add getAnimationDuration method

ios/Classes/SwiftPolyvoxFilamentPlugin.swift

@@ -447,6 +447,18 @@ public class SwiftPolyvoxFilamentPlugin: NSObject, FlutterPlugin, FlutterTexture
             
             play_animation(unsafeBitCast(assetManager, to:UnsafeMutableRawPointer.self), asset, Int32(index), loop, reverse, crossfade)
             result(true)
+        case "getAnimationDuration":
+            guard let args = call.arguments as? [Any], args.count == 3,
+                  let assetManager = args[0] as? Int64,
+                  let asset = args[1] as? EntityId,
+                  let animationIndex = args[2] as? Int else {
+                result(FlutterError(code: "INVALID_ARGUMENTS", message: "Expected correct arguments for getAnimationDuration", details: nil))
+                return
+            }
+            
+            let dur = get_animation_duration(unsafeBitCast(assetManager, to:UnsafeMutableRawPointer.self), asset, Int32(animationIndex))
+            result(dur)
+            
         case "setAnimationFrame":
             guard let args = call.arguments as? [Any], args.count == 4,
                   let assetManager = args[0] as? Int64,

ios/include/AssetManager.hpp

@@ -28,6 +28,7 @@ namespace polyvox {
             void remove(EntityId entity);
             void destroyAll();
             unique_ptr<vector<string>> getAnimationNames(EntityId entity);
+            float getAnimationDuration(EntityId entity, int animationIndex);
             unique_ptr<vector<string>> getMorphTargetNames(EntityId entity, const char *meshName);
             void transformToUnitCube(EntityId e);
             inline void updateTransform(EntityId e);

ios/include/PolyvoxFilamentApi.h

@@ -73,6 +73,7 @@ void set_animation_frame(void* assetManager, EntityId asset, int animationIndex,
 void stop_animation(void* assetManager, EntityId asset, int index);
 int get_animation_count(void* assetManager, EntityId asset);
 void get_animation_name(void* assetManager, EntityId asset, char *const outPtr, int index);
+float get_animation_duration(void* assetManager, EntityId asset, int index);
 void get_morph_target_name(void* assetManager, EntityId asset, const char *meshName, char *const outPtr, int index);
 int get_morph_target_name_count(void* assetManager, EntityId asset, const char *meshName);
 void remove_asset(const void* const viewer, EntityId asset);

ios/src/AssetManager.cpp

@@ -708,6 +708,20 @@ void AssetManager::setAnimationFrame(EntityId entity, int animationIndex, int an
   asset.mAnimator->updateBoneMatrices();
 }
 
+float AssetManager::getAnimationDuration(EntityId entity, int animationIndex) {
+    const auto& pos = _entityIdLookup.find(entity);
+
+  unique_ptr<vector<string>> names = make_unique<vector<string>>();
+
+  if(pos == _entityIdLookup.end()) {
+    Log("ERROR: asset not found for entity id.");
+    return -1.0f;
+  }
+
+  auto& asset = _assets[pos->second];
+  return asset.mAnimator->getAnimationDuration(animationIndex);
+}
+
 unique_ptr<vector<string>> AssetManager::getAnimationNames(EntityId entity) {
 
   const auto& pos = _entityIdLookup.find(entity);

ios/src/PolyvoxFilamentApi.cpp

@@ -280,15 +280,16 @@ extern "C" {
     // ((AssetManager*)assetManager)->setAnimationFrame(asset, animationIndex, animationFrame);
   }
 
+
+  FLUTTER_PLUGIN_EXPORT float get_animation_duration(void* assetManager, EntityId asset, int animationIndex) {
+    return ((AssetManager*)assetManager)->getAnimationDuration(asset, animationIndex);
+  }
+
   FLUTTER_PLUGIN_EXPORT int get_animation_count(
     void* assetManager,
     EntityId asset) {
-    //std::packaged_task<int()> lambda([=]() mutable  {
       auto names = ((AssetManager*)assetManager)->getAnimationNames(asset);
       return names->size();
-    
-
-    //return fut.get();
   }
 
   FLUTTER_PLUGIN_EXPORT void get_animation_name(

lib/filament_controller.dart

@@ -246,6 +246,13 @@ class FilamentController {
     return names.cast<String>();
   }
 
+  Future<double> getAnimationDuration(
+      FilamentEntity asset, int animationIndex) async {
+    var duration = await _channel.invokeMethod(
+        "getAnimationDuration", [_assetManager, asset, animationIndex]);
+    return duration as double;
+  }
+
   ///
   /// Animates morph target weights/bone transforms (where each frame requires a duration of [frameLengthInMs].
   /// [morphWeights] is a list of doubles in frame-major format.