[refactor] RocketComponent positioning is now centralized in AxialMethod class

- also relaxed visibility for Component::setAxialMethod(...)

core/src/net/sf/openrocket/file/rocksim/importt/FinSetHandler.java

@@ -325,7 +325,8 @@ class FinSetHandler extends AbstractElementHandler {
 		result.setBaseRotation(radialAngle);
 		result.setCrossSection(convertTipShapeCode(tipShapeCode));
 		result.setAxialMethod(axialMethod);
-		PositionDependentHandler.setLocation(result, axialMethod, location);
+		result.setAxialOffset(location);
+
 		return result;
 		
 	}

core/src/net/sf/openrocket/file/rocksim/importt/InnerBodyTubeHandler.java

@@ -15,7 +15,6 @@ import net.sf.openrocket.file.simplesax.PlainTextHandler;
 import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.InnerTube;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 /**
  * A SAX handler for Rocksim inside tubes.
@@ -99,17 +98,6 @@ class InnerBodyTubeHandler extends PositionDependentHandler<InnerTube> {
 		return bodyTube;
 	}
 	
-	/**
-	 * Set the relative position onto the component.  This cannot be done directly because setRelativePosition is not 
-	 * public in all components.
-	 * 
-	 * @param position  the OpenRocket position
-	 */
-	@Override
-	public void setAxialMethod(AxialMethod position) {
-		bodyTube.setAxialMethod(position);
-	}
-	
 	/**
 	 * Get the required type of material for this component.
 	 *

core/src/net/sf/openrocket/file/rocksim/importt/LaunchLugHandler.java

@@ -16,7 +16,6 @@ import net.sf.openrocket.file.simplesax.PlainTextHandler;
 import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.LaunchLug;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 /**
  * The SAX handler for Rocksim Launch Lugs.
@@ -91,17 +90,6 @@ class LaunchLugHandler extends PositionDependentHandler<LaunchLug> {
 		return lug;
 	}
 	
-	/**
-	 * Set the relative position onto the component.  This cannot be done directly because setRelativePosition is not 
-	 * public in all components.
-	 * 
-	 * @param newMethod  the OpenRocket position
-	 */
-	@Override
-	public void setAxialMethod(AxialMethod newMethod) {
-		lug.setAxialMethod(newMethod);
-	}
-	
 	/**
 	 * Get the required type of material for this component.
 	 *

core/src/net/sf/openrocket/file/rocksim/importt/MassObjectHandler.java

@@ -17,7 +17,6 @@ import net.sf.openrocket.rocketcomponent.MassComponent;
 import net.sf.openrocket.rocketcomponent.MassObject;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
 import net.sf.openrocket.rocketcomponent.ShockCord;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 import org.xml.sax.SAXException;
 
@@ -184,17 +183,6 @@ class MassObjectHandler extends PositionDependentHandler<MassObject> {
 		return current;
 	}
 	
-	/**
-	 * Set the relative position onto the component.  This cannot be done directly because setRelativePosition is not
-	 * public in all components.
-	 *
-	 * @param position the OpenRocket position
-	 */
-	@Override
-	public void setAxialMethod( AxialMethod position) {
-		current.setAxialMethod(position);
-	}
-	
 	/**
 	 * Get the required type of material for this component.  Does not apply to MassComponents, but does apply to Shock
 	 * Cords.

core/src/net/sf/openrocket/file/rocksim/importt/PositionDependentHandler.java

@@ -15,18 +15,18 @@ import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 import org.xml.sax.SAXException;
 
 /**
- * An abstract base class that handles position dependencies for all lower level components that
+ * An abstract base class that handles axialMethod dependencies for all lower level components that
- * are position aware.
+ * are axialMethod aware.
  *
- * @param <C>   the specific position dependent RocketComponent subtype for which the concrete handler can create
+ * @param <C>   the specific axialMethod dependent RocketComponent subtype for which the concrete handler can create
  */
 public abstract class PositionDependentHandler<C extends RocketComponent> extends BaseHandler<C> {
 	
-	/** Temporary position value. */
+	/** Temporary axialMethod value. */
 	private Double positionValue = 0d;
 	
-	/** Temporary position. */
+	/** Temporary axialMethod. */
-	private AxialMethod position = AxialMethod.TOP;
+	private AxialMethod axialMethod = AxialMethod.TOP;
 	
 	public PositionDependentHandler(DocumentLoadingContext context) {
 		super(context);
@@ -43,15 +43,15 @@ public abstract class PositionDependentHandler<C extends RocketComponent> extend
 			positionValue = Double.parseDouble(content) / RocksimCommonConstants.ROCKSIM_TO_OPENROCKET_LENGTH;
 		}
 		if (RocksimCommonConstants.LOCATION_MODE.equals(element)) {
-			position = RocksimLocationMode.fromCode(Integer.parseInt(
+			axialMethod = RocksimLocationMode.fromCode(Integer.parseInt(
 					content)).asOpenRocket();
 		}
 	}
 	
 	/**
-	 * This method sets the position information onto the component.  Rocksim splits the location/position
+	 * This method sets the axialMethod information onto the component.  Rocksim splits the location/axialMethod
 	 * information into two disparate data elements.  Both pieces of data are necessary to map into OpenRocket's
-	 * position model.
+	 * axialMethod model.
 	 *
 	 * @param element     the element name
 	 * @param attributes  the attributes
@@ -63,31 +63,18 @@ public abstract class PositionDependentHandler<C extends RocketComponent> extend
 	public void endHandler(String element, HashMap<String, String> attributes,
 			String content, WarningSet warnings) throws SAXException {
 		super.endHandler(element, attributes, content, warnings);
-		setAxialMethod(position);
+		setLocation();
-		setLocation(getComponent(), position, positionValue);
 	}
 
