X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FMain%2Ffg_props.cxx;h=770ca620ea91c281920b2277b6a4418bbdfada57;hb=6077e8a8248db3e27ff10cd654219c8dbb758861;hp=4d42d8c08a42e4fd7335fa11e0eae807ba12d941;hpb=d0eaafb1e1c1260a4a2549d63d439dc9407162da;p=flightgear.git

diff --git a/src/Main/fg_props.cxx b/src/Main/fg_props.cxx
index 4d42d8c08..770ca620e 100644
--- a/src/Main/fg_props.cxx
+++ b/src/Main/fg_props.cxx
@@ -27,6 +27,9 @@
 #include <simgear/misc/exception.hxx>
 #include <simgear/magvar/magvar.hxx>
 #include <simgear/timing/sg_time.hxx>
+#include <simgear/misc/sg_path.hxx>
+#include <simgear/scene/material/matlib.hxx>
+#include <simgear/sound/soundmgr.hxx>
 
 #include STL_IOSTREAM
 
@@ -34,12 +37,11 @@
 #include <Aircraft/aircraft.hxx>
 #include <Time/tmp.hxx>
 #include <FDM/UIUCModel/uiuc_aircraftdir.h>
-#ifndef FG_NEW_ENVIRONMENT
+#ifdef FG_WEATHERCM
 #  include <WeatherCM/FGLocalWeatherDatabase.h>
 #else
 #  include <Environment/environment.hxx>
-#endif // FG_NEW_ENVIRONMENT
-#include <Objects/matlib.hxx>
+#endif // FG_WEATHERCM
 
 #include <GUI/gui.h>
 
@@ -47,21 +49,21 @@
 #include "fgfs.hxx"
 #include "fg_props.hxx"
 
-#if !defined(SG_HAVE_NATIVE_SGI_COMPILERS)
 SG_USING_STD(istream);
 SG_USING_STD(ostream);
-#endif
 
-#if !defined(FG_NEW_ENVIRONMENT)
+#ifdef FG_WEATHERCM
 static double getWindNorth ();
 static double getWindEast ();
 static double getWindDown ();
-#endif // FG_NEW_ENVIRONMENT
+#endif // FG_WEATHERCM
 
 static bool winding_ccw = true; // FIXME: temporary
 
 static bool fdm_data_logging = false; // FIXME: temporary
 
+static bool frozen = false;	// FIXME: temporary
+
 
 
 ////////////////////////////////////////////////////////////////////////
@@ -98,23 +100,24 @@ LogClassMapping log_class_mappings [] = {
 /**
  * Get the logging classes.
  */
-static string
+static const char *
 getLoggingClasses ()
 {
   sgDebugClass classes = logbuf::get_log_classes();
-  string result = "";
+  static string result = "";	// FIXME
   for (int i = 0; log_class_mappings[i].c != SG_UNDEFD; i++) {
     if ((classes&log_class_mappings[i].c) > 0) {
-      if (result != (string)"")
+      if (!result.empty())
 	result += '|';
       result += log_class_mappings[i].name;
     }
   }
-  return result;
+  return result.c_str();
 }
 
 
-static void addLoggingClass (const string &name)
+static void
+addLoggingClass (const string &name)
 {
   sgDebugClass classes = logbuf::get_log_classes();
   for (int i = 0; log_class_mappings[i].c != SG_UNDEFD; i++) {
@@ -131,8 +134,9 @@ static void addLoggingClass (const string &name)
  * Set the logging classes.
  */
 static void
-setLoggingClasses (string classes)
+setLoggingClasses (const char * c)
 {
+  string classes = c;
   logbuf::set_log_classes(SG_NONE);
 
   if (classes == "none") {
@@ -140,7 +144,7 @@ setLoggingClasses (string classes)
     return;
   }
 
