view src/video/xbios/SDL_xbios_sb3.c @ 1542:a8bf1aa21020

Fixed bug #15 SDL_blit_A.mmx-speed.patch.txt -- Speed improvements and a bugfix for the current GCC inline mmx asm code: - Changed some ops and removed some resulting useless ones. - Added some instruction parallelism (some gain) The resulting speed on my Xeon improved upto 35% depending on the function (measured in fps). - Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was setting the alpha component on the destination surfaces (to opaque-alpha) even when the surface had none. SDL_blit_A.mmx-msvc.patch.txt -- MSVC mmx intrinsics version of the same GCC asm code. MSVC compiler tries to parallelize the code and to avoid register stalls, but does not always do a very good job. Per-surface blending MSVC functions run quite a bit faster than their pure-asm counterparts (upto 55% faster for 16bit ones), but the per-pixel blending runs somewhat slower than asm. - BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all variants) can now also handle formats other than (A)RGB8888. Formats like RGBA8888 and some quite exotic ones are allowed -- like RAGB8888, or actually anything having channels aligned on 8bit boundary and full 8bit alpha (for per-pixel alpha blending). The performance cost of this change is virtually 0 for per-surface alpha blending (no extra ops inside the loop) and a single non-MMX op inside the loop for per-pixel blending. In testing, the per-pixel alpha blending takes a ~2% performance hit, but it still runs much faster than the current code in CVS. If necessary, a separate function with this functionality can be made. This code requires Processor Pack for VC6.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:39:29 +0000
parents d910939febfa
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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
*/
#include "SDL_config.h"

/*
	ScreenBlaster 3 functions

	Patrice Mandin
*/

/*--- Includes ---*/

#include "SDL_stdinc.h"
#include "SDL_xbios.h"
#include "SDL_xbios_sb3.h"

/*--- Defines ---*/

const int SDL_XBIOS_scpn_planes_device[]={
	SCPN_DEV_1BPP,
	SCPN_DEV_4BPP,
	SCPN_DEV_8BPP,
	SCPN_DEV_16BPP,
	SCPN_DEV_2BPP,
	SCPN_DEV_4BPP,
	SCPN_DEV_1BPP
};

/*--- Functions ---*/

int SDL_XBIOS_SB3Usable(scpn_cookie_t *cookie_scpn)
{
	scpn_screeninfo_t *scrinfo;
	int bpp;

	/* Check if current SB3 mode is usable, i.e. 8 or 16bpp */
	scrinfo = cookie_scpn->screen_info;
	bpp = 1<<(SDL_XBIOS_scpn_planes_device[scrinfo->device]);

	if ((bpp==8) || (bpp==16)) {
		return 1;
	}

	return 0;
}

void SDL_XBIOS_SB3Init(_THIS, scpn_cookie_t *cookie_scpn)
{
	scpn_screeninfo_t *scrinfo;

	/* SB3 prevent changing video modes, we can only use current one */
	if (XBIOS_modelist) {
		SDL_free(XBIOS_modelist);
		XBIOS_nummodes = 0;
		XBIOS_modelist = NULL;
	}

	scrinfo = cookie_scpn->screen_info;
	scrinfo->h_pos = scrinfo->v_pos = 0;

	SDL_XBIOS_AddMode(this,
		-1,
		scrinfo->virtual_width, scrinfo->virtual_height,
		1<<(SDL_XBIOS_scpn_planes_device[scrinfo->device]),
		SDL_FALSE
	);
}