Undo invalidate back to delete

- Makes more sense given how the method is used.

src/main/java/com/jozufozu/flywheel/api/backend/Engine.java

@@ -11,8 +11,18 @@ import net.minecraft.client.Camera;
 import net.minecraft.core.Vec3i;
 
 public interface Engine extends InstancerProvider {
+	/**
+	 * Create a plan that will be executed every frame.
+	 * @return A new plan.
+	 */
 	Plan<RenderContext> createFramePlan();
 
+	/**
+	 * Render all instances necessary for the given stage.
+	 * @param executor The task executor running the frame plan.
+	 * @param context The render context for this frame.
+	 * @param stage The stage to render.
+	 */
 	void renderStage(TaskExecutor executor, RenderContext context, RenderStage stage);
 
 	void renderCrumblingInstance(TaskExecutor taskExecutor, RenderContext context, Instance instance, int progress);
@@ -25,7 +35,15 @@ public interface Engine extends InstancerProvider {
 	 */
 	boolean updateRenderOrigin(Camera camera);
 
+	/**
+	 * @return The current render origin.
+	 */
 	Vec3i renderOrigin();
 
-	void invalidate();
+	/**
+	 * Free all resources associated with this engine.
+	 * <br>
+	 * This engine will not be used again after this method is called.
+	 */
+	void delete();
 }

src/main/java/com/jozufozu/flywheel/api/instance/InstancerProvider.java

@@ -5,7 +5,9 @@ import com.jozufozu.flywheel.api.model.Model;
 
 public interface InstancerProvider {
 	/**
-	 * Get an instancer for the given instance type, model, and render stage. Calling this method twice with the same arguments will return the same instancer.
+	 * Get an instancer for the given instance type, model, and render stage.
+	 * <br>
+	 * Calling this method twice with the same arguments will return the same instancer.
 	 *
 	 * @return An instancer for the given instance type, model, and render stage.
 	 */

src/main/java/com/jozufozu/flywheel/backend/engine/batching/BatchingEngine.java

@@ -104,7 +104,7 @@ public class BatchingEngine extends AbstractEngine implements SimplyComposedPlan
 	}
 
 	@Override
-	public void invalidate() {
+	public void delete() {
 		instancers.clear();
 
 		meshPools.values()

src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectEngine.java

@@ -90,7 +90,7 @@ public class IndirectEngine extends AbstractEngine {
 	}
 
 	@Override
-	public void invalidate() {
+	public void delete() {
 		drawManager.invalidate();
 	}
 }

src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancingEngine.java

@@ -135,7 +135,7 @@ public class InstancingEngine extends AbstractEngine {
 	}
 
 	@Override
-	public void invalidate() {
+	public void delete() {
 		drawManager.invalidate();
 	}
 }

src/main/java/com/jozufozu/flywheel/impl/visualization/VisualizationManagerImpl.java

@@ -249,6 +249,6 @@ public class VisualizationManagerImpl implements VisualizationManager {
 		blockEntities.invalidate();
 		entities.invalidate();
 		effects.invalidate();
-		engine.invalidate();
+		engine.delete();
 	}
 }