/***************************************************************************

    okim6295.h

    OKIM 6295 ADCPM sound chip.

***************************************************************************/

#pragma once

#ifndef __OKIM6295_H__
#define __OKIM6295_H__




//**************************************************************************
//  CONSTANTS
//**************************************************************************

enum
{
	OKIM6295_PIN7_LOW = 0,
	OKIM6295_PIN7_HIGH = 1
};



//**************************************************************************
//  INTERFACE CONFIGURATION MACROS
//**************************************************************************

#define MCFG_OKIM6295_ADD(_tag, _clock, _pin7) \
	MCFG_DEVICE_ADD(_tag, OKIM6295, _clock) \
	MCFG_OKIM6295_PIN7(_pin7)

#define MCFG_OKIM6295_REPLACE(_tag, _clock, _pin7) \
	MCFG_DEVICE_REPLACE(_tag, OKIM6295, _clock) \
	MCFG_OKIM6295_PIN7(_pin7)

#define MCFG_OKIM6295_PIN7(_pin7) \
	okim6295_device::static_set_pin7(*device, _pin7); \



//**************************************************************************
//  TYPE DEFINITIONS
//**************************************************************************


// ======================> adpcm_state

// Internal ADPCM state, used by external ADPCM generators with compatible specs to the OKIM 6295.
class adpcm_state
{
public:
	adpcm_state() { compute_tables(); reset(); }

	void reset();
	INT16 clock(UINT8 nibble);

	INT32	m_signal;
	INT32	m_step;

private:
	static const INT8 s_index_shift[8];
	static int s_diff_lookup[49*16];

	static void compute_tables();
	static bool s_tables_computed;
};



// ======================> okim6295_device

class okim6295_device : public device_t,
						public device_sound_interface,
						public device_memory_interface
{
public:
	// construction/destruction
	okim6295_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);

	// inline configuration helpers
	static void static_set_pin7(device_t &device, int pin7);

	// runtime configuration
	void set_bank_base(offs_t base, bool bDontUpdateStream = false);
	void set_pin7(int pin7);

	UINT8 read_status();
	void write_command(UINT8 command);

	DECLARE_READ8_MEMBER( read );
	DECLARE_WRITE8_MEMBER( write );

protected:
	// device-level overrides
	virtual void device_start();
	virtual void device_reset();
	virtual void device_post_load();
	virtual void device_clock_changed();

	// device_memory_interface overrides
	virtual const address_space_config *memory_space_config(address_spacenum spacenum = AS_0) const;

	// device_sound_interface overrides
	virtual void sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples);

	// a single voice
	class okim_voice
	{
	public:
		okim_voice();
		void generate_adpcm(direct_read_data &direct, stream_sample_t *buffer, int samples);

		adpcm_state m_adpcm;			// current ADPCM state
		bool		m_playing;
		offs_t		m_base_offset;		// pointer to the base memory location
		UINT32		m_sample;			// current sample number
		UINT32		m_count;			// total samples to play
		INT8		m_volume;			// output volume
	};

	// configuration state
	const address_space_config  m_space_config;

	// internal state
	static const int OKIM6295_VOICES = 4;

	okim_voice			m_voice[OKIM6295_VOICES];
	INT32				m_command;
	bool				m_bank_installed;
	offs_t				m_bank_offs;
	sound_stream *		m_stream;
	UINT8				m_pin7_state;
	direct_read_data *	m_direct;

	static const UINT8 s_volume_table[16];
};


// device type definition
extern const device_type OKIM6295;


#endif /* __OKIM6295_H__ */
