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#include <audio/audiolib.h>
static char *rcsid = "$Id: nas.c,v 1.6 1998/02/21 14:55:43 david Exp $";
#define FALSE 0
#define TRUE 1
#define SAMPLE_RATE 8000
static nasbug = FALSE; /* Debug Flag */
static sound_enabled = FALSE;
static AuServer *au_server;
static AuDeviceID *au_device;
static AuFlowID au_channel[4];
static int waveform = AuWaveFormSquare;
static int au_channel_clock[4] =
{64000, 64000, 64000, 64000};
static int M[4] =
{1, 1, 1, 1};
static int AUDCTL = 0x00;
static int AUDF[4] =
{0, 0, 0, 0};
static int AUDC[4] =
{0, 0, 0, 0};
void NAS_Initialise(int *argc, char *argv[])
{
int i, j;
for (i = j = 1; i < *argc; i++) {
if (strcmp(argv[i], "-sound") == 0)
sound_enabled = TRUE;
else if (strcmp(argv[i], "-squarewave") == 0)
waveform = AuWaveFormSquare;
else if (strcmp(argv[i], "-sinewave") == 0)
waveform = AuWaveFormSine;
else if (strcmp(argv[i], "-nasbug") == 0)
nasbug = TRUE;
else {
if (strcmp(argv[i], "-help") == 0) {
printf("\t-sound Enable NAS sound support\n");
printf("\t-squarewave Generate sound with a square wave\n");
printf("\t-sinewave Generate sound with a sine wave\n");
printf("\t-nasbug Enable debug code in nas.c\n");
}
argv[j++] = argv[i];
}
}
*argc = j;
if (sound_enabled) {
au_server = AuOpenServer(NULL, 0, NULL, 0, NULL, NULL);
if (!au_server) {
printf("Unable to open audio server\n");
exit(1);
}
for (au_device = NULL, i = 0; i < AuServerNumDevices(au_server); i++) {
if ((AuDeviceKind(AuServerDevice(au_server, i)) ==
AuComponentKindPhysicalOutput) &&
AuDeviceNumTracks(AuServerDevice(au_server, i)) == 1) {
au_device = (AuDeviceID *) AuDeviceIdentifier(AuServerDevice(au_server, i));
break;
}
}
au_channel[0] = AuCreateFlow(au_server, NULL);
au_channel[1] = AuCreateFlow(au_server, NULL);
au_channel[2] = AuCreateFlow(au_server, NULL);
au_channel[3] = AuCreateFlow(au_server, NULL);
for (i = 0; i < 4; i++) {
AuElement elements[3];
int freq = 0;
int volume = AuFixedPointFromFraction(0, 100);
AuMakeElementImportWaveForm(&elements[0], SAMPLE_RATE,
waveform,
AuUnlimitedSamples,
freq,
0, NULL);
AuMakeElementMultiplyConstant(&elements[1], 0, volume);
AuMakeElementExportDevice(&elements[2], 1, (int) au_device, SAMPLE_RATE,
AuUnlimitedSamples, 0, NULL);
AuSetElements(au_server, au_channel[i], AuTrue, 3, elements, NULL);
AuStartFlow(au_server, au_channel[i], NULL);
}
}
}
void NAS_Exit(void)
{
if (sound_enabled) {
int i;
for (i = 0; i < 4; i++) {
AuStopFlow(au_server, au_channel[i], NULL);
}
AuCloseServer(au_server);
}
}
NAS_SetFrequency(int channel, int frequency)
{
if (frequency < 8000) {
static AuElementParameters parms;
parms.flow = channel;
parms.element_num = 0;
parms.num_parameters = AuParmsImportWaveForm;
parms.parameters[AuParmsImportWaveFormFrequency] = frequency;
parms.parameters[AuParmsImportWaveFormNumSamples] = AuUnlimitedSamples;
AuSetElementParameters(au_server, 1, &parms, NULL);
}
}
NAS_SetVolume(int channel, int volume)
{
static AuElementParameters parms;
parms.flow = channel;
parms.element_num = 1;
parms.num_parameters = AuParmsMultiplyConstant;
parms.parameters[AuParmsMultiplyConstantConstant] = volume;
AuSetElementParameters(au_server, 1, &parms, NULL);
}
static int join12 = FALSE;
static int join34 = FALSE;
void NAS_UpdateSound(void)
{
if (sound_enabled) {
int i;
for (i = 0; i < 4; i++) {
int freqtmp;
int flag = FALSE;
if ((i < 2) && join12) {
if (i == 1) {
int N = ((AUDF[1] << 8) | AUDF[0]) + M[0];
if (nasbug)
printf("join12: N=%d\n", N);
freqtmp = au_channel_clock[0] / (N + N);
flag = TRUE;
}
}
else if ((i >= 2) && join34) {
if (i == 3) {
int N = ((AUDF[3] << 8) | AUDF[2]) + M[2];
if (nasbug)
printf("join34: N=%d\n", N);
freqtmp = au_channel_clock[2] / (N + N);
flag = TRUE;
}
}
else {
int N = AUDF[i] + M[i];
freqtmp = au_channel_clock[i] / (N + N);
flag = TRUE;
}
if (flag) {
int distortion = AUDC[i] & 0xf0;
int voltmp;
if ((distortion == 0xa0) || (distortion == 0xd0))
voltmp = AuFixedPointFromFraction((AUDC[i] & 0x0f), 30);
else
voltmp = AuFixedPointFromFraction(0, 30);
NAS_SetFrequency(au_channel[i], freqtmp);
NAS_SetVolume(au_channel[i], voltmp);
}
}
AuFlush(au_server);
}
}
void Atari_AUDC(int channel, int byte)
{
AUDC[channel - 1] = byte;
}
void Atari_AUDF(int channel, int byte)
{
AUDF[channel - 1] = byte;
}
void Atari_AUDCTL(int byte)
{
AUDCTL = byte;
if (byte & 0x01) {
au_channel_clock[0] = 15000;
au_channel_clock[1] = 15000;
au_channel_clock[2] = 15000;
au_channel_clock[3] = 15000;
}
else {
au_channel_clock[0] = 64000;
au_channel_clock[1] = 64000;
au_channel_clock[2] = 64000;
au_channel_clock[3] = 64000;
}
M[0] = M[1] = M[2] = M[3] = 1;
join34 = (byte & 0x08) ? TRUE : FALSE; /* Clock channel 4 with channel 3 */
join12 = (byte & 0x10) ? TRUE : FALSE; /* Clock channel 2 with channel 1 */
if (byte & 0x20) {
au_channel_clock[2] = 1790000; /* Clock channel 3 with 1.79 MHZ */
M[2] = (join34) ? 7 : 4;
}
if (byte & 0x40) {
au_channel_clock[0] = 1790000; /* Clock channel 1 with 1.79 MHZ */
M[0] = (join12) ? 7 : 4;
}
if (nasbug && (byte & 0xfe))
printf("AUDCTL: %02x\n", byte);
}
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