feat: Add GLSL effects toggle and enhance shader for CRT-like post-processing

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

packages/wolf_3d_renderer/lib/wolf_3d_glsl_renderer.dart

@@ -11,12 +11,16 @@ import 'package:wolf_3d_renderer/wolf_3d_asset_painter.dart';
 
 /// Displays software-rendered frames through a GLSL post-processing pass.
 class WolfGlslRenderer extends BaseWolfRenderer {
+  /// Whether CRT-like post effects are enabled in the shader pass.
+  final bool effectsEnabled;
+
   /// Callback when shader loading fails and software fallback should be used.
   final VoidCallback? onUnavailable;
 
   /// Creates a GLSL renderer bound to [engine].
   const WolfGlslRenderer({
     required super.engine,
+    this.effectsEnabled = false,
     super.onKeyEvent,
     this.onUnavailable,
     super.key,
@@ -113,6 +117,8 @@ class _WolfGlslRendererState extends BaseWolfRendererState<WolfGlslRenderer> {
           painter: _GlslFramePainter(
             frame: _renderedFrame!,
             shader: _shader!,
+            effectsEnabled: widget.effectsEnabled,
+            elapsedSeconds: widget.engine.timeAliveMs / 1000.0,
           ),
           child: const SizedBox.expand(),
         ),
@@ -152,10 +158,14 @@ class _WolfGlslRendererState extends BaseWolfRendererState<WolfGlslRenderer> {
 class _GlslFramePainter extends CustomPainter {
   final ui.Image frame;
   final ui.FragmentShader shader;
+  final bool effectsEnabled;
+  final double elapsedSeconds;
 
   _GlslFramePainter({
     required this.frame,
     required this.shader,
+    required this.effectsEnabled,
+    required this.elapsedSeconds,
   });
 
   @override
@@ -167,6 +177,8 @@ class _GlslFramePainter extends CustomPainter {
       ..setFloat(1, size.height)
       ..setFloat(2, texelX)
       ..setFloat(3, texelY)
+      ..setFloat(4, effectsEnabled ? 1.0 : 0.0)
+      ..setFloat(5, elapsedSeconds)
       ..setImageSampler(0, frame);
 
     final Paint paint = Paint()
@@ -178,6 +190,9 @@ class _GlslFramePainter extends CustomPainter {
 
   @override
   bool shouldRepaint(covariant _GlslFramePainter oldDelegate) {
-    return oldDelegate.frame != frame || oldDelegate.shader != shader;
+    return oldDelegate.frame != frame ||
+        oldDelegate.shader != shader ||
+        oldDelegate.effectsEnabled != effectsEnabled ||
+        oldDelegate.elapsedSeconds != elapsedSeconds;
   }
 }