 	/**
-	 * Set the relative position onto the component.  This cannot be done directly because setRelativePosition is not
+	 * Set the axialMethod of a component.
-	 * public in all components.
-	 *
-	 * @param position  the OpenRocket position
 	 */
-	protected abstract void setAxialMethod(AxialMethod position);
+	protected void setLocation() {
-	
+		getComponent().setAxialMethod(axialMethod);
-	/**
+		if (axialMethod.equals(AxialMethod.BOTTOM)) {
-	 * Set the position of a component.
+			getComponent().setAxialOffset(-1d * positionValue);
-	 *
+		} else {
-	 * @param component  the component
+			getComponent().setAxialOffset(positionValue);
-	 * @param position   the relative position
-	 * @param location   the actual position value
-	 */
-	public static void setLocation(RocketComponent component, AxialMethod position, double location) {
-		if (position.equals(AxialMethod.BOTTOM)) {
-			component.setAxialOffset(-1d * location);
-		}
-		else {
-			component.setAxialOffset(location);
 		}
 	}
 	

core/src/net/sf/openrocket/file/rocksim/importt/RecoveryDeviceHandler.java

@@ -11,7 +11,6 @@ import net.sf.openrocket.file.rocksim.RocksimCommonConstants;
 import net.sf.openrocket.file.rocksim.RocksimDensityType;
 import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.RecoveryDevice;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 import org.xml.sax.SAXException;
 
@@ -96,17 +95,6 @@ public abstract class RecoveryDeviceHandler<C extends RecoveryDevice> extends Po
 		return result;
 	}
 
-	/**
-	 * Set the relative position onto the component.  This cannot be done directly because setRelativePosition is not
-	 * public in all components.
-	 *
-	 * @param position the OpenRocket position
-	 */
-	@Override
-	public void setAxialMethod( AxialMethod position) {
-		getComponent().setAxialMethod(position);
-	}
-	
 	/**
 	 * Get the required type of material for this component.  This is the OpenRocket type, which does NOT always
 	 * correspond to Rocksim.  Some streamer material is defined as BULK in the Rocksim file.  In those cases

core/src/net/sf/openrocket/file/rocksim/importt/RingHandler.java

@@ -19,7 +19,6 @@ import net.sf.openrocket.rocketcomponent.EngineBlock;
 import net.sf.openrocket.rocketcomponent.RingComponent;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
 import net.sf.openrocket.rocketcomponent.TubeCoupler;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 /**
  * A SAX handler for centering rings, tube couplers, and bulkheads.
@@ -180,17 +179,6 @@ class RingHandler extends PositionDependentHandler<CenteringRing> {
 		result.setThickness(result.getThickness());
 	}
 	
-	/**
-	 * Set the relative position onto the component.  This cannot be done directly because setAxialMethod is not
-	 * public in all components.
-	 *
-	 * @param position the OpenRocket position
-	 */
-	@Override
-	public void setAxialMethod(AxialMethod position) {
-		ring.setAxialMethod(position);
-	}
-	
 	@Override
 	public void endHandler(String element, HashMap<String, String> attributes, String content, WarningSet warnings) throws SAXException {
 		super.endHandler(element, attributes, content, warnings);

core/src/net/sf/openrocket/file/rocksim/importt/TubeFinSetHandler.java

@@ -9,7 +9,6 @@ import net.sf.openrocket.file.simplesax.PlainTextHandler;
 import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
 import net.sf.openrocket.rocketcomponent.TubeFinSet;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 import org.xml.sax.SAXException;
 
@@ -44,17 +43,6 @@ public class TubeFinSetHandler extends PositionDependentHandler<TubeFinSet> {
     	}
     }
 
-
-    /**
-   	 * Set the relative position onto the component.
-   	 *
-   	 * @param position  the OpenRocket position
-   	 */
-    @Override
-    protected void setAxialMethod(final AxialMethod position) {
-        tubeFin.setAxialMethod(position);
-    }
-
     /**
      * Get the OR instance after the XML parsing is done.
      *

core/src/net/sf/openrocket/rocketcomponent/ComponentAssembly.java

@@ -33,6 +33,10 @@ public abstract class ComponentAssembly extends RocketComponent implements  Axia
 		super( AxialMethod.AFTER);
 	}
 
+	public ComponentAssembly( final AxialMethod initialAxialMethod) {
+		super(initialAxialMethod);
+	}
+
 	@Override
 	public boolean allowsChildren(){
 		return true;
@@ -40,7 +44,7 @@ public abstract class ComponentAssembly extends RocketComponent implements  Axia
 	
 	@Override
 	public double getAxialOffset() {
-		return asPositionValue( this.axialMethod );
+		return getAxialOffset( this.axialMethod );
 	}
 
 	/**

core/src/net/sf/openrocket/rocketcomponent/FlightConfiguration.java

@@ -476,7 +476,7 @@ public class FlightConfiguration implements FlightConfigurableParameter<FlightCo
      * Copy all available information attached to this, and attached copies to the
      * new configuration
      *
-     * @param copyId attached the new configuration to this Id
+     * @param newId attached the new configuration to this Id
      * @return the new configuration
      */
     @Override

core/src/net/sf/openrocket/rocketcomponent/LaunchLug.java

@@ -21,7 +21,7 @@ public class LaunchLug extends ExternalComponent implements AnglePositionable, C
 	private double thickness;
 	
 	private double radialDirection = 0;
-	protected double radialDistance = 0;
+	private double radialDistance = 0;
 	
 	private int instanceCount = 1;
 	private double instanceSeparation = 0; // front-front along the positive rocket axis. i.e. [1,0,0];
@@ -99,14 +99,6 @@ public class LaunchLug extends ExternalComponent implements AnglePositionable, C
 		return false;
 	}
 
