add gltfio FFI methods and expose texture/render target creation directly

thermion_dart/native/include/c_api/TGltfAssetLoader.h

@@ -0,0 +1,30 @@
+#ifndef _T_GLTF_ASSET_LOADER_H
+#define _T_GLTF_ASSET_LOADER_H
+
+#include "APIExport.h"
+#include "APIBoundaryTypes.h"
+#include "TMaterialInstance.h"
+#include "TTexture.h"
+#include "ResourceBuffer.hpp"
+#include "MathUtils.hpp"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+EMSCRIPTEN_KEEPALIVE TGltfAssetLoader *GltfAssetLoader_create(TEngine *tEngine, TMaterialProvider *tMaterialProvider);
+EMSCRIPTEN_KEEPALIVE TGltfResourceLoader *GltfResourceLoader_create(TEngine *tEngine);
+EMSCRIPTEN_KEEPALIVE TFilamentAsset *GltfAssetLoader_load(
+    TGltfAssetLoader *tAssetLoader,
+    TGltfResourceLoader *tResourceLoader,
+    uint8_t *data,
+    size_t length,
+    uint8_t numInstances
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif