From a7e73f6485e2aad2bcaa67bd56f717e5cec39b6c Mon Sep 17 00:00:00 2001
From: richard <richard@rdg.cc>
Date: Sun, 16 Dec 2012 22:58:02 -0800
Subject: [PATCH] Fix bug with custom expressions where old sub expressions
 remained in an expression after it was changed.

Fix bug to allow flight variables to be used inside index expressions.
---
 .../simulation/customexpression/CustomExpression.java |  6 ++++--
 .../CustomExpressionSimulationListener.java           |  4 +---
 .../simulation/customexpression/IndexExpression.java  | 11 +++++++++--
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/core/src/net/sf/openrocket/simulation/customexpression/CustomExpression.java b/core/src/net/sf/openrocket/simulation/customexpression/CustomExpression.java
index c8973ed2d..a78916921 100644
--- a/core/src/net/sf/openrocket/simulation/customexpression/CustomExpression.java
+++ b/core/src/net/sf/openrocket/simulation/customexpression/CustomExpression.java
@@ -86,6 +86,7 @@ public class CustomExpression implements Cloneable{
 		this.expression = expression;
 		
 		// Replace any indexed variables
+		subExpressions.clear();
 		expression = subTimeIndexes(expression);
 		expression = subTimeRanges(expression);
 		
@@ -450,13 +451,13 @@ public class CustomExpression implements Cloneable{
 		if ( !expressions.isEmpty() ) {
 			// check if expression already exists
 			if ( expressions.contains(this) ){
-				log.user("Expression already in document. This unit : "+this.getUnit()+", existing unit : "+expressions.get(0).getUnit());
+				log.debug("Expression already in document");
 				return;
 			}
 		}
 			
 		if (this.checkAll()){
-			log.user("Custom expression added to rocket document");
+			log.user("New custom expression added to rocket document");
 			doc.addCustomExpression( this );
 		}
 	}
@@ -470,6 +471,7 @@ public class CustomExpression implements Cloneable{
 		else {
 			int index = doc.getCustomExpressions().indexOf(this);
 			doc.getCustomExpressions().set(index, newExpression);
+			log.debug("Overwriting custom expression already in document");
 		}
 	}
 	
diff --git a/core/src/net/sf/openrocket/simulation/customexpression/CustomExpressionSimulationListener.java b/core/src/net/sf/openrocket/simulation/customexpression/CustomExpressionSimulationListener.java
index 243f7b155..ecba29943 100644
--- a/core/src/net/sf/openrocket/simulation/customexpression/CustomExpressionSimulationListener.java
+++ b/core/src/net/sf/openrocket/simulation/customexpression/CustomExpressionSimulationListener.java
@@ -29,11 +29,9 @@ public class CustomExpressionSimulationListener extends	AbstractSimulationListen
 		FlightDataBranch data = status.getFlightData();
 		for (CustomExpression expression : expressions ) {
 			double value = expression.evaluateDouble(status);
-			//log.debug("Setting value of custom expression "+expression.toString()+" = "+value);
+			log.debug("Setting value of custom expression "+expression.toString()+" = "+value);
 			data.setValue(expression.getType(), value);
 		}
-		
-
 	}
 
 	@Override
diff --git a/core/src/net/sf/openrocket/simulation/customexpression/IndexExpression.java b/core/src/net/sf/openrocket/simulation/customexpression/IndexExpression.java
index 6fb084de4..f712d7f93 100644
--- a/core/src/net/sf/openrocket/simulation/customexpression/IndexExpression.java
+++ b/core/src/net/sf/openrocket/simulation/customexpression/IndexExpression.java
@@ -3,6 +3,7 @@ package net.sf.openrocket.simulation.customexpression;
 import java.util.List;
 
 import de.congrace.exp4j.Calculable;
+import de.congrace.exp4j.ExpressionBuilder;
 import de.congrace.exp4j.Variable;
 import net.sf.openrocket.document.OpenRocketDocument;
 import net.sf.openrocket.logging.LogHelper;
@@ -27,7 +28,6 @@ public class IndexExpression extends CustomExpression {
 	
 	@Override
 	public Variable evaluate(SimulationStatus status){
-		
 		Calculable calc = buildExpression();
 		if (calc == null){
 			return new Variable("Unknown");
@@ -42,15 +42,22 @@ public class IndexExpression extends CustomExpression {
 		List<Double> time = status.getFlightData().get(FlightDataType.TYPE_TIME);
 		LinearInterpolator interp = new LinearInterpolator(time, data); 
 		
+		// Set the variables in the expression to evaluate
+		for (FlightDataType etype : status.getFlightData().getTypes()){
+			double value = status.getFlightData().getLast(etype); 
+			calc.setVariable( new Variable(etype.getSymbol(), value ) );
+		}
+		
 		// Evaluate this expression to get the t value
+		//System.out.println("Evaluating expression to get t value "+this.getExpressionString());
 		try{
 			double tvalue = calc.calculate().getDoubleValue();
+			//System.out.println("t = "+tvalue);
 			return new Variable(hash(), interp.getValue( tvalue ) );
 		}
 		catch (java.util.EmptyStackException e){
 			log.user("Unable to calculate time index for indexed expression "+getExpressionString()+" due to empty stack exception");
 			return new Variable("Unknown");
 		}
-		
 	}
 }