-	
-	@Override
-	public void setAxialMethod( AxialMethod position) {
-		super.setAxialMethod(position);
-		fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
-	}
-	
-	
 	@Override
 	protected void loadFromPreset(ComponentPreset preset) {
 		if (preset.has(ComponentPreset.OUTER_DIAMETER)) {

core/src/net/sf/openrocket/rocketcomponent/PodSet.java

@@ -157,7 +157,7 @@ public class PodSet extends ComponentAssembly implements RingInstanceable {
 			// remember the implicit (this instanceof Stage)
 			throw new BugException("found a pod positioned via: AFTER, but is not on the centerline?!: " + this.getName() + "  is " + this.getAxialMethod().name() );
 		} else {
-			returnValue = super.asPositionValue(this.axialMethod);
+			returnValue = super.getAxialOffset(this.axialMethod);
 		}
 		
 		if (0.000001 > Math.abs(returnValue)) {

core/src/net/sf/openrocket/rocketcomponent/Rocket.java

@@ -11,8 +11,10 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import net.sf.openrocket.l10n.Translator;
+import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 import net.sf.openrocket.startup.Application;
 import net.sf.openrocket.util.ArrayList;
+import net.sf.openrocket.util.Coordinate;
 import net.sf.openrocket.util.MathUtil;
 import net.sf.openrocket.util.StateChangeListener;
 import net.sf.openrocket.util.UniqueID;
@@ -74,6 +76,7 @@ public class Rocket extends ComponentAssembly {
 	/////////////  Constructor  /////////////
 	
 	public Rocket() {
+	    super(AxialMethod.ABSOLUTE);
 		modID = UniqueID.next();
 		massModID = modID;
 		aeroModID = modID;
@@ -245,6 +248,17 @@ public class Rocket extends ComponentAssembly {
 		this.stageMap.remove(oldStage.getStageNumber());
 	}
 
+	@Override
+	public void setAxialMethod(final AxialMethod newAxialMethod) {
+		this.axialMethod = AxialMethod.ABSOLUTE;
+	}
+
+	@Override
+    public void setAxialOffset( final double requestOffset ) {
+    	this.axialOffset = 0.;
+		this.position = Coordinate.ZERO;
+    }
+
 	public ReferenceType getReferenceType() {
 		checkState();
 		return refType;
@@ -707,9 +721,9 @@ public class Rocket extends ComponentAssembly {
 	 * Return a flight configuration.  If the supplied index is out of bounds, an exception is thrown.
 	 * If the default instance is allowed, the default will be at index 0. 
 	 *
-	 * @param 	includeDefault 	Whether to allow returning the default instance
+	 * @param 	allowDefault 	Whether to allow returning the default instance
 	 * @param 	configIndex 	The flight configuration index number
-	 * @return	a 				FlightConfiguration instance 
+	 * @return	FlightConfiguration instance
 	 */
 	public FlightConfiguration getFlightConfigurationByIndex( int configIndex, final boolean allowDefault ) {
 		if( allowDefault ){

core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java

@@ -910,7 +910,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 
 	/**
 	 * Get the positioning of the component relative to its parent component.
-	 * This is one of the enums of {@link Position}.  A setter method is not provided,
+	 * This is one of the enums of {@link AxialMethod}.  A setter method is not provided,
 	 * but can be provided by a subclass.
 	 */
 	public final AxialMethod getAxialMethod() {
@@ -929,7 +929,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 	 *
 	 * @param newAxialMethod	the relative positioning.
 	 */
-	protected void setAxialMethod(final AxialMethod newAxialMethod) {
+	public void setAxialMethod(final AxialMethod newAxialMethod) {
 		if (newAxialMethod == this.axialMethod) {
 			// no change.
 			return;
@@ -938,44 +938,32 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		// this variable does not change the internal representation
 		// the relativePosition (method) is just the lens through which external code may view this component's position. 
 		this.axialMethod = newAxialMethod;
+		fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 	}
 
 	/**
 	 * Determine position relative to given position argument.  Note: This is a side-effect free method.  No state
 	 * is modified.
 	 *
-	 * @param outOffsetMethod the relative position to be used as the basis for the computation
+	 * @param asMethod the relative positioning method to be used for the computation
-	 * @param relativeTo  the position is computed relative the the given component
 	 *
 	 * @return double position of the component relative to the parent, with respect to <code>position</code>
 	 */
-	public double asPositionValue(AxialMethod asMethod) {
+	public double getAxialOffset(AxialMethod asMethod) {
 		double parentLength = 0;
 		if (null != this.parent) {
 			parentLength = this.parent.length;
 		}
 
-		double result = Double.NaN;
+		if(AxialMethod.ABSOLUTE == asMethod){
-		if( AxialMethod.AFTER == asMethod) {
+			return this.getComponentLocations()[0].x;
-			result = this.position.x - parentLength;
-		}else if( AxialMethod.ABSOLUTE == asMethod) {
-			result = this.getComponentLocations()[0].x;
-		}else if( AxialMethod.TOP == asMethod) {
-			result = this.position.x;
-		}else if( AxialMethod.MIDDLE == asMethod) {
-			result = this.position.x + ( this.length - parentLength) / 2;
-		}else if( AxialMethod.BOTTOM == asMethod) {
-			result = this.position.x + ( this.length - parentLength);
 		}else {
-			throw new BugException("Unknown position type: " + asMethod.name() );
+			return asMethod.getAsOffset(this.position.x, this.length, parentLength);
 		}
-		
-		return result;
 	}
 	
 	public double getAxialOffset() {
-		mutex.verify();
+		return this.axialOffset;
-		return this.asPositionValue(this.axialMethod);
 	}
 	
 	public double getRadiusOffset() {
@@ -1003,7 +991,6 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		return false;
 	}
 	
