From 64b6ed774bf3b6cbdc23b27c85a0f7e3b8b3f532 Mon Sep 17 00:00:00 2001
From: Restart <45609733+RestartFU@users.noreply.github.com>
Date: Fri, 15 Mar 2024 17:50:01 -0400
Subject: [PATCH] world/chunk: Added function to compare chunks (#855)

* push

* simplify
---
 server/world/chunk/chunk.go     | 20 ++++++++++++++++++++
 server/world/chunk/sub_chunk.go | 15 +++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/server/world/chunk/chunk.go b/server/world/chunk/chunk.go
index c3412f5c7..9adf4b092 100644
--- a/server/world/chunk/chunk.go
+++ b/server/world/chunk/chunk.go
@@ -2,6 +2,7 @@ package chunk
 
 import (
 	"github.com/df-mc/dragonfly/server/block/cube"
+	"slices"
 )
 
 // Chunk is a segment in the world with a size of 16x16x256 blocks. A chunk contains multiple sub chunks
@@ -42,6 +43,25 @@ func New(air uint32, r cube.Range) *Chunk {
 	}
 }
 
+// Equals returns if the chunk passed is equal to the current one
+func (chunk *Chunk) Equals(c *Chunk) bool {
+	if !chunk.recalculateHeightMap && !c.recalculateHeightMap && !slices.Equal(c.heightMap, chunk.heightMap) {
+		return false
+	}
+
+	if c.r != chunk.r || c.air != chunk.air || len(c.sub) != len(chunk.sub) {
+		return false
+	}
+
+	for i, s := range c.sub {
+		if !s.Equals(chunk.sub[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
 // Range returns the cube.Range of the Chunk as passed to New.
 func (chunk *Chunk) Range() cube.Range {
 	return chunk.r
diff --git a/server/world/chunk/sub_chunk.go b/server/world/chunk/sub_chunk.go
index aee76ae11..42db56b93 100644
--- a/server/world/chunk/sub_chunk.go
+++ b/server/world/chunk/sub_chunk.go
@@ -9,6 +9,21 @@ type SubChunk struct {
 	skyLight   []uint8
 }
 
+// Equals returns if the sub chunk passed is equal to the current one.
+func (sub *SubChunk) Equals(s *SubChunk) bool {
+	if s.air != sub.air || len(s.storages) != len(sub.storages) {
+		return false
+	}
+
+	for i, st := range s.storages {
+		if !st.Equal(sub.storages[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
 // NewSubChunk creates a new sub chunk. All sub chunks should be created through this function
 func NewSubChunk(air uint32) *SubChunk {
 	return &SubChunk{air: air}