move setStencilHighlight/removeStencilHighlight to Scene

thermion_dart/test/scene_tests.dart

@@ -0,0 +1,30 @@
+import 'package:thermion_dart/thermion_dart.dart';
+import 'package:test/test.dart';
+import 'helpers.dart';
+
+void main() async {
+  final testHelper = TestHelper("scene");
+  await testHelper.setup();
+
+  test('show stencil highlight', () async {
+    await testHelper.withViewer((viewer) async {
+      await viewer.view.setStencilBufferEnabled(true);
+      final cube = await viewer.createGeometry(
+          GeometryHelper.cube(
+            normals: true,
+            uvs: true,
+          ),
+          keepData: true,
+          materialInstances: []);
+
+      await viewer.addToScene(cube);
+
+      final scene = await viewer.view.getScene();
+      await scene.setStencilHighlight(cube);
+
+      await testHelper.capture(viewer.view, "stencil_highlight");
+      await scene.removeStencilHighlight(cube);
+      await testHelper.capture(viewer.view, "stencil_highlight_removed");
+    }, createStencilBuffer: true);
+  });
+}