-	
 	protected void setAfter() {
 		checkState();
 		
@@ -1013,8 +1000,6 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		}
 		
 		// if first component in the stage. => position from the top of the parent
-		double newAxialPosition= 0;
-		
 		final int thisIndex = this.parent.getChildPosition( this );
 		if( 0 < thisIndex ) {
 			RocketComponent referenceComponent = parent.getChild( thisIndex - 1 );
@@ -1022,78 +1007,52 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 			double refLength = referenceComponent.getLength();
 			double refRelX = referenceComponent.getPosition().x;
 
-			newAxialPosition = refRelX + refLength;
+			this.axialMethod = AxialMethod.AFTER;
+			this.axialOffset = 0.;
+			this.position = this.position.setX(refRelX + refLength);
 		}
-		
-		this.position = this.position.setX( newAxialPosition );
 	}
 	
 	/**
 	 * Set the position value of the component.  The exact meaning of the value
 	 * depends on the current relative positioning.
-	 * <p>
-	 * Mince many components do not support setting the relative position.  A component that does support
-	 * it should override this with a public method that simply calls this
-	 * supermethod AND fire a suitable ComponentChangeEvent.
 	 *
-	 * @param value		the position value of the component.
+	 * @param newOffset  the position value of the component.
 	 */
-	public void setAxialOffset(double _value) {
+	public void setAxialOffset(double newOffset) {
-		this.setAxialOffset(this.axialMethod, _value);
+		this.setAxialOffset(this.axialMethod, newOffset);
 		this.fireComponentChangeEvent(ComponentChangeEvent.BOTH_CHANGE);
 	}
 
-	
+	final protected void setAxialOffset( final AxialMethod requestedMethod, final double requestedOffset) {
-	protected void setAxialOffset( final AxialMethod requestedMethod, double requestedOffset) {
 		checkState();
 
-		AxialMethod newMethod = requestedMethod;
-		double newOffset = requestedOffset;
 		double newX = Double.NaN;
 
-		if ( this.isAfter()){
+		if (null == this.parent) {
-			newMethod= AxialMethod.AFTER;
-		}
-		
-		
-		if( this instanceof Rocket ){
-			newMethod = AxialMethod.ABSOLUTE;
-			newOffset = 0.;
-			newX = 0.;
-		}else if(null == this.parent) {
 			// best-effort approximation.  this should be corrected later on in the initialization process.
-			newX = newOffset; 
+			newX = requestedOffset;
-		}else {
+		} else if (AxialMethod.ABSOLUTE == requestedMethod){
-			final double refLength = this.parent.getLength();
+			// in this case, this is simply the intended result
-			
+			newX = requestedOffset - this.parent.getComponentLocations()[0].x;
-			if( AxialMethod.ABSOLUTE == newMethod) {
+		} else if ( this.isAfter()){
-				newX = newOffset - this.parent.getComponentLocations()[0].x;
-			}else if( AxialMethod.AFTER == newMethod) {
-				newOffset = 0;
 			this.setAfter();
-				newX = this.position.x;
+			return;
-			}else if( AxialMethod.TOP == newMethod) {
-				newX = newOffset;
-			}else if( AxialMethod.MIDDLE == newMethod) {
-				newX = (refLength - this.length) / 2 + newOffset;
-			}else if( AxialMethod.BOTTOM == newMethod) {
-				newX = (refLength - this.length) + newOffset;
 		} else {
-				throw new BugException("Unknown position type: " + this.axialMethod);
+			newX = requestedMethod.getAsPosition(requestedOffset, this.length, this.parent.getLength());
-			}
 		}
 		
 		// snap to zero if less than the threshold 'EPSILON'
 		final double EPSILON = 0.000001;
 		if (EPSILON > Math.abs(newX)) {
 			newX = 0.0;
-		}
+		} else if (Double.isNaN(newX)){
-		if (Double.isNaN(newX)){
 			throw new BugException("setAxialOffset is broken -- attempted to update as NaN: " + this.toDebugDetail());
 		}
 
-		this.axialMethod = newMethod;
+		// store for later:
-		this.axialOffset = newOffset;
+		this.axialMethod = requestedMethod;
+		this.axialOffset = requestedOffset;
 		this.position = this.position.setX( newX );
 	}
 	
@@ -1118,12 +1077,9 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 	 * For example, the absolute position of any given instance is the parent's position 
 	 * plus the instance position returned by this method   
 	 * <p>
-	 * NOTE: this default implementation simply returns this.position
 	 * NOTE: the length of this array returned always equals this.getInstanceCount()
 	 *
-	 * @param c   an array of coordinates to shift.
+	 * @return    an generated (i.e. new) array of instance locations
-	 * @return    an array of shifted coordinates.  The method may modify the contents
-	 * 			  of the passed array and return the array itself.
 	 */
 	// @Override Me !
 	public Coordinate[] getInstanceLocations(){
@@ -1145,10 +1101,11 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 	 *
 	 * <p>
 	 * NOTE: the length of this array returned always equals this.getInstanceCount()
-	 * @return
+	 * NOTE: default implementation just returns (0,0,0)
+	 *
+	 * @returns returns an array of coordinates, relative to its parent's position
 	 */
 	public Coordinate[] getInstanceOffsets(){
-		// According to the language specification, Java will initialized double values to 0.0
 		return new Coordinate[]{Coordinate.ZERO};
 	}
 
@@ -1159,13 +1116,15 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		return getComponentLocations();
 	}
 	
