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CLK/Components/AY38910/AY38910.hpp

105 lines
2.5 KiB
C++

//
// AY-3-8910.hpp
// Clock Signal
//
// Created by Thomas Harte on 14/10/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#ifndef AY_3_8910_hpp
#define AY_3_8910_hpp
#include "../../Outputs/Speaker.hpp"
namespace GI {
/*!
Provides emulation of an AY-3-8910 / YM2149, which is a three-channel sound chip with a
noise generator and a volume envelope generator, which also provides two bidirectional
interface ports.
*/
class AY38910: public ::Outputs::Filter<AY38910> {
public:
/// Creates a new AY38910.
AY38910();
/// Sets the clock rate at which this AY38910 will be run.
void set_clock_rate(double clock_rate);
enum ControlLines {
BC1 = (1 << 0),
BC2 = (1 << 1),
BDIR = (1 << 2)
};
/// Sets the value the AY would read from its data lines if it were not outputting.
void set_data_input(uint8_t r);
/// Gets the value that would appear on the data lines if only the AY is outputting.
uint8_t get_data_output();
/// Sets the current control line state, as a bit field.
void set_control_lines(ControlLines control_lines);
/*!
Gets the value that would appear on the requested interface port if it were in output mode.
@parameter port_b @c true to get the value for Port B, @c false to get the value for Port A.
*/
uint8_t get_port_output(bool port_b);
/*!
Sets the value that would appear on the requested interface port if it were in output mode.
@parameter port_b @c true to get the value for Port B, @c false to get the value for Port A.
*/
void set_port_input(bool port_b, uint8_t value);
// to satisfy ::Outputs::Speaker (included via ::Outputs::Filter; not for public consumption
void get_samples(unsigned int number_of_samples, int16_t *target);
private:
int selected_register_;
uint8_t registers_[16], output_registers_[16];
uint8_t port_inputs_[2];
int master_divider_;
int tone_periods_[3];
int tone_counters_[3];
int tone_outputs_[3];
int noise_period_;
int noise_counter_;
int noise_shift_register_;
int noise_output_;
int envelope_period_;
int envelope_divider_;
int envelope_position_;
int envelope_shapes_[16][32];
int envelope_overflow_masks_[16];
int volumes_[16];
enum ControlState {
Inactive,
LatchAddress,
Read,
Write
} control_state_;
void select_register(uint8_t r);
void set_register_value(uint8_t value);
uint8_t get_register_value();
uint8_t data_input_, data_output_;
int16_t output_volume_;
inline void evaluate_output_volume();
inline void update_bus();
};
};
#endif /* AY_3_8910_hpp */