add method for setting material color

ios/Classes/SwiftPolyvoxFilamentPlugin.swift

@@ -615,7 +615,18 @@ public class SwiftPolyvoxFilamentPlugin: NSObject, FlutterPlugin, FlutterTexture
         case "setCameraFocusDistance":
             set_camera_focus_distance(viewer, call.arguments as! Float)
             result(true)
-            
+        case "setMaterialColor":
+            guard let args = call.arguments as? [Any], args.count == 5,
+                  let assetManager = args[0] as? Int64,
+                  let asset = args[1] as? EntityId,
+                  let meshName = args[2] as? String, 
+                  let materialIndex = args[3] as? Int32, 
+                  let color = args[4] as? [Double] else {
+                result(FlutterError(code: "INVALID_ARGUMENTS", message: "Expected correct arguments for setMaterialColor", details: nil))
+                return
+            }
+            set_material_color(unsafeBitCast(assetManager, to:UnsafeMutableRawPointer.self), asset, meshName, materialIndex, Float(color[0]), Float(color[1]), Float(color[2]), Float(color[3]))
+            result(true)
             
         case "hideMesh":
             guard let args = call.arguments as? [Any], args.count == 3,

ios/include/AssetManager.hpp

@@ -40,6 +40,7 @@ namespace polyvox {
             const utils::Entity* getLightEntities(EntityId e) const noexcept;
             size_t getLightEntityCount(EntityId e) const noexcept;
             void updateAnimations();
+            bool setMaterialColor(EntityId e, const char* meshName, int materialInstance, const float r, const float g, const float b, const float a);
 
             bool setMorphAnimationBuffer(
                 EntityId entityId,

ios/include/PolyvoxFilamentApi.h

@@ -82,6 +82,7 @@ void remove_asset(const void* const viewer, EntityId asset);
 void clear_assets(const void* const viewer);
 void load_texture(void* assetManager, EntityId asset, const char *assetPath, int renderableIndex);
 void set_texture(void* assetManager, EntityId asset);
+bool set_material_color(void* assetManager, EntityId asset, const char* meshName, int materialIndex, const float r, const float g, const float b, const float a);
 void transform_to_unit_cube(void* assetManager, EntityId asset);
 void set_position(void* assetManager, EntityId asset, float x, float y, float z);
 void set_rotation(void* assetManager, EntityId asset, float rads, float x, float y, float z);

ios/src/PolyvoxFilamentApi.cpp

@@ -337,6 +337,10 @@ extern "C" {
     // ((AssetManager*)assetManager)->setTexture();
   }
 
+  bool set_material_color(void* assetManager, EntityId asset, const char* meshName, int materialIndex, const float r, const float g, const float b, const float a) {
+    return ((AssetManager*)assetManager)->setMaterialColor(asset, meshName, materialIndex, r, g, b, a);
+  }
+
   FLUTTER_PLUGIN_EXPORT void transform_to_unit_cube(void* assetManager, EntityId asset) {
       ((AssetManager*)assetManager)->transformToUnitCube(asset);
   }