- Implemented a DampingMoment simulation listener example

- Added ability for simulation listeners to reserve their own data types. To support this:
  -- All data types can now be found from just the OpenRocketDocument (reduces some code duplication also).
  -- Custom expressions rebuilt after loading from file in case they use a listeners reserved type
- Fixed (possibly unrelated) issue where datatypes would be deleted and re-made each step if a customexpression used a range or index subexpression

core/src/net/sf/openrocket/document/OpenRocketDocument.java

@@ -1,8 +1,12 @@
 package net.sf.openrocket.document;
 
 import java.io.File;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 
 import net.sf.openrocket.document.events.DocumentChangeEvent;
 import net.sf.openrocket.document.events.DocumentChangeListener;
@@ -13,7 +17,10 @@ import net.sf.openrocket.rocketcomponent.ComponentChangeEvent;
 import net.sf.openrocket.rocketcomponent.ComponentChangeListener;
 import net.sf.openrocket.rocketcomponent.Configuration;
 import net.sf.openrocket.rocketcomponent.Rocket;
+import net.sf.openrocket.simulation.FlightDataType;
 import net.sf.openrocket.simulation.customexpression.CustomExpression;
+import net.sf.openrocket.simulation.exception.SimulationListenerException;
+import net.sf.openrocket.simulation.listeners.SimulationListener;
 import net.sf.openrocket.startup.Application;
 import net.sf.openrocket.util.ArrayList;
 
@@ -121,6 +128,43 @@ public class OpenRocketDocument implements ComponentChangeListener {
 		return customExpressions;
 	}
 	
+	/*
+	 * Returns a set of all the flight data types defined or available in any way in the rocket document
+	 */
+	public Set<FlightDataType> getFlightDataTypes(){
+		Set<FlightDataType> allTypes = new LinkedHashSet<FlightDataType>();
+		
+		// built in
+		Collections.addAll(allTypes, FlightDataType.ALL_TYPES);
+		
+		// custom expressions
+		for (CustomExpression exp : customExpressions){
+			allTypes.add(exp.getType());
+		}
+		
+		// simulation listeners
+		for (Simulation sim : simulations){
+			for (String className : sim.getSimulationListeners()) {
+				SimulationListener l = null;
+				try {
+					Class<?> c = Class.forName(className);
+					l = (SimulationListener) c.newInstance();
+					
+					Collections.addAll(allTypes, l.getFlightDataTypes());
+					//System.out.println("This document has expression datatype from "+l.getName());
+				} catch (Exception e) {
+					log.error("Could not instantiate listener: " + className);
+				}
+			}			
+		}
+		
+		// imported data
+		/// not implemented yet
+		
+		
+		return allTypes;
+	}
+	
 
 	public Rocket getRocket() {
 		return rocket;

core/src/net/sf/openrocket/file/openrocket/importt/OpenRocketLoader.java

@@ -704,8 +704,6 @@ class OpenRocketContentHandler extends AbstractElementHandler {
 	}
 }
 
-
-
 class DatatypeHandler extends AbstractElementHandler {
 	private final DocumentLoadingContext context;
 	private final OpenRocketContentHandler contentHandler;
@@ -1288,10 +1286,14 @@ class SimulationsHandler extends AbstractElementHandler {
 	public void closeElement(String element, HashMap<String, String> attributes,
 			String content, WarningSet warnings) throws SAXException {
 		attributes.remove("status");
+		
+		//Finished loading. Rebuilding custom expressions in case something has changed such as listener variable come available.
+		for (CustomExpression exp : doc.getCustomExpressions()){
+			exp.setExpression(exp.getExpressionString());
+		}
+		
 		super.closeElement(element, attributes, content, warnings);
 	}
-	
-	
 }
 
 class SingleSimulationHandler extends AbstractElementHandler {

core/src/net/sf/openrocket/simulation/FlightDataType.java

@@ -269,8 +269,8 @@ public class FlightDataType implements Comparable<FlightDataType> {
 		if (type != null) {
 			// found it from symbol
 			
-			// if name was not give (empty string), can use the one we found name
+			// if name was not given (empty string), can use the one we found
-			if ( s.equals("") || s == null ){
+			if ( s == null || s.isEmpty()){
 				s = type.getName();
 			}
 			if ( u == null ){
@@ -279,14 +279,19 @@ public class FlightDataType implements Comparable<FlightDataType> {
 			
