From a43fe2bc9a1ae6a140b9aec8b8e159d620858198 Mon Sep 17 00:00:00 2001
From: Jozufozu <jozsefaug@gmail.com>
Date: Fri, 17 Dec 2021 22:41:22 -0800
Subject: [PATCH] No need for getDirtyBitSet

 - Faster and simpler to just do one loop
---
 .../backend/instancing/AbstractInstancer.java | 13 --------
 .../instancing/instancing/GPUInstancer.java   | 33 +++++++------------
 2 files changed, 11 insertions(+), 35 deletions(-)

diff --git a/src/main/java/com/jozufozu/flywheel/backend/instancing/AbstractInstancer.java b/src/main/java/com/jozufozu/flywheel/backend/instancing/AbstractInstancer.java
index 06e6071fd..af7005abb 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/instancing/AbstractInstancer.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/instancing/AbstractInstancer.java
@@ -70,19 +70,6 @@ public abstract class AbstractInstancer<D extends InstanceData> implements Insta
 		return getModelVertexCount() * numInstances();
 	}
 
-	protected BitSet getDirtyBitSet() {
-		final int size = data.size();
-		final BitSet dirtySet = new BitSet(size);
-
-		for (int i = 0; i < size; i++) {
-			D element = data.get(i);
-			if (element.checkDirtyAndClear()) {
-				dirtySet.set(i);
-			}
-		}
-		return dirtySet;
-	}
-
 	protected void removeDeletedInstances() {
 		// Figure out which elements are to be removed.
 		final int oldSize = this.data.size();
diff --git a/src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/GPUInstancer.java b/src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/GPUInstancer.java
index 879f35785..fc1480ebf 100644
--- a/src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/GPUInstancer.java
+++ b/src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/GPUInstancer.java
@@ -150,31 +150,20 @@ public class GPUInstancer<D extends InstanceData> extends AbstractInstancer<D> {
 
 		if (size <= 0) return;
 
-		final int stride = instanceFormat.getStride();
-		final BitSet dirtySet = getDirtyBitSet();
+		try (MappedBuffer mapped = instanceVBO.getBuffer(0, glBufferSize)) {
 
-		if (dirtySet.isEmpty()) return;
+			final StructWriter<D> writer = type.asInstanced()
+					.getWriter(mapped);
 
-		final int firstDirty = dirtySet.nextSetBit(0);
-		final int lastDirty = dirtySet.previousSetBit(size);
-
-		final int offset = firstDirty * stride;
-		final int length = (1 + lastDirty - firstDirty) * stride;
-
-		if (length > 0) {
-			try (MappedBuffer mapped = instanceVBO.getBuffer(offset, length)) {
-
-				StructWriter<D> writer = type.asInstanced()
-						.getWriter(mapped);
-
-				dirtySet.stream()
-						.forEach(i -> {
-							writer.seek(i);
-							writer.write(data.get(i));
-						});
-			} catch (Exception e) {
-				Flywheel.log.error("Error updating GPUInstancer:", e);
+			for (int i = 0; i < size; i++) {
+				final D element = data.get(i);
+				if (element.checkDirtyAndClear()) {
+					writer.seek(i);
+					writer.write(element);
+				}
 			}
+		} catch (Exception e) {
+			Flywheel.log.error("Error updating GPUInstancer:", e);
 		}
 	}