changes

lib/domain/models/effects/custom_pen_effect.dart

@@ -0,0 +1,71 @@
+import 'dart:ui';
+import 'dart:math' as math;
+
+import 'package:doddle/domain/models/effects/pen_effect.dart';
+
+class CustomPenEffect extends PenEffect {
+  final _random = math.Random();
+  
+  // Map to store effect data for each point
+  Map<int, List<_PointEffect>> _pointEffects = {};
+
+  @override
+  void paint(Canvas canvas, Path path, Paint paint) {
+    // Extract points from path by computing path metrics
+    final metrics = path.computeMetrics();
+    for (var metric in metrics) {
+      final length = metric.length;
+      final numPoints = (length / 5).ceil(); // Sample points every 5 pixels
+      
+      for (var i = 0; i < numPoints; i++) {
+        final distance = (i * length) / (numPoints - 1);
+        final pos = metric.getTangentForOffset(distance)?.position;
+        
+        if (pos != null) {
+            _pointEffects[i] = List.generate(3, (_) => _PointEffect(
+              jitter: Offset(
+                _random.nextDouble() * 10 - 5,
+                _random.nextDouble() * 10 - 5
+              ),
+              opacity: 0.3,
+              strokeWidth: drawController.penSize! * 0.5
+            ));
+          
+          // Draw dots using stored effects
+          for (var effect in _pointEffects[i]!) {
+            canvas.drawCircle(
+              pos.translate(effect.jitter.dx, effect.jitter.dy),
+              effect.strokeWidth,
+              Paint()
+                ..color = drawController.currentColor.withOpacity(effect.opacity)
+                ..style = PaintingStyle.fill
+            );
+          }
+        }
+      }
+    }
+
+    // Draw original path with reduced opacity
+    canvas.drawPath(
+      path,
+      Paint()
+        ..color = drawController.currentColor.withOpacity(0.5)
+        ..strokeWidth = drawController.penSize! * 0.8
+        ..strokeCap = StrokeCap.round
+        ..style = PaintingStyle.stroke
+    );
+  }
+}
+
+// Class to store effect data for each point
+class _PointEffect {
+  final Offset jitter;
+  final double opacity;
+  final double strokeWidth;
+
+  _PointEffect({
+    required this.jitter,
+    required this.opacity, 
+    required this.strokeWidth
+  });
+}

lib/domain/models/effects/glow_with_dots_effect.dart

@@ -8,7 +8,8 @@ class GlowWithDotsEffect extends PenEffect {
 
     final pathWithDots = dashPath(  
           path,
-          dashArray: CircularIntervalList<double>(<double>[5, 10]), // Changed to create 5px dashes with 10px gaps
+          dashArray: CircularIntervalList<double>(<double>[5
+          , 10]), // Changed to create 5px dashes with 10px gaps
         );
 
     canvas.drawPath(

lib/presentation/common/widgets/tools/brush_tool_grid.dart

@@ -16,6 +16,7 @@ class BrushToolGrid extends ConsumerWidget {
       BrushTool(penTool: PenTool.glowWithDotsPen, picture: Assets.svg.pen5Preview.svg()),
       BrushTool(penTool: PenTool.normalWithShaderPen, picture: Assets.svg.pen6Preview.svg()),
       BrushTool(penTool: PenTool.sprayPen, picture: Assets.svg.pen3Preview.svg()),
+      BrushTool(penTool: PenTool.customPen, picture: Assets.svg.pen4Preview.svg()),
     ];
 
     final selectedPenTool = ref.watch(canvasProvider).penTool;

lib/presentation/painting/sketcher.dart

@@ -1,4 +1,5 @@
 import 'package:doddle/domain/models/draw_controller.dart';
+import 'package:doddle/domain/models/effects/custom_pen_effect.dart';
 import 'package:doddle/domain/models/effects/eraser_effect.dart';
 import 'package:doddle/domain/models/effects/glow_effect.dart';
 import 'package:doddle/domain/models/effects/glow_with_dots_effect.dart';
@@ -21,6 +22,7 @@ class Sketcher extends CustomPainter {
 
   
   Sketcher(this.controller, this.ref) : _effects = {
+    PenTool.customPen: CustomPenEffect()..initialize(ref),
     PenTool.eraserPen: EraserEffect()..initialize(ref),
     PenTool.sprayPen: SprayEffect()..initialize(ref),
     PenTool.glowPen: GlowEffect()..initialize(ref),