variable_blur 0.0.3

A Flutter package that provides customizable blur effects including tilt-shift blur for creating depth-of-field and variable blur effects in your Flutter applications.

Variable Blur

A Flutter package that provides customizable blur effects including tilt-shift blur for creating depth-of-field and variable blur effects in your Flutter applications.

Features

• Variable Blur Effects: Apply blur effects with different intensities on different sides of a widget
• Tilt-Shift Blur: Create professional depth-of-field effects similar to tilt-shift photography
• Customizable Blur Sides: Control blur intensity independently on top, bottom, left, and right sides
• Performance Optimized: Uses GPU shaders for smooth, high-performance blur rendering
• Color Tinting: Add custom color tints to blur effects
• Quality Control: Adjustable quality settings for performance optimization

Getting started

Add this package to your pubspec.yaml:

dependencies:
  variable_blur: ^0.0.1

Then run:

flutter pub get

Import the package in your Dart code:

import 'package:variable_blur/variable_blur.dart';

Usage

Basic Variable Blur

Wrap any widget with VariableBlur to apply customizable blur effects:

VariableBlur(
  sigma: 5.0,
  blurSides: BlurSides.horizontal(left: 1.0, right: 1.0),
  child: Container(
    width: 200,
    height: 200,
    decoration: BoxDecoration(
      image: DecorationImage(
        image: AssetImage('assets/your_image.jpg'),
        fit: BoxFit.cover,
      ),
    ),
  ),
)

Tilt-Shift Photography Effect

Create a tilt-shift blur effect for depth-of-field photography:

VariableBlur(
  sigma: 8.0,
  blurSides: BlurSides.vertical(top: 1.0, bottom: 1.0),
  quality: BlurQuality.high,
  child: Image.asset('assets/landscape.jpg'),
)

Dynamic Scroll-Based Blur

Create dynamic blur effects that respond to user interactions:

class ScrollBlurExample extends StatefulWidget {
  @override
  _ScrollBlurExampleState createState() => _ScrollBlurExampleState();
}

class _ScrollBlurExampleState extends State<ScrollBlurExample> {
  double blurSigma = 0.0;
  final ScrollController _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(_onScroll);
  }

  void _onScroll() {
    const maxBlur = 8.0;
    const scrollThreshold = 200.0;

    setState(() {
      blurSigma = maxBlur * (_scrollController.offset / scrollThreshold).clamp(0.0, 1.0);
    });
  }

  @override
  Widget build(BuildContext context) {
    return CustomScrollView(
      controller: _scrollController,
      slivers: [
        SliverAppBar(
          expandedHeight: 300,
          flexibleSpace: VariableBlur(
            sigma: blurSigma,
            blurSides: BlurSides.vertical(bottom: 1.0),
            child: FlexibleSpaceBar(
              background: Image.asset('assets/header_image.jpg', fit: BoxFit.cover),
            ),
          ),
        ),
        // Your scrollable content here
      ],
    );
  }
}

Blur Sides Configuration

Control blur intensity on different sides:

// Horizontal blur only
BlurSides.horizontal(left: 0.5, right: 0.8)

// Vertical blur only
BlurSides.vertical(top: 1.0, bottom: 0.3)

// Custom configuration for all sides
BlurSides._(top: 0.2, bottom: 0.8, left: 0.0, right: 1.0)

API Reference

VariableBlur

The main widget for applying variable blur effects.

Parameter	Type	Default	Description
child	Widget	required	The widget to apply blur effects to
sigma	double	required	The blur intensity (0.0 = no blur, higher = more blur)
blurSides	BlurSides	required	Configuration for which sides to blur
quality	BlurQuality	BlurQuality.high	Quality setting for performance optimization

BlurSides

Configuration class for controlling blur on different sides.

Constructors

• BlurSides.horizontal({double left, double right}) - Apply blur horizontally
• BlurSides.vertical({double top, double bottom}) - Apply blur vertically
• BlurSides._({double top, double bottom, double left, double right}) - Custom configuration

BlurQuality

Enum for controlling blur quality vs performance:

• BlurQuality.low - Faster rendering, lower quality
• BlurQuality.medium - Balanced quality and performance
• BlurQuality.high - Best quality, slower rendering

Performance Tips

1. Use appropriate quality settings: Lower quality settings for animations, higher for static effects
2. Limit blur sigma values: Very high sigma values (>15) can impact performance
3. Consider widget tree placement: Apply blur as close to the target widget as possible
4. Cache blur effects: For static content, consider using RepaintBoundary

Examples

The package includes several examples in the /example folder:

• Basic variable blur effects
• Tilt-shift photography simulation
• Scroll-responsive blur backgrounds
• Performance optimization techniques

Run the example app:

cd example
flutter run