Move the C version of fgfdm_log.c to examples/dds/ and convert it to C++ as fg_dds_log.cpp using the SimGear provided hepper classes.

examples/dds/README

@@ -0,0 +1,18 @@
+Data Distribution Service (DDS) logger
+
+This example uses a waitset to listens to the FlightGear GUI, FDM adn Ctrls
+DDS topics and logs some data for any of them when new data arrives.
+
+Run FlightGear with any combination  of the following command line arguments to
+get it to produce new DDS samples:
+
+fgfs
+ --native-gui=dds,out,30
+ --native-fdm=dds,out,60
+ --native-ctrls=dds,out,10
+
+
+The executable has to be linkes against the CycloneDDS ddsc component and
+all *.c files in src/Network/DDS:
+
+gcc -I ../../src fgfdm_log.c ../../src/Network/DDS/*.c  -l ddsc -o fgfdm_log

examples/dds/fgfdm_log.c

@@ -1,11 +1,14 @@
-#include "dds/dds.h"
-#include "dds_gui.h"
-#include "dds_fdm.h"
-#include "dds_ctrls.h"
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 
+#include <dds/dds.h>
+
+#include <Network/DDS/dds_gui.h>
+#include <Network/DDS/dds_fdm.h>
+#include <Network/DDS/dds_ctrls.h>
+
+
 /* An array of one message(aka sample in dds terms) will be used. */
 #define MAX_SAMPLES 1
 
@@ -119,7 +122,7 @@ int main()
   if (status < 0)
       DDS_FATAL("ds_waitset_attach: %s\n", dds_strretcode(-status));
 
-  /* Create an Ctrls Topic. */
+  /* Create a Ctrls Topic. */
   ctrls_topic = dds_create_topic(
     participant, &FG_DDS_Ctrls_desc, "FG_DDS_Ctrls", NULL, NULL);
   if(ctrls_topic < 0)
@@ -160,7 +163,7 @@ int main()
       printf("GUI Message:\n");
       printf(" version: %i\n", gui->version);
       printf(" tuned_freq: %lf\n", gui->longitude);
-      printf(" nav_radial  %lf\n", gui->latitude);
+      printf(" nav_radial: %lf\n", gui->latitude);
       printf("    dist_nm: %lf\n", gui->altitude);
     }
 

src/Network/DDS/CMakeLists.txt

@@ -12,12 +12,12 @@ set(HEADERS
         dds_gui.h
 	)
 
-add_executable(fgfdm_log
+add_executable(fg_dds_log
     WIN32
     MACOSX_BUNDLE
-    fgfdm_log.c
+    fg_dds_log.cpp
     ${SOURCES}
 )
-target_link_libraries(fgfdm_log CycloneDDS::ddsc)
+setup_fgfs_libraries(fg_dds_log)
 
 flightgear_component(Network "${SOURCES}" "${HEADERS}")

src/Network/DDS/fg_dds_log.cpp

@@ -0,0 +1,123 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <map>
+
+#include <simgear/io/SGDataDistributionService.hxx>
+
+#include "dds_gui.h"
+#include "dds_fdm.h"
+#include "dds_ctrls.h"
+
+/* An array of one message(aka sample in dds terms) will be used. */
+#define MAX_SAMPLES 1
+
+#ifndef _WIN32
+# include <termios.h>
+
+void set_mode(int want_key)
+{
+    static struct termios tios_old, tios_new;
+    if (!want_key) {
+        tcsetattr(STDIN_FILENO, TCSANOW, &tios_old);
+        return;
+    }
+
+    tcgetattr(STDIN_FILENO, &tios_old);
+    tios_new = tios_old;
+    tios_new.c_lflag &= ~(ICANON | ECHO);
+    tcsetattr(STDIN_FILENO, TCSANOW, &tios_new);
+}
+
+int get_key()
+{
+    int c = 0;
+    struct timeval tv;
+    fd_set fs;
+    tv.tv_usec = tv.tv_sec = 0;
+
+    FD_ZERO(&fs);
+    FD_SET(STDIN_FILENO, &fs);
+    select(STDIN_FILENO + 1, &fs, 0, 0, &tv);
+
+    if (FD_ISSET(STDIN_FILENO, &fs)) {
+        c = getchar();
+    }
+    return c;
+}
+#else
+# include <conio.h>
+
+int get_key()
+{
+   if (kbhit()) {
+      return getch();
+   }
+   return 0;
+}
+
+void set_mode(int want_key)
+{
+}
+#endif
+
+int main()
+{
+  SG_DDS participant;
+  std::map<std::string, SG_DDS_Topic *> topics;
+
+  topics["gui"] = new SG_DDS_Topic();
+  topics["fdm"] = new SG_DDS_Topic();
+  topics["ctrls"] = new SG_DDS_Topic();
+
+  topics["gui"]->setup("FG_DDS_GUI", &FG_DDS_GUI_desc, sizeof(FG_DDS_GUI));
+  topics["fdm"]->setup("FG_DDS_FDM", &FG_DDS_FDM_desc, sizeof(FG_DDS_FDM));
+  topics["ctrls"]->setup("FG_DDS_Ctrls", &FG_DDS_Ctrls_desc, sizeof(FG_DDS_Ctrls));
+
+  participant.add(topics["gui"], SG_IO_IN);
+  participant.add(topics["fdm"], SG_IO_IN);
+  participant.add(topics["ctrls"], SG_IO_IN);
+
+  set_mode(1);
+  while(participant.wait(0.1f))
+  {
+    FG_DDS_Ctrls ctrls;
+    FG_DDS_FDM fdm;
+    FG_DDS_GUI gui;
+
+    if (topics["gui"]->read((char*)&gui, sizeof(gui)) == sizeof(gui)) {
+      printf("=== [fgfdm_log] Received : ");
+      printf("GUI Message:\n");
+      printf(" version: %i\n", gui.version);
+      printf(" tuned_freq: %lf\n", gui.longitude);
+      printf(" nav_radial: %lf\n", gui.latitude);
+      printf("    dist_nm: %lf\n", gui.altitude);
+    }
+
+    if (topics["fdm"]->read((char*)&fdm, sizeof(fdm)) == sizeof(fdm)) {
+      printf("=== [fgfdm_log] Received : ");
+      printf("FDM Message:\n");
+      printf(" version: %i\n", fdm.version);
+      printf("  longitude: %lf\n", fdm.longitude);
+      printf("   latitude: %lf\n", fdm.latitude);
+      printf("   altitude: %lf\n", fdm.altitude);
+    }
+
+    if (topics["ctrls"]->read((char*)&ctrls, sizeof(ctrls)) == sizeof(ctrls)) {
+      printf("=== [fgfdm_log] Received : ");
+      printf("Ctrls Message:\n");
+      printf(" version: %i\n", ctrls.version);
+      printf("    aileron: %lf\n", ctrls.aileron);
+      printf("   elevator: %lf\n", ctrls.elevator);
+      printf("     rudder: %lf\n", ctrls.rudder);
+    }
+
+    fflush(stdout);
+
+    if (get_key()) break;
+  }
+  set_mode(0);
+
+  return EXIT_SUCCESS;
+}