Fix crash on resource reload

- Properly delete MaterialManagers and ShaderContexts
 - Reload renderers on resource reload
 - More utility methods in WorldAttached

src/main/java/com/jozufozu/flywheel/backend/Backend.java

@@ -24,6 +24,8 @@ import net.minecraft.util.math.vector.Matrix4f;
 import net.minecraft.world.IWorld;
 import net.minecraft.world.World;
 
+import javax.annotation.Nullable;
+
 public class Backend {
 	public static final Logger log = LogManager.getLogger(Backend.class);
 
@@ -175,8 +177,14 @@ public class Backend {
 	/**
 	 * Used to avoid calling Flywheel functions on (fake) worlds that don't specifically support it.
 	 */
-	public static boolean isFlywheelWorld(IWorld world) {
-		return (world instanceof IFlywheelWorld && ((IFlywheelWorld) world).supportsFlywheel()) || world == Minecraft.getInstance().world;
+	public static boolean isFlywheelWorld(@Nullable IWorld world) {
+		if (world == null)
+			return false;
+
+		if (world instanceof IFlywheelWorld && ((IFlywheelWorld) world).supportsFlywheel())
+			return true;
+
+		return world == Minecraft.getInstance().world;
 	}
 
 	public static boolean isGameActive() {

src/main/java/com/jozufozu/flywheel/backend/ShaderContext.java

@@ -58,6 +58,7 @@ public abstract class ShaderContext<P extends GlProgram> implements IShaderConte
 	@Override
 	public void delete() {
 		programs.values().forEach(IMultiProgram::delete);
+		programs.clear();
 	}
 
 	/**

src/main/java/com/jozufozu/flywheel/backend/ShaderSources.java

@@ -19,6 +19,15 @@ import java.util.stream.Stream;
 import javax.annotation.Nonnull;
 import javax.annotation.ParametersAreNonnullByDefault;
 
+import com.jozufozu.flywheel.backend.instancing.InstancedRenderDispatcher;
+import com.jozufozu.flywheel.event.ForgeEvents;
+
+import net.minecraft.client.Minecraft;
+
+import net.minecraft.client.world.ClientWorld;
+
+import net.minecraftforge.event.world.WorldEvent;
+
 import org.lwjgl.system.MemoryUtil;
 
 import com.google.common.collect.Lists;
@@ -89,9 +98,14 @@ public class ShaderSources implements ISelectiveResourceReloadListener {
 				}
 
 				Backend.log.info("Loaded all shader programs.");
- 
+
 				// no need to hog all that memory
 				shaderSource.clear();
+
+				ClientWorld world = Minecraft.getInstance().world;
+				if (Backend.isFlywheelWorld(world)) {
+					InstancedRenderDispatcher.loadAllInWorld(world);
+				}
 			}
 		}
 	}

src/main/java/com/jozufozu/flywheel/backend/gl/GlObject.java

@@ -18,7 +18,9 @@ public abstract class GlObject {
 
 	protected final void checkHandle() {
 		if (!this.isHandleValid()) {
-			throw new IllegalStateException("Handle is not valid");
+			String descriptor = getDescriptor();
+			String message = (descriptor == null ? "" : (descriptor + " ")) + "handle is not valid.";
+			throw new IllegalStateException(message);
 		}
 	}
 
@@ -32,7 +34,9 @@ public abstract class GlObject {
 
 	public void delete() {
 		if (!isHandleValid()) {
-			throw new IllegalStateException("Handle already deleted.");
+			String descriptor = getDescriptor();
+			String message = (descriptor == null ? "" : (descriptor + " ")) + "handle already deleted.";
+			throw new IllegalStateException(message);
 		}
 
 		deleteInternal(handle);
@@ -40,4 +44,8 @@ public abstract class GlObject {
 	}
 
 	protected abstract void deleteInternal(int handle);
+
+	protected String getDescriptor() {
+		return "";
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/gl/shader/GlProgram.java

@@ -74,4 +74,8 @@ public abstract class GlProgram extends GlObject {
 		glDeleteProgram(handle);
 	}
 
+	@Override
+	public String toString() {
+		return "program " + name;
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/instancing/InstanceManager.java

@@ -37,7 +37,7 @@ public abstract class InstanceManager<T> implements MaterialManager.OriginShiftL
 		this.dynamicInstances = new Object2ObjectOpenHashMap<>();
 		this.tickableInstances = new Object2ObjectOpenHashMap<>();
 
