From 098223eb31b958b353350953e2d088d6525880d5 Mon Sep 17 00:00:00 2001
From: JoePfeiffer <joseph@pfeifferfamily.net>
Date: Wed, 18 Jan 2023 10:14:08 -0700
Subject: [PATCH] Check for gaps and overlaps in airframe

---
 core/resources/l10n/messages.properties       |  2 ++
 .../aerodynamics/BarrowmanCalculator.java     | 33 ++++++++++---------
 .../sf/openrocket/aerodynamics/Warning.java   |  6 ++++
 3 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/core/resources/l10n/messages.properties b/core/resources/l10n/messages.properties
index b5b965b22..b87bfd771 100644
--- a/core/resources/l10n/messages.properties
+++ b/core/resources/l10n/messages.properties
@@ -1864,6 +1864,8 @@ Warning.LargeAOA.str1 = Large angle of attack encountered.
 Warning.LargeAOA.str2 = Large angle of attack encountered (
 Warning.DISCONTINUITY = Discontinuity in rocket body diameter
 Warning.OPEN_AIRFRAME_FORWARD = Forward end of airframe is open (radius is > 0)
+Warning.AIRFRAME_GAP = Gap in rocket airframe
+Warning.AIRFRAME_OVERLAP = Two airframe sections overlap
 Warning.THICK_FIN = Thick fins may not simulate accurately.
 Warning.JAGGED_EDGED_FIN = Jagged-edged fin predictions may be inaccurate.
 Warning.LISTENERS_AFFECTED = Listeners modified the flight simulation
diff --git a/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java b/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
index ce2d5ce61..686119fac 100644
--- a/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
+++ b/core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
@@ -309,25 +309,28 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
 					// We're going to say it's discontinuous if it is presented to the user as having two different
 					// string representations.  Hopefully there are enough digits in the string that it will
 					// present as different if the discontinuity is big enough to matter.
-					if (!UnitGroup.UNITS_LENGTH.getDefaultUnit().toStringUnit(2.0*sym.getForeRadius()).equals(UnitGroup.UNITS_LENGTH.getDefaultUnit().toStringUnit(2.0*prevComp.getAftRadius()))) {
-						//					if ( !MathUtil.equals(sym.getForeRadius(), prevComp.getAftRadius())) {
-						warnings.add( Warning.DIAMETER_DISCONTINUITY, sym + ", " + prevComp);					
+					if (!UnitGroup.UNITS_LENGTH.getDefaultUnit().toStringUnit(2.0*sym.getForeRadius())
+						.equals(UnitGroup.UNITS_LENGTH.getDefaultUnit().toStringUnit(2.0*prevComp.getAftRadius()))) {
+						warnings.add( Warning.DIAMETER_DISCONTINUITY, prevComp + ", " + sym);					
+					}
+
+					// check for gap in airframe.  We'll use a textual comparison as above to see if there is a
+					// gap or overlap, then use arithmetic comparison to see which it is.  This won't be quite as reliable
+					// as the case for radius, since we never actually display the absolute X position
+					double compX = comp.toAbsolute(Coordinate.NUL)[0].x;
+					double prevX = prevComp.toAbsolute(new Coordinate(prevComp.getLength(), 0, 0, 0))[0].x;
+					if (!UnitGroup.UNITS_LENGTH.getDefaultUnit().toStringUnit(compX)
+						.equals(UnitGroup.UNITS_LENGTH.getDefaultUnit().toStringUnit(prevX))) {
+						if (compX > prevX) {
+							warnings.add(Warning.AIRFRAME_GAP,  prevComp + ", " + sym);
+						} else {
+							warnings.add(Warning.AIRFRAME_OVERLAP,  prevComp + ", " + sym);
+						}
 					}
 				}
-				
-				// double x = component.toAbsolute(Coordinate.NUL)[0].x;
-				// // Check for lengthwise discontinuity
-				// if (x > componentX + 0.0001) {
-				//	if (!MathUtil.equals(radius, 0)) {
-				//		warnings.add(Warning.DISCONTINUITY);
-				//		radius = 0;
-                //}
-				//componentX = component.toAbsolute(new Coordinate(component.getLengthAerodynamic()))[0].x;
-				
-			}else if( comp instanceof ComponentAssembly ){
+			} else if (comp instanceof ComponentAssembly) {
 				checkGeometry(configuration, comp, warnings);
 			}
-			
 		}
 	}
 		
diff --git a/core/src/net/sf/openrocket/aerodynamics/Warning.java b/core/src/net/sf/openrocket/aerodynamics/Warning.java
index b3c31fecc..6274a71c1 100644
--- a/core/src/net/sf/openrocket/aerodynamics/Warning.java
+++ b/core/src/net/sf/openrocket/aerodynamics/Warning.java
@@ -361,6 +361,12 @@ public abstract class Warning {
 
 	/** A <code>Warning</code> that a ComponentAssembly has an open forward end */	
 	public static final Warning OPEN_AIRFRAME_FORWARD = new Other(trans.get("Warning.OPEN_AIRFRAME_FORWARD"));
+
+	/** A <code>Warning</code> that there is a gap in the airframe */
+	public static final Warning AIRFRAME_GAP = new Other(trans.get("Warning.AIRFRAME_GAP"));
+
+	/** A <code>Warning</code> that two airframe components overlap*/
+	public static final Warning AIRFRAME_OVERLAP = new Other(trans.get("Warning.AIRFRAME_OVERLAP"));
 	
 	/** A <code>Warning</code> that the fins are thick compared to the rocket body. */
 	////Thick fins may not be modeled accurately.