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gzdoom/game-music-emu/gme/Multi_Buffer.h

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// Multi-channel sound buffer interface, and basic mono and stereo buffers
// Blip_Buffer 0.4.1
#ifndef MULTI_BUFFER_H
#define MULTI_BUFFER_H
#include "blargg_common.h"
#include "Blip_Buffer.h"
// Interface to one or more Blip_Buffers mapped to one or more channels
// consisting of left, center, and right buffers.
class Multi_Buffer {
public:
Multi_Buffer( int samples_per_frame );
virtual ~Multi_Buffer() { }
// Set the number of channels available
virtual blargg_err_t set_channel_count( int );
// Get indexed channel, from 0 to channel count - 1
struct channel_t {
Blip_Buffer* center;
Blip_Buffer* left;
Blip_Buffer* right;
};
enum { type_index_mask = 0xFF };
enum { wave_type = 0x100, noise_type = 0x200, mixed_type = wave_type | noise_type };
virtual channel_t channel( int index, int type ) = 0;
// See Blip_Buffer.h
virtual blargg_err_t set_sample_rate( long rate, int msec = blip_default_length ) = 0;
virtual void clock_rate( long ) = 0;
virtual void bass_freq( int ) = 0;
virtual void clear() = 0;
long sample_rate() const;
// Length of buffer, in milliseconds
int length() const;
// See Blip_Buffer.h
virtual void end_frame( blip_time_t ) = 0;
// Number of samples per output frame (1 = mono, 2 = stereo)
int samples_per_frame() const;
// Count of changes to channel configuration. Incremented whenever
// a change is made to any of the Blip_Buffers for any channel.
unsigned channels_changed_count() { return channels_changed_count_; }
// See Blip_Buffer.h
virtual long read_samples( blip_sample_t*, long ) = 0;
virtual long samples_avail() const = 0;
public:
BLARGG_DISABLE_NOTHROW
protected:
void channels_changed() { channels_changed_count_++; }
private:
// noncopyable
Multi_Buffer( const Multi_Buffer& );
Multi_Buffer& operator = ( const Multi_Buffer& );
unsigned channels_changed_count_;
long sample_rate_;
int length_;
int const samples_per_frame_;
};
// Uses a single buffer and outputs mono samples.
class Mono_Buffer : public Multi_Buffer {
Blip_Buffer buf;
channel_t chan;
public:
// Buffer used for all channels
Blip_Buffer* center() { return &buf; }
public:
Mono_Buffer();
~Mono_Buffer();
blargg_err_t set_sample_rate( long rate, int msec = blip_default_length );
void clock_rate( long rate ) { buf.clock_rate( rate ); }
void bass_freq( int freq ) { buf.bass_freq( freq ); }
void clear() { buf.clear(); }
long samples_avail() const { return buf.samples_avail(); }
long read_samples( blip_sample_t* p, long s ) { return buf.read_samples( p, s ); }
channel_t channel( int, int ) { return chan; }
void end_frame( blip_time_t t ) { buf.end_frame( t ); }
};
// Uses three buffers (one for center) and outputs stereo sample pairs.
class Stereo_Buffer : public Multi_Buffer {
public:
// Buffers used for all channels
Blip_Buffer* center() { return &bufs [0]; }
Blip_Buffer* left() { return &bufs [1]; }
Blip_Buffer* right() { return &bufs [2]; }
public:
Stereo_Buffer();
~Stereo_Buffer();
blargg_err_t set_sample_rate( long, int msec = blip_default_length );
void clock_rate( long );
void bass_freq( int );
void clear();
channel_t channel( int, int ) { return chan; }
void end_frame( blip_time_t );
long samples_avail() const { return bufs [0].samples_avail() * 2; }
long read_samples( blip_sample_t*, long );
private:
enum { buf_count = 3 };
Blip_Buffer bufs [buf_count];
channel_t chan;
int stereo_added;
int was_stereo;
void mix_stereo_no_center( blip_sample_t*, blargg_long );
void mix_stereo( blip_sample_t*, blargg_long );
void mix_mono( blip_sample_t*, blargg_long );
};
// Silent_Buffer generates no samples, useful where no sound is wanted
class Silent_Buffer : public Multi_Buffer {
channel_t chan;
public:
Silent_Buffer();
blargg_err_t set_sample_rate( long rate, int msec = blip_default_length );
void clock_rate( long ) { }
void bass_freq( int ) { }
void clear() { }
channel_t channel( int, int ) { return chan; }
void end_frame( blip_time_t ) { }
long samples_avail() const { return 0; }
long read_samples( blip_sample_t*, long ) { return 0; }
};
inline blargg_err_t Multi_Buffer::set_sample_rate( long rate, int msec )
{
sample_rate_ = rate;
length_ = msec;
return 0;
}
inline blargg_err_t Silent_Buffer::set_sample_rate( long rate, int msec )
{
return Multi_Buffer::set_sample_rate( rate, msec );
}
inline int Multi_Buffer::samples_per_frame() const { return samples_per_frame_; }
inline long Multi_Buffer::sample_rate() const { return sample_rate_; }
inline int Multi_Buffer::length() const { return length_; }
#endif