-  if (classes == "" || classes == "all") { // default
+  if (classes.empty() || classes == "all") { // default
     logbuf::set_log_classes(SG_ALL);
     SG_LOG(SG_GENERAL, SG_INFO, "Enabled all logging classes: "
 	   << getLoggingClasses());
@@ -165,7 +169,7 @@ setLoggingClasses (string classes)
 /**
  * Get the logging priority.
  */
-static string
+static const char *
 getLoggingPriority ()
 {
   switch (logbuf::get_log_priority()) {
@@ -191,13 +195,14 @@ getLoggingPriority ()
  * Set the logging priority.
  */
 static void
-setLoggingPriority (string priority)
+setLoggingPriority (const char * p)
 {
+  string priority = p;
   if (priority == "bulk") {
     logbuf::set_log_priority(SG_BULK);
   } else if (priority == "debug") {
     logbuf::set_log_priority(SG_DEBUG);
-  } else if (priority == "" || priority == "info") { // default
+  } else if (priority.empty() || priority == "info") { // default
     logbuf::set_log_priority(SG_INFO);
   } else if (priority == "warn") {
     logbuf::set_log_priority(SG_WARN);
@@ -210,42 +215,43 @@ setLoggingPriority (string priority)
 }
 
 
-#if 0
 /**
- * Get the pause state of the sim.
+ * Return the current frozen state.
  */
 static bool
 getFreeze ()
 {
-  return globals->get_freeze();
+  return frozen;
 }
 
 
 /**
- * Set the pause state of the sim.
+ * Set the current frozen state.
  */
 static void
-setFreeze (bool freeze)
-{
-    globals->set_freeze(freeze);
-    if ( freeze ) {
-        // BusyCursor( 0 );
-        current_atcdisplay->CancelRepeatingMessage();
-        current_atcdisplay->RegisterRepeatingMessage("****    SIM IS FROZEN    ****    SIM IS FROZEN    ****");
-    } else {
-        // BusyCursor( 1 );
-        current_atcdisplay->CancelRepeatingMessage();
+setFreeze (bool f)
+{
+    frozen = f;
+
+    // Stop sound on a pause
+    SGSoundMgr *s = globals->get_soundmgr();
+    if ( s != NULL ) {
+        if ( f ) {
+            s->pause();
+        } else {
+            s->resume();
+        }
     }
 }
-#endif
+
 
 /**
  * Return the current aircraft directory (UIUC) as a string.
  */
-static string 
+static const char *
 getAircraftDir ()
 {
-  return aircraft_dir;
+  return aircraft_dir.c_str();
 }
 
 
@@ -253,39 +259,34 @@ getAircraftDir ()
  * Set the current aircraft directory (UIUC).
  */
 static void
-setAircraftDir (string dir)
+setAircraftDir (const char * dir)
 {
-  if (getAircraftDir() != dir) {
-    aircraft_dir = dir;
-//     needReinit(); FIXME!!
-  }
+  aircraft_dir = dir;
 }
 
 
 /**
  * Return the number of milliseconds elapsed since simulation started.
  */
-static long
-getElapsedTime_ms ()
+static double
+getElapsedTime_sec ()
 {
-  return globals->get_elapsed_time_ms();
+  return globals->get_sim_time_sec();
 }
 
 
 /**
  * Return the current Zulu time.
  */
-static string 
+static const char *
 getDateString ()
 {
-  string out;
-  char buf[64];
+  static char buf[64];		// FIXME
   struct tm * t = globals->get_time_params()->getGmt();
   sprintf(buf, "%.4d-%.2d-%.2dT%.2d:%.2d:%.2d",
 	  t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
 	  t->tm_hour, t->tm_min, t->tm_sec);
-  out = buf;
-  return out;
+  return buf;
 }
 
 
@@ -293,7 +294,7 @@ getDateString ()
  * Set the current Zulu time.
  */
 static void
-setDateString (string date_string)
+setDateString (const char * date_string)
 {
   static const SGPropertyNode *cur_time_override
 	= fgGetNode("/sim/time/cur-time-override", true);
@@ -304,7 +305,7 @@ setDateString (string date_string)
 
