mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-12-29 12:41:48 +01:00
removed unused code
This commit is contained in:
ekeeke31
parent
fe055c2a2c
commit
da37355e04
@ -1,165 +0,0 @@
|
|||||||
/* http://www.slack.net/~ant/ */
|
|
||||||
|
|
||||||
#include "blip.h"
|
|
||||||
|
|
||||||
#include <assert.h>
|
|
||||||
#include <string.h>
|
|
||||||
#include <stdlib.h>
|
|
||||||
#include <stddef.h>
|
|
||||||
|
|
||||||
/* Copyright (C) 2003-2008 Shay Green. This module is free software; you
|
|
||||||
can redistribute it and/or modify it under the terms of the GNU Lesser
|
|
||||||
General Public License as published by the Free Software Foundation; either
|
|
||||||
version 2.1 of the License, or (at your option) any later version. This
|
|
||||||
module is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
||||||
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
|
|
||||||
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
|
|
||||||
details. You should have received a copy of the GNU Lesser General Public
|
|
||||||
License along with this module; if not, write to the Free Software Foundation,
|
|
||||||
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
|
|
||||||
|
|
||||||
enum { buf_extra = 2 }; /* extra samples to save past end */
|
|
||||||
enum { time_bits = 16 }; /* bits in fraction of fixed-point sample counts */
|
|
||||||
enum { time_unit = 1 << time_bits };
|
|
||||||
enum { phase_bits = 15 }; /* bits in fraction of deltas in buffer */
|
|
||||||
enum { phase_count = 1 << phase_bits };
|
|
||||||
enum { phase_shift = time_bits - phase_bits };
|
|
||||||
|
|
||||||
typedef int buf_t; /* type of element in delta buffer */
|
|
||||||
|
|
||||||
struct blip_buffer_t
|
|
||||||
{
|
|
||||||
int factor; /* clocks to samples conversion factor */
|
|
||||||
int offset; /* fractional position of clock 0 in delta buffer */
|
|
||||||
int amp; /* current output amplitude (sum of all deltas up to now) */
|
|
||||||
int size; /* size of delta buffer */
|
|
||||||
buf_t *buf; /* delta buffer, only size elements actually allocated */
|
|
||||||
};
|
|
||||||
|
|
||||||
blip_buffer_t* blip_alloc( int clock_rate, int sample_rate, int size )
|
|
||||||
{
|
|
||||||
/* Allocate space for structure and delta buffer */
|
|
||||||
blip_buffer_t* s = (blip_buffer_t*) malloc( sizeof(blip_buffer_t) );
|
|
||||||
if (!s) return 0;
|
|
||||||
s->buf = (buf_t*) malloc((size + buf_extra) * sizeof (buf_t) );
|
|
||||||
if ( s->buf != NULL )
|
|
||||||
{
|
|
||||||
/* Calculate output:input ratio and convert to fixed-point */
|
|
||||||
double ratio = (double) sample_rate / clock_rate;
|
|
||||||
s->factor = (int) (ratio * time_unit + 0.5);
|
|
||||||
|
|
||||||
s->size = size;
|
|
||||||
blip_clear( s );
|
|
||||||
}
|
|
||||||
return s;
|
|
||||||
}
|
|
||||||
|
|
||||||
void blip_free( blip_buffer_t* s )
|
|
||||||
{
|
|
||||||
if (s->buf) free(s->buf);
|
|
||||||
free( s );
|
|
||||||
}
|
|
||||||
|
|
||||||
void blip_clear( blip_buffer_t* s )
|
|
||||||
{
|
|
||||||
s->offset = 0;
|
|
||||||
s->amp = 0;
|
|
||||||
memset( s->buf, 0, (s->size + buf_extra) * sizeof (buf_t) );
|
|
||||||
}
|
|
||||||
|
|
||||||
void blip_add( blip_buffer_t* s, int clocks, int delta )
|
|
||||||
{
|
|
||||||
/* Convert to fixed-point time in terms of output samples */
|
|
||||||
int fixed_time = clocks * s->factor + s->offset;
|
|
||||||
|
|
||||||
/* Extract whole and fractional parts */
|
|
||||||
int index = fixed_time >> time_bits; /* whole */
|
|
||||||
int phase = fixed_time >> phase_shift & (phase_count - 1); /* fraction */
|
|
||||||
|
|
||||||
/* Split delta between first and second samples */
|
|
||||||
int second = delta * phase;
|
|
||||||
int first = delta * phase_count - second;
|
|
||||||
|
|
||||||
/* Be sure index is within buffer */
|
|
||||||
assert( index >= 0 && index+1 < s->size + buf_extra );
|
|
||||||
|
|
||||||
/* Add deltas to buffer */
|
|
||||||
s->buf [index ] += first;
|
|
||||||
s->buf [index+1] += second;
|
|
||||||
}
|
|
||||||
|
|
||||||
int blip_clocks_needed( const blip_buffer_t* s, int samples )
|
|
||||||
{
|
|
||||||
int fixed_needed;
|
|
||||||
if ( samples > s->size )
|
|
||||||
samples = s->size;
|
|
||||||
|
|
||||||
/* Fixed-point number of samples needed in addition to those in buffer */
|
|
||||||
fixed_needed = samples * time_unit - s->offset;
|
|
||||||
|
|
||||||
/* If more are needed, convert to clocks and round up */
|
|
||||||
return (fixed_needed <= 0) ? 0 : (fixed_needed - 1) / s->factor + 1;
|
|
||||||
}
|
|
||||||
|