-	
 	/** 
 	 * Provides locations of all instances of component *accounting for all parent instancing*
 	 * 
 	 * <p>
 	 * NOTE: the length of this array MAY OR MAY NOT EQUAL this.getInstanceCount()
-	 * @return
+     *    --> RocketComponent::getInstanceCount() counts how many times this component replicates on its own
+     *    --> vs. the total instance count due to parent assembly instancing
+     *
+	 * @return Coordinates of all instance locations in the rocket, relative to the rocket's origin
 	 */
 	public Coordinate[] getComponentLocations() {
 		if (null == this.parent) {
@@ -1175,23 +1134,20 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 			Coordinate[] parentPositions = this.parent.getComponentLocations();
 			int parentCount = parentPositions.length;
 			
-			// override <instance>.getInstanceOffsets()  in the subclass you want to fix.
+			// override <instance>.getInstanceLocations() in each subclass
-			Coordinate[] instanceOffsets = this.getInstanceLocations();
+			Coordinate[] instanceLocations = this.getInstanceLocations();
-			int instanceCount = instanceOffsets.length;
+			int instanceCount = instanceLocations.length;
 			
 			// usual case optimization
 			if((1 == parentCount)&&(1 == instanceCount)){
-				return new Coordinate[]{parentPositions[0].add(instanceOffsets[0])};
+				return new Coordinate[]{parentPositions[0].add(instanceLocations[0])};
 			}
 			
 			int thisCount = instanceCount*parentCount;
 			Coordinate[] thesePositions = new Coordinate[thisCount];
 			for (int pi = 0; pi < parentCount; pi++) {
 				for( int ii = 0; ii < instanceCount; ii++ ){
-//					System.err.println("        #"+pi+", "+ii+" = "+(pi + parentCount*ii));
+					thesePositions[pi + parentCount*ii] = parentPositions[pi].add(instanceLocations[ii]);
-//					System.err.println("        "+parentPositions[pi]+" + "+instanceOffsets[ii]);
-					thesePositions[pi + parentCount*ii] = parentPositions[pi].add(instanceOffsets[ii]);
-//					System.err.println("                         ="+thesePositions[pi+parentCount*ii]);
 				}
 			}
 			return thesePositions;
@@ -1229,16 +1185,6 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		return toReturn;
 	}
 
-	//	public Coordinate[] toAbsolute(final Coordinate[] toMove) {
-	//		Coordinate[] toReturn = new Coordinate[toMove.length];
-	//		
-	//		Coordinate translation = this.getAbsolutePositionVector();
-	//		for (int coordIndex = 0; coordIndex < toMove.length; coordIndex++) {
-	//			toReturn[coordIndex] = translation.add(toMove[coordIndex]);
-	//		}
-	//		return toReturn;
-	//	}
-	
 	/**
 	 * Return coordinate <code>c</code> described in the coordinate system of
 	 * <code>dest</code>.  If <code>dest</code> is <code>null</code> returns

core/src/net/sf/openrocket/rocketcomponent/position/AxialMethod.java

@@ -31,7 +31,7 @@ public enum AxialMethod implements DistanceMethod {
 
 		@Override
 		public double getAsOffset(double position, double innerLength, double outerLength){
-		    return outerLength - position;
+		    return position - outerLength;
 		}
     },
 
@@ -60,7 +60,7 @@ public enum AxialMethod implements DistanceMethod {
 
 		@Override
 		public double getAsPosition(double offset, double innerLength, double outerLength){
-			return (outerLength - innerLength) / 2 - offset;
+			return offset + (outerLength - innerLength) / 2;
 		}
 
 		@Override
@@ -76,7 +76,7 @@ public enum AxialMethod implements DistanceMethod {
 
 		@Override
 		public double getAsPosition(double offset, double innerLength, double outerLength){
-			return outerLength - innerLength - offset;
+			return offset + (outerLength - innerLength);
 		}
 
 		@Override

core/test/net/sf/openrocket/file/rocksim/importt/InnerBodyTubeHandlerTest.java

@@ -9,7 +9,6 @@ import net.sf.openrocket.file.simplesax.PlainTextHandler;
 import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.BodyTube;
 import net.sf.openrocket.rocketcomponent.InnerTube;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 import org.junit.Assert;
 
@@ -119,20 +118,6 @@ public class InnerBodyTubeHandlerTest extends RocksimTestBase {
         Assert.assertEquals("Test Name", component.getName());
     }
 
-    /**
-     * Method: setRelativePosition(AxialMethod position)
-     *
-     * @throws Exception thrown if something goes awry
-     */
-    @org.junit.Test
-    public void testSetRelativePosition() throws Exception {
-        BodyTube tube = new BodyTube();
-        InnerBodyTubeHandler handler = new InnerBodyTubeHandler(null, tube, new WarningSet());
-        InnerTube component = (InnerTube) getField(handler, "bodyTube");
-        handler.setAxialMethod(AxialMethod.ABSOLUTE);
-        Assert.assertEquals(AxialMethod.ABSOLUTE, component.getAxialMethod());
-    }
-
     /**
      * Method: getComponent()
      *

core/test/net/sf/openrocket/file/rocksim/importt/LaunchLugHandlerTest.java

@@ -10,7 +10,6 @@ import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.BodyTube;
 import net.sf.openrocket.rocketcomponent.ExternalComponent;
 import net.sf.openrocket.rocketcomponent.LaunchLug;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 import org.junit.Assert;
 
@@ -110,20 +109,6 @@ public class LaunchLugHandlerTest extends RocksimTestBase {
         Assert.assertEquals("Test Name", component.getName());
     }
 
