view src/video/xbios/SDL_xbios_centscreen.c @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +0000
parents d910939febfa
children 782fd950bd46 c121d94672cb 568c9b3c0167
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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"

/*
	Centscreen extension definitions

	Patrice Mandin
*/

#include <mint/falcon.h>

#include "SDL_xbios.h"
#include "SDL_xbios_centscreen.h"

int SDL_XBIOS_CentscreenInit(_THIS)
{
	centscreen_mode_t	curmode, listedmode;
	unsigned long result;
	int cur_handle;	/* Current Centscreen mode handle */

	/* Reset current mode list */
	if (XBIOS_modelist) {
		SDL_free(XBIOS_modelist);
		XBIOS_nummodes = 0;
		XBIOS_modelist = NULL;
	}

	/* Add Centscreen modes */
	Vread(&curmode);
	cur_handle = curmode.handle;
	curmode.mode = curmode.physx = curmode.physy = curmode.plan =
		curmode.logx = curmode.logy = -1;

	result = Vfirst(&curmode, &listedmode);
	if (result==0) {
		while (result==0) {
			/* Don't add modes with virtual screen */
			if ((listedmode.mode & CSCREEN_VIRTUAL)==0) {
				/* Don't add modes with bpp<8 */
				if (listedmode.plan>=8) {
					SDL_XBIOS_AddMode(this, listedmode.mode, listedmode.physx,
						listedmode.physy, listedmode.plan, SDL_FALSE
					);
				}
			}
			SDL_memcpy(&curmode, &listedmode, sizeof(centscreen_mode_t));
			curmode.mode = curmode.physx = curmode.physy = curmode.plan =
				curmode.logx = curmode.logy = -1;
			result = Vnext(&curmode, &listedmode);
		}		
	} else {
		fprintf(stderr, "No suitable Centscreen modes\n");
	}

	return cur_handle;
}

void SDL_XBIOS_CentscreenSetmode(_THIS, int width, int height, int planes)
{
	centscreen_mode_t	newmode, curmode;
	
	newmode.handle = newmode.mode = newmode.logx = newmode.logy = -1;
	newmode.physx = width;
	newmode.physy = height;
	newmode.plan = planes;
	Vwrite(0, &newmode, &curmode);

	/* Disable screensaver */
	Vread(&newmode);
	newmode.mode &= ~(CSCREEN_SAVER|CSCREEN_ENERGYSTAR);
	Vwrite(0, &newmode, &curmode);
}

void SDL_XBIOS_CentscreenRestore(_THIS, int prev_handle)
{
	centscreen_mode_t	newmode, curmode;

	/* Restore old video mode */
	newmode.handle = prev_handle;
	newmode.mode = newmode.physx = newmode.physy = newmode.plan =
		newmode.logx = newmode.logy = -1;
	Vwrite(0, &newmode, &curmode);
}