 			// if something has changed, then we need to remove the old one
 			// otherwise, just return what we found
-			if ( !u.equals(type.getUnitGroup()) ||
+			if ( !u.equals(type.getUnitGroup()) )
-				 !s.equals(type.getName())
-				)
 			   {
 				oldPriority = type.priority;
-				
 				EXISTING_TYPES.remove(type);
-				log.info("Something changed with the type "+type.getName()+", removed old version.");
+				log.info("Unitgroup of type "+type.getName() + 
+						 ", has changed from "+type.getUnitGroup().toString() + 
+						 " to "+u.toString() +
+						 ". Removing old version.");
+			}
+			else if (!s.equals(type.getName())) {
+				oldPriority = type.priority;
+				EXISTING_TYPES.remove(type);
+				log.info("Name of type "+type.getName()+", has changed to "+s+". Removing old version.");
 			}
 			else{
 				return type;

core/src/net/sf/openrocket/simulation/customexpression/CustomExpression.java

@@ -34,11 +34,12 @@ public class CustomExpression implements Cloneable{
 	private List<CustomExpression> subExpressions = new ArrayList<CustomExpression>();
 	
 	public CustomExpression(OpenRocketDocument doc){
+		this.doc = doc;
+		
 		setName("");
 		setSymbol("");
 		setUnit("");
 		setExpression("");
-		this.doc = doc;
 	}
 	
 	public CustomExpression(OpenRocketDocument doc, 
@@ -171,6 +172,7 @@ public class CustomExpression implements Cloneable{
 	// get a list of all the names of all the available variables
 	protected ArrayList<String> getAllNames(){
 		ArrayList<String> names = new ArrayList<String>();
+		/*
 		for (FlightDataType type : FlightDataType.ALL_TYPES)
 			names.add(type.getName());
 
@@ -181,12 +183,22 @@ public class CustomExpression implements Cloneable{
 					names.add(exp.getName());
 			}
 		}
+		*/
+		for (FlightDataType type : doc.getFlightDataTypes()){
+			String symb = type.getName();
+			if (name == null) continue;
+			
+			if (!name.equals( this.getName() )){
+				names.add(symb);
+			}
+		}
 		return names;
 	}
 	
 	// get a list of all the symbols of the available variables ignoring this one
 	protected ArrayList<String> getAllSymbols(){
 		ArrayList<String> symbols = new ArrayList<String>();
+		/*
 		for (FlightDataType type : FlightDataType.ALL_TYPES)
 			symbols.add(type.getSymbol());
 		
@@ -196,6 +208,14 @@ public class CustomExpression implements Cloneable{
 					symbols.add(exp.getSymbol());
 			}
 		}
+		*/
+		for (FlightDataType type : doc.getFlightDataTypes()){
+			String symb = type.getSymbol();			
+			if (!symb.equals( this.getSymbol() )){
+				symbols.add(symb);
+			}
+		}
+		
 		return symbols;
 	}
 	
@@ -305,6 +325,7 @@ public class CustomExpression implements Cloneable{
 		
 		//// Define the available variables as empty
 		// The built in data types
+		/*
 		for (FlightDataType type : FlightDataType.ALL_TYPES){
 			builder.withVariable(new Variable(type.getSymbol()));
 		}
@@ -312,12 +333,16 @@ public class CustomExpression implements Cloneable{
 		for (String symb : getAllSymbols()){
 			builder.withVariable(new Variable(symb));
 		}
+		*/
+		for (FlightDataType type : doc.getFlightDataTypes()){
+			builder.withVariable(new Variable(type.getSymbol()));
+		}
 		
 		// Try to build
 		try {
 			builder.build();
 		} catch (Exception e) {
-			log.user("Custom expression invalid : " + e.toString());
+			log.user("Custom expression " + this.toString() + " invalid : " + e.toString());
 			return false;
 		}
 		
@@ -341,14 +366,14 @@ public class CustomExpression implements Cloneable{
 	 * Builds a specified expression, log any errors and returns null in case of error.
 	 */
 	protected Calculable buildExpression(ExpressionBuilder b){
-		Calculable calc;
+		Calculable calc = null;
 		try {
 			calc = b.build();
 		} catch (UnknownFunctionException e1) {
-			log.user("Unknown function. Could not build custom expression "+name);
+			log.user("Unknown function. Could not build custom expression "+this.toString());
 			return null;
 		} catch (UnparsableExpressionException e1) {
-			log.user("Unparsable expression. Could not build custom expression "+name+". "+e1.getMessage());
+			log.user("Unparsable expression. Could not build custom expression "+this.toString()+". "+e1.getMessage());
 			return null;
 		}
 		
@@ -396,10 +421,13 @@ public class CustomExpression implements Cloneable{
 	 */
 	public FlightDataType getType(){
 		