 				// Scan for basic ISO format
 				// YYYY-MM-DDTHH:MM:SS
-  int ret = sscanf(date_string.c_str(), "%d-%d-%dT%d:%d:%d",
+  int ret = sscanf(date_string, "%d-%d-%dT%d:%d:%d",
 		   &(new_time.tm_year), &(new_time.tm_mon),
 		   &(new_time.tm_mday), &(new_time.tm_hour),
 		   &(new_time.tm_min), &(new_time.tm_sec));
@@ -339,40 +340,15 @@ setDateString (string date_string)
 /**
  * Return the GMT as a string.
  */
-static string 
+static const char *
 getGMTString ()
 {
-  string out;
-  char buf[16];
+  static char buf[16];		// FIXME
   struct tm *t = globals->get_time_params()->getGmt();
   sprintf(buf, " %.2d:%.2d:%.2d",
 	  t->tm_hour, t->tm_min, t->tm_sec);
   // cout << t << " " << buf << endl;
-  out = buf;
-  return out;
-}
-
-
-/**
- * Get the texture rendering state.
- */
-static bool
-getTextures ()
-{
-  return (material_lib.get_step() == 0);
-}
-
-
-/**
- * Set the texture rendering state.
- */
-static void
-setTextures (bool textures)
-{
-  if (textures)
-    material_lib.set_step(0);
-  else
-    material_lib.set_step(1);
+  return buf;
 }
 
 
@@ -402,11 +378,14 @@ getMagDip ()
 static double
 getHeadingMag ()
 {
-  return current_aircraft.fdm_state->get_Psi() * SGD_RADIANS_TO_DEGREES - getMagVar();
+  double magheading;
+  magheading = current_aircraft.fdm_state->get_Psi() * SGD_RADIANS_TO_DEGREES - getMagVar();
+  if (magheading < 0) magheading += 360;
+  return magheading;
 }
 
 
-#if !defined(FG_NEW_ENVIRONMENT)
+#ifdef FG_WEATHERCM
 
 /**
  * Get the current visibility (meters).
@@ -464,7 +443,7 @@ getWindEast ()
 static void
 setWindEast (double speed)
 {
-  cout << "Set wind-east to " << speed << endl;
+  SG_LOG(SG_GENERAL, SG_INFO,, "Set wind-east to " << speed );
   current_aircraft.fdm_state->set_Velocities_Local_Airmass(getWindNorth(),
 							   speed,
 							   getWindDown());
@@ -492,7 +471,7 @@ setWindDown (double speed)
 							   speed);
 }
 
-#endif // FG_NEW_ENVIRONMENT
+#endif // FG_WEATHERCM
 
 static long
 getWarp ()
@@ -579,23 +558,23 @@ setFDMDataLogging (bool state)
 void
 fgInitProps ()
 {
+  SG_LOG(SG_GENERAL, SG_DEBUG, "start of fgInitProps()" );
 				// Simulation
   fgTie("/sim/logging/priority", getLoggingPriority, setLoggingPriority);
   fgTie("/sim/logging/classes", getLoggingClasses, setLoggingClasses);
-  // fgTie("/sim/freeze", getFreeze, setFreeze);
+  fgTie("/sim/freeze/master", getFreeze, setFreeze);
   fgTie("/sim/aircraft-dir", getAircraftDir, setAircraftDir);
 
-  fgTie("/sim/time/elapsed-ms", getElapsedTime_ms);
+  fgTie("/sim/time/elapsed-sec", getElapsedTime_sec);
   fgTie("/sim/time/gmt", getDateString, setDateString);
   fgSetArchivable("/sim/time/gmt");
   fgTie("/sim/time/gmt-string", getGMTString);
-  fgTie("/sim/rendering/textures", getTextures, setTextures);
 
 				// Orientation
   fgTie("/orientation/heading-magnetic-deg", getHeadingMag);
 
 				// Environment
-#if !defined(FG_NEW_ENVIRONMENT)
+#ifdef FG_WEATHERCM
   fgTie("/environment/visibility-m", getVisibility, setVisibility);
   fgSetArchivable("/environment/visibility-m");
   fgTie("/environment/wind-from-north-fps", getWindNorth, setWindNorth);
@@ -616,7 +595,8 @@ fgInitProps ()
   fgTie("/sim/temp/winding-ccw", getWindingCCW, setWindingCCW, false);
   fgTie("/sim/temp/full-screen", getFullScreen, setFullScreen);
   fgTie("/sim/temp/fdm-data-logging", getFDMDataLogging, setFDMDataLogging);
-	
+
+  SG_LOG(SG_GENERAL, SG_DEBUG, "end of fgInitProps()" );
 }
 
