1
2// Multi-channel sound buffer interface, and basic mono and stereo buffers
3
4// Blip_Buffer 0.3.3. Copyright (C) 2003-2005 Shay Green. GNU LGPL license.
5
6#ifndef MULTI_BUFFER_H
7#define MULTI_BUFFER_H
8
9#include "Blip_Buffer.h"
10
11// Multi_Buffer is an interface to one or more Blip_Buffers mapped to one or
12// more channels consisting of left, center, and right buffers.
13class Multi_Buffer {
14public:
15 Multi_Buffer( int samples_per_frame );
16 virtual ~Multi_Buffer() { }
17
18 // Set the number of channels available
19 virtual blargg_err_t set_channel_count( int );
20
21 // Get indexed channel, from 0 to channel count - 1
22 struct channel_t {
23 Blip_Buffer* center;
24 Blip_Buffer* left;
25 Blip_Buffer* right;
26 };
27 virtual channel_t channel( int index ) = 0;
28
29 // See Blip_Buffer.h
30 // to do: rename to set_sample_rate
31 virtual blargg_err_t sample_rate( long rate, int msec = blip_default_length ) = 0;
32 virtual void clock_rate( long ) = 0;
33 virtual void bass_freq( int ) = 0;
34 virtual void clear() = 0;
35 long sample_rate() const;
36
37 // Length of buffer, in milliseconds
38 int length() const;
39
40 // See Blip_Buffer.h. For optimal operation, pass false for 'added_stereo'
41 // if nothing was added to the left and right buffers of any channel for
42 // this time frame.
43 virtual void end_frame( blip_time_t, bool added_stereo = true ) = 0;
44
45 // Number of samples per output frame (1 = mono, 2 = stereo)
46 int samples_per_frame() const;
47
48 // See Blip_Buffer.h
49 virtual long read_samples( blip_sample_t*, long ) = 0;
50 virtual long samples_avail() const = 0;
51
52private:
53 // noncopyable
54 Multi_Buffer( const Multi_Buffer& );
55 Multi_Buffer& operator = ( const Multi_Buffer& );
56
57 long sample_rate_;
58 int length_;
59 int const samples_per_frame_;
60};
61
62// Mono_Buffer uses a single buffer and outputs mono samples.
63class Mono_Buffer : public Multi_Buffer {
64 Blip_Buffer buf;
65public:
66 Mono_Buffer();
67 ~Mono_Buffer();
68
69 // Buffer used for all channels
70 Blip_Buffer* center();
71
72 // See Multi_Buffer
73 blargg_err_t sample_rate( long rate, int msec = blip_default_length );
74 using Multi_Buffer::sample_rate;
75 void clock_rate( long );
76 void bass_freq( int );
77 void clear();
78 channel_t channel( int );
79 void end_frame( blip_time_t, bool unused = true );
80 long samples_avail() const;
81 long read_samples( blip_sample_t*, long );
82};
83
84// Stereo_Buffer uses three buffers (one for center) and outputs stereo sample pairs.
85class Stereo_Buffer : public Multi_Buffer {
86public:
87 Stereo_Buffer();
88 ~Stereo_Buffer();
89
90 // Buffers used for all channels
91 Blip_Buffer* center();
92 Blip_Buffer* left();
93 Blip_Buffer* right();
94
95 // See Multi_Buffer
96 blargg_err_t sample_rate( long, int msec = blip_default_length );
97 using Multi_Buffer::sample_rate;
98 void clock_rate( long );
99 void bass_freq( int );
100 void clear();
101 channel_t channel( int index );
102 void end_frame( blip_time_t, bool added_stereo = true );
103
104 long samples_avail() const;
105 long read_samples( blip_sample_t*, long );
106
107private:
108 enum { buf_count = 3 };
109 Blip_Buffer bufs [buf_count];
110 channel_t chan;
111 bool stereo_added;
112 bool was_stereo;
113
114 void mix_stereo( blip_sample_t*, long );
115 void mix_mono( blip_sample_t*, long );
116};
117
118
119// End of public interface
120
121inline blargg_err_t Multi_Buffer::sample_rate( long rate, int msec )
122{
123 sample_rate_ = rate;
124 length_ = msec;
125 return blargg_success;
126}
127
128inline int Multi_Buffer::samples_per_frame() const { return samples_per_frame_; }
129
130inline Blip_Buffer* Stereo_Buffer::left() { return &bufs [1]; }
131
132inline Blip_Buffer* Stereo_Buffer::center() { return &bufs [0]; }
133
134inline Blip_Buffer* Stereo_Buffer::right() { return &bufs [2]; }
135
136inline long Stereo_Buffer::samples_avail() const { return bufs [0].samples_avail() * 2; }
137
138inline Stereo_Buffer::channel_t Stereo_Buffer::channel( int index ) { return chan; }
139
140inline long Multi_Buffer::sample_rate() const { return sample_rate_; }
141
142inline int Multi_Buffer::length() const { return length_; }
143
144inline Blip_Buffer* Mono_Buffer::center() { return &buf; }
145
146inline void Mono_Buffer::clock_rate( long rate ) { buf.clock_rate( rate ); }
147
148inline void Mono_Buffer::clear() { buf.clear(); }
149
150inline void Mono_Buffer::bass_freq( int freq ) { buf.bass_freq( freq ); }
151
152inline long Mono_Buffer::read_samples( blip_sample_t* p, long s ) { return buf.read_samples( p, s ); }
153
154inline long Mono_Buffer::samples_avail() const { return buf.samples_avail(); }
155
156#endif
157
158