-    /**
-     * Method: setRelativePosition(AxialMethod position)
-     *
-     * @throws Exception thrown if something goes awry
-     */
-    @org.junit.Test
-    public void testSetRelativePosition() throws Exception {
-        BodyTube tube = new BodyTube();
-        LaunchLugHandler handler = new LaunchLugHandler(null, tube, new WarningSet());
-        LaunchLug component = (LaunchLug) getField(handler, "lug");
-        handler.setAxialMethod(AxialMethod.ABSOLUTE);
-        Assert.assertEquals(AxialMethod.ABSOLUTE, component.getAxialMethod());
-    }
-
     /**
      * Method: getComponent()
      *

core/test/net/sf/openrocket/file/rocksim/importt/MassObjectHandlerTest.java

@@ -9,7 +9,6 @@ import net.sf.openrocket.file.simplesax.PlainTextHandler;
 import net.sf.openrocket.material.Material;
 import net.sf.openrocket.rocketcomponent.BodyTube;
 import net.sf.openrocket.rocketcomponent.MassComponent;
-import net.sf.openrocket.rocketcomponent.position.AxialMethod;
 
 import org.junit.Assert;
 
@@ -91,20 +90,6 @@ public class MassObjectHandlerTest extends RocksimTestBase {
 
     }
 
-    /**
-     * Method: setRelativePosition(AxialMethod position)
-     *
-     * @throws Exception thrown if something goes awry
-     */
-    @org.junit.Test
-    public void testSetRelativePosition() throws Exception {
-        BodyTube tube = new BodyTube();
-        MassObjectHandler handler = new MassObjectHandler(null, tube, new WarningSet());
-        MassComponent component = (MassComponent) getField(handler, "mass");
-        handler.setAxialMethod(AxialMethod.ABSOLUTE);
-        Assert.assertEquals(AxialMethod.ABSOLUTE, component.getAxialMethod());
-    }
-
     /**
      * Method: getComponent()
      *

core/test/net/sf/openrocket/file/rocksim/importt/ParachuteHandlerTest.java

@@ -113,7 +113,7 @@ public class ParachuteHandlerTest extends RocksimTestBase {
         BodyTube tube = new BodyTube();
         ParachuteHandler handler = new ParachuteHandler(null, tube, new WarningSet());
         Parachute component = (Parachute) getField(handler, "chute");
-        handler.setAxialMethod(AxialMethod.ABSOLUTE);
+        handler.getComponent().setAxialMethod(AxialMethod.ABSOLUTE);
         Assert.assertEquals(AxialMethod.ABSOLUTE, component.getAxialMethod());
     }
 

core/test/net/sf/openrocket/file/rocksim/importt/RingHandlerTest.java

@@ -247,21 +247,6 @@ public class RingHandlerTest extends RocksimTestBase {
 		CenteringRing component = (CenteringRing) getField(handler, "ring");
     }
     
-    /**
-     * Method: setAxialMethod(AxialMethod position)
-     *
-     * @throws Exception thrown if something goes awry
-     */
-    @org.junit.Test
-    public void testsetAxialMethod() throws Exception {
-        BodyTube tube = new BodyTube();
-        RingHandler handler = new RingHandler(null, tube, new WarningSet());
-        CenteringRing component = (CenteringRing) getField(handler, "ring");
-        handler.setAxialMethod(AxialMethod.ABSOLUTE);
-        Assert.assertEquals(AxialMethod.ABSOLUTE, component.getAxialMethod());
-    }
-
-    
     /**
      * Method: getComponent()
      *

core/test/net/sf/openrocket/file/rocksim/importt/StreamerHandlerTest.java

@@ -109,7 +109,7 @@ public class StreamerHandlerTest extends RocksimTestBase {
         BodyTube tube = new BodyTube();
         StreamerHandler handler = new StreamerHandler(null, tube, new WarningSet());
         Streamer component = (Streamer) getField(handler, "streamer");
-        handler.setAxialMethod(AxialMethod.ABSOLUTE);
+        handler.getComponent().setAxialMethod(AxialMethod.ABSOLUTE);
         Assert.assertEquals(AxialMethod.ABSOLUTE, component.getAxialMethod());
     }
 

core/test/net/sf/openrocket/rocketcomponent/ParallelStageTest.java

@@ -2,8 +2,7 @@ package net.sf.openrocket.rocketcomponent;
 
 //import junit.framework.TestCase;
 import static org.hamcrest.CoreMatchers.equalTo;
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.*;
-import static org.junit.Assert.assertThat;
 
 import org.junit.Test;
 
@@ -18,20 +17,15 @@ public class ParallelStageTest extends BaseTestCase {
 	// tolerance for compared double test results
 	protected final double EPSILON = 0.000001;
 	
-	protected final Coordinate ZERO = new Coordinate(0., 0., 0.);
-	
-	
 	/* From OpenRocket Technical Documentation
 	 *  
 	 * 3.1.4 Coordinate systems
 	 * During calculation of the aerodynamic properties a coordinate system fixed to the rocket will be used. 
 	 * The origin of the coordinates is at the nose cone tip with the positive x-axis directed along the rocket 
-	@@ -41,70 +35,302 @@ public class BodyTubeTest extends TestCase {
 	 * when discussing the fins. During simulation, however, the y- and z-axes are fixed in relation to the rocket,
 	 * and do not necessarily align with the plane of the pitching moments.
 	 */
 
-	
 	public ParallelStage createExtraBooster() {
        double tubeRadius = 0.8;
        
@@ -106,7 +100,7 @@ public class ParallelStageTest extends BaseTestCase {
 	// WARNING:   this test will not pass unless 'testAddTopStage' is passing as well -- that function tests the dependencies...
 	@Test
 	public void testCreateCoreStage() {
-		// vvvv function under test vvvv  ( which indirectly tests initialization code, and that the test setup creates the preconditions that we expect 		
+		// vvvv function under test vvvv
 		final Rocket rocket = TestRockets.makeFalcon9Heavy();
 		// ^^^^ function under test ^^^^
 
@@ -195,7 +189,7 @@ public class ParallelStageTest extends BaseTestCase {
 		
 		assertThat(" 'setInstancecount(int)' failed: ", 2, equalTo(parallelBoosterSet.getInstanceCount()));
 		