+		
 		UnitGroup ug = UnitGroup.SIUNITS.get(unit); 
 		if ( ug == null ){
+			log.debug("SI unit not found for "+unit+" in expression "+toString()+". Making a new fixed unit.");
 			ug = new FixedUnitGroup(unit);
 		}
+		//UnitGroup ug = new FixedUnitGroup(unit);
 		
 		FlightDataType type = FlightDataType.getType(name, symbol, ug);
 		
@@ -442,7 +470,7 @@ public class CustomExpression implements Cloneable{
 	
 	@Override
 	public String toString(){
-		return "Custom expression : "+this.name.toString()+ " " + this.expression.toString();
+		return "[Expression name="+this.name.toString()+ " expression=" + this.expression+" unit="+this.unit+"]";
 	}
 	
 	@Override

core/src/net/sf/openrocket/simulation/customexpression/CustomExpressionSimulationListener.java

@@ -3,13 +3,16 @@ package net.sf.openrocket.simulation.customexpression;
 import java.util.ArrayList;
 import java.util.List;
 
+import net.sf.openrocket.logging.LogHelper;
 import net.sf.openrocket.simulation.FlightDataBranch;
 import net.sf.openrocket.simulation.SimulationStatus;
 import net.sf.openrocket.simulation.exception.SimulationException;
 import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+import net.sf.openrocket.startup.Application;
 
 public class CustomExpressionSimulationListener extends	AbstractSimulationListener {
 
+	private static final LogHelper log = Application.getLogger();
 	private final List<CustomExpression> expressions;
 	
 	public CustomExpressionSimulationListener(List<CustomExpression> expressions) {
@@ -25,10 +28,17 @@ public class CustomExpressionSimulationListener extends	AbstractSimulationListen
 		// Calculate values for custom expressions
 		FlightDataBranch data = status.getFlightData();
 		for (CustomExpression expression : expressions ) {
-			data.setValue(expression.getType(), expression.evaluateDouble(status));
+			double value = expression.evaluateDouble(status);
+			//log.debug("Setting value of custom expression "+expression.toString()+" = "+value);
+			data.setValue(expression.getType(), value);
 		}
 		
 
 	}
 
+	@Override
+	public boolean isSystemListener(){
+		return true;
+	}
+	
 }

core/src/net/sf/openrocket/simulation/customexpression/IndexExpression.java

@@ -23,7 +23,6 @@ public class IndexExpression extends CustomExpression {
 		setExpression(indexText);
 		this.setName("");
 		this.setSymbol(typeText);
-		
 	}
 	
 	@Override
@@ -35,7 +34,10 @@ public class IndexExpression extends CustomExpression {
 		}
 		
 		// From the given datatype, get the time and function values and make an interpolator
-		FlightDataType type = getType();
+
+		//Note: must get in a way that flight data system will figure out units. Otherwise there will be a type conflict when we get the new data.
+		FlightDataType type = FlightDataType.getType(null, getSymbol(), null);  
+				
 		List<Double> data = status.getFlightData().get(type);
 		List<Double> time = status.getFlightData().get(FlightDataType.TYPE_TIME);
 		LinearInterpolator interp = new LinearInterpolator(time, data); 

core/src/net/sf/openrocket/simulation/customexpression/RangeExpression.java

@@ -40,7 +40,6 @@ public class RangeExpression extends CustomExpression {
 		this.expression = variableType+startTime+endTime; // this is used just for generating the hash
 		
 		log.info("New range expression, "+startTime + " to "+endTime);
-		
 	}
 	
 	/*
@@ -73,7 +72,9 @@ public class RangeExpression extends CustomExpression {
 		}		
 		
 		// From the given datatype, get the time and function values and make an interpolator
-		FlightDataType type = getType();
+
+		//Note: must get in a way that flight data system will figure out units. Otherwise there will be a type conflict when we get the new data.
+		FlightDataType type = FlightDataType.getType(null, getSymbol(), null);
 		
 		List<Double> data = status.getFlightData().get(type);
 		List<Double> time = status.getFlightData().get(FlightDataType.TYPE_TIME);

core/src/net/sf/openrocket/simulation/listeners/AbstractSimulationListener.java

@@ -1,5 +1,7 @@
 package net.sf.openrocket.simulation.listeners;
 
