/*
 * This is an alternate backend for the sound effect system.
 * It uses SDL_mixer to provide a more reliable playback,
 * and allow processing of multiple audio formats.
 *
 *  -- MD2211 (2006-08-29)
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <SDL/SDL.h>
#include <SDL/SDL_audio.h>
#include <SDL/SDL_mixer.h>

#include "error.h"
#include "mono.h"
#include "fix.h"
#include "vecmat.h"
#include "gr.h" // needed for piggy.h
#include "piggy.h"
#include "digi.h"
#include "sounds.h"
#include "wall.h"
#include "newdemo.h"
#include "kconfig.h"
#include "altsound.h"

#define MIX_DIGI_DEBUG 0


//edited 05/17/99 Matt Mueller - added ifndef NO_ASM
//added on 980905 by adb to add inline fixmul for mixer on i386
#ifndef NO_ASM
#ifdef __i386__
#define do_fixmul(x,y)				\
({						\
	int _ax, _dx;				\
	asm("imull %2\n\tshrdl %3,%1,%0"	\
	    : "=a"(_ax), "=d"(_dx)		\
	    : "rm"(y), "i"(16), "0"(x));	\
	_ax;					\
})
extern inline fix fixmul(fix x, fix y) { return do_fixmul(x,y); }
#endif
#endif
//end edit by adb
//end edit -MM

//changed on 980905 by adb to increase number of concurrent sounds
#define MAX_SOUND_SLOTS 32
//end changes by adb
#define SOUND_BUFFER_SIZE 512

#define MIN_VOLUME 10

/* This table is used to add two sound values together and pin
 * the value to avoid overflow.  (used with permission from ARDI)
 * DPH: Taken from SDL/src/SDL_mixer.c.
 */
static const Uint8 mix8[] =
{
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03,
  0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
  0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
  0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24,
  0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
  0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
  0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
  0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B,
  0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
  0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71,
  0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
  0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
  0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
  0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D,
  0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
  0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
  0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE,
  0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9,
  0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4,
  0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
  0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA,
  0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5,
  0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};

#define SOF_USED			1		// Set if this sample is used
#define SOF_PLAYING			2		// Set if this sample is playing on a channel
#define SOF_LINK_TO_OBJ		4		// Sound is linked to a moving object. If object dies, then finishes play and quits.
#define SOF_LINK_TO_POS		8		// Sound is linked to segment, pos
#define SOF_PLAY_FOREVER	16		// Play forever (or until level is stopped), otherwise plays once

typedef struct sound_object {
	short		signature;		// A unique signature to this sound
	ubyte		flags;			// Used to tell if this slot is used and/or currently playing, and how long.
	fix		max_volume;		// Max volume that this sound is playing at
	fix		max_distance;	        // The max distance that this sound can be heard at...
	int		volume;			// Volume that this sound is playing at
	int 		pan;			// Pan value that this sound is playing at
	int		handle; 		// What handle this sound is playing on.  Valid only if SOF_PLAYING is set.
	short		soundnum;		// The sound number that is playing
	union {	
		struct {
			short		segnum; 			// Used if SOF_LINK_TO_POS field is used
			short		sidenum;
			vms_vector	position;
		}pos;
		struct {
			short		 objnum;			 // Used if SOF_LINK_TO_OBJ field is used
			short		 objsignature;
		}obj;
	}link;
} sound_object;
#define lp_segnum link.pos.segnum
#define lp_sidenum link.pos.sidenum
#define lp_position link.pos.position

#define lo_objnum link.obj.objnum
#define lo_objsignature link.obj.objsignature

#define MAX_SOUND_OBJECTS 16
sound_object SoundObjects[MAX_SOUND_OBJECTS];
short next_signature=0;

