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 Co-authored-by: Dylan Xaldin Co-authored-by: pop4959 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 2cf20ef14ad18346f942395546ad31f2d774f81a..ed8cfa36f41643b191714b2ae6176f58f93bd4b2 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> 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 = i + m; long p = j + n; - if (o * o + p * p > 4096L && sampler.getValue(o, 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 = k - m * 2; float q = l - n * 2; float r = 100.0F - Mth.sqrt(h * h + q * q) * g;