q&d hack to circumvent the dangling pointer issue #26

src/net/torvald/UnsafePtr.kt

@@ -32,12 +32,16 @@ class UnsafePtr(val ptr: Long, val allocSize: Long) {
     fun destroy() {
         if (!destroyed) {
             UnsafeHelper.unsafe.freeMemory(ptr)
+
+            println("[UnsafePtr] Destroying pointer $this; called from:")
+            Thread.currentThread().stackTrace.forEach { println("[UnsafePtr] $it") }
+
             destroyed = true
         }
     }
 
     private inline fun checkNullPtr(index: Long) {
-        if (destroyed) throw NullPointerException("The pointer is already destroyed (0x${ptr.toString(16)})")
+        if (destroyed) throw NullPointerException("The pointer is already destroyed ($this)")
 
         // OOB Check: debugging purposes only -- comment out for the production
         //if (index !in 0 until allocSize) throw IndexOutOfBoundsException("Index: $index; alloc size: $allocSize")
@@ -67,4 +71,5 @@ class UnsafePtr(val ptr: Long, val allocSize: Long) {
         UnsafeHelper.unsafe.setMemory(ptr, allocSize, byte)
     }
 
+    override fun toString() = "0x${ptr.toString(16)} with size $allocSize"
 }

src/net/torvald/terrarum/TitleScreen.kt

@@ -253,7 +253,9 @@ class TitleScreen(val batch: SpriteBatch) : Screen {
         gdxClearAndSetBlend(.64f, .754f, .84f, 1f)
 
 
-        IngameRenderer.invoke(gamePaused = false, world = demoWorld, uisToDraw = uiContainer)
+        if (!demoWorld.disposed) { // FIXME q&d hack to circumvent the dangling pointer issue #26
+            IngameRenderer.invoke(gamePaused = false, world = demoWorld, uisToDraw = uiContainer)
+        }
 
 
         batch.inUse {

src/net/torvald/terrarum/gameworld/BlockLayer.kt

@@ -12,6 +12,7 @@ import net.torvald.terrarum.AppLoader.printdbg
  */
 open class BlockLayer(val width: Int, val height: Int) : Disposable {
 
+    // using unsafe pointer gets you 100 fps, whereas using directbytebuffer gets you 90
     private val ptr = UnsafeHelper.allocate(width * height * BYTES_PER_BLOCK)
 
     //private val directByteBuffer: ByteBuffer

src/net/torvald/terrarum/gameworld/GameWorld.kt

@@ -93,6 +93,9 @@ open class GameWorld : Disposable {
     var generatorSeed: Long = 0
         internal set
 
+    var disposed = false
+        private set
+
 
     constructor(worldIndex: Int, width: Int, height: Int, creationTIME_T: Long, lastPlayTIME_T: Long, totalPlayTime: Int) {
         if (width <= 0 || height <= 0) throw IllegalArgumentException("Non-positive width/height: ($width, $height)")
@@ -461,6 +464,8 @@ open class GameWorld : Disposable {
         layerWall.dispose()
         layerTerrain.dispose()
         //nullWorldInstance?.dispose() // must be called ONLY ONCE; preferably when the app exits
+
+        disposed = true
     }
 
     companion object {