Add mesh-holding blocks to shadow drawlist. (#13203)

When mesh chunking and shadows are enabled, make sure that the mesh-holding blocks are added to the shadow drawlist.
Otherwise those portions of the shadows will not be rendered.

1 files changed, 22 insertions, 2 deletions

diff --git a/src/client/clientmap.cpp b/src/client/clientmap.cpp
index af77e5ab2..39c811b85 100644
--- a/src/client/clientmap.cpp
+++ b/src/client/clientmap.cpp
@@ -1121,6 +1121,9 @@ void ClientMap::updateDrawListShadow(v3f shadow_light_pos, v3f shadow_light_dir,
 	// Number of blocks occlusion culled
 	u32 blocks_occlusion_culled = 0;
 
+	std::set<v3s16> shortlist;
+	MeshGrid mesh_grid = m_client->getMeshGrid();
+
 	for (auto &sector_it : m_sectors) {
 		MapSector *sector = sector_it.second;
 		if (!sector)
@@ -1134,8 +1137,8 @@ void ClientMap::updateDrawListShadow(v3f shadow_light_pos, v3f shadow_light_dir,
 			Loop through blocks in sector
 		*/
 		for (MapBlock *block : sectorblocks) {
-			if (!block->mesh) {
-				// Ignore if mesh doesn't exist
+			if (mesh_grid.cell_size == 1 && !block->mesh) {
+				// fast out in the case of no mesh chunking
 				continue;
 			}
 
@@ -1144,6 +1147,17 @@ void ClientMap::updateDrawListShadow(v3f shadow_light_pos, v3f shadow_light_dir,
 			if (projection.getDistanceFrom(block_pos) > radius)
 				continue;
 
+			if (mesh_grid.cell_size > 1) {
+				// Block meshes are stored in the corner block of a chunk
+				// (where all coordinate are divisible by the chunk size)
+				// Add them to the de-dup set.
+				shortlist.emplace(mesh_grid.getMeshPos(block->getPos()));
+			}
+			if (!block->mesh) {
+				// Ignore if mesh doesn't exist
+				continue;
+			}
+
 			blocks_in_range_with_mesh++;
 
 			// This block is in range. Reset usage timer.
@@ -1155,6 +1169,12 @@ void ClientMap::updateDrawListShadow(v3f shadow_light_pos, v3f shadow_light_dir,
 			}
 		}
 	}
+	for (auto pos : shortlist) {
+		MapBlock * block = getBlockNoCreateNoEx(pos);
+		if (block && block->mesh && m_drawlist_shadow.emplace(pos, block).second) {
+			block->refGrab();
+		}
+	}
 
 	g_profiler->avg("SHADOW MapBlock meshes in range [#]", blocks_in_range_with_mesh);
 	g_profiler->avg("SHADOW MapBlocks occlusion culled [#]", blocks_occlusion_culled);