//added/changed on 980905 by adb to make sfx volume work, on 990221 by adb changed F1_0 to F1_0 / 2
#define SOUND_MAX_VOLUME (F1_0 / 2)

int digi_volume = SOUND_MAX_VOLUME;
//end edit by adb

int digi_lomem = 0;

static int digi_initialised = 0;

struct sound_slot {
 int soundno;
 int playing;   // Is there a sample playing on this channel?
 int looped;    // Play this sample looped?
 fix pan;       // 0 = far left, 1 = far right
 fix volume;    // 0 = nothing, 1 = fully on
 //changed on 980905 by adb from char * to unsigned char * 
 unsigned char *samples;
 //end changes by adb
 unsigned int length; // Length of the sample
 unsigned int position; // Position we are at at the moment.
} SoundSlots[MAX_SOUND_SLOTS];

//MD2211
Mix_Chunk SoundChunks[MAX_SOUNDS];
#define SOUND_MIXING_CHANNELS 64

static SDL_AudioSpec WaveSpec;
static int digi_sounds_initialized = 0;

//added on 980905 by adb to add rotating/volume based sound kill system
static int digi_max_channels = 16;
static int next_handle = 0;
int SampleHandles[32];
void reset_sounds_on_channel(int channel);
//end edit by adb

void digi_reset_digi_sounds(void);


/* Initialise audio devices. */
int digi_init()
{
 if (MIX_DIGI_DEBUG) printf("digi_init\n");
 if (SDL_InitSubSystem(SDL_INIT_AUDIO)<0) Error("SDL audio initialisation failed: %s.",SDL_GetError());

 // We can afford it! 
 WaveSpec.freq = 44100;
 WaveSpec.format = AUDIO_S16;
 WaveSpec.channels = 2;
 
 if (Mix_OpenAudio(WaveSpec.freq, WaveSpec.format, WaveSpec.channels, SOUND_BUFFER_SIZE)) {
//edited on 10/05/98 by Matt Mueller - should keep running, just with no sound.
	 printf("\nError: Couldn't open audio: %s\n", SDL_GetError());
//killed  exit(2);
	 return 1;
//end edit -MM
 }

 Mix_AllocateChannels(SOUND_MIXING_CHANNELS);
 Mix_Pause(0);

 atexit(digi_close);
 digi_initialised = 1;
 return 0;
}

/* Toggle audio */
void digi_reset() { }

/* Shut down audio */
void digi_close()
{
 if (!digi_initialised) return;
 digi_initialised = 0;
 Mix_CloseAudio();
}

int fix2byte(fix f) {
  return (f / 256) % 256;
}

int digi_start_sound(int soundnum, fix volume, fix pan)
{
 if (!digi_initialised) return -1;

 int mix_vol = fix2byte(fixmul(digi_volume, volume));
 int mix_pan = fix2byte(pan);

 if (MIX_DIGI_DEBUG) printf("digi_start_sound %d, volume %d, pan %d\n", soundnum, mix_vol, mix_pan);

 int channel = Mix_PlayChannel(-1, &(SoundChunks[soundnum]), 0);
 Mix_SetPanning(channel, 255-mix_pan, mix_pan);
 Mix_SetDistance(channel, 255-mix_vol);

 return 0;
}

int digi_start_sound_object(int obj)
{
 if (!digi_initialised) return -1;

 if (MIX_DIGI_DEBUG) printf("digi_start_sound_object %d (%d)\n", obj, SoundObjects[obj].soundnum);

 int channel = Mix_PlayChannel(-1, &(SoundChunks[SoundObjects[obj].soundnum]), -1);

 SoundObjects[obj].signature = next_signature++;
 SoundObjects[obj].handle = channel;
 SoundObjects[obj].flags |= SOF_PLAYING;

 return 0;
}

// Play the given sound number.
// Volume is max at F1_0.
void digi_play_sample( int soundno, fix max_volume )
{
#ifdef NEWDEMO
	if ( Newdemo_state == ND_STATE_RECORDING )
		newdemo_record_sound( soundno );
#endif
	if (!digi_initialised) return;

        if (digi_xlat_sound(soundno) < 0 ) return;

	digi_start_sound(soundno, max_volume, F0_5);
}

// Play the given sound number. If the sound is already playing,
// restart it.
void digi_play_sample_once( int soundno, fix max_volume )
{
	int i;

