feat: add export / file packing

destrum/src/Assets/AssetManager.cpp

@@ -1,11 +1,14 @@
 #include <destrum/Assets/AssetManager.h>
 
+#include <memory>
 #include <optional>
 #include <stdexcept>
 
 #include <destrum/Assets/ModelFile.h>
 #include <destrum/FS/AssetFS.h>
 
+#include "AssetFSIOSystem.h"
+
 namespace {
     std::string ToReference(std::string_view reference) {
         if (reference.empty()) {
@@ -30,6 +33,14 @@ namespace {
         return std::nullopt;
     }
 
+    // Assimp opens files itself, so with packed assets it has to go through AssetFS
+    std::unique_ptr<Assimp::IOSystem> MakeIOSystem() {
+        if (!AssetFS::GetInstance().IsPacked()) {
+            return nullptr;
+        }
+        return std::make_unique<AssetFSIOSystem>();
+    }
+
     // Cooked texture paths are relative to the model file, imported ones are absolute
     void ResolveTexturePaths(ModelDoc::ModelAsset& model, const std::filesystem::path& modelDir) {
         for (ModelDoc::MaterialInfo& material : model.materials) {
@@ -95,7 +106,7 @@ ModelDoc::ModelAsset AssetManager::LoadCookedOrImport(
     const ModelDoc::LoadOptions& options) const
 {
     if (const auto cookedPath = FindCookedModel(reference)) {
-        ModelDoc::ModelAsset model = ModelFile::ReadFromFile(*cookedPath);
+        ModelDoc::ModelAsset model = ModelFile::Read(AssetFS::GetInstance().ReadFile(*cookedPath));
         if (ModelFile::SupportsLoadOptions(model, options)) {
             ModelFile::ApplyLoadOptions(model, options);
             ResolveTexturePaths(model, cookedPath->parent_path());
@@ -105,7 +116,7 @@ ModelDoc::ModelAsset AssetManager::LoadCookedOrImport(
         spdlog::debug("Importing {}, its cooked model doesn't match the requested load options", reference);
     }
 
-    return ModelDoc::LoadModel(Resolve(reference).generic_string(), options);
+    return ModelDoc::LoadModel(Resolve(reference).generic_string(), options, MakeIOSystem());
 }
 
 std::vector<SkeletalAnimation> AssetManager::LoadAnimationClips(
@@ -115,7 +126,8 @@ std::vector<SkeletalAnimation> AssetManager::LoadAnimationClips(
     const std::string sourceReference = ToReference(reference);
     auto clips = ModelDoc::LoadAnimationClips(
         Resolve(sourceReference).generic_string(),
-        targetSkeleton);
+        targetSkeleton,
+        MakeIOSystem());
     for (std::size_t index = 0; index < clips.size(); ++index) {
         auto& clip = clips[index];
         clip.assetReference.path = sourceReference;