Fix ASCII rasterizer scaling for CLI

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

packages/wolf_3d_renderer/lib/wolf_3d_flutter_renderer.dart

@@ -26,22 +26,13 @@ class _WolfFlutterRendererState
   @override
   Color get scaffoldColor => const Color.fromARGB(255, 4, 64, 64);
 
-  @override
-  void dispose() {
-    _renderedFrame?.dispose();
-    super.dispose();
-  }
-
   @override
   void performRender() {
-    // Avoid overlapping render calls since decodeImageFromPixels is async
     if (_isRendering) return;
     _isRendering = true;
 
-    // 1. Rasterize the frame into the pixel buffer
     _rasterizer.render(widget.engine, _frameBuffer);
 
-    // 2. Convert raw pixels to a Flutter ui.Image
     ui.decodeImageFromPixels(
       _frameBuffer.pixels.buffer.asUint8List(),
       _frameBuffer.width,
@@ -61,13 +52,16 @@ class _WolfFlutterRendererState
 
   @override
   Widget buildViewport(BuildContext context) {
+    // If we don't have a frame yet, show the loading state
+    if (_renderedFrame == null) {
+      return const CircularProgressIndicator(color: Colors.white24);
+    }
+
     return Padding(
       padding: const EdgeInsets.all(16.0),
       child: AspectRatio(
         aspectRatio: 4 / 3,
-        child: CustomPaint(
-          painter: BufferPainter(_renderedFrame),
-        ),
+        child: CustomPaint(painter: BufferPainter(_renderedFrame)),
       ),
     );
   }