#ifdef NEWDEMO
	if ( Newdemo_state == ND_STATE_RECORDING )
		newdemo_record_sound( soundno );
#endif

	if (!digi_initialised) return;

        if (digi_xlat_sound(soundno) < 0 ) return;

        for (i=0; i < MAX_SOUND_SLOTS; i++)
          if (SoundSlots[i].soundno == soundno)
            SoundSlots[i].playing = 0;
	digi_start_sound(soundno, max_volume, F0_5);

}

void digi_play_sample_3d( int soundno, int angle, int volume, int no_dups ) // Volume from 0-0x7fff
{
	no_dups = 1;

#ifdef NEWDEMO
	if ( Newdemo_state == ND_STATE_RECORDING )		{
		if ( no_dups )
			newdemo_record_sound_3d_once( soundno, angle, volume );
		else
			newdemo_record_sound_3d( soundno, angle, volume );
	}
#endif
	if (!digi_initialised) return;
        if (digi_xlat_sound(soundno) < 0 ) return;

	if (volume < MIN_VOLUME ) return;
	digi_start_sound(soundno, volume, angle);
}

void digi_get_sound_loc( vms_matrix * listener, vms_vector * listener_pos, int listener_seg, vms_vector * sound_pos, int sound_seg, fix max_volume, int *volume, int *pan, fix max_distance )
{	  
	vms_vector	vector_to_sound;
	fix angle_from_ear, cosang,sinang;
	fix distance;
	fix path_distance;

	*volume = 0;
	*pan = 0;

	max_distance = (max_distance*5)/4;		// Make all sounds travel 1.25 times as far.

	//	Warning: Made the vm_vec_normalized_dir be vm_vec_normalized_dir_quick and got illegal values to acos in the fang computation.
	distance = vm_vec_normalized_dir_quick( &vector_to_sound, sound_pos, listener_pos );
		
	if (distance < max_distance )	{
		int num_search_segs = f2i(max_distance/20);
		if ( num_search_segs < 1 ) num_search_segs = 1;

		path_distance = find_connected_distance(listener_pos, listener_seg, sound_pos, sound_seg, num_search_segs, WID_RENDPAST_FLAG );
		if ( path_distance > -1 )	{
			*volume = max_volume - fixdiv(path_distance,max_distance);
			//mprintf( (0, "Sound path distance %.2f, volume is %d / %d\n", f2fl(distance), *volume, max_volume ));
			if (*volume > 0 )	{
				angle_from_ear = vm_vec_delta_ang_norm(&listener->rvec,&vector_to_sound,&listener->uvec);
				fix_sincos(angle_from_ear,&sinang,&cosang);
				//mprintf( (0, "volume is %.2f\n", f2fl(*volume) ));
				if (Config_channels_reversed) cosang *= -1;
				*pan = (cosang + F1_0)/2;
			} else {
				*volume = 0;
			}
		}
	}																					  
}

int digi_link_sound_to_object2( int soundnum, short objnum, int forever, fix max_volume, fix  max_distance )
{
	int i,volume,pan;
	object * objp;

	if ( max_volume < 0 ) return -1;
//	if ( max_volume > F1_0 ) max_volume = F1_0;

	if (!digi_initialised) return -1;
	if (soundnum < 0 ) return -1;
        if (Sounddat(soundnum)->data==NULL) {
		Int3();
		return -1;
	}
	if ((objnum<0)||(objnum>Highest_object_index))
		return -1;

	if ( !forever )	{
		// Hack to keep sounds from building up...
		digi_get_sound_loc( &Viewer->orient, &Viewer->pos, Viewer->segnum, &Objects[objnum].pos, Objects[objnum].segnum, max_volume,&volume, &pan, max_distance );
                digi_play_sample_3d(soundnum, pan, volume, 0 );
		return -1;
	}

       	for (i=0; i<MAX_SOUND_OBJECTS; i++ )
        	if (SoundObjects[i].flags==0)
	           break;

	if (i==MAX_SOUND_OBJECTS) {
		mprintf((1, "Too many sound objects!\n" ));
		return -1;
	}

