/*	SGLUDDSP.h 	Copyright (C) 2012 Paul C. Pratt 	You can redistribute this file and/or modify it under the terms	of version 2 of the GNU General Public License as published by	the Free Software Foundation.  You should have received a copy	of the license along with this file; see the file COPYING. 	This file 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	license for more details.*/ /*	Sound GLUe for "/Dev/DSP"		OSS and related, accessed through "/dev/dsp"*/ LOCALVAR int audio_fd = -1;LOCALVAR blnr audio_started; #if 4 == kLn2SoundSampSzLOCALPROC ConvertSoundBlockToNative(tpSoundSamp p){	int i; 	for (i = kOneBuffLen; --i >= 0; ) {		*p++ -= 0x8000;	}}#else#define ConvertSoundBlockToNative(p)#endif LOCALPROC MySound_WriteOut(void){	int retry_count = 32; label_retry:	if (--retry_count > 0) {		int err;		struct audio_buf_info info; 		if (ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info) != 0) {			fprintf(stderr, "SNDCTL_DSP_GETOSPACE fails\n");		} else {			tpSoundSamp NextPlayPtr;			ui4b PlayNowSize = 0;			ui4b MaskedFillOffset = ThePlayOffset & kOneBuffMask;			ui4b PrivateBuffUsed = TheFillOffset - ThePlayOffset;			int used = (info.fragstotal * info.fragsize) - info.bytes; 			if (audio_started) {				ui4b TotPendBuffs = used >> kLnOneBuffSz; 				if (TotPendBuffs < MinFilledSoundBuffs) {					MinFilledSoundBuffs = TotPendBuffs;				}				/* fprintf(stderr, "buffer used %d\n", (int)used); */			} else {				if (PrivateBuffUsed >= kAllBuffLen - kOneBuffLen) {					audio_started = trueblnr;				} else {					info.bytes = 0;				}			} 			if (MaskedFillOffset != 0) {				/* take care of left overs */				PlayNowSize = kOneBuffLen - MaskedFillOffset;				NextPlayPtr =					TheSoundBuffer + (ThePlayOffset & kAllBuffMask);			} else if (0 !=				((TheFillOffset - ThePlayOffset) >> kLnOneBuffLen))			{				PlayNowSize = kOneBuffLen;				NextPlayPtr =					TheSoundBuffer + (ThePlayOffset & kAllBuffMask);			} else {				/* nothing to play now */			} #if 4 == kLn2SoundSampSz			PlayNowSize <<= 1;#endif 			if (PlayNowSize > info.bytes) {				PlayNowSize = info.bytes;			} 			if (0 != PlayNowSize) {				err = write(					audio_fd, NextPlayPtr, PlayNowSize);				if (err < 0) {					if (- EAGAIN == err) {						/* buffer full, try again later */						fprintf(stderr, "pcm write: EAGAIN\n");					} else if (- EPIPE == err) {						/* buffer seems to have emptied */						fprintf(stderr, "pcm write emptied\n");						goto label_retry;					} else {						fprintf(stderr, "audio_fd write error: %d\n",							err);					}				} else {					ThePlayOffset += err#if 4 == kLn2SoundSampSz						>> 1#endif						;					goto label_retry;				}			}		}	}} LOCALPROC MySound_Start(void){	if (audio_fd >= 0) {		MySound_Start0();		audio_started = falseblnr;	}} LOCALPROC MySound_Stop(void){	if (audio_fd >= 0) {		if (0 !=			ioctl(audio_fd, SNDCTL_DSP_RESET /* SNDCTL_DSP_HALT */,				NULL))		{			fprintf(stderr, "SNDCTL_DSP_RESET fails\n");		}	}} #if 4 == kLn2SoundSampSz#define MyDesiredFormat AFMT_S16_NE#else#define MyDesiredFormat AFMT_U8#endif LOCALFUNC blnr MySound_Init(void){	blnr IsOk = falseblnr; 	audio_fd = open(AudioDevPath, O_WRONLY, 0);	if (audio_fd < 0) {		fprintf(stderr, "open /dev/dsp fails: %d\n", audio_fd);	} else {		int fragment_value =  (16 /* 16 fragments */ << 16)#if 4 == kLn2SoundSampSz			| 10 /* of 1024 bytes */#else			| 9 /* of 512 bytes */#endif			;		int channels_value = 1;		int fmt_value = MyDesiredFormat;		int speed_value = SOUND_SAMPLERATE; 		/* fprintf(stderr, "open /dev/dsp works\n"); */ 		if (0 !=			ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &fragment_value))		{			fprintf(stderr, "SNDCTL_DSP_SETFRAGMENT fails\n");		} else if ((0 !=				ioctl(audio_fd, SNDCTL_DSP_CHANNELS, &channels_value))			|| (channels_value != 1))		{			fprintf(stderr, "SNDCTL_DSP_CHANNELS fails\n");		} else if ((0 !=				ioctl(audio_fd, SNDCTL_DSP_SETFMT, &fmt_value))			|| (fmt_value != MyDesiredFormat))		{			fprintf(stderr, "SNDCTL_DSP_SETFMT fails\n");		} else if ((0 !=				ioctl(audio_fd, SNDCTL_DSP_SPEED, &speed_value))			|| (speed_value != SOUND_SAMPLERATE))		{			fprintf(stderr, "SNDCTL_DSP_SPEED fails\n");		} else		{			IsOk = trueblnr;		} 		if (! IsOk) {			(void) close(audio_fd);			audio_fd = -1;		}	} 	return trueblnr; /* keep going, even if no sound */} LOCALPROC MySound_UnInit(void){	if (audio_fd >= 0) {		if (close(audio_fd) != 0) {			fprintf(stderr, "close /dev/dsp fails\n");		}		audio_fd = -1;	}} GLOBALOSGLUPROC MySound_EndWrite(ui4r actL){	if (MySound_EndWrite0(actL)) {		ConvertSoundBlockToNative(TheSoundBuffer			+ ((TheFillOffset - kOneBuffLen) & kAllBuffMask));		if (audio_fd >= 0) {			MySound_WriteOut();		}	}} LOCALPROC MySound_SecondNotify(void){	if (audio_fd >= 0) {		MySound_SecondNotify0();	}}