diff --git a/dart/freeform-gradient/README.md b/dart/freeform-gradient/README.md index 5401909..50c0188 100644 --- a/dart/freeform-gradient/README.md +++ b/dart/freeform-gradient/README.md @@ -1,16 +1,10 @@ -# Hello World application with Flutter + Nix +# Flutter freeform gradiant This is a demonstration project to show usage of Flutter with Nix. ## Getting Started -If you have `direnv` installed, run: - -```sh -direnv allow -``` - -Otherwise, enter in the `nix-shell`: +Enter in the `nix-shell`: ```sh nix-shell @@ -29,49 +23,3 @@ flutter run ``` If you have any issue, you can run `flutter doctor` to get a diagnostic and potential solution to fix your issues. - -## How to use it with your projects - -Create a `shell.nix` file with this content: - -```nix -{ pkgs ? import {} }: - -let - flutter = (import (builtins.fetchTarball - "https://github.com/babariviere/nixpkgs/archive/flutter-init.tar.gz") {}).flutter; # this will be replaced when merged into NixOS -in pkgs.mkShell { - buildInputs = [ flutter ]; -} -``` - -After this, enter into your nix-shell and you are good to go. - -## Updating - -### To update the whole environment, do the following in order: - -- `niv init` will update nix/sources.nix if a new one is available -- Make sure you have a backup of your nix/sources.json. If you're not in a git repo or use another vcs: `cp nix/sources.json nix/sources.json.bak` -- `niv update` will update sources.json i.e. your version of nixpkgs used in this environment - - you may need to edit nix/android.nix if any of the attributes in there can't be found after this. -- `direnv reload` will rebuild/reload your environment (may not be necessary if it automatically reloads) - - alternatively, run `nix-shell` again (?) -- `flutter packages update` to update flutter/dart packages and get rid of the warning that you're using a different version of flutter than what was last referenced - -## Global install - -If you want to install `flutter` on your system, add this to your `/etc/nixos/configuration.nix`: - -```nix -{ - environment.systemPackages = [ - (import (builtins.fetchTarball - "https://github.com/babariviere/nixpkgs/archive/flutter-init.tar.gz") {}).flutter - ]; -} -``` - -## Have an issue ? - -Create an issue on this repository with your issue and I will try to help you as much as I can ! diff --git a/dart/freeform-gradient/lib/main.dart b/dart/freeform-gradient/lib/main.dart index 5a7af45..807a6ab 100644 --- a/dart/freeform-gradient/lib/main.dart +++ b/dart/freeform-gradient/lib/main.dart @@ -1,111 +1,212 @@ +import 'dart:math'; + import 'package:flutter/material.dart'; +import 'dart:ui' as ui; +import 'dart:async'; +import 'dart:typed_data'; +import 'package:vector_math/vector_math.dart' as vector; -void main() => runApp(MyApp()); +void main() => runApp(Root()); -class MyApp extends StatelessWidget { - // This widget is the root of your application. - @override - Widget build(BuildContext context) { - return MaterialApp( - title: 'Flutter Demo', - theme: ThemeData( - // This is the theme of your application. - // - // Try running your application with "flutter run". You'll see the - // application has a blue toolbar. Then, without quitting the app, try - // changing the primarySwatch below to Colors.green and then invoke - // "hot reload" (press "r" in the console where you ran "flutter run", - // or simply save your changes to "hot reload" in a Flutter IDE). - // Notice that the counter didn't reset back to zero; the application - // is not restarted. - primarySwatch: Colors.blue, - ), - home: MyHomePage(title: 'Flutter Demo Home Page'), - ); - } -} - -class MyHomePage extends StatefulWidget { - MyHomePage({Key key, this.title}) : super(key: key); - - // This widget is the home page of your application. It is stateful, meaning - // that it has a State object (defined below) that contains fields that affect - // how it looks. - - // This class is the configuration for the state. It holds the values (in this - // case the title) provided by the parent (in this case the App widget) and - // used by the build method of the State. Fields in a Widget subclass are - // always marked "final". - - final String title; +class Root extends StatefulWidget { + const Root({ + Key key, + }) : super(key: key); @override - _MyHomePageState createState() => _MyHomePageState(); + RootState createState() => RootState(); } -class _MyHomePageState extends State { - int _counter = 0; +class RootState extends State { + double angle = 0; - void _incrementCounter() { - setState(() { - // This call to setState tells the Flutter framework that something has - // changed in this State, which causes it to rerun the build method below - // so that the display can reflect the updated values. If we changed - // _counter without calling setState(), then the build method would not be - // called again, and so nothing would appear to happen. - _counter++; + @override + initState() { + super.initState(); + + Timer.periodic(Duration(milliseconds: 10), (timer) { + setState(() { + angle += 0.04; + }); }); } @override Widget build(BuildContext context) { - // This method is rerun every time setState is called, for instance as done - // by the _incrementCounter method above. - // - // The Flutter framework has been