	SoundObjects[i].signature=next_signature++;
	SoundObjects[i].flags = SOF_USED | SOF_LINK_TO_OBJ;
	if ( forever )
		SoundObjects[i].flags |= SOF_PLAY_FOREVER;
	SoundObjects[i].lo_objnum = objnum;
	SoundObjects[i].lo_objsignature = Objects[objnum].signature;
	SoundObjects[i].max_volume = max_volume;
	SoundObjects[i].max_distance = max_distance;
	SoundObjects[i].volume = 0;
	SoundObjects[i].pan = 0;
	SoundObjects[i].soundnum = soundnum;

	objp = &Objects[SoundObjects[i].lo_objnum];
	digi_get_sound_loc( &Viewer->orient, &Viewer->pos, Viewer->segnum, 
                       &objp->pos, objp->segnum, SoundObjects[i].max_volume,
                       &SoundObjects[i].volume, &SoundObjects[i].pan, SoundObjects[i].max_distance );

	if (!forever || SoundObjects[i].volume >= MIN_VOLUME)
	       digi_start_sound_object(i);

	return SoundObjects[i].signature;
}

int digi_link_sound_to_object( int soundnum, short objnum, int forever, fix max_volume )
{ return digi_link_sound_to_object2( soundnum, objnum, forever, max_volume, 256*F1_0); }

int digi_link_sound_to_pos2( int soundnum, short segnum, short sidenum, vms_vector * pos, int forever, fix max_volume, fix max_distance )
{
	int i, volume, pan;

	if ( max_volume < 0 ) return -1;
//	if ( max_volume > F1_0 ) max_volume = F1_0;

	if (!digi_initialised) return -1;
        if (digi_xlat_sound(soundnum) < 0 ) return -1;
        if (Sounddat(soundnum)->data==NULL) {
		Int3();
		return -1;
	}

	if ((segnum<0)||(segnum>Highest_segment_index))
		return -1;

	if ( !forever )	{
		// Hack to keep sounds from building up...
		digi_get_sound_loc( &Viewer->orient, &Viewer->pos, Viewer->segnum, pos, segnum, max_volume, &volume, &pan, max_distance );
                digi_play_sample_3d( soundnum, pan, volume, 0 );
		return -1;
	}

	for (i=0; i<MAX_SOUND_OBJECTS; i++ )
		if (SoundObjects[i].flags==0)
			break;
	
	if (i==MAX_SOUND_OBJECTS) {
		mprintf((1, "Too many sound objects!\n" ));
		return -1;
	}


	SoundObjects[i].signature=next_signature++;
	SoundObjects[i].flags = SOF_USED | SOF_LINK_TO_POS;
	if ( forever )
		SoundObjects[i].flags |= SOF_PLAY_FOREVER;
	SoundObjects[i].lp_segnum = segnum;
	SoundObjects[i].lp_sidenum = sidenum;
	SoundObjects[i].lp_position = *pos;
	SoundObjects[i].soundnum = soundnum;
	SoundObjects[i].max_volume = max_volume;
	SoundObjects[i].max_distance = max_distance;
	SoundObjects[i].volume = 0;
	SoundObjects[i].pan = 0;
	digi_get_sound_loc( &Viewer->orient, &Viewer->pos, Viewer->segnum, 
					   &SoundObjects[i].lp_position, SoundObjects[i].lp_segnum,
					   SoundObjects[i].max_volume,
                       &SoundObjects[i].volume, &SoundObjects[i].pan, SoundObjects[i].max_distance );
	
	if (!forever || SoundObjects[i].volume >= MIN_VOLUME)
		digi_start_sound_object(i);

	return SoundObjects[i].signature;
}

int digi_link_sound_to_pos( int soundnum, short segnum, short sidenum, vms_vector * pos, int forever, fix max_volume )
{
	return digi_link_sound_to_pos2( soundnum, segnum, sidenum, pos, forever, max_volume, F1_0 * 256 );
}


