/*

Name:
MDRIVER.C

Description:
These routines are used to access the available soundcard drivers.

Portability:
All systems - all compilers

*/
#include <stdio.h>
#include <stdlib.h>
#include "mikmod.h"
#include "string.h"

void swab(char *sl_buffer,char *sl_buffer2,UWORD stodo)
{
UWORD i;

i=stodo>>1;

for(i=0;i<stodo;i++)
        {
        *sl_buffer2++ = *(sl_buffer+1);
        *sl_buffer2++ = *sl_buffer;

        sl_buffer+=2;
        }

}


DRIVER *firstdriver=NULL,*md_driver;

UWORD md_device         =0;
UWORD md_mixfreq        =44100;
UWORD md_mode           =0;
UWORD md_dmabufsize     =8192;
UBYTE md_numchn         =0;
UBYTE md_bpm            =125;

static void dummyplay(void)
{
}

void (*md_player)(void)=dummyplay;

static void *sl_fp;
static SWORD  sl_old;
static UWORD sl_infmt;
static UWORD sl_outfmt;
static SWORD  sl_buffer[1024];

static BOOL isplaying=0;


void SL_Init(FILE *fp,UWORD infmt,UWORD outfmt)
{
	sl_old=0;
	sl_fp=fp;
	sl_infmt=infmt;
	sl_outfmt=outfmt;
}


void SL_Exit(void)
{
}


void SL_Load(void *buffer,ULONG length)
{
	SBYTE *bptr=buffer;
	SWORD *wptr=buffer;
	UWORD stodo;
	int t;

	/* compute number of samples to load */
	if(sl_outfmt & SF_16BITS) length>>=1;

	while(length){

		stodo=(length<1024) ? length : 1024;

		if(sl_infmt&SF_16BITS){
			fread(sl_buffer,sizeof(SWORD),stodo,sl_fp);
#ifdef MM_BIG_ENDIAN
			if(!(sl_infmt&SF_BIG_ENDIAN))
				swab((char *)sl_buffer,(char *)sl_buffer,stodo<<1);
#else
                        /* assume machine is little endian by default */
			if(sl_infmt&SF_BIG_ENDIAN)
				swab((char *)sl_buffer,(char *)sl_buffer,stodo<<1);
#endif
		}
		else{
			SBYTE *s;
			SWORD *d;

			fread(sl_buffer,sizeof(SBYTE),stodo,sl_fp);

			s=(SBYTE *)sl_buffer;
			d=sl_buffer;
			s+=stodo;
			d+=stodo;

                        for(t=0;t<stodo;t++){
				s--;
				d--;
				*d=(*s)<<8;
			}
		}

		if(sl_infmt & SF_DELTA){
			for(t=0;t<stodo;t++){
				sl_buffer[t]+=sl_old;
				sl_old=sl_buffer[t];
			}
		}

		if((sl_infmt^sl_outfmt) & SF_SIGNED){
			for(t=0;t<stodo;t++){
				sl_buffer[t]^=0x8000;
			}
		}

		if(sl_outfmt & SF_16BITS){
			for(t=0;t<stodo;t++) *(wptr++)=sl_buffer[t];
		}
		else{
			for(t=0;t<stodo;t++) *(bptr++)=sl_buffer[t]>>8;
		}

		length-=stodo;
	}
}


void MD_InfoDriver(void)
{
	int t;
	DRIVER *l;

	/* list all registered devicedrivers: */

	for(t=1,l=firstdriver; l!=NULL; l=l->next, t++){
		printf("%d. %s\n",t,l->Version);
	}
}


void MD_RegisterDriver(DRIVER *drv)
{
	if(firstdriver==NULL){
		firstdriver=drv;
		drv->next=NULL;
	}
	else{
		drv->next=firstdriver;
		firstdriver=drv;
	}
}


SWORD MD_SampleLoad(FILE *fp,ULONG size,ULONG reppos,ULONG repend,UWORD flags)
{
	SWORD result=md_driver->SampleLoad(fp,size,reppos,repend,flags);
	SL_Exit();
	return result;
}


void MD_SampleUnLoad(SWORD handle)
{
	md_driver->SampleUnLoad(handle);
}


BOOL MD_Init(void)
{
	UWORD t;

	/* if md_device==0, try to find a device number */

	if(md_device==0){

		for(t=1,md_driver=firstdriver; md_driver!=NULL; md_driver=md_driver->next, t++){
			if(md_driver->IsPresent()) break;
		}

		if(md_driver==NULL){
			myerr="You don't have any of the supported sound-devices";
			return 0;
		}

		md_device=t;
	}

	/* if n>0 use that driver */

	for(t=1,md_driver=firstdriver; md_driver!=NULL && t!=md_device; md_driver=md_driver->next, t++);

	if(md_driver==NULL){
		myerr="Device number out of range";
		return 0;
	}

	return(md_driver->Init());
}


void MD_Exit(void)
{
	md_driver->Exit();
}


void MD_PlayStart(void)
{
	/* safety valve, prevents entering
	   playstart twice: */

	if(isplaying) return;
	md_driver->PlayStart();
	isplaying=1;
}


void MD_PlayStop(void)
{
	/* safety valve, prevents calling playStop when playstart
	   hasn't been called: */

	if(isplaying){
		isplaying=0;
		md_driver->PlayStop();
	}
}


void MD_SetBPM(UBYTE bpm)
{
	md_bpm=bpm;
}


void MD_RegisterPlayer(void (*player)(void))
{
	md_player=player;
}


void MD_Update(void)
{
	if(isplaying) md_driver->Update();
}


void MD_VoiceSetVolume(UBYTE voice,UBYTE vol)
{
	md_driver->VoiceSetVolume(voice,vol);
}


void MD_VoiceSetFrequency(UBYTE voice,ULONG frq)
{
	md_driver->VoiceSetFrequency(voice,frq);
}


void MD_VoiceSetPanning(UBYTE voice,ULONG pan)
{
	md_driver->VoiceSetPanning(voice,pan);
}


void MD_VoicePlay(UBYTE voice,SWORD handle,ULONG start,ULONG size,ULONG reppos,ULONG repend,UWORD flags)
{
	md_driver->VoicePlay(voice,handle,start,size,reppos,repend,flags);
}