// Filename 		: SOUND.C
// Coded by 		: Scott Evans
// Created/Modified : 8/7/98
// Description		: Sound effects library


#include <sound.h>


// The sound objects list

OBJECT_LIST_HEADER sound_objects;
word volume_control,sound_on;


// Function 		: InitSoundData()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Load the sound data into sound memory

// Parameters		: se - pointer to sound effects data
//				      vh - vab header main memory address
//					  vb - vab body main memory address

// Returns			: Pointer to allocated structure, NULL for error

// Notes			: Will always allocate a sound data structure


SOUND_DATA *InitSoundData(SOUND_EFFECT *se,u_byte *vh,u_byte *vb)
{
	static SOUND_DATA sound_data[MAX_SOUND_DATA];
    static u_byte sno=0;
    word vabid;
    
    // Initialise the sound objects list
    
    InitObjectList(&sound_objects);
    
    // Transfer sound data, wait for data to be transfered
    
    vabid=SsVabTransfer(vh,vb,-1,SS_WAIT_COMPLETED);

	#ifdef PSX

	SsStart();

	#endif

	// Flag any problems
    
	if(vabid>=0)
    {
    	// Allocate a sound data structure
        
        sno=++sno%MAX_SOUND_DATA;
        
        // Initialise the structure
        
        sound_data[sno].vabid=vabid;
        sound_data[sno].l=&sound_objects;
        sound_data[sno].seffects=se;
        
        // Set the default value of the volume control
        
        volume_control=0;
        
		// Allow sounds to be played

		sound_on=1;

        // Return a pointer to allocated data
        
		#ifdef DEBUG_INFO

		sprintf(fm_string,"Completed (%d)\n",vabid);
    	PrintFM(fm_string);

		#endif

    	return(&sound_data[sno]);
    }
    
	// A problem with the VAB so don't allow any sounds to be played

	sound_on=0;

	#ifdef DEBUG_INFO

    sprintf(fm_string,"Failed (%d)\n",vabid);
    PrintFM(fm_string);
    
    #endif
        
   	return(0);
}


// Function 		: PlaySoundEffect()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Plays a sound effect

// Parameters		: sd - pointer to sound data
//					  n - number of sound effect to play

// Returns			: The sound effect object, NULL for error

// Notes			: None


OBJECT *PlaySoundEffect(SOUND_DATA *sd,VOLUME *vol,word n)
{
	SOUND_EFFECT *se,*old;
    OBJECT *o,*s,*l;
    word lowest=SS_MAX_PRIORITY;
    word left,right;
    
	if(sound_on)
	{
	    if((o=CreateObject(sd->l,SOUND_OBJECT)))
	    {
	    	// Find the correct sound effect
	    
	    	se=&sd->seffects[n];
	        
	        // Assign this effect to the object
	        
	        o->type.sfx.effect=se;
	        o->type.sfx.vabid=sd->vabid;
			o->type.sfx.priority=se->priority;

			// Make sure the object gets processed

			o->active=1;

	        // Set the duration of the sound effect
	        
	        SetObjectsTimer(o,se->timer);
	        
			// Set the sound handler

			SetObjectsHandler(o,HandleSoundEffect);

	        // Calculate the volume
	        
	        left=vol->left-volume_control-se->left_vol;
	        left=(left<0 ? 0 : left);
	        
	        right=vol->right-volume_control-se->right_vol;
	        right=(right<0 ? 0 : right);
	        
			// Try and play the sound effect
	        
			if((o->type.sfx.voice=SsUtKeyOn(sd->vabid,se->prog_no,se->tone_no,se->pitch,se->fine_pitch,left,right))<0)
	        {   
	            // Could not find a free voice, so kill the sound with the lowest priority
	            
	            s=sound_objects.start;
	           
	            while(s)
	            {
	            	if(s->type.sfx.priority<=lowest && s!=o)
	                {
	                	l=s;
	                    lowest=s->type.sfx.priority;
	                }				
	            }
	            
				old=(SOUND_EFFECT *)l->type.sfx.effect;

	            // Free the voice used by the sound
	            
				SsUtKeyOff(l->type.sfx.voice,l->type.sfx.vabid,old->prog_no,old->tone_no,old->pitch);
				
				#ifdef  DEBUG_INFO

				PrintFM("Voice Off\n");

				#endif

				// Now play the sound
	            
	            o->type.sfx.voice=SsUtKeyOn(sd->vabid,se->prog_no,se->tone_no,se->pitch,se->fine_pitch,left,right);                        
	        }
	        
	        return(o);
	    }
    }

	#ifdef DEBUG_INFO

	sprintf(fm_string,"Failed (%d)\n",n);
	PrintFM(fm_string);

	#endif

    return(0);
}


// Function 		: HandleSoundEffect()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Handles a sound effect object

// Parameters		: o - object to handle

// Returns			: None

// Notes			: None


void HandleSoundEffect(OBJECT *o)
{
	SOUND_EFFECT *se;

	// Has the sound expired yet
    
    if(o->timer)
    	o->timer--;
    else
    {
    	// Turn off the voice used by the sound
        
		se=(SOUND_EFFECT *)o->type.sfx.effect;

        SsUtKeyOff(o->type.sfx.voice,o->type.sfx.vabid,se->prog_no,se->tone_no,se->pitch);

        // Remove the object from the list
        
        RemoveObjectFromList(&sound_objects,o); 
    }
}


// Function 		: UpdateSoundEffects()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Update all the sound effect objects

// Parameters		: None

// Returns			: None

// Notes			: None


void UpdateSoundEffects(void)
{
	UpdateObjects(&sound_objects);
}


// Function 		: CloseSound()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Closes the VAB and kills all the active sound objects

// Parameters		: None

// Returns			: None

// Notes			: None


void CloseSound(SOUND_DATA *sd)
{
	// Kill all the sound objects
    
    ClearObjectList(sd->l);
    
    // Close the VAB
    
    SsVabClose(sd->vabid);
    
	#ifdef DEBUG_INFO

    PrintFM("Completed\n");

	#endif
}


// Function 		: GetVolumeControl()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Gets the value of the master volume control

// Parameters		: None

// Returns			: Value of volume control

// Notes			: None


word GetVolumeControl(void)
{
	return(volume_control);
}


// Function 		: SetVolumeControl()
// Coded by			: Scott Evans
// Created/Modified	: 8/7/98

// Description		: Sets the value of the master volume control

// Parameters		: v - new value

// Returns			: None

// Notes			: None


void SetVolumeControl(word v)
{
	volume_control=v;
}


// Function 		: KillSounds()
// Coded by			: Scott Evans
// Created/Modified	: 10/7/98

// Description		: Kills all sound objects and voices

// Parameters		: None

// Returns			: None

// Notes			: None


void KillSounds(void)
{
	Silence();
	ClearObjectList(&sound_objects);
}