void digi_kill_sound_linked_to_segment( int segnum, int sidenum, int soundnum )
{
	int i,killed;

	if (!digi_initialised) return;
	if (MIX_DIGI_DEBUG) printf("digi_kill_sound_linked_to_segment %d %d %d", segnum, sidenum, soundnum);

	killed = 0;

	for (i=0; i<MAX_SOUND_OBJECTS; i++ )	{
		if ( (SoundObjects[i].flags & SOF_USED) && (SoundObjects[i].flags & SOF_LINK_TO_POS) )	{
			if ((SoundObjects[i].lp_segnum == segnum) && (SoundObjects[i].soundnum==soundnum ) && (SoundObjects[i].lp_sidenum==sidenum) ) {
				if ( SoundObjects[i].flags & SOF_PLAYING )	{
				        SoundSlots[SoundObjects[i].handle].playing = 0;
				}
				SoundObjects[i].flags = 0;	// Mark as dead, so some other sound can use this sound
				killed++;
			}
		}
	}
	// If this assert happens, it means that there were 2 sounds
	// that got deleted. Weird, get John.
	if ( killed > 1 )	{
		mprintf( (1, "ERROR: More than 1 sounds were deleted from seg %d\n", segnum ));
	}
}

void digi_kill_sound_linked_to_object( int objnum )
{
	int i,killed;

	if (!digi_initialised) return;
	if (MIX_DIGI_DEBUG) printf("digi_kill_sound_linked_to_object %d", objnum);

	killed = 0;

	for (i=0; i<MAX_SOUND_OBJECTS; i++ )	{
		if ( (SoundObjects[i].flags & SOF_USED) && (SoundObjects[i].flags & SOF_LINK_TO_OBJ ) )	{
			if (SoundObjects[i].lo_objnum == objnum)   {
				if ( SoundObjects[i].flags & SOF_PLAYING )	{
                                     SoundSlots[SoundObjects[i].handle].playing = 0;
				}
				SoundObjects[i].flags = 0;	// Mark as dead, so some other sound can use this sound
				killed++;
			}
		}
	}
	// If this assert happens, it means that there were 2 sounds
	// that got deleted. Weird, get John.
	if ( killed > 1 )	{
		mprintf( (1, "ERROR: More than 1 sounds were deleted from object %d\n", objnum ));
	}
}

void digi_sync_sounds()
{
	int i;
	int oldvolume, oldpan;
	int mix_pan, mix_vol;

	if (!digi_initialised) return;

	for (i=0; i<MAX_SOUND_OBJECTS; i++ )	{
		if ( SoundObjects[i].flags & SOF_USED )	{
			oldvolume = SoundObjects[i].volume;
			oldpan = SoundObjects[i].pan;

			if ( !(SoundObjects[i].flags & SOF_PLAY_FOREVER) )	{
			 	// Check if its done.
				if (SoundObjects[i].flags & SOF_PLAYING) {
					if (!SoundSlots[SoundObjects[i].handle].playing) {
						SoundObjects[i].flags = 0;	// Mark as dead, so some other sound can use this sound
						continue;		// Go on to next sound...
					}
				}
			}			
		
			//MD2211
			//We don't have a callback mixer anymore; hence, looped sounds must be updated here
			if (SoundObjects[i].flags & SOF_PLAYING) {
				mix_pan = fix2byte(SoundObjects[i].pan);
				mix_vol = fix2byte(SoundObjects[i].volume);
				//printf("mixing sound_object %d: vol %d, pan %d\n", i, mix_vol, mix_pan);
				Mix_SetPanning(SoundObjects[i].handle, 255-mix_pan, mix_pan);
				Mix_SetDistance(SoundObjects[i].handle, 255-mix_vol);
			}
			//end MD2211

			if ( SoundObjects[i].flags & SOF_LINK_TO_POS )	{
				digi_get_sound_loc( &Viewer->orient, &Viewer->pos, Viewer->segnum, 
								&SoundObjects[i].lp_position, SoundObjects[i].lp_segnum,
								SoundObjects[i].max_volume,
                                &SoundObjects[i].volume, &SoundObjects[i].pan, SoundObjects[i].max_distance );

