From 0e7eeabe73e2b0e47343575256667a03aebd3575 Mon Sep 17 00:00:00 2001
From: Lars <larsh@apache.org>
Date: Sat, 31 May 2025 19:59:33 -0700
Subject: [PATCH] allow copy to vmanip directly from a mono-block

---
 src/client/mapblock_mesh.cpp |  2 +-
 src/mapblock.cpp             |  6 +-----
 src/voxel.cpp                | 10 +++++++---
 src/voxel.h                  |  2 +-
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/client/mapblock_mesh.cpp b/src/client/mapblock_mesh.cpp
index 07381b473..ac50f71a6 100644
--- a/src/client/mapblock_mesh.cpp
+++ b/src/client/mapblock_mesh.cpp
@@ -57,7 +57,7 @@ void MeshMakeData::fillBlockData(const v3s16 &bp, MapNode *data)
 	VoxelArea data_area(v3s16(0,0,0), data_size - v3s16(1,1,1));
 
 	v3s16 blockpos_nodes = bp * MAP_BLOCKSIZE;
-	m_vmanip.copyFrom(data, data_area, v3s16(0,0,0), blockpos_nodes, data_size);
+	m_vmanip.copyFrom(data, MAP_BLOCKSIZE * MAP_BLOCKSIZE * MAP_BLOCKSIZE, data_area, v3s16(0,0,0), blockpos_nodes, data_size);
 }
 
 void MeshMakeData::fillSingleNode(MapNode data, MapNode padding)
diff --git a/src/mapblock.cpp b/src/mapblock.cpp
index 5cc4d07ae..e0e4c5c64 100644
--- a/src/mapblock.cpp
+++ b/src/mapblock.cpp
@@ -212,13 +212,9 @@ void MapBlock::copyTo(VoxelManipulator &dst)
 	v3s16 data_size(MAP_BLOCKSIZE, MAP_BLOCKSIZE, MAP_BLOCKSIZE);
 	VoxelArea data_area(v3s16(0,0,0), data_size - v3s16(1,1,1));
 
-	bool was_mono_block = m_is_mono_block;
-	deconvertMonoblock();
 	// Copy from data to VoxelManipulator
-	dst.copyFrom(data, data_area, v3s16(0,0,0),
+	dst.copyFrom(data, m_is_mono_block ? 1 : nodecount, data_area, v3s16(0,0,0),
 			getPosRelative(), data_size);
-	if (was_mono_block)
-		tryConvertToMonoblock();
 }
 
 void MapBlock::copyFrom(const VoxelManipulator &src)
diff --git a/src/voxel.cpp b/src/voxel.cpp
index 5a69b0725..2f6204e8e 100644
--- a/src/voxel.cpp
+++ b/src/voxel.cpp
@@ -177,7 +177,7 @@ void VoxelManipulator::addArea(const VoxelArea &area)
 	delete[] old_flags;
 }
 
-void VoxelManipulator::copyFrom(MapNode *src, const VoxelArea& src_area,
+void VoxelManipulator::copyFrom(MapNode *src, size_t n_nodes, const VoxelArea& src_area,
 		v3s16 from_pos, v3s16 to_pos, const v3s16 &size)
 {
 	/* The reason for this optimised code is that we're a member function
@@ -216,8 +216,12 @@ void VoxelManipulator::copyFrom(MapNode *src, const VoxelArea& src_area,
 
 	for (s16 z = 0; z < size.Z; z++) {
 		for (s16 y = 0; y < size.Y; y++) {
-			memcpy(&m_data[i_local], &src[i_src], size.X * sizeof(*m_data));
-			memset(&m_flags[i_local], 0, size.X);
+			if (n_nodes == 1) {
+				std::fill(m_data + i_local, m_data + i_local + size.X, src[0]);
+			} else {
+				std::copy(src + i_src, src + i_src + size.X, m_data + i_local);
+			}
+			std::fill(m_flags + i_local, m_flags + i_local + size.X, 0);
 			i_src += src_step;
 			i_local += dest_step;
 		}
diff --git a/src/voxel.h b/src/voxel.h
index 7fbaadc28..b9d6bb8ae 100644
--- a/src/voxel.h
+++ b/src/voxel.h
@@ -482,7 +482,7 @@ public:
 		Copy data and set flags to 0
 		dst_area.getExtent() <= src_area.getExtent()
 	*/
-	void copyFrom(MapNode *src, const VoxelArea& src_area,
+	void copyFrom(MapNode *src, size_t n_nodes, const VoxelArea& src_area,
 			v3s16 from_pos, v3s16 to_pos, const v3s16 &size);
 
 	// Copy data