frodo-wii/Src/SID_SDL.i
2009-01-01 16:54:17 +00:00

133 lines
2.3 KiB
OpenEdge ABL

/*
* SID_linux.i - 6581 emulation, Linux specific stuff
*
* Frodo (C) 1994-1997,2002 Christian Bauer
* Linux sound stuff by Bernd Schmidt
*/
#include <unistd.h>
#include <fcntl.h>
#include <SDL.h>
#include <SDL_mixer.h>
#include "VIC.h"
static int divisor = 0;
static int to_output = 0;
static int buffer_pos = 0;
void DigitalRenderer::fill_audio(Uint8 *stream, int len)
{
int cnt = 0;
int bytes_to_write = to_output * sizeof(Uint16);
int buf_size = this->sndbufsize * sizeof(Uint16);
memset(stream, 0, len);
if (to_output <= 0)
return;
while (cnt < bytes_to_write && cnt < len)
{
int datalen = buf_size;
if (datalen > bytes_to_write)
datalen = bytes_to_write;
if (datalen > len - cnt)
datalen = len - cnt;
calc_buffer(sound_buffer, datalen);
memcpy(stream + cnt, (Uint8*)this->sound_buffer, datalen);
cnt += datalen;
}
if (to_output - cnt / 2 <= 0)
to_output = 0;
else
to_output -= cnt / 2;
}
void DigitalRenderer::fill_audio_helper(void *udata, Uint8 *stream, int len)
{
DigitalRenderer *p_this = (DigitalRenderer *)udata;
p_this->fill_audio(stream, len);
}
/*
* Initialization
*/
void DigitalRenderer::init_sound(void)
{
this->sndbufsize = 512;
/* Set the audio format */
this->spec.freq = 44100;
this->spec.format = AUDIO_S16MSB;
this->spec.channels = 2; /* 1 = mono, 2 = stereo */
this->spec.samples = 512;
this->spec.callback = this->fill_audio_helper;
this->spec.userdata = (void*)this;
ready = false;
if ( SDL_OpenAudio(&this->spec, NULL) < 0 ) {
fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
return ;
}
this->sound_buffer = new int16[this->sndbufsize];
ready = true;
SDL_PauseAudio(0);
}
/*
* Destructor
*/
DigitalRenderer::~DigitalRenderer()
{
SDL_CloseAudio();
}
/*
* Pause sound output
*/
void DigitalRenderer::Pause(void)
{
SDL_PauseAudio(1);
}
/*
* Resume sound output
*/
void DigitalRenderer::Resume(void)
{
SDL_PauseAudio(0);
}
/*
* Fill buffer, sample volume (for sampled voice)
*/
void DigitalRenderer::EmulateLine(void)
{
if (!ready)
return;
sample_buf[sample_in_ptr] = volume;
sample_in_ptr = (sample_in_ptr + 1) % SAMPLE_BUF_SIZE;
/*
* Now see how many samples have to be added for this line
*/
divisor += SAMPLE_FREQ;
while (divisor >= 0)
divisor -= TOTAL_RASTERS*SCREEN_FREQ, to_output++;
}