-		materialManager.onOriginShift(this);
+		materialManager.addListener(this);
 	}
 
 	public void tick(double cameraX, double cameraY, double cameraZ) {

src/main/java/com/jozufozu/flywheel/backend/instancing/InstancedRenderDispatcher.java

@@ -40,7 +40,6 @@ import net.minecraft.util.LazyValue;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.vector.Matrix4f;
 import net.minecraft.world.IWorld;
-import net.minecraft.world.World;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.api.distmarker.OnlyIn;
 import net.minecraftforge.event.TickEvent;
@@ -124,15 +123,7 @@ public class InstancedRenderDispatcher {
 	public static void onReloadRenderers(ReloadRenderersEvent event) {
 		ClientWorld world = event.getWorld();
 		if (Backend.getInstance().canUseInstancing() && world != null) {
-			Contexts.WORLD.getMaterialManager(world).delete();
-
-			TileInstanceManager tiles = getTiles(world);
-			tiles.invalidate();
-			world.loadedTileEntityList.forEach(tiles::add);
-
-			EntityInstanceManager entities = getEntities(world);
-			entities.invalidate();
-			world.getAllEntities().forEach(entities::add);
+			loadAllInWorld(world);
 		}
 	}
 
@@ -188,4 +179,14 @@ public class InstancedRenderDispatcher {
 		if (breaking != null)
 			glBindTexture(GL_TEXTURE_2D, breaking.getGlTextureId());
 	}
+
+	public static void loadAllInWorld(ClientWorld world) {
+		Contexts.WORLD.getMaterialManager(world).delete();
+
+		TileInstanceManager tiles = tileInstanceManager.replace(world);
+		world.loadedTileEntityList.forEach(tiles::add);
+
+		EntityInstanceManager entities = entityInstanceManager.replace(world);
+		world.getAllEntities().forEach(entities::add);
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/instancing/MaterialManager.java

@@ -91,8 +91,11 @@ public class MaterialManager<P extends WorldProgram> {
 
 	public void delete() {
 		atlasMaterials.values().forEach(InstanceMaterial::delete);
-
 		materials.values().stream().flatMap(m -> m.values().stream()).forEach(InstanceMaterial::delete);
+
+		atlasMaterials.clear();
+		atlasRenderers.clear();
+		materials.clear();
 	}
 
 	@SuppressWarnings("unchecked")
@@ -131,7 +134,7 @@ public class MaterialManager<P extends WorldProgram> {
 		return originCoordinate;
 	}
 
-	public void onOriginShift(OriginShiftListener listener) {
+	public void addListener(OriginShiftListener listener) {
 		listeners.add(listener);
 	}
 

src/main/java/com/jozufozu/flywheel/backend/package-info.java

@@ -0,0 +1,7 @@
+@ParametersAreNonnullByDefault
+@MethodsReturnNonnullByDefault
+package com.jozufozu.flywheel.backend;
+
+import mcp.MethodsReturnNonnullByDefault;
+
+import javax.annotation.ParametersAreNonnullByDefault;

src/main/java/com/jozufozu/flywheel/core/WorldContext.java

@@ -21,7 +21,6 @@ import com.jozufozu.flywheel.backend.loading.Shader;
 import com.jozufozu.flywheel.backend.loading.ShaderLoadingException;
 import com.jozufozu.flywheel.backend.loading.ShaderTransformer;
 import com.jozufozu.flywheel.core.shader.ExtensibleGlProgram;
-import com.jozufozu.flywheel.core.shader.IMultiProgram;
 import com.jozufozu.flywheel.core.shader.StateSensitiveMultiProgram;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.util.WorldAttached;
@@ -38,7 +37,7 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 	protected Supplier<Stream<ResourceLocation>> specStream;
 	protected TemplateFactory templateFactory;
 
-	private final WorldAttached<MaterialManager<P>> materialManager = new WorldAttached<>($ -> new MaterialManager<>(this));
+	private final WorldAttached<MaterialManager<P>> worldAttachedMMs = new WorldAttached<>($ -> new MaterialManager<>(this));
 
 	private final Map<ShaderType, ResourceLocation> builtins = new EnumMap<>(ShaderType.class);
 	private final Map<ShaderType, String> builtinSources = new EnumMap<>(ShaderType.class);
@@ -71,7 +70,7 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 	}
 
 	public MaterialManager<P> getMaterialManager(IWorld world) {
-		return materialManager.get(world);
+		return worldAttachedMMs.get(world);
 	}
 
 	public WorldContext<P> withSpecStream(Supplier<Stream<ResourceLocation>> specStream) {
@@ -89,8 +88,6 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 
 	@Override
 	public void load() {
-		programs.values().forEach(IMultiProgram::delete);
-		programs.clear();
 
