update ViewerWidget

thermion_flutter/thermion_flutter/lib/src/widgets/src/viewer_widget.dart

@@ -1,77 +1,97 @@
 import 'package:flutter/material.dart';
 import 'package:thermion_flutter/thermion_flutter.dart' hide Texture;
 
-enum ViewerManipulatorType { ORBIT, FIRST_PERSON }
+enum ManipulatorType { NONE, ORBIT, FREE_FLIGHT }
 
-class ViewerOptions {
-  ///
+class ViewerWidget extends StatefulWidget {
   ///
+  /// The widget to display before the viewport has loaded.
   ///
   final Widget initial;
 
   ///
-  /// When true, an FPS counter will be displayed at the top right of the widget
+  /// The initial position for the camera (looking towards (0,0,0)).
+  ///
+  late final Vector3 initialCameraPosition;
+
+  ///
+  /// When true, an FPS counter will be overlaid above the viewer widget.
   ///
   final bool showFpsCounter;
 
   ///
-  ///
+  /// The path to the (glTF) asset to be loaded into the scene.
   ///
   final String? assetPath;
 
   ///
-  ///
+  /// The path to the (KTX) skybox to be loaded into the scene.
   ///
   final String? skyboxPath;
 
   ///
-  ///
+  /// The path to the (KTX) image-based light to be loaded into the scene.
   ///
   final String? iblPath;
 
   ///
-  ///
+  /// A direct light to add to the scene.
   ///
   final LightType? directLightType;
 
   ///
-  ///
+  /// If true, the glTF asset will be rescaled so its bounding box fits within a 1x1x1 cube. Defaults to true.
   ///
   final bool transformToUnitCube;
 
   ///
-  ///
+  /// If true, enables postprocessing (ACES tone mapping and basic anti-aliaising). Defaults to true.
   ///
   final bool postProcessing;
 
   ///
-  ///
+  /// The fill color to use for the background. If a skybox is provided, the fill color won't be visible.
   ///
   final Color? background;
 
   ///
+  /// Disposing this widget will unload all scene resources (i.e. the asset, skybox, etc). but will leave the underlying engine intact.
+  /// If [destroyEngineOnUnload] is true, disposing the widget will also destroy the engine and rendering thread.
+  /// Defaults to false.
   ///
-  ///
-  final bool destroyAppOnUnload;
+  final bool destroyEngineOnUnload;
 
-  const ViewerOptions(
-      {this.initial =
+  ///
+  /// The type of camera manipulator to use to respond to viewport gestures. Defaults to ORBIT (pinch to zoom in/out, swipe to rotate around the asset at a fixed distance).
+  ///
+  final ManipulatorType manipulatorType;
+
+  ///
+  /// A callback that can be used to access the viewer.
+  ///
+  final Future Function(ThermionViewer)? onViewerAvailable;
+
+  ///
+  ///
+  ///
+  ViewerWidget(
+      {super.key,
+      this.initial =
           const DecoratedBox(decoration: BoxDecoration(color: Colors.red)),
+      Vector3? initialCameraPosition,
       this.showFpsCounter = false,
       this.transformToUnitCube = true,
       this.postProcessing = true,
-      this.destroyAppOnUnload = false,
+      this.destroyEngineOnUnload = false,
       this.assetPath,
       this.skyboxPath,
       this.iblPath,
       this.directLightType,
-      this.background});
-}
-
-class ViewerWidget extends StatefulWidget {
-  final ViewerOptions options;
-
-  const ViewerWidget({super.key, this.options = const ViewerOptions()});
+      this.background,
+      this.onViewerAvailable,
+      this.manipulatorType = ManipulatorType.ORBIT}) {
+    this.initialCameraPosition = initialCameraPosition ?? Vector3(0, 0, 5);
+  }
 
   @override
   State<StatefulWidget> createState() {
@@ -86,14 +106,98 @@ class _ViewerWidgetState extends State<ViewerWidget> {
   void initState() {
     super.initState();
     ThermionFlutterPlugin.createViewer().then((viewer) async {
-      viewer = viewer;
-
+      this.viewer = viewer;
+      await _configure();
       setState(() {});
     });
   }
 