+import java.util.List;
+
 import net.sf.openrocket.aerodynamics.AerodynamicForces;
 import net.sf.openrocket.aerodynamics.FlightConditions;
 import net.sf.openrocket.models.atmosphere.AtmosphericConditions;
@@ -8,6 +10,7 @@ import net.sf.openrocket.motor.MotorInstance;
 import net.sf.openrocket.rocketcomponent.MotorMount;
 import net.sf.openrocket.rocketcomponent.RecoveryDevice;
 import net.sf.openrocket.simulation.AccelerationData;
+import net.sf.openrocket.simulation.FlightDataType;
 import net.sf.openrocket.simulation.FlightEvent;
 import net.sf.openrocket.simulation.MassData;
 import net.sf.openrocket.simulation.SimulationStatus;
@@ -67,7 +70,13 @@ public class AbstractSimulationListener implements SimulationListener, Simulatio
 		return false;
 	}
 	
-	
+	/**
+	 * Return an array of any flight data types this listener creates.
+	 */
+	@Override
+	public FlightDataType[] getFlightDataTypes(){
+		return new FlightDataType[] {};
+	}
 	
 	
 	////  SimulationEventListener  ////

core/src/net/sf/openrocket/simulation/listeners/SimulationComputationListener.java

@@ -1,9 +1,12 @@
 package net.sf.openrocket.simulation.listeners;
 
+import java.util.List;
+
 import net.sf.openrocket.aerodynamics.AerodynamicForces;
 import net.sf.openrocket.aerodynamics.FlightConditions;
 import net.sf.openrocket.models.atmosphere.AtmosphericConditions;
 import net.sf.openrocket.simulation.AccelerationData;
+import net.sf.openrocket.simulation.FlightDataType;
 import net.sf.openrocket.simulation.MassData;
 import net.sf.openrocket.simulation.SimulationStatus;
 import net.sf.openrocket.simulation.exception.SimulationException;
@@ -64,4 +67,5 @@ public interface SimulationComputationListener extends SimulationListener {
 	
 	public double postSimpleThrustCalculation(SimulationStatus status, double thrust) throws SimulationException;
 
+	public FlightDataType[] getFlightDataTypes();
 }

core/src/net/sf/openrocket/simulation/listeners/SimulationEventListener.java

@@ -1,9 +1,12 @@
 package net.sf.openrocket.simulation.listeners;
 
+import java.util.List;
+
 import net.sf.openrocket.motor.MotorId;
 import net.sf.openrocket.motor.MotorInstance;
 import net.sf.openrocket.rocketcomponent.MotorMount;
 import net.sf.openrocket.rocketcomponent.RecoveryDevice;
+import net.sf.openrocket.simulation.FlightDataType;
 import net.sf.openrocket.simulation.FlightEvent;
 import net.sf.openrocket.simulation.SimulationStatus;
 import net.sf.openrocket.simulation.exception.SimulationException;
@@ -56,6 +59,10 @@ public interface SimulationEventListener {
 	 */
 	public boolean recoveryDeviceDeployment(SimulationStatus status, RecoveryDevice recoveryDevice)
 			throws SimulationException;
+
+
+
+	public FlightDataType[] getFlightDataTypes();
 	
 
 }

core/src/net/sf/openrocket/simulation/listeners/SimulationListener.java

@@ -1,5 +1,8 @@
 package net.sf.openrocket.simulation.listeners;
 
+import java.util.List;
+
+import net.sf.openrocket.simulation.FlightDataType;
 import net.sf.openrocket.simulation.SimulationStatus;
 import net.sf.openrocket.simulation.exception.SimulationException;
 
@@ -76,4 +79,11 @@ public interface SimulationListener {
 	 */
 	public boolean isSystemListener();
 	
+	
+	/**
+	 * Return a list of any flight data types this listener creates.
+	 */
+	public FlightDataType[] getFlightDataTypes();
+	
+	
 }

