/**********************************************************************************
Common Audio plugin spec, version #1.1 maintained by zilmar (zilmar@emulation64.com)

All questions or suggestions should go through the mailing list.
http://www.egroups.com/group/Plugin64-Dev
**********************************************************************************
Notes:
------

Setting the approprate bits in the MI_INTR_REG and calling CheckInterrupts which 
are both passed to the DLL in InitiateAudio will generate an Interrupt from with in 
the plugin.

**********************************************************************************/
#ifndef _AUDIO_H_INCLUDED__
#define _AUDIO_H_INCLUDED__

#if defined(__cplusplus)
extern "C" {
#endif

/* Note: BOOL, BYTE, WORD, DWORD, TRUE, FALSE are defined in windows.h */

#define PLUGIN_TYPE_AUDIO			3

#define EXPORT						__declspec(dllexport)
#define CALL						_cdecl

#define SYSTEM_NTSC					0
#define SYSTEM_PAL					1
#define SYSTEM_MPAL					2

/***** Structures *****/
typedef struct {
	WORD Version;        /* Should be set to 0x0101 */
	WORD Type;           /* Set to PLUGIN_TYPE_AUDIO */
	char Name[100];      /* Name of the DLL */

	/* If DLL supports memory these memory options then set them to TRUE or FALSE
	   if it does not support it */
	BOOL NormalMemory;   /* a normal BYTE array */ 
	BOOL MemoryBswaped;  /* a normal BYTE array where the memory has been pre
	                          bswap on a dword (32 bits) boundry */
} PLUGIN_INFO;


typedef struct {
	HWND hwnd;
	HINSTANCE hinst;

	BOOL MemoryBswaped;    // If this is set to TRUE, then the memory has been pre
	                       //   bswap on a dword (32 bits) boundry 
						   //	eg. the first 8 bytes are stored like this:
	                       //        4 3 2 1   8 7 6 5
	BYTE * HEADER;	// This is the rom header (first 40h bytes of the rom
					// This will be in the same memory format as the rest of the memory.
	BYTE * RDRAM;
	BYTE * DMEM;
	BYTE * IMEM;

	DWORD * MI_INTR_REG;

	DWORD * AI_DRAM_ADDR_REG;
	DWORD * AI_LEN_REG;
	DWORD * AI_CONTROL_REG;
	DWORD * AI_STATUS_REG;
	DWORD * AI_DACRATE_REG;
	DWORD * AI_BITRATE_REG;

	void (*CheckInterrupts)( void );
} AUDIO_INFO;

/******************************************************************
  Function: AiDacrateChanged
  Purpose:  This function is called to notify the dll that the
            AiDacrate registers value has been changed.
  input:    The System type:
               SYSTEM_NTSC	0
               SYSTEM_PAL	1
               SYSTEM_MPAL	2
  output:   none
*******************************************************************/ 
EXPORT void CALL AiDacrateChanged (int SystemType);

/******************************************************************
  Function: AiLenChanged
  Purpose:  This function is called to notify the dll that the
            AiLen registers value has been changed.
  input:    none
  output:   none
*******************************************************************/ 
EXPORT void CALL AiLenChanged (void);

/******************************************************************
  Function: AiReadLength
  Purpose:  This function is called to allow the dll to return the
            value that AI_LEN_REG should equal
  input:    none
  output:   The amount of bytes still left to play.
*******************************************************************/ 
EXPORT DWORD CALL AiReadLength (void);

/******************************************************************
  Function: AiUpdate
  Purpose:  This function is called to allow the dll to update
            things on a regular basis (check how long to sound to
			go, copy more stuff to the buffer, anyhting you like).
			The function is designed to go in to the message loop
			of the main window ... but can be placed anywhere you 
			like.
  input:    if Wait is set to true, then this function should wait
            till there is a messgae in the its message queue.
  output:   none
*******************************************************************/ 
EXPORT void CALL AiUpdate (BOOL Wait);

/******************************************************************
  Function: CloseDLL
  Purpose:  This function is called when the emulator is closing
            down allowing the dll to de-initialise.
  input:    none
  output:   none
*******************************************************************/ 
EXPORT void CALL CloseDLL (void);

/******************************************************************
  Function: DllAbout
  Purpose:  This function is optional function that is provided
            to give further information about the DLL.
  input:    a handle to the window that calls this function
  output:   none
*******************************************************************/ 
EXPORT void CALL DllAbout ( HWND hParent );

/******************************************************************
  Function: DllConfig
  Purpose:  This function is optional function that is provided
            to allow the user to configure the dll
  input:    a handle to the window that calls this function
  output:   none
*******************************************************************/ 
EXPORT void CALL DllConfig ( HWND hParent );

/******************************************************************
  Function: DllTest
  Purpose:  This function is optional function that is provided
            to allow the user to test the dll
  input:    a handle to the window that calls this function
  output:   none
*******************************************************************/ 
EXPORT void CALL DllTest ( HWND hParent );

/******************************************************************
  Function: GetDllInfo
  Purpose:  This function allows the emulator to gather information
            about the dll by filling in the PluginInfo structure.
  input:    a pointer to a PLUGIN_INFO stucture that needs to be
            filled by the function. (see def above)
  output:   none
*******************************************************************/ 
EXPORT void CALL GetDllInfo ( PLUGIN_INFO * PluginInfo );

/******************************************************************
  Function: InitiateSound
  Purpose:  This function is called when the DLL is started to give
            information from the emulator that the n64 audio 
			interface needs
  Input:    Audio_Info is passed to this function which is defined
            above.
  Output:   TRUE on success
            FALSE on failure to initialise
             
  ** note on interrupts **:
  To generate an interrupt set the appropriate bit in MI_INTR_REG
  and then call the function CheckInterrupts to tell the emulator
  that there is a waiting interrupt.
*******************************************************************/ 
EXPORT BOOL CALL InitiateAudio (AUDIO_INFO Audio_Info);

/******************************************************************
  Function: ProcessAList
  Purpose:  This function is called when there is a Alist to be
            processed. The Dll will have to work out all the info
			about the AList itself.
  input:    none
  output:   none
*******************************************************************/ 
EXPORT void CALL ProcessAList(void);

/******************************************************************
  Function: RomClosed
  Purpose:  This function is called when a rom is closed.
  input:    none
  output:   none
*******************************************************************/ 
EXPORT void CALL RomClosed (void);

#if defined(__cplusplus)
}
#endif

#endif