 		Backend.log.info("Loading context '{}'", name);
 
@@ -130,7 +127,7 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 	public void delete() {
 		super.delete();
 
-		materialManager.forEach(MaterialManager::delete);
+		worldAttachedMMs.empty(MaterialManager::delete);
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/core/shader/ExtensibleGlProgram.java

@@ -49,10 +49,19 @@ public class ExtensibleGlProgram extends GlProgram {
 
 	@Override
 	public String toString() {
-		return "ExtensibleGlProgram{" +
-				"name=" + name +
-				", extensions=" + extensions +
-				'}';
+		StringBuilder builder = new StringBuilder();
+		builder.append("program ")
+			   .append(name)
+			   .append('[');
+
+		for (IExtensionInstance extension : extensions) {
+			builder.append(extension)
+				   .append('+');
+		}
+
+		builder.append(']');
+
+		return builder.toString();
 	}
 
 	/**

src/main/java/com/jozufozu/flywheel/event/ForgeEvents.java

@@ -4,8 +4,6 @@ import java.util.ArrayList;
 
 import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.instancing.InstancedRenderDispatcher;
-import com.jozufozu.flywheel.backend.instancing.entity.EntityInstanceManager;
-import com.jozufozu.flywheel.backend.instancing.tile.TileInstanceManager;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.world.ClientWorld;
@@ -42,15 +40,8 @@ public class ForgeEvents {
 		IWorld world = event.getWorld();
 
 		if (Backend.isFlywheelWorld(world)) {
-			ClientWorld clientWorld = (ClientWorld) world;
-
-			TileInstanceManager tiles = InstancedRenderDispatcher.getTiles(world);
-			tiles.invalidate();
-			clientWorld.loadedTileEntityList.forEach(tiles::add);
-
-			EntityInstanceManager entities = InstancedRenderDispatcher.getEntities(world);
-			entities.invalidate();
-			clientWorld.getAllEntities().forEach(entities::add);
+			InstancedRenderDispatcher.loadAllInWorld((ClientWorld) world);
 		}
 	}
+
 }

src/main/java/com/jozufozu/flywheel/util/WorldAttached.java

@@ -2,19 +2,21 @@ package com.jozufozu.flywheel.util;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 import net.minecraft.world.IWorld;
 
 public class WorldAttached<T> {
 
 	Map<IWorld, T> attached;
-	private final WorldAttacher<T> factory;
+	private final Function<IWorld, T> factory;
 
-	public WorldAttached(WorldAttacher<T> factory) {
+	public WorldAttached(Function<IWorld, T> factory) {
 		this.factory = factory;
 		attached = new HashMap<>();
 	}
@@ -24,7 +26,7 @@ public class WorldAttached<T> {
 		T t = attached.get(world);
 		if (t != null)
 			return t;
-		T entry = factory.attach(world);
+		T entry = factory.apply(world);
 		put(world, entry);
 		return entry;
 	}
@@ -33,20 +35,46 @@ public class WorldAttached<T> {
 		attached.put(world, entry);
 	}
 
-	public void forEach(Consumer<T> consumer) {
+	/**
+	 * Replaces the entry with a new one from the factory and returns the new entry.
+	 */
+	@Nonnull
+	public T replace(IWorld world) {
+		attached.remove(world);
+
+		return get(world);
+	}
+
+	/**
+	 * Replaces the entry with a new one from the factory and returns the new entry.
+	 */
+	@Nonnull
+	public T replace(IWorld world, Consumer<T> finalizer) {
+		T remove = attached.remove(world);
+
+		finalizer.accept(remove);
+
+		return get(world);
+	}
+
+	/**
+	 * Deletes all entries after calling a function on them.
+	 *
+	 * @param finalizer Do something with all of the world-value pairs
+	 */
+	public void empty(BiConsumer<IWorld, T> finalizer) {
+		attached.forEach(finalizer);
+		attached.clear();
+	}
+
+	/**
+	 * Deletes all entries after calling a function on them.
+	 *
+	 * @param finalizer Do something with all of the values
+	 */
+	public void empty(Consumer<T> finalizer) {
 		attached.values()
-				.forEach(consumer);
+				.forEach(finalizer);
+		attached.clear();
 	}
-
-	@FunctionalInterface
-	public interface WorldAttacher<T> extends Function<IWorld, T> {
-		@Nonnull
-		T attach(IWorld world);
-
-		@Override
-		default T apply(IWorld world) {
-			return attach(world);
-		}
-	}
-
 }