view src/video/xbios/SDL_xbios_blowup.h @ 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 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"

/*
	Blowup extension definitions

	Patrice Mandin
*/

#ifndef _SDL_xbios_blowup_h
#define _SDL_xbios_blowup_h

#include "SDL_xbios.h"

/*--- Types ---*/

typedef struct {
	/* 64 bytes */
	unsigned short	enabled;		/* Extended mode enabled ? 0=yes, <>0=no */
	unsigned short	dummy10[6];
	unsigned short	registers_0E;	/* value for register 0xffff820e */
	unsigned short	registers_10;	/* value for register 0xffff8210 */
	unsigned short	dummy11[23];

	/* 64 bytes */
	unsigned short	width;			/* width-1 */
	unsigned short	height;			/* height-1 */
	unsigned short	dummy20;
	unsigned long	screensize;		/* screensize in bytes */
	unsigned short	dummy21[8];
	unsigned short	virtual;		/* Virtual screen ? */
	unsigned short	virwidth;		/* Virtual screen width */
	unsigned short	virheight;		/* Virtual screen height */

	unsigned short dummy22;
	unsigned short monitor;			/* Monitor defined for this mode */
	unsigned short extension;		/* Extended mode defined ? 0=yes, 1=no */
	unsigned short dummy23[13];

	/* 64 bytes */
	unsigned short	dummy30;
	unsigned short	registers_82[6];	/* values for registers 0xffff8282-8c */
	unsigned short	dummy31[9];

	unsigned short	dummy32;
	unsigned short	registers_A2[6];	/* values for registers 0xffff82a2-ac */
	unsigned short	dummy33[9];

	/* 64 bytes */
	unsigned short	registers_C0;	/* value for register 0xffff82c0 */
	unsigned short	registers_C2;	/* value for register 0xffff82c2 */
	unsigned short	dummy40[30];
} __attribute__((packed)) blow_mode_t;

typedef struct {
	blow_mode_t	blowup_modes[10];
	unsigned char	num_mode[6];
	unsigned long	dummy;
	unsigned short	montype;
} __attribute__((packed)) blow_cookie_t;

/*--- Functions prototypes ---*/

void SDL_XBIOS_BlowupInit(_THIS, blow_cookie_t *cookie_blow);

#endif /* _SDL_xbios_blowup_h */