Replace channel valid boolean with more versatile enum.

Author: wb2osz

atest.c

@@ -564,8 +564,10 @@ int main (int argc, char *argv[])
 	my_audio_config.adev[0].bits_per_sample = format.wbitspersample;
  	my_audio_config.adev[0].num_channels = format.nchannels;
 
-	my_audio_config.achan[0].valid = 1;
-	if (format.nchannels == 2) my_audio_config.achan[1].valid = 1;
+	my_audio_config.achan[0].medium = MEDIUM_RADIO;
+	if (format.nchannels == 2) {
+	  my_audio_config.achan[1].medium = MEDIUM_RADIO;
+	}
 
 	text_color_set(DW_COLOR_INFO);
 	dw_printf ("%d samples per second.  %d bits per sample.  %d audio channels.\n",

audio.h

@@ -53,6 +53,13 @@ typedef enum retry_e {
 		RETRY_INVERT_TWO_SEP=4,
 		RETRY_MAX = 5}  retry_t;
 
+// Type of communication medium associated with the channel.
+
+enum medium_e { MEDIUM_NONE = 0,	// Channel is not valid for use.
+		MEDIUM_RADIO,		// Internal modem for radio.
+		MEDIUM_IGATE,		// Access IGate as ordinary channel.
+		MEDIUM_NETTNC };	// Remote network TNC.  (possible future)
+
 
 typedef enum sanity_e { SANITY_APRS, SANITY_AX25, SANITY_NONE } sanity_t;
 
@@ -102,19 +109,31 @@ struct audio_s {
 					/* Command line option uses "strftime" format string. */
 
 
-	/* Properties for each audio channel, common to receive and transmit. */
+	/* Properties for each channel, common to receive and transmit. */
 	/* Can be different for each radio channel. */
 
+	/* originally a "channel" was always connected to an internal modem. */
+	/* In version 1.6, this is generalized so that a channel (as seen by client application) */
+	/* can be connected to something else.  Initially, this will allow application */
+	/* access to the IGate.  Later we might have network TNCs or other internal functions. */
+
 
 	struct achan_param_s {
 
-	    int valid;			/* Is this channel valid?  */
+	    // Originally there was a boolean, called "valid", to indicate that the
+	    // channel is valid.  This has been replaced with the new "medium" which
+	    // will allow channels to correspond to things other than internal modems.
+
+	    enum medium_e medium;	// MEDIUM_NONE for invalid.
+					// MEDIUM_RADIO for internal modem.  (only possibility earlier)
+					// MEDIUM_IGATE allows application access to IGate.
+
 
 	    char mycall[AX25_MAX_ADDR_LEN];      /* Call associated with this radio channel. */
                                 	/* Could all be the same or different. */
 
 
-	    enum modem_t { MODEM_AFSK, MODEM_BASEBAND, MODEM_SCRAMBLE, MODEM_QPSK, MODEM_8PSK, MODEM_OFF } modem_type;
+	    enum modem_t { MODEM_AFSK, MODEM_BASEBAND, MODEM_SCRAMBLE, MODEM_QPSK, MODEM_8PSK, MODEM_OFF, MODEM_16_QAM, MODEM_64_QAM } modem_type;
 
 					/* Usual AFSK. */
 					/* Baseband signal. Not used yet. */

beacon.c

@@ -183,7 +183,8 @@ void beacon_init (struct audio_s *pmodem, struct misc_config_s *pconfig, struct
 
 	  if (chan < 0) chan = 0;	/* For IGate, use channel 0 call. */
 
-	  if (g_modem_config_p->achan[chan].valid) {
+	  if (g_modem_config_p->achan[chan].medium == MEDIUM_RADIO ||
+	      g_modem_config_p->achan[chan].medium == MEDIUM_NETTNC) {
 
 	    if (strlen(g_modem_config_p->achan[chan].mycall) > 0 &&
 			 strcasecmp(g_modem_config_p->achan[chan].mycall, "N0CALL") != 0 &&

cdigipeater.c

@@ -129,8 +129,10 @@ void cdigipeater (int from_chan, packet_t pp)
 {
 	int to_chan;
 
+	// Connected mode is allowed only for channels with internal modem.
+	// It probably wouldn't matter for digipeating but let's keep that rule simple and consistent.
 
-	if ( from_chan < 0 || from_chan >= MAX_CHANS || ( ! save_audio_config_p->achan[from_chan].valid) ) {
+	if ( from_chan < 0 || from_chan >= MAX_CHANS || save_audio_config_p->achan[from_chan].medium != MEDIUM_RADIO) {
 	  text_color_set(DW_COLOR_ERROR);
 	  dw_printf ("cdigipeater: Did not expect to receive on invalid channel %d.\n", from_chan);
 	  return;