[nostalgia/core] Upgrade TileSheet format to support subsheets and add conversion system

src/nostalgia/core/media.hpp

@@ -4,27 +4,40 @@
 
 #pragma once
 
+#include <ox/std/defines.hpp>
+
 #include <ox/claw/claw.hpp>
 #include <ox/fs/fs.hpp>
 
 #include "context.hpp"
+#include "typeconv.hpp"
 
 namespace nostalgia::core {
 
 template<typename T>
 ox::Result<AssetRef<T>> readObj(Context *ctx, const ox::FileAddress &file, bool forceLoad = false) noexcept {
 #ifndef OX_BARE_METAL
+	constexpr auto readConvert = [](const ox::Buffer &buff) -> ox::Result<T> {
+		auto [obj, err] = ox::readClaw<T>(buff);
+		if (err) {
+			if (err != ox::Error_ClawTypeVersionMismatch && err != ox::Error_ClawTypeMismatch) {
+				return err;
+			}
+			oxReturnError(convert(buff, T::TypeName, T::TypeVersion, &obj));
+		}
+		return obj;
+	};
 	oxRequire(path, file.getPath());
 	if (forceLoad) {
 		oxRequire(buff, ctx->rom->read(file));
-		oxRequire(obj, ox::readClaw<T>(buff));
+		oxRequire(obj, readConvert(buff));
 		oxRequire(cached, ctx->assetManager.template setAsset(path, obj));
 		return cached;
 	} else {
 		auto [cached, err] = ctx->assetManager.template getAsset<T>(path);
 		if (err) {
 			oxRequire(buff, ctx->rom->read(file));
-			oxRequire(obj, ox::readClaw<T>(buff));
+			oxRequire(obj, readConvert(buff));
 			oxReturnError(ctx->assetManager.template setAsset(path, obj).moveTo(&cached));
 		}
 		return cached;