 
@@ -639,12 +619,12 @@ bool
 fgSaveFlight (ostream &output, bool write_all)
 {
 
-  fgSetBool("/sim/startup/onground", false);
-  fgSetArchivable("/sim/startup/onground");
-  fgSetBool("/sim/startup/trim", false);
-  fgSetArchivable("/sim/startup/trim");
-  fgSetString("/sim/startup/speed-set", "UVW");
-  fgSetArchivable("/sim/startup/speed-set");
+  fgSetBool("/sim/presets/onground", false);
+  fgSetArchivable("/sim/presets/onground");
+  fgSetBool("/sim/presets/trim", false);
+  fgSetArchivable("/sim/presets/trim");
+  fgSetString("/sim/presets/speed-set", "UVW");
+  fgSetArchivable("/sim/presets/speed-set");
 
   try {
     writeProperties(output, globals->get_props(), write_all);
@@ -670,9 +650,9 @@ fgLoadFlight (istream &input)
     return false;
   }
 
-  fgSetBool("/sim/startup/onground", false);
-  fgSetBool("/sim/startup/trim", false);
-  fgSetString("/sim/startup/speed-set", "UVW");
+  fgSetBool("/sim/presets/onground", false);
+  fgSetBool("/sim/presets/trim", false);
+  fgSetString("/sim/presets/speed-set", "UVW");
 
   copyProperties(&props, globals->get_props());
   // When loading a flight, make it the
@@ -682,396 +662,177 @@ fgLoadFlight (istream &input)
 }
 
 
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGCondition.
-////////////////////////////////////////////////////////////////////////
-
-FGCondition::FGCondition ()
-{
-}
-
-FGCondition::~FGCondition ()
-{
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGPropertyCondition.
-////////////////////////////////////////////////////////////////////////
-
-FGPropertyCondition::FGPropertyCondition (const string &propname)
-  : _node(fgGetNode(propname, true))
+bool
+fgLoadProps (const char * path, SGPropertyNode * props, bool in_fg_root)
 {
-}
+    string fullpath;
+    if (in_fg_root) {
+        SGPath loadpath(globals->get_fg_root());
+        loadpath.append(path);
+        fullpath = loadpath.str();
+    } else {
+        fullpath = path;
+    }
 
-FGPropertyCondition::~FGPropertyCondition ()
-{
+    try {
+        readProperties(fullpath, props);
+    } catch (const sg_exception &e) {
+        guiErrorMessage("Error reading properties: ", e);
+        return false;
+    }
+    return true;
 }
 
 
 
 ////////////////////////////////////////////////////////////////////////
-// Implementation of FGNotCondition.
+// Property convenience functions.
 ////////////////////////////////////////////////////////////////////////
 
-FGNotCondition::FGNotCondition (FGCondition * condition)
-  : _condition(condition)
+SGPropertyNode *
+fgGetNode (const char * path, bool create)
 {
+  return globals->get_props()->getNode(path, create);
 }
 
-FGNotCondition::~FGNotCondition ()
+SGPropertyNode * 
+fgGetNode (const char * path, int index, bool create)
 {
-  delete _condition;
+  return globals->get_props()->getNode(path, index, create);
 }
 
 bool
-FGNotCondition::test () const
+fgHasNode (const char * path)
 {
-  return !(_condition->test());
+  return (fgGetNode(path, false) != 0);
 }
 
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGAndCondition.
-////////////////////////////////////////////////////////////////////////
-
-FGAndCondition::FGAndCondition ()
+void
+fgAddChangeListener (SGPropertyChangeListener * listener, const char * path)
 {
+  fgGetNode(path, true)->addChangeListener(listener);
 }
 