core/src/net/sf/openrocket/simulation/listeners/example/DampingMoment.java

@@ -0,0 +1,129 @@
+package net.sf.openrocket.simulation.listeners.example;
+
+import java.util.List;
+import java.util.Map;
+
+import net.sf.openrocket.aerodynamics.AerodynamicCalculator;
+import net.sf.openrocket.aerodynamics.AerodynamicForces;
+import net.sf.openrocket.aerodynamics.FlightConditions;
+import net.sf.openrocket.motor.MotorId;
+import net.sf.openrocket.motor.MotorInstance;
+import net.sf.openrocket.motor.MotorInstanceConfiguration;
+import net.sf.openrocket.rocketcomponent.MotorMount;
+import net.sf.openrocket.rocketcomponent.RocketComponent;
+import net.sf.openrocket.simulation.FlightDataBranch;
+import net.sf.openrocket.simulation.FlightDataType;
+import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.exception.SimulationException;
+import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+import net.sf.openrocket.unit.UnitGroup;
+import net.sf.openrocket.util.ArrayList;
+import net.sf.openrocket.util.Coordinate;
+import net.sf.openrocket.util.PolyInterpolator;
+
+public class DampingMoment extends AbstractSimulationListener {
+	
+	private static final FlightDataType type = FlightDataType.getType("Damping moment coefficient", "Cdm", UnitGroup.UNITS_COEFFICIENT);
+	private static final FlightDataType[] typeList = {type};
+	
+	public String getName(){
+		return "Damping moment listener";
+	}
+	
+	/**
+	 * Return a list of any flight data types this listener creates.
+	 */
+	public FlightDataType[] getFlightDataTypes(){
+		return typeList;
+	}
+	
+	@Override
+	public FlightConditions postFlightConditions(SimulationStatus status, FlightConditions flightConditions) throws SimulationException {
+		
+		// Save it as a flightdatatype
+		
+		//status.getFlightData().setValue(type, aerodynamicPart + propulsivePart);
+		status.getFlightData().setValue(type, calculate(status, flightConditions));
+
+		return flightConditions;
+	}
+	
+	private double calculate(SimulationStatus status, FlightConditions flightConditions){
+		
+		// Work out the propulsive/jet damping part of the moment.
+		
+		// dm/dt = (thrust - ma)/v
+		FlightDataBranch data = status.getFlightData();
+		
+		List<Double> mpAll = data.get(FlightDataType.TYPE_PROPELLANT_MASS);
+		List<Double> time = data.get(FlightDataType.TYPE_TIME);
+		if (mpAll == null || time == null){
+			return Double.NaN;
+		}
+		
+		int len = mpAll.size();
+		
+		// This isn't as accurate as I would like
+		double mdot=Double.NaN;
+		if (len > 2){
+			// Using polynomial interpolator for derivative. Doesn't help much
+			//double[] x = { time.get(len-5), time.get(len-4), time.get(len-3), time.get(len-2), time.get(len-1) };
+			//double[] y = { mpAll.get(len-5), mpAll.get(len-4), mpAll.get(len-3), mpAll.get(len-2), mpAll.get(len-1) };
+			//PolyInterpolator interp = new PolyInterpolator(x);
+			//double[] coeff = interp.interpolator(y);
+			//double dt = .01;
+			//mdot = (interp.eval(x[4], coeff) - interp.eval(x[4]-dt, coeff))/dt; 
+						
+			mdot = (mpAll.get(len-1) - mpAll.get(len-2)) / (time.get(len-1) - time.get(len-2));
+		}
+		
+		double cg = data.getLast(FlightDataType.TYPE_CG_LOCATION);
+		
+		// find the maximum distance from nose to nozzle. 
+		double nozzleDistance = 0;
+		for (MotorId id: status.getMotorConfiguration().getMotorIDs()){
+			MotorInstanceConfiguration config = status.getMotorConfiguration();
+			Coordinate position = config.getMotorPosition(id);
+			
+			double x = position.x + config.getMotorInstance(id).getParentMotor().getLength();
+			if (x > nozzleDistance){
+				nozzleDistance = x;
+			}			
+		}
+		
+		// now can get the propulsive part
+		double propulsivePart = mdot * Math.pow(nozzleDistance - cg, 2);
+		
+		// Work out the aerodynamic part of the moment.
+		double aerodynamicPart = 0;
+		
+		AerodynamicCalculator aerocalc = status.getSimulationConditions().getAerodynamicCalculator();
+		
+		// Must go through each component ...
+		Map<RocketComponent, AerodynamicForces> forces = aerocalc.getForceAnalysis(status.getConfiguration(), flightConditions, null);
+		for (Map.Entry<RocketComponent, AerodynamicForces> entry : forces.entrySet()){
+			
+			RocketComponent comp = entry.getKey();
+			
+			if (!comp.isAerodynamic()) continue;
+			
+			//System.out.println(comp.toString());
+			
+			double CNa = entry.getValue().getCNa(); //?
+			double Cp = entry.getValue().getCP().length();
+			double z = comp.getPositionValue(); //?
+			
+			aerodynamicPart += CNa*Math.pow(z-Cp, 2);
+		}
+		
+		double v = flightConditions.getVelocity();
+		double rho = flightConditions.getAtmosphericConditions().getDensity();
+		double ar = flightConditions.getRefArea();
+		
+		aerodynamicPart = aerodynamicPart * .5 * rho * v * ar;
+		
+		return aerodynamicPart + propulsivePart;
+	
+	}
+	
+}