			} else if ( SoundObjects[i].flags & SOF_LINK_TO_OBJ )	{
				object * objp;
	
				objp = &Objects[SoundObjects[i].lo_objnum];
		
				if ((objp->type==OBJ_NONE) || (objp->signature!=SoundObjects[i].lo_objsignature))  {
					// The object that this is linked to is dead, so just end this sound if it is looping.
					if ( (SoundObjects[i].flags & SOF_PLAYING)  && (SoundObjects[i].flags & SOF_PLAY_FOREVER))	{
					     SoundSlots[SoundObjects[i].handle].playing = 0;
	//MD2211
	if (MIX_DIGI_DEBUG) printf("stop sound_object %d: dead\n", i);
	Mix_HaltChannel(SoundObjects[i].handle);

					}
					SoundObjects[i].flags = 0;	// Mark as dead, so some other sound can use this sound
					continue;		// Go on to next sound...
				} else {
					digi_get_sound_loc( &Viewer->orient, &Viewer->pos, Viewer->segnum, 
	                                &objp->pos, objp->segnum, SoundObjects[i].max_volume,
                                   &SoundObjects[i].volume, &SoundObjects[i].pan, SoundObjects[i].max_distance );
				}
			}
			 
			if (oldvolume != SoundObjects[i].volume) 	{
				if ( SoundObjects[i].volume < MIN_VOLUME || Function_mode == FMODE_MENU)	 {
					// Sound is too far away, so stop it from playing.
	//MD2211
	if (MIX_DIGI_DEBUG) printf("stop sound_object %d: too far away\n", i);
	Mix_HaltChannel(SoundObjects[i].handle);

					if ((SoundObjects[i].flags & SOF_PLAYING)&&(SoundObjects[i].flags & SOF_PLAY_FOREVER))	{
                                        	SoundSlots[SoundObjects[i].handle].playing = 0;
						SoundObjects[i].flags &= ~SOF_PLAYING;		// Mark sound as not playing
					}
				} else {
					if (!(SoundObjects[i].flags & SOF_PLAYING))	{
						digi_start_sound_object(i);
					} else {
					        SoundSlots[SoundObjects[i].handle].volume = fixmuldiv(SoundObjects[i].volume,digi_volume,F1_0);
					}
				}
			}
				
			if (oldpan != SoundObjects[i].pan) 	{
				if (SoundObjects[i].flags & SOF_PLAYING)
                                        SoundSlots[SoundObjects[i].handle].pan = SoundObjects[i].pan;
			}
		}
	}
}

void digi_init_sounds()
{
	int i;

 //MD2211
 SDL_AudioCVT cvt;
 Uint32 dlen;
 Uint8 *data;

	if (!digi_initialised) return;

	digi_reset_digi_sounds();

	for (i=0; i<MAX_SOUND_OBJECTS; i++ )	{
		if (digi_sounds_initialized) {
			if ( SoundObjects[i].flags & SOF_PLAYING )	{
			        SoundSlots[SoundObjects[i].handle].playing=0;
			}
		}
		SoundObjects[i].flags = 0;	// Mark as dead, so some other sound can use this sound
	}
	digi_sounds_initialized = 1;

	
/****** MD2211 - Port to SDL_mixer (2006-08-30) *****
 Here we build an array of converted sound effects, for use by SDL_Mixer
 at the frequency that was set in digi_init()
 The Mix_Chunk is fed raw sound data via a hack. Using Mix_LoadWAV would be better.
*/

 for (i=0; i<MAX_SOUNDS; i++ ) {
	data = Sounddat(i)->data;
	dlen = Sounddat(i)->length;