-FGAndCondition::~FGAndCondition ()
+void
+fgAddChangeListener (SGPropertyChangeListener * listener,
+		     const char * path, int index)
 {
-  for (unsigned int i = 0; i < _conditions.size(); i++)
-    delete _conditions[i];
+  fgGetNode(path, index, true)->addChangeListener(listener);
 }
 
 bool
-FGAndCondition::test () const
+fgGetBool (const char * name, bool defaultValue)
 {
-  int nConditions = _conditions.size();
-  for (int i = 0; i < nConditions; i++) {
-    if (!_conditions[i]->test())
-      return false;
-  }
-  return true;
+  return globals->get_props()->getBoolValue(name, defaultValue);
 }
 
-void
-FGAndCondition::addCondition (FGCondition * condition)
+int
+fgGetInt (const char * name, int defaultValue)
 {
-  _conditions.push_back(condition);
+  return globals->get_props()->getIntValue(name, defaultValue);
 }
 
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGOrCondition.
-////////////////////////////////////////////////////////////////////////
-
-FGOrCondition::FGOrCondition ()
+int
+fgGetLong (const char * name, long defaultValue)
 {
+  return globals->get_props()->getLongValue(name, defaultValue);
 }
 
-FGOrCondition::~FGOrCondition ()
+float
+fgGetFloat (const char * name, float defaultValue)
 {
-  for (unsigned int i = 0; i < _conditions.size(); i++)
-    delete _conditions[i];
+  return globals->get_props()->getFloatValue(name, defaultValue);
 }
 
-bool
-FGOrCondition::test () const
+double
+fgGetDouble (const char * name, double defaultValue)
 {
-  int nConditions = _conditions.size();
-  for (int i = 0; i < nConditions; i++) {
-    if (_conditions[i]->test())
-      return true;
-  }
-  return false;
+  return globals->get_props()->getDoubleValue(name, defaultValue);
 }
 
-void
-FGOrCondition::addCondition (FGCondition * condition)
+const char *
+fgGetString (const char * name, const char * defaultValue)
 {
-  _conditions.push_back(condition);
+  return globals->get_props()->getStringValue(name, defaultValue);
 }
 
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGComparisonCondition.
-////////////////////////////////////////////////////////////////////////
-
-static int
-doComparison (const SGPropertyNode * left, const SGPropertyNode *right)
+bool
+fgSetBool (const char * name, bool val)
 {
-  switch (left->getType()) {
-  case SGPropertyNode::BOOL: {
-    bool v1 = left->getBoolValue();
-    bool v2 = right->getBoolValue();
-    if (v1 < v2)
-      return FGComparisonCondition::LESS_THAN;
-    else if (v1 > v2)
-      return FGComparisonCondition::GREATER_THAN;
-    else
-      return FGComparisonCondition::EQUALS;
-    break;
-  }
-  case SGPropertyNode::INT: {
-    int v1 = left->getIntValue();
-    int v2 = right->getIntValue();
-    if (v1 < v2)
-      return FGComparisonCondition::LESS_THAN;
-    else if (v1 > v2)
-      return FGComparisonCondition::GREATER_THAN;
-    else
-      return FGComparisonCondition::EQUALS;
-    break;
-  }
-  case SGPropertyNode::LONG: {
-    long v1 = left->getLongValue();
-    long v2 = right->getLongValue();
-    if (v1 < v2)
-      return FGComparisonCondition::LESS_THAN;
-    else if (v1 > v2)
-      return FGComparisonCondition::GREATER_THAN;
-    else
-      return FGComparisonCondition::EQUALS;
-    break;
-  }
-  case SGPropertyNode::FLOAT: {
-    float v1 = left->getFloatValue();
-    float v2 = right->getFloatValue();
-    if (v1 < v2)
-      return FGComparisonCondition::LESS_THAN;
-    else if (v1 > v2)
-      return FGComparisonCondition::GREATER_THAN;
-    else
-      return FGComparisonCondition::EQUALS;
-    break;
-  }
-  case SGPropertyNode::DOUBLE: {
-    double v1 = left->getDoubleValue();
-    double v2 = right->getDoubleValue();
-    if (v1 < v2)
-      return FGComparisonCondition::LESS_THAN;
-    else if (v1 > v2)
-      return FGComparisonCondition::GREATER_THAN;
-    else
-      return FGComparisonCondition::EQUALS;
-    break;
-  }
-  case SGPropertyNode::STRING: 
-  case SGPropertyNode::NONE:
-  case SGPropertyNode::UNSPECIFIED: {
-    string v1 = left->getStringValue();
-    string v2 = right->getStringValue();
-    if (v1 < v2)
-      return FGComparisonCondition::LESS_THAN;
-    else if (v1 > v2)
-      return FGComparisonCondition::GREATER_THAN;
-    else
-      return FGComparisonCondition::EQUALS;
-    break;
-  }
-  }
-  throw sg_exception("Unrecognized node type");
-  return 0;
+  return globals->get_props()->setBoolValue(name, val);
 }
 
