Initial flame_lua_runtime package

test/runtime/rendering/runtime_viewport_test.dart

@@ -0,0 +1,98 @@
+import 'package:flame/components.dart';
+import 'package:flame_lua_runtime/runtime/display/runtime_viewport.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('RuntimeViewport', () {
+    test('fits design size inside screen with letterboxing', () {
+      final transform = RuntimeViewport.compute(
+        screenSize: Vector2(1280, 720),
+        config: const RuntimeViewportConfig(
+          designWidth: 720,
+          designHeight: 720,
+        ),
+      );
+
+      expect(transform.x, 280);
+      expect(transform.y, 0);
+      expect(transform.width, 720);
+      expect(transform.height, 720);
+      expect(transform.scaleX, 1);
+      expect(transform.scaleY, 1);
+    });
+
+    test('fills screen by preserving aspect ratio and cropping', () {
+      final transform = RuntimeViewport.compute(
+        screenSize: Vector2(1280, 720),
+        config: const RuntimeViewportConfig(
+          designWidth: 720,
+          designHeight: 720,
+          scaleMode: RuntimeScaleMode.fill,
+        ),
+      );
+
+      expect(transform.x, 0);
+      expect(transform.y, -280);
+      expect(transform.width, 1280);
+      expect(transform.height, 1280);
+      expect(transform.scaleX, closeTo(1.777777, 0.00001));
+      expect(transform.scaleY, closeTo(1.777777, 0.00001));
+    });
+
+    test('stretches design independently on both axes', () {
+      final transform = RuntimeViewport.compute(
+        screenSize: Vector2(1440, 720),
+        config: const RuntimeViewportConfig(
+          designWidth: 720,
+          designHeight: 720,
+          scaleMode: RuntimeScaleMode.stretch,
+        ),
+      );
+
+      expect(transform.x, 0);
+      expect(transform.y, 0);
+      expect(transform.width, 1440);
+      expect(transform.height, 720);
+      expect(transform.scaleX, 2);
+      expect(transform.scaleY, 1);
+    });
+
+    test('centers design without scaling', () {
+      final transform = RuntimeViewport.compute(
+        screenSize: Vector2(1000, 800),
+        config: const RuntimeViewportConfig(
+          designWidth: 720,
+          designHeight: 720,
+          scaleMode: RuntimeScaleMode.none,
+        ),
+      );
+
+      expect(transform.x, 140);
+      expect(transform.y, 40);
+      expect(transform.width, 720);
+      expect(transform.height, 720);
+      expect(transform.scaleX, 1);
+      expect(transform.scaleY, 1);
+    });
+
+    test('applies transform to root component', () {
+      final root = PositionComponent();
+      RuntimeViewport.apply(
+        root,
+        const RuntimeViewportTransform(
+          x: 10,
+          y: 20,
+          width: 300,
+          height: 400,
+          scaleX: 2,
+          scaleY: 3,
+          scaleMode: RuntimeScaleMode.stretch,
+        ),
+      );
+
+      expect(root.position, Vector2(10, 20));
+      expect(root.size, Vector2(300, 400));
+      expect(root.scale, Vector2(2, 3));
+    });
+  });
+}