feat: add app.save_world() function and update documentation

src/voxels/Chunk.hpp

@@ -8,6 +8,7 @@
 #include "constants.hpp"
 #include "lighting/Lightmap.hpp"
 #include "util/SmallHeap.hpp"
+#include "maths/aabb.hpp"
 #include "voxel.hpp"
 
 inline constexpr int CHUNK_DATA_LEN = CHUNK_VOL * 4;
@@ -75,4 +76,11 @@ public:
     bool decode(const ubyte* data);
 
     static void convert(ubyte* data, const ContentReport* report);
+
+    AABB getAABB() const {
+        return AABB(
+            glm::vec3(x * CHUNK_W, -INFINITY, z * CHUNK_D),
+            glm::vec3((x + 1) * CHUNK_W, INFINITY, (z + 1) * CHUNK_D)
+        );
+    }
 };

src/voxels/GlobalChunks.cpp

@@ -24,6 +24,10 @@ GlobalChunks::GlobalChunks(Level* level)
     chunksMap.max_load_factor(CHUNKS_MAP_MAX_LOAD_FACTOR);
 }
 
+void GlobalChunks::setOnUnload(consumer<Chunk&> onUnload) {
+    this->onUnload = std::move(onUnload);
+}
+
 std::shared_ptr<Chunk> GlobalChunks::fetch(int x, int z) {
     const auto& found = chunksMap.find(keyfrom(x, z));
     if (found == chunksMap.end()) {
@@ -160,6 +164,9 @@ void GlobalChunks::decref(Chunk* chunk) {
         ekey.pos[0] = chunk->x;
         ekey.pos[1] = chunk->z;
 
+        if (onUnload) {
+            onUnload(*chunk);
+        }
         save(chunk);
         chunksMap.erase(ekey.key);
         refCounters.erase(found);
@@ -170,17 +177,11 @@ void GlobalChunks::save(Chunk* chunk) {
     if (chunk == nullptr) {
         return;
     }
-    AABB aabb(
-        glm::vec3(chunk->x * CHUNK_W, -INFINITY, chunk->z * CHUNK_D),
-        glm::vec3(
-            (chunk->x + 1) * CHUNK_W, INFINITY, (chunk->z + 1) * CHUNK_D
-        )
-    );
+    AABB aabb = chunk->getAABB();
     auto entities = level->entities->getAllInside(aabb);
     auto root = dv::object();
     root["data"] = level->entities->serialize(entities);
     if (!entities.empty()) {
-        level->entities->despawn(std::move(entities));
         chunk->flags.entities = true;
     }
     level->getWorld()->wfile->getRegions().put(

src/voxels/GlobalChunks.hpp

@@ -8,6 +8,7 @@
 #include <glm/gtx/hash.hpp>
 
 #include "voxel.hpp"
+#include "delegates.hpp"
 
 class Chunk;
 class Level;
@@ -30,10 +31,14 @@ class GlobalChunks {
     std::unordered_map<uint64_t, std::shared_ptr<Chunk>> chunksMap;
     std::unordered_map<glm::ivec2, std::shared_ptr<Chunk>> pinnedChunks;
     std::unordered_map<ptrdiff_t, int> refCounters;
+
+    consumer<Chunk&> onUnload;
 public:
     GlobalChunks(Level* level);
     ~GlobalChunks() = default;
 
+    void setOnUnload(consumer<Chunk&> onUnload);
+
     std::shared_ptr<Chunk> fetch(int x, int z);
     std::shared_ptr<Chunk> create(int x, int z);