	// FIXME Weird: sounds having length 1900572 crash memcpy() with a segfault!
	// I haven't yet found a better way to determine that they're unused slots
	if (data && dlen != 1900572) {
		//printf("converting %d\n", i);

		SDL_BuildAudioCVT(&cvt, AUDIO_U8, 1, Sounddat(i)->freq, WaveSpec.format, WaveSpec.channels, WaveSpec.freq);

		cvt.buf = malloc(dlen * cvt.len_mult);
		cvt.len = dlen;

		memcpy(cvt.buf, data, dlen);

		if (SDL_ConvertAudio(&cvt)) printf("conversion failed\n");

		SoundChunks[i].abuf = cvt.buf;
		SoundChunks[i].alen = dlen * cvt.len_mult;
		SoundChunks[i].allocated = 1;
		SoundChunks[i].volume = 128; // Max volume = 128
 	} else {
		//printf("NOT converting %d (%d %d %d)\n", i, Sounddat(i)->bits, Sounddat(i)->freq, Sounddat(i)->length);
	}
 }
}

//added on 980905 by adb from original source to make sfx volume work
void digi_set_digi_volume( int dvolume )
{
	dvolume = fixmuldiv( dvolume, SOUND_MAX_VOLUME, 0x7fff);
	if ( dvolume > SOUND_MAX_VOLUME )
		digi_volume = SOUND_MAX_VOLUME;
	else if ( dvolume < 0 )
		digi_volume = 0;
	else
		digi_volume = dvolume;

	if ( !digi_initialised ) return;

	digi_sync_sounds();
}
//end edit by adb

void digi_set_volume( int dvolume, int mvolume ) {
	digi_set_digi_volume(dvolume);
	digi_set_midi_volume(mvolume);
}

int digi_is_sound_playing(int soundno)
{
	int i;

	for (i = 0; i < MAX_SOUND_SLOTS; i++)
		  //changed on 980905 by adb: added SoundSlots[i].playing &&
		  if (SoundSlots[i].playing && SoundSlots[i].soundno == soundno)
		  //end changes by adb
			return 1;
	return 0;
}


void digi_pause_all() { }
void digi_resume_all() { }
void digi_stop_all() {
	int i;
	// ... Ano. The lack of this was causing ambient sounds to crash.
	// fixed, added digi_stop_all 07/19/01 - bluecow
	
	for (i=0; i<MAX_SOUND_OBJECTS; i++ )	{
		if ( SoundObjects[i].flags & SOF_USED )	{
			SoundSlots[SoundObjects[i].handle].playing = 0;
			SoundObjects[i].flags = 0;
		}
	}
}

 //added on 980905 by adb to make sound channel setting work
void digi_set_max_channels(int n) { 
	digi_max_channels	= n;

	if ( digi_max_channels < 1 ) 
		digi_max_channels = 1;
	if ( digi_max_channels > (MAX_SOUND_SLOTS-MAX_SOUND_OBJECTS) ) 
		digi_max_channels = (MAX_SOUND_SLOTS-MAX_SOUND_OBJECTS);

	if ( !digi_initialised ) return;

	digi_reset_digi_sounds();
}

int digi_get_max_channels() { 
	return digi_max_channels; 
}
// end edit by adb

void digi_reset_digi_sounds() {
 int i;

 for (i=0; i< MAX_SOUND_SLOTS; i++)
  SoundSlots[i].playing=0;
 
 //added on 980905 by adb to reset sound kill system
 memset(SampleHandles, 255, sizeof(SampleHandles));
 next_handle = 0;
 //end edit by adb
}


// MIDI stuff follows.
//added/killed on 11/25/98 by Matthew Mueller
//void digi_set_midi_volume( int mvolume ) { }
//void digi_play_midi_song( char * filename, char * melodic_bank, char * drum_bank, int loop ) {}
//void digi_stop_current_song()
//{
//#ifdef HMIPLAY
//        char buf[10];
//    
//        sprintf(buf,"s");
//        send_ipc(buf);
//#endif
//}
//end this section kill - MM