From 6bb865867e2c0846d1656346e388ee3383c858be Mon Sep 17 00:00:00 2001
From: Bixilon <bixilon@bixilon.de>
Date: Mon, 3 May 2021 14:08:33 +0200
Subject: [PATCH] rendering: WorldRenderer: improve chunk cache clearing

---
 .../minosoft/gui/rendering/RenderWindow.kt    |  6 +++
 .../gui/rendering/chunk/WorldRenderer.kt      | 42 ++++++++++---------
 2 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt b/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt
index 1bdd6b59e..f6b40f5c3 100644
--- a/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt
+++ b/src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.kt
@@ -56,6 +56,7 @@ class RenderWindow(
     val connection: PlayConnection,
     val rendering: Rendering,
 ) {
+    private lateinit var renderThread: Thread
     val renderStats = RenderStats()
     var screenDimensions = Vec2i(900, 500)
         private set
@@ -116,6 +117,7 @@ class RenderWindow(
     }
 
     fun init(latch: CountUpAndDownLatch) {
+        renderThread = Thread.currentThread()
         Log.log(LogMessageType.RENDERING_LOADING) { "Creating window..." }
         val stopwatch = Stopwatch()
         // Setup an error callback. The default implementation
@@ -406,4 +408,8 @@ class RenderWindow(
     fun getClipboardText(): String {
         return glfwGetClipboardString(windowId) ?: ""
     }
+
+    fun assertOnRenderThread() {
+        check(Thread.currentThread() == renderThread) { "Current thread (${Thread.currentThread().name} is not the render thread!" }
+    }
 }
diff --git a/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt b/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt
index e5acae7b7..05d686538 100644
--- a/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt
+++ b/src/main/java/de/bixilon/minosoft/gui/rendering/chunk/WorldRenderer.kt
@@ -351,32 +351,36 @@ class WorldRenderer(
     fun clearChunkCache() {
         // ToDo: Stop all preparations
         queuedChunks.clear()
+        val chunkMeshes = allChunkSections.toSynchronizedMap().values
+        allChunkSections.clear()
+        visibleChunks.clear()
         renderWindow.renderQueue.add {
-            visibleChunks.clear()
-            for ((location, _) in allChunkSections) {
-                unloadChunk(location)
+            for (meshCollection in chunkMeshes) {
+                unloadMeshes(meshCollection.values)
             }
         }
     }
 
     fun unloadChunk(chunkPosition: Vec2i) {
         queuedChunks.remove(chunkPosition)
-        renderWindow.renderQueue.add {
-            allChunkSections[chunkPosition]?.let {
-                for ((_, meshCollection) in it) {
-                    meshCollection.opaqueSectionArrayMesh.let {
-                        it.unload()
-                        meshes--
-                        triangles -= it.trianglesCount
-                    }
-                    meshCollection.transparentSectionArrayMesh?.let {
-                        it.unload()
-                        meshes--
-                        triangles -= it.trianglesCount
-                    }
-                }
-                allChunkSections.remove(chunkPosition)
-                visibleChunks.remove(chunkPosition)
+        val chunkMesh = allChunkSections[chunkPosition] ?: return
+        allChunkSections.remove(chunkPosition)
+        visibleChunks.remove(chunkPosition)
+        renderWindow.renderQueue.add { unloadMeshes(chunkMesh.values) }
+    }
+
+    private fun unloadMeshes(meshes: Collection<ChunkMeshCollection>) {
+        renderWindow.assertOnRenderThread()
+        for (meshCollection in meshes) {
+            meshCollection.opaqueSectionArrayMesh.let {
+                it.unload()
+                this.meshes--
+                triangles -= it.trianglesCount
+            }
+            meshCollection.transparentSectionArrayMesh?.let {
+                it.unload()
+                this.meshes--
+                triangles -= it.trianglesCount
             }
         }
     }