2.0 and later.
The changes necessary to add support for software surfaces seem to be
relatively small. I only had to hack src/video/svga/SDL_svgavideo.c (see
attached patch). The code worked fine for me, but it is no more than a
proof of concept and should be reviewed (probably has a memory leak when
switching modes). It also uses the vgagl library (included in the
svgalib package) and needs to be linked against it.
-Alex
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 19 Mar 2006 12:04:40 +0000 |
| parents | c9b51268668f |
| children | eb5e61b72da3 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 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 */ /* * 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