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// Multi-channel effects buffer with echo and individual panning for each channel
// Game_Music_Emu 0.6-pre
#ifndef EFFECTS_BUFFER_H
#define EFFECTS_BUFFER_H
#include "Multi_Buffer.h"
// See Simple_Effects_Buffer (below) for a simpler interface
class Effects_Buffer : public Multi_Buffer {
public:
// To reduce memory usage, fewer buffers can be used (with a best-fit
// approach if there are too few), and maximum echo delay can be reduced
Effects_Buffer( int max_bufs = 32, int echo_size = 24 * 1024 );
struct pan_vol_t
{
float vol; // 0.0 = silent, 0.5 = half volume, 1.0 = normal
float pan; // -1.0 = left, 0.0 = center, +1.0 = right
};
// Global configuration
struct config_t
{
bool enabled; // false = disable all effects
// Current sound is echoed at adjustable left/right delay,
// with reduced treble and volume (feedback).
float treble; // 1.0 = full treble, 0.1 = very little, 0.0 = silent
int delay [2]; // left, right delays (msec)
float feedback; // 0.0 = no echo, 0.5 = each echo half previous, 1.0 = cacophony
pan_vol_t side_chans [2]; // left and right side channel volume and pan
};
config_t& config() { return config_; }
// Limits of delay (msec)
int min_delay() const;
int max_delay() const;
// Per-channel configuration. Two or more channels with matching parameters are
// optimized to internally use the same buffer.
struct chan_config_t : pan_vol_t
{
// (inherited from pan_vol_t)
//float vol; // these only affect center channel
//float pan;
bool surround; // if true, negates left volume to put sound in back
bool echo; // false = channel doesn't have any echo
};
chan_config_t& chan_config( int i ) { return chans [i + extra_chans].cfg; }
// Applies any changes made to config() and chan_config()
virtual void apply_config();
// Implementation
public:
~Effects_Buffer();
blargg_err_t set_sample_rate( int samples_per_sec, int msec = blip_default_length );
blargg_err_t set_channel_count( int, int const* = NULL );
void clock_rate( int );
void bass_freq( int );
void clear();
channel_t channel( int );
void end_frame( blip_time_t );
int read_samples( blip_sample_t [], int );
int samples_avail() const { return (bufs [0].samples_avail() - mixer.samples_read) * 2; }
enum { stereo = 2 };
typedef int fixed_t;
protected:
enum { extra_chans = stereo * stereo };
private:
config_t config_;
int clock_rate_;
int bass_freq_;
int echo_size;
struct chan_t
{
fixed_t vol [stereo];
chan_config_t cfg;
channel_t channel;
};
blargg_vector<chan_t> chans;
struct buf_t : Tracked_Blip_Buffer
{
// nasty: Blip_Buffer has something called fixed_t
Effects_Buffer::fixed_t vol [stereo];
bool echo;
void* operator new ( size_t, void* p ) { return p; }
void operator delete ( void* ) { }
~buf_t() { }
};
buf_t* bufs;
int bufs_size;
int bufs_max; // bufs_size <= bufs_max, to limit memory usage
Stereo_Mixer mixer;
struct {
int delay [stereo];
fixed_t treble;
fixed_t feedback;
fixed_t low_pass [stereo];
} s;
blargg_vector<fixed_t> echo;
int echo_pos;
bool no_effects;
bool no_echo;
void assign_buffers();
void clear_echo();
void mix_effects( blip_sample_t out [], int pair_count );
blargg_err_t new_bufs( int size );
void delete_bufs();
};
// Simpler interface and lower memory usage
class Simple_Effects_Buffer : public Effects_Buffer {
public:
struct config_t
{
bool enabled; // false = disable all effects
float echo; // 0.0 = none, 1.0 = lots
float stereo; // 0.0 = channels in center, 1.0 = channels on left/right
bool surround; // true = put some channels in back
};
config_t& config() { return config_; }
// Applies any changes made to config()
void apply_config();
// Implementation
public:
Simple_Effects_Buffer();
private:
config_t config_;
void chan_config(); // hide
};
#endif
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