-
-FGComparisonCondition::FGComparisonCondition (Type type, bool reverse)
-  : _type(type),
-    _reverse(reverse),
-    _left_property(0),
-    _right_property(0),
-    _right_value(0)
+bool
+fgSetInt (const char * name, int val)
 {
+  return globals->get_props()->setIntValue(name, val);
 }
 
-FGComparisonCondition::~FGComparisonCondition ()
+bool
+fgSetLong (const char * name, long val)
 {
-  delete _right_value;
+  return globals->get_props()->setLongValue(name, val);
 }
 
 bool
-FGComparisonCondition::test () const
+fgSetFloat (const char * name, float val)
 {
-				// Always fail if incompletely specified
-  if (_left_property == 0 ||
-      (_right_property == 0 && _right_value == 0))
-    return false;
-
-				// Get LESS_THAN, EQUALS, or GREATER_THAN
-  int cmp =
-    doComparison(_left_property,
-		 (_right_property != 0 ? _right_property : _right_value));
-  if (!_reverse)
-    return (cmp == _type);
-  else
-    return (cmp != _type);
+  return globals->get_props()->setFloatValue(name, val);
 }
 
-void
-FGComparisonCondition::setLeftProperty (const string &propname)
+bool
+fgSetDouble (const char * name, double val)
 {
-  _left_property = fgGetNode(propname, true);
+  return globals->get_props()->setDoubleValue(name, val);
 }
 
-void
-FGComparisonCondition::setRightProperty (const string &propname)
+bool
+fgSetString (const char * name, const char * val)
 {
-  delete _right_value;
-  _right_value = 0;
-  _right_property = fgGetNode(propname, true);
+  return globals->get_props()->setStringValue(name, val);
 }
 