|
||||||
void blip_end_frame( blip_buffer_t* s, int clocks )
|
|
||||||
{
|
|
||||||
s->offset += clocks * s->factor;
|
|
||||||
|
|
||||||
/* Ensure time wasn't past end of buffer */
|
|
||||||
assert( blip_samples_avail( s ) <= s->size );
|
|
||||||
}
|
|
||||||
|
|
||||||
int blip_samples_avail( const blip_buffer_t* s )
|
|
||||||
{
|
|
||||||
return s->offset >> time_bits;
|
|
||||||
}
|
|
||||||
|
|
||||||
/* Removes n samples from buffer */
|
|
||||||
static void remove_samples( blip_buffer_t* s, int n )
|
|
||||||
{
|
|
||||||
int remain = blip_samples_avail( s ) + buf_extra - n;
|
|
||||||
|
|
||||||
s->offset -= n * time_unit;
|
|
||||||
assert( s->offset >= 0 );
|
|
||||||
|
|
||||||
/* Copy remaining samples to beginning of buffer and clear the rest */
|
|
||||||
memmove( s->buf, &s->buf [n], remain * sizeof (buf_t) );
|
|
||||||
memset( &s->buf [remain], 0, n * sizeof (buf_t) );
|
|
||||||
}
|
|
||||||
|
|
||||||
int blip_read_samples( blip_buffer_t* s, short out [], int count, int stereo )
|
|
||||||
{
|
|
||||||
/* can't read more than available */
|
|
||||||
int avail = blip_samples_avail( s );
|
|
||||||
if ( count > avail )
|
|
||||||
count = avail;
|
|
||||||
|
|
||||||
if ( count )
|
|
||||||
{
|
|
||||||
/* Sum deltas and write out */
|
|
||||||
int i;
|
|
||||||
for ( i = 0; i < count; ++i )
|
|
||||||
{
|
|
||||||
int sample;
|
|
||||||
|
|
||||||
/* Apply slight high-pass filter */
|
|
||||||
s->amp -= s->amp >> 9;
|
|
||||||
|
|
||||||
/* Add next delta */
|
|
||||||
s->amp += s->buf [i];
|
|
||||||
|
|
||||||
/* Calculate output sample */
|
|
||||||
sample = s->amp >> phase_bits;
|
|
||||||
|
|
||||||
/* Keep within 16-bit sample range */
|
|
||||||
if ( sample < -32768 ) sample = -32768;
|
|
||||||
if ( sample > +32767 ) sample = +32767;
|
|
||||||
|
|
||||||
out [i << stereo] = sample;
|
|
||||||
}
|
|
||||||
|
|
||||||
remove_samples( s, count );
|
|
||||||
}
|
|
||||||
|
|
||||||
return count;
|
|
||||||
}
|
|
||||||
@ -1,51 +0,0 @@
|
|||||||
/* Fast sound synthesis buffer for use in real-time emulators of electronic
|
|
||||||
sound generator chips like those in early video game consoles. Uses linear
|
|
||||||
interpolation. Higher-quality versions are available that use sinc-based
|
|
||||||
band-limited synthesis. */
|
|
||||||
|
|
||||||
#ifndef BLIP_H
|
|
||||||
#define BLIP_H
|
|
||||||
|
|
||||||
#ifdef __cplusplus
|
|
||||||
extern "C" {
|
|
||||||
#endif
|
|
||||||
|
|
||||||
/* Creates a new blip_buffer with specified input clock rate, output
|
|
||||||
sample rate, and size (in samples), or returns NULL if out of memory. */
|
|
||||||
typedef struct blip_buffer_t blip_buffer_t;
|
|
||||||
blip_buffer_t* blip_alloc( int clock_rate, int sample_rate, int size );
|
|
||||||
|
|
||||||
/* Frees memory used by a blip_buffer. No effect if NULL is passed. */
|
|
||||||
void blip_free( blip_buffer_t* );
|
|
||||||
|
|
||||||
/* Removes all samples and clears buffer. */
|
|
||||||
void blip_clear( blip_buffer_t* );
|
|
||||||
|
|
||||||
/* Adds an amplitude transition of delta at specified time in source clocks.
|
|
||||||
Delta can be negative. */
|
|
||||||
void blip_add( blip_buffer_t*, int time, int delta );
|
|
||||||
|
|
||||||
/* Number of additional clocks needed until n samples will be available.
|
|
||||||
If buffer cannot even hold n samples, returns number of clocks until buffer
|
|
||||||
becomes full. */
|
|
||||||
int blip_clocks_needed( const blip_buffer_t*, int samples_needed );
|
|
||||||
|
|
||||||
/* Ends current time frame of specified duration and make its samples available
|
|
||||||
(along with any still-unread samples) for reading with read_samples(), then
|
|
||||||
begins a new time frame at the end of the current frame. */
|
|
||||||
void blip_end_frame( blip_buffer_t*, int duration );
|
|
||||||
|
|
||||||
/* Number of samples available for reading with read(). */
|
|
||||||
int blip_samples_avail( const blip_buffer_t* );
|
|
||||||
|
|
||||||
/* Reads at most n samples out of buffer into out, removing them from from
|
|
||||||
the buffer. Returns number of samples actually read and removed. If stereo is
|
|
||||||
true, increments 'out' one extra time after writing each sample, to allow
|
|
||||||
easy interleving of two channels into a stereo output buffer. */
|
|
||||||
int blip_read_samples( blip_buffer_t*, short out [], int n, int stereo );
|
|
||||||
|
|
||||||
#ifdef __cplusplus
|
|
||||||
}
|
|
||||||
#endif
|
|
||||||
|
|
||||||
#endif
|
|
||||||
Loading…
Reference in New Issue
Block a user