Paper/patches/server/0432-Significantly-improve-performance-of-the-end-generat.patch
Spottedleaf 8c5b837e05 Rework async chunk api implementation
Firstly, the old methods all routed to the CompletableFuture method.
However, the CF method could not guarantee that if the caller
was off-main that the future would be "completed" on-main. Since
the callback methods used the CF one, this meant that the callback
methods did not guarantee that the callbacks were to be called on
the main thread.

Now, all methods route to getChunkAtAsync(x, z, gen, urgent, cb)
so that the methods with the callback are guaranteed to invoke
the callback on the main thread. The CF behavior remains unchanged;
it may still appear to complete on main if invoked off-main.

Secondly, remove the scheduleOnMain invocation in the async
chunk completion. This unnecessarily delays the callback
by 1 tick.

Thirdly, add getChunksAtAsync(minX, minZ, maxX, maxZ, ...) which
will load chunks within an area. This method is provided as a helper
as keeping all chunks loaded within an area can be complicated to
implement for plugins (due to the lacking ticket API), and is
already implemented internally anyways.

Fourthly, remove the ticket addition that occured with getChunkAt
and getChunkAtAsync. The ticket addition may delay the unloading
of the chunk unnecessarily. It also fixes a very rare timing bug
where the future/callback would be completed after the chunk
unloads.
2024-11-18 23:00:59 -08:00

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: SuperCoder7979 <25208576+SuperCoder7979@users.noreply.github.com>
Date: Tue, 3 Nov 2020 23:48:05 -0600
Subject: [PATCH] Significantly improve performance of the end generation
This patch implements a noise cache for the end which significantly reduces the computation time of generation. This results in about a 3x improvement.
Original code by SuperCoder7979 and Gegy in Lithium, licensed under LGPL-3.0 (Source: https://github.com/jellysquid3/lithium-fabric)
Co-authored-by: Gegy <gegy1000@gmail.com>
Co-authored-by: Dylan Xaldin <Puremin0rez515@gmail.com>
Co-authored-by: pop4959 <pop4959@gmail.com>
diff --git a/src/main/java/net/minecraft/world/level/levelgen/DensityFunctions.java b/src/main/java/net/minecraft/world/level/levelgen/DensityFunctions.java
index b09bc1dac649ce9f4826edc1923c843804226993..ac8447e20531ad59d5e26c6db541d6e844d56c0f 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/DensityFunctions.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/DensityFunctions.java
@@ -509,6 +509,16 @@ public final class DensityFunctions {
);
private static final float ISLAND_THRESHOLD = -0.9F;
private final SimplexNoise islandNoise;
+ // Paper start - Perf: Optimize end generation
+ private static final class NoiseCache {
+ public long[] keys = new long[8192];
+ public float[] values = new float[8192];
+ public NoiseCache() {
+ java.util.Arrays.fill(keys, Long.MIN_VALUE);
+ }
+ }
+ private static final ThreadLocal<java.util.Map<SimplexNoise, NoiseCache>> noiseCache = ThreadLocal.withInitial(java.util.WeakHashMap::new);
+ // Paper end - Perf: Optimize end generation
public EndIslandDensityFunction(long seed) {
RandomSource randomSource = new LegacyRandomSource(seed);
@@ -524,12 +534,26 @@ public final class DensityFunctions {
float f = 100.0F - Mth.sqrt((long) x * (long) x + (long) z * (long) z) * 8.0F; // Paper - cast ints to long to avoid integer overflow
f = Mth.clamp(f, -100.0F, 80.0F);
+ NoiseCache cache = noiseCache.get().computeIfAbsent(sampler, noiseKey -> new NoiseCache()); // Paper - Perf: Optimize end generation
for (int m = -12; m <= 12; m++) {
for (int n = -12; n <= 12; n++) {
long o = (long)(i + m);
long p = (long)(j + n);
- if (o * o + p * p > 4096L && sampler.getValue((double)o, (double)p) < -0.9F) {
- float g = (Mth.abs((float)o) * 3439.0F + Mth.abs((float)p) * 147.0F) % 13.0F + 9.0F;
+ // Paper start - Perf: Optimize end generation by using a noise cache
+ long key = net.minecraft.world.level.ChunkPos.asLong((int) o, (int) p);
+ int index = (int) it.unimi.dsi.fastutil.HashCommon.mix(key) & 8191;
+ float g = Float.MIN_VALUE;
+ if (cache.keys[index] == key) {
+ g = cache.values[index];
+ } else {
+ if (o * o + p * p > 4096L && sampler.getValue((double)o, (double)p) < -0.9F) {
+ g = (Mth.abs((float)o) * 3439.0F + Mth.abs((float)p) * 147.0F) % 13.0F + 9.0F;
+ }
+ cache.keys[index] = key;
+ cache.values[index] = g;
+ }
+ if (g != Float.MIN_VALUE) {
+ // Paper end - Perf: Optimize end generation
float h = (float)(k - m * 2);
float q = (float)(l - n * 2);
float r = 100.0F - Mth.sqrt(h * h + q * q) * g;