From 4f4a55b8d22b24fa78b1dd88747529191aa13102 Mon Sep 17 00:00:00 2001
From: JoePfeiffer <joseph@pfeifferfamily.net>
Date: Thu, 16 Mar 2023 19:29:38 -0600
Subject: [PATCH] Change BarrowmanCalculator to compute base drag for current
 component, not previous component

---
 .../aerodynamics/BarrowmanCalculator.java     | 49 ++++++++-----------
 1 file changed, 20 insertions(+), 29 deletions(-)

diff --git a/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java b/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
index 63ede7ad9..97d7dd303 100644
--- a/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
+++ b/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
@@ -755,11 +755,17 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
 		final InstanceMap imap = configuration.getActiveInstances();
 	    for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) {
 			final RocketComponent c = entry.getKey();
-			
+
 			if (!(c instanceof SymmetricComponent)) {
 				continue;
 			}
 
+			
+			if (c.isCDOverridden() ||
+				c.isCDOverriddenByAncestor()) {
+				continue;
+			}
+			
 			SymmetricComponent s = (SymmetricComponent) c;
 			double foreRadius = s.getForeRadius();
 			double aftRadius = s.getAftRadius();
@@ -770,35 +776,20 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
 			}
 
 			int instanceCount = entry.getValue().size();
-			
-			if (c.isCDOverridden() ||
-				c.isCDOverriddenByAncestor()) {
-				continue;
+
+			// get forward radius of next component
+			final SymmetricComponent nextComponent = s.getNextSymmetricComponent();
+			double nextRadius;
+			if ((nextComponent != null) && configuration.isComponentActive(nextComponent)) {
+				nextRadius = nextComponent.getForeRadius();
+			} else {
+				nextRadius = 0.0;
 			}
-				
-			// if aft radius of previous component is greater than my forward radius, set
-			// its aft CD
-			double radius = 0;
-			final SymmetricComponent prevComponent = s.getPreviousSymmetricComponent();
-			if (prevComponent != null && configuration.isComponentActive(prevComponent)) {
-				radius = prevComponent.getAftRadius();
-			}
-			
-			if (radius > foreRadius) {
-				double area = Math.PI * (pow2(radius) - pow2(foreRadius));
-				double cd = base * area / conditions.getRefArea();
-				total += instanceCount * cd;
-				if ((forceMap != null) && (prevComponent != null)) {
-					forceMap.get(prevComponent).setBaseCD(cd);
-				}
-			}
-				
-			// if I'm the last component, set my base CD
-			// note:  the iterator *should* serve up the next component.... buuuut ....
-			//        this code is tested, and there's no compelling reason to change.
-			final SymmetricComponent n = s.getNextSymmetricComponent();
-			if ((n == null) || !configuration.isStageActive(n.getStageNumber())) {
-				double area = Math.PI * pow2(aftRadius);
+
+			// if fore radius of next component is less than my aft radius, set my
+			// base CD
+			if (nextRadius < aftRadius) {
+				double area = Math.PI * (pow2(aftRadius) - pow2(nextRadius));
 				double cd = base * area / conditions.getRefArea();
 				total += instanceCount * cd;
 				if (forceMap != null) {