frodo-wii/Src/SID_SDL.h

/*
 *  SID_linux.h - 6581 emulation, Linux specific stuff
 *
 *  Frodo (C) 1994-1997,2002-2005 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

//#include <unistd.h>
//#include <fcntl.h>
//#include <sys/ioctl.h>
//#include <linux/soundcard.h>

#include <SDL.h>

#include "VIC.h"

SDL_AudioSpec *sdl_audio_desired, *sdl_audio;
int16 *sdl_buffer ATTRIBUTE_ALIGN(32);
DigitalRenderer* p;
bool paused = false;

void fill_audio(void *udata, Uint8 *stream, int len) {
	
        if(paused == true) {

                memset(stream, 0x0, len);

        } else
        
         {

               // memcpy(stream, sbuffer, len);
			 p->calc_buffer((int16*)stream, len);
             
        }

}

/*
 *  Initialization
 */

void DigitalRenderer::init_sound(void)
{
	int arg;
	unsigned long format;

	ready = false;
	p = this;
	sndbufsize=0x138*4;

	sdl_audio_desired = (SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec));
	sdl_audio = (SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec));

	sdl_audio_desired->freq=32000;
	sdl_audio_desired->format=AUDIO_S16MSB;
	sdl_audio_desired->channels=2;
	sdl_audio_desired->samples=sndbufsize/2;
	sdl_audio_desired->callback=fill_audio;
	sdl_audio_desired->userdata=NULL;

	if (SDL_OpenAudio(sdl_audio_desired, sdl_audio) < 0) {
		fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
	}
	free(sdl_audio_desired);
	SDL_PauseAudio(0);

	/*devfd = open("/dev/dsp", O_WRONLY);
	if (devfd < 0)
		return;

	ioctl(devfd, SNDCTL_DSP_GETFMTS, &format);
	if (!(format & AFMT_S16_LE))
		return;
	format = AFMT_S16_LE;
	ioctl(devfd, SNDCTL_DSP_SETFMT, &format);*/

	// Buffer size: 2^9 == 512 bytes. Note that too large buffers will not work
	// very well: The speed of the C64 is slowed down to an average speed of
	// 100% by the blocking write() call in EmulateLine(). If you use a buffer
	// of, say 4096 bytes, that will happen only about every 4 frames, which
	// means that the emulation runs much faster in some frames, and much
	// slower in others.
	// On really fast machines, it might make sense to use an even smaller
	// buffer size.
	/*arg = 0x00100009;
	ioctl(devfd, SNDCTL_DSP_SETFRAGMENT, &arg);
	arg = 0;
	ioctl(devfd, SNDCTL_DSP_STEREO, &arg);
	arg = 44100;
	ioctl(devfd, SNDCTL_DSP_SPEED, &arg);
	ioctl(devfd, SOUND_PCM_READ_RATE, &arg);
	if (arg < 43000 || arg > 45000)
		return;*/

	/*ioctl(devfd, SNDCTL_DSP_GETBLKSIZE, &sndbufsize);*/
	sound_buffer = new int16[sndbufsize];
	sdl_buffer=sound_buffer;
	ready = true;
}


/*
 *  Destructor
 */

DigitalRenderer::~DigitalRenderer()
{
	free(sdl_audio);
	SDL_CloseAudio();

	/*if (devfd >= 0)
		close(devfd);*/
}


/*
 *  Pause sound output
 */

void DigitalRenderer::Pause(void)
{
	SDL_PauseAudio(1);
	paused = true;

}


/*
 * Resume sound output
 */

void DigitalRenderer::Resume(void)
{
	SDL_PauseAudio(0);
	paused = false;

}


/*
 * Fill buffer, sample volume (for sampled voice)
 */

void DigitalRenderer::EmulateLine(void)
{
	static int divisor = 0;
	static int to_output = 0;
	static int buffer_pos = 0;

	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++;

	// Calculate the sound data only when we have enough to fill
	// the buffer entirely
	if ((buffer_pos + to_output) >= sndbufsize) {
		int datalen = sndbufsize - buffer_pos;
		to_output -= datalen;
		calc_buffer(sound_buffer + buffer_pos, datalen*2);
		//write(devfd, sound_buffer, sndbufsize*2);
		buffer_pos = 0;
	}
*/
}