From 58378ffcbaa1a3bc5df51f877122c90f534e2b90 Mon Sep 17 00:00:00 2001
From: James Seibel <jeseibel@gondtc.com>
Date: Wed, 30 Aug 2023 07:43:59 -0500
Subject: [PATCH] Fix disappearing LOD sections

Its still a bit of a duck tape solution, but should be good enough for now
---
 .../core/render/LodRenderSection.java         | 48 ++++++++-----------
 1 file changed, 20 insertions(+), 28 deletions(-)

diff --git a/core/src/main/java/com/seibel/distanthorizons/core/render/LodRenderSection.java b/core/src/main/java/com/seibel/distanthorizons/core/render/LodRenderSection.java
index 6a3f3322a..2778e0286 100644
--- a/core/src/main/java/com/seibel/distanthorizons/core/render/LodRenderSection.java
+++ b/core/src/main/java/com/seibel/distanthorizons/core/render/LodRenderSection.java
@@ -103,23 +103,7 @@ public class LodRenderSection implements IDebugRenderable
 	// rendering //
 	//===========//
 	
-	public void enableRendering()
-	{
-		// FIXME this is a temporary fix for sections not building the first time,
-		//  this may cause LODs to flash when first loading
-		//  Problem reproduction steps:
-		//  1. connect to a multiplayer server
-		//  2. enter spectator
-		//  3. fly in one direction until section detail levels 7 and 8 appear
-		//  4. empty LODs should appear
-		if (!this.isRenderingEnabled)
-		{
-			// this only needs to be called when first enabling the section
-			//this.markBufferDirty();
-		}
-		
-		this.isRenderingEnabled = true;
-	}
+	public void enableRendering() { this.isRenderingEnabled = true; }
 	public void disableRendering() { this.isRenderingEnabled = false; }
 	
 	
@@ -141,6 +125,13 @@ public class LodRenderSection implements IDebugRenderable
 		// don't re-load or double load the render source
 		if (this.renderSource != null || this.renderSourceLoadFuture != null)
 		{
+			// since the render source has been loaded, make sure the render buffers are populated
+			// FIXME this is a duck tape solution, since the renderBufferRef should be populated elsewhere, but this does fix empty LODs when moving around the world
+			if (this.activeRenderBufferRef.get() == null)
+			{
+				this.markBufferDirty(); // empty LOD fix #3, all solutions revolve around markBufferDirty()
+			}
+			
 			return;
 		}
 		
@@ -223,16 +214,17 @@ public class LodRenderSection implements IDebugRenderable
 		return this.renderSource != null
 				&&
 				(
-						(
-								// if true; either this section represents empty chunks or un-generated chunks. 
-								// Either way, there isn't any data to render, but this should be considered "loaded"
-								this.renderSource.isEmpty()
-						)
-								||
-								(
-										// check if the buffers have been loaded
-										this.activeRenderBufferRef.get() != null
-								)
+					(
+						// if true; either this section represents empty chunks or un-generated chunks. 
+						// Either way, there isn't any data to render, but this should be considered "loaded"
+						this.renderSource.isEmpty()
+					)
+					||
+					(
+						// check if the buffers have been loaded
+						this.activeRenderBufferRef.get() != null // in the case of missing sections, this is probably null
+						&& this.lastSwapLocalVersion != -1
+					)
 				);
 	}
 	
@@ -283,7 +275,7 @@ public class LodRenderSection implements IDebugRenderable
 	}
 	
 	/** @return true if this section is loaded and set to render */
-	public boolean canBuildBuffer() { return this.renderSource != null && this.buildRenderBufferFuture == null && !this.renderSource.isEmpty() && this.isBufferOutdated(); }
+	public boolean canBuildBuffer() { return this.renderSourceLoadFuture == null && this.renderSource != null && this.buildRenderBufferFuture == null && !this.renderSource.isEmpty() && this.isBufferOutdated(); }
 	private boolean isBufferOutdated() { return this.neighborUpdated || this.renderSource.localVersion.get() != this.lastSwapLocalVersion; }
 	
 	/** @return true if this section is loaded and set to render */