-		assertEquals( RadiusMethod.FREE.clampToZero(), false );
+		assertFalse( RadiusMethod.FREE.clampToZero());
 		assertEquals(" error while setting radius method: ", RadiusMethod.FREE, parallelBoosterSet.getRadiusMethod() );
 		assertEquals(" error while setting radius offset: ", 2.0, parallelBoosterSet.getRadiusOffset(), EPSILON);
 
@@ -220,7 +214,7 @@ public class ParallelStageTest extends BaseTestCase {
 		
 		assertThat(" 'setInstancecount(int)' failed: ", 2, equalTo(parallelBoosterStage.getInstanceCount()));
 		
-		assertEquals( RadiusMethod.SURFACE.clampToZero(), true );
+		assertTrue( RadiusMethod.SURFACE.clampToZero());
 		assertEquals(" error while setting radius method: ", RadiusMethod.SURFACE, parallelBoosterStage.getRadiusMethod() );
 		assertEquals(" error while setting radius offset: ", 0.0, parallelBoosterStage.getRadiusOffset(), EPSILON);
 		
@@ -260,7 +254,7 @@ public class ParallelStageTest extends BaseTestCase {
 		parallelBoosterStage.setRadius( RadiusMethod.RELATIVE, targetRadiusOffset );
 		// ^^ function under test
 
-		assertEquals( RadiusMethod.RELATIVE.clampToZero(), false );
+		assertFalse(RadiusMethod.RELATIVE.clampToZero());
 		assertEquals(" error while setting radius method: ", RadiusMethod.RELATIVE, parallelBoosterStage.getRadiusMethod() );
 		assertEquals(" error while setting radius offset: ", targetRadiusOffset, parallelBoosterStage.getRadiusOffset() , EPSILON);
 		
@@ -333,7 +327,7 @@ public class ParallelStageTest extends BaseTestCase {
 		double expectedRelativeX = 0.236;
 		double expectedAbsoluteX = 0.8;
 
-		// when subStages should be freely movable		
+		// when substages should be freely movable
 		// vv function under test
 		boosterStage.setAxialOffset(AxialMethod.ABSOLUTE, targetAbsoluteX);
 		// ^^ function under test
@@ -341,7 +335,7 @@ public class ParallelStageTest extends BaseTestCase {
 		assertEquals("setAxialOffset( method, double) failed: ", AxialMethod.ABSOLUTE, boosterStage.getAxialMethod() );
 		assertEquals("setAxialOffset( method, double) failed: ", targetAbsoluteX, boosterStage.getAxialOffset(), EPSILON );
 				
-		double actualRelativeX = boosterStage.asPositionValue(AxialMethod.TOP);
+		double actualRelativeX = boosterStage.getAxialOffset(AxialMethod.TOP);
 		assertEquals(" 'setAxialPosition(double)' failed: Relative position: ", expectedRelativeX, actualRelativeX, EPSILON );
 
 		double actualAbsoluteX = boosterStage.getComponentLocations()[0].x;
@@ -422,7 +416,6 @@ public class ParallelStageTest extends BaseTestCase {
 		Assert.assertEquals( 0.16, boosterStage.getPosition().x, EPSILON );
 
 		Assert.assertEquals( 0.724, boosterStage.getComponentLocations()[0].x, EPSILON );
-		
 	}
 	
 	@Test
@@ -456,14 +449,14 @@ public class ParallelStageTest extends BaseTestCase {
 		// ^^ function under test
 		
 		Assert.assertEquals( targetOffset, boosterStage.getAxialOffset(), EPSILON );
-		Assert.assertEquals( 0.2, boosterStage.getPosition().x, EPSILON );
+		Assert.assertEquals( targetOffset, boosterStage.getPosition().x, EPSILON );
 		
-		final double expectedRelativePositionX = targetOffset;
+		final double expectedRelativePositionX = 0.2;
 		final double resultantRelativePosition = boosterStage.getPosition().x;
 		Assert.assertEquals(expectedRelativePositionX, resultantRelativePosition, EPSILON);
 				
 		// vv function under test
-		final double actualAbsoluteX = boosterStage.asPositionValue(AxialMethod.ABSOLUTE);
+		final double actualAbsoluteX = boosterStage.getAxialOffset(AxialMethod.ABSOLUTE);
 		// ^^ function under test
 		
 		Assert.assertEquals( 0.764, actualAbsoluteX, EPSILON );
@@ -486,7 +479,7 @@ public class ParallelStageTest extends BaseTestCase {
 	
 		
 		// vv function under test
-		double actualPositionXAfter = boosterStage.asPositionValue(AxialMethod.AFTER);
+		double actualPositionXAfter = boosterStage.getAxialOffset(AxialMethod.AFTER);
 		// ^^ function under test
 		
 		Assert.assertEquals( -0.6, actualPositionXAfter, EPSILON );
@@ -508,7 +501,7 @@ public class ParallelStageTest extends BaseTestCase {
 		Assert.assertEquals( 0.2, boosterStage.getPosition().x, EPSILON );
 			
 		// vv function under test
-		final double actualAxialPosition = boosterStage.asPositionValue(AxialMethod.MIDDLE);
+		final double actualAxialPosition = boosterStage.getAxialOffset(AxialMethod.MIDDLE);
 		// ^^ function under test
 		
 		Assert.assertEquals( 0.24, actualAxialPosition, EPSILON );
@@ -530,7 +523,7 @@ public class ParallelStageTest extends BaseTestCase {
 		Assert.assertEquals( 0.2, boosterStage.getPosition().x, EPSILON );
 		
 		// vv function under test
-		double actualAxialBottomOffset = boosterStage.asPositionValue(AxialMethod.BOTTOM);
+		double actualAxialBottomOffset = boosterStage.getAxialOffset(AxialMethod.BOTTOM);
 		// ^^ function under test
 		