 void
-FGComparisonCondition::setRightValue (const SGPropertyNode *node)
-{
-  _right_property = 0;
-  delete _right_value;
-  _right_value = new SGPropertyNode(*node);
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-// Read a condition and use it if necessary.
-////////////////////////////////////////////////////////////////////////
-
-                                // Forward declaration
-static FGCondition * readCondition (const SGPropertyNode * node);
-
-static FGCondition *
-readPropertyCondition (const SGPropertyNode * node)
-{
-  return new FGPropertyCondition(node->getStringValue());
-}
-
-static FGCondition *
-readNotCondition (const SGPropertyNode * node)
+fgSetArchivable (const char * name, bool state)
 {
-  int nChildren = node->nChildren();
-  for (int i = 0; i < nChildren; i++) {
-    const SGPropertyNode * child = node->getChild(i);
-    FGCondition * condition = readCondition(child);
-    if (condition != 0)
-      return new FGNotCondition(condition);
-  }
-  SG_LOG(SG_COCKPIT, SG_ALERT, "Panel: empty 'not' condition");
-  return 0;
-}
-
-static FGCondition *
-readAndConditions (const SGPropertyNode * node)
-{
-  FGAndCondition * andCondition = new FGAndCondition;
-  int nChildren = node->nChildren();
-  for (int i = 0; i < nChildren; i++) {
-    const SGPropertyNode * child = node->getChild(i);
-    FGCondition * condition = readCondition(child);
-    if (condition != 0)
-      andCondition->addCondition(condition);
-  }
-  return andCondition;
-}
-
-static FGCondition *
-readOrConditions (const SGPropertyNode * node)
-{
-  FGOrCondition * orCondition = new FGOrCondition;
-  int nChildren = node->nChildren();
-  for (int i = 0; i < nChildren; i++) {
-    const SGPropertyNode * child = node->getChild(i);
-    FGCondition * condition = readCondition(child);
-    if (condition != 0)
-      orCondition->addCondition(condition);
-  }
-  return orCondition;
-}
-
-static FGCondition *
-readComparison (const SGPropertyNode * node,
-		FGComparisonCondition::Type type,
-		bool reverse)
-{
-  FGComparisonCondition * condition = new FGComparisonCondition(type, reverse);
-  condition->setLeftProperty(node->getStringValue("property[0]"));
-  if (node->hasValue("property[1]"))
-    condition->setRightProperty(node->getStringValue("property[1]"));
+  SGPropertyNode * node = globals->get_props()->getNode(name);
+  if (node == 0)
+    SG_LOG(SG_GENERAL, SG_ALERT,
+	   "Attempt to set archive flag for non-existant property "
+	   << name);
   else
-    condition->setRightValue(node->getChild("value", 0));
-
-  return condition;
+    node->setAttribute(SGPropertyNode::ARCHIVE, state);
 }
 
-static FGCondition *
-readCondition (const SGPropertyNode * node)
+void
+fgSetReadable (const char * name, bool state)
 {
-  const string &name = node->getName();
-  if (name == "property")
-    return readPropertyCondition(node);
-  else if (name == "not")
-    return readNotCondition(node);
-  else if (name == "and")
-    return readAndConditions(node);
-  else if (name == "or")
-    return readOrConditions(node);
-  else if (name == "less-than")
-    return readComparison(node, FGComparisonCondition::LESS_THAN, false);
-  else if (name == "less-than-equals")
-    return readComparison(node, FGComparisonCondition::GREATER_THAN, true);
-  else if (name == "greater-than")
-    return readComparison(node, FGComparisonCondition::GREATER_THAN, false);
-  else if (name == "greater-than-equals")
-    return readComparison(node, FGComparisonCondition::LESS_THAN, true);
-  else if (name == "equals")
-    return readComparison(node, FGComparisonCondition::EQUALS, false);
-  else if (name == "not-equals")
-    return readComparison(node, FGComparisonCondition::EQUALS, true);
+  SGPropertyNode * node = globals->get_props()->getNode(name);
+  if (node == 0)
+    SG_LOG(SG_GENERAL, SG_ALERT,
+	   "Attempt to set read flag for non-existant property "
+	   << name);
   else
-    return 0;
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-// Implementation of FGConditional.
-////////////////////////////////////////////////////////////////////////
-
-FGConditional::FGConditional ()
-  : _condition (0)
-{
-}
-
-FGConditional::~FGConditional ()
-{
-  delete _condition;
+    node->setAttribute(SGPropertyNode::READ, state);
 }
 
 void
-FGConditional::setCondition (FGCondition * condition)
+fgSetWritable (const char * name, bool state)
 {
-  delete _condition;
-  _condition = condition;
-}
-
-bool
-FGConditional::test () const
-{
-  return ((_condition == 0) || _condition->test());
+  SGPropertyNode * node = globals->get_props()->getNode(name);
+  if (node == 0)
+    SG_LOG(SG_GENERAL, SG_ALERT,
+	   "Attempt to set write flag for non-existant property "
+	   << name);
+  else
+    node->setAttribute(SGPropertyNode::WRITE, state);
 }
 
-
-
-// The top-level is always an implicit 'and' group
-FGCondition *
-fgReadCondition (const SGPropertyNode * node)
+void
+fgUntie (const char * name)
 {
-  return readAndConditions(node);
+  if (!globals->get_props()->untie(name))
+    SG_LOG(SG_GENERAL, SG_WARN, "Failed to untie property " << name);
 }