upgrade to Filament 1.21.0

ios/include/gltfio/MaterialProvider.h

@@ -34,6 +34,11 @@ enum class AlphaMode : uint8_t {
     BLEND
 };
 
+// The following struct gets hashed so all padding bits should be explicit.
+// Tell the compiler to emit a warning if it adds any padding.
+#pragma clang diagnostic push
+#pragma clang diagnostic warning "-Wpadded"
+
 /**
  * \struct MaterialKey MaterialProvider.h gltfio/MaterialProvider.h
  * \brief Small POD structure that specifies the requirements for a glTF material.
@@ -88,9 +93,12 @@ struct alignas(4) MaterialKey {
     bool hasSheen : 1;
     bool hasIOR : 1;
     bool hasVolume : 1;
+    uint8_t padding : 5;
 };
 
-static_assert(sizeof(MaterialKey) == 16, "MaterialKey has unexpected padding.");
+static_assert(sizeof(MaterialKey) == 16, "MaterialKey has unexpected size.");
+
+#pragma clang diagnostic pop
 
 bool operator==(const MaterialKey& k1, const MaterialKey& k2);
 
@@ -133,9 +141,10 @@ public:
      * @param uvmap Output argument that gets populated with a small table that maps from a glTF uv
      *              index to a Filament uv index.
      * @param label Optional tag that is not a part of the cache key.
+     * @param extras Optional extras as stringified JSON (not a part of the cache key). Don't store the pointer.
      */
     virtual filament::MaterialInstance* createMaterialInstance(MaterialKey* config, UvMap* uvmap,
-            const char* label = "material") = 0;
+            const char* label = "material", const char* extras = nullptr) = 0;
 
     /**
      * Gets a weak reference to the array of cached materials.