 		Assert.assertEquals( 0.28, actualAxialBottomOffset, EPSILON );
@@ -552,7 +545,7 @@ public class ParallelStageTest extends BaseTestCase {
 		Assert.assertEquals( 0.120, boosterStage.getPosition().x, EPSILON);
 		
 		// vv function under test
-		double actualAxialTopOffset = boosterStage.asPositionValue(AxialMethod.TOP);
+		double actualAxialTopOffset = boosterStage.getAxialOffset(AxialMethod.TOP);
 		// ^^ function under test
 				
 		Assert.assertEquals( 0.12, actualAxialTopOffset, EPSILON);

swing/src/net/sf/openrocket/gui/configdialog/FinSetConfig.java

@@ -257,7 +257,7 @@ public abstract class FinSetConfig extends RocketComponentConfig {
 						if (!rings.isEmpty()) {
 						    AxialMethod temp = (AxialMethod) em.getSelectedItem();
 							em.setSelectedItem(AxialMethod.TOP);
-							double len = computeFinTabLength(rings, component.asPositionValue(AxialMethod.TOP),
+							double len = computeFinTabLength(rings, component.getAxialOffset(AxialMethod.TOP),
 										component.getLength(), mts, parent);
 							mtl.setValue(len);
 							//Be nice to the user and set the tab relative position enum back the way they had it.
@@ -306,8 +306,8 @@ public abstract class FinSetConfig extends RocketComponentConfig {
 			Collections.sort(rings, new Comparator<CenteringRing>() {
 				@Override
 				public int compare(CenteringRing centeringRing, CenteringRing centeringRing1) {
-					return (int) (1000d * (centeringRing.asPositionValue(AxialMethod.TOP) -
+					return (int) (1000d * (centeringRing.getAxialOffset(AxialMethod.TOP) -
-							centeringRing1.asPositionValue(AxialMethod.TOP)));
+							centeringRing1.getAxialOffset(AxialMethod.TOP)));
 						}
 			});
 			
@@ -316,7 +316,7 @@ public abstract class FinSetConfig extends RocketComponentConfig {
 				//Handle centering rings that overlap or are adjacent by synthetically merging them into one virtual ring.
 				if (!positionsFromTop.isEmpty() &&
 						positionsFromTop.get(positionsFromTop.size() - 1).bottomSidePositionFromTop() >=
-                                centeringRing.asPositionValue(AxialMethod.TOP)) {
+                                centeringRing.getAxialOffset(AxialMethod.TOP)) {
 					SortableRing adjacent = positionsFromTop.get(positionsFromTop.size() - 1);
 					adjacent.merge(centeringRing, relativeTo);
 				} else {
@@ -441,7 +441,7 @@ public abstract class FinSetConfig extends RocketComponentConfig {
 		 */
 		SortableRing(CenteringRing r, RocketComponent relativeTo) {
 			thickness = r.getLength();
-			positionFromTop = r.asPositionValue(AxialMethod.TOP);
+			positionFromTop = r.getAxialOffset(AxialMethod.TOP);
 		}
 		
 		/**
@@ -450,7 +450,7 @@ public abstract class FinSetConfig extends RocketComponentConfig {
 		 * @param adjacent the adjacent ring
 		 */
 		public void merge(CenteringRing adjacent, RocketComponent relativeTo) {
-			double v = adjacent.asPositionValue(AxialMethod.TOP);
+			double v = adjacent.getAxialOffset(AxialMethod.TOP);
 			if (positionFromTop < v) {
 				thickness = (v + adjacent.getLength()) - positionFromTop;
 			} else {

swing/src/net/sf/openrocket/gui/print/visitor/CenteringRingStrategy.java

@@ -87,8 +87,8 @@ public class CenteringRingStrategy extends AbstractPrintStrategy<Void> {
      * @return true if the two physically intersect, from which we infer that the centering ring supports the tube
      */
     private boolean overlaps(CenteringRing one, InnerTube two) {
-        final double crTopPosition = one.asPositionValue( AxialMethod.ABSOLUTE);
+        final double crTopPosition = one.getAxialOffset( AxialMethod.ABSOLUTE);
-        final double mmTopPosition = two.asPositionValue( AxialMethod.ABSOLUTE);
+        final double mmTopPosition = two.getAxialOffset( AxialMethod.ABSOLUTE);
         final double crBottomPosition = one.getLength() + crTopPosition;
         final double mmBottomPosition = two.getLength() + mmTopPosition;
 

swing/src/net/sf/openrocket/gui/scalefigure/FinPointFigure.java

@@ -159,7 +159,7 @@ public class FinPointFigure extends AbstractScaleFigure {
         Transition body = (Transition) finset.getParent();
         final float xResolution_m = 0.01f; // distance between draw points, in meters
 
-        final double xFinStart = finset.asPositionValue(AxialMethod.TOP); //<<  in body frame
+        final double xFinStart = finset.getAxialOffset(AxialMethod.TOP); //<<  in body frame
 
         // vv in fin-frame == draw-frame vv
         final double xOffset = -xFinStart;
@@ -355,7 +355,7 @@ public class FinPointFigure extends AbstractScaleFigure {
 	    
 	    // update to bound the parent body:
 	    SymmetricComponent parent = (SymmetricComponent)this.finset.getParent(); 
-        final double xFinFront = finset.asPositionValue(AxialMethod.TOP);
+        final double xFinFront = finset.getAxialOffset(AxialMethod.TOP);
         final double xParent = -xFinFront;
 	    final double yParent = -parent.getRadius(xParent); // from parent centerline to fin front.
 	    final double rParent = Math.max(parent.getForeRadius(), parent.getAftRadius());