+  void didUpdateWidget(ViewerWidget oldWidget) {
+    if (oldWidget.manipulatorType != widget.manipulatorType) {
+      _setViewportWidget();
+      setState(() {});
+    }
+
+    if (oldWidget.initialCameraPosition != widget.initialCameraPosition ||
+        oldWidget.showFpsCounter != widget.showFpsCounter ||
+        oldWidget.assetPath != widget.assetPath ||
+        oldWidget.skyboxPath != widget.skyboxPath ||
+        oldWidget.iblPath != widget.iblPath ||
+        oldWidget.directLightType != widget.directLightType ||
+        oldWidget.transformToUnitCube != widget.transformToUnitCube ||
+        oldWidget.postProcessing != widget.postProcessing ||
+        oldWidget.background != widget.background ||
+        oldWidget.destroyEngineOnUnload != widget.destroyEngineOnUnload) {
+      throw UnsupportedError(
+          "Only manipulatorType can be changed at runtime. To change any other properties, create a new widget.");
+    }
+  }
+
+  void _setViewportWidget() {
+    switch (widget.manipulatorType) {
+      case ManipulatorType.NONE:
+        viewport = thermionWidget;
+      case ManipulatorType.ORBIT:
+        viewport = ThermionListenerWidget(
+            key: ObjectKey(ManipulatorType.ORBIT),
+            inputHandler: DelegateInputHandler.fixedOrbit(viewer!,
+                minimumDistance: widget.initialCameraPosition.length),
+            child: thermionWidget);
+      case ManipulatorType.FREE_FLIGHT:
+        viewport = ThermionListenerWidget(
+            key: ObjectKey(ManipulatorType.FREE_FLIGHT),
+            inputHandler: DelegateInputHandler.flight(viewer!),
+            child: thermionWidget);
+    }
+  }
+
+  ThermionAsset? asset;
+  late final ThermionWidget? thermionWidget;
+  Widget? viewport;
+
+  Future _configure() async {
+    if (widget.assetPath != null) {
+      asset = await viewer!.loadGltf(widget.assetPath!);
+    }
+
+    if (widget.skyboxPath != null) {
+      await viewer!.loadSkybox(widget.skyboxPath!);
+    }
+
+    if (widget.iblPath != null) {
+      await viewer!.loadIbl(widget.iblPath!);
+    }
+
+    if (widget.postProcessing) {
+      await viewer!.setPostProcessing(true);
+      await viewer!.setAntiAliasing(false, true, false);
+    }
+
+    final camera = await viewer!.getActiveCamera();
+
+    await camera.lookAt(widget.initialCameraPosition);
+
+    if (widget.background != null) {
+      await viewer!.setBackgroundColor(widget.background!.r,
+          widget.background!.g, widget.background!.b, widget.background!.a);
+    }
+
+    await viewer!.setRendering(true);
+
+    thermionWidget = ThermionWidget(
+      key: ObjectKey(DateTime.now()),
+      viewer: viewer!,
+      showFpsCounter: widget.showFpsCounter,
+    );
+
+    _setViewportWidget();
+
+    widget.onViewerAvailable?.call(viewer!);
+  }
+
   @override
   void dispose() {
+    super.dispose();
     if (viewer != null) {
       _tearDown();
     }
@@ -101,16 +205,13 @@ class _ViewerWidgetState extends State<ViewerWidget> {
 
   Future _tearDown() async {
     await viewer!.dispose();
-    if (widget.options.destroyAppOnUnload) {
+    if (widget.destroyEngineOnUnload) {
       await FilamentApp.instance!.destroy();
     }
   }
 
   @override
   Widget build(BuildContext context) {
-    if (viewer == null) {
-      return widget.options.initial!;
-    }
-    return ThermionWidget(viewer: viewer!);
+    return viewport != null ? SizedBox.expand(child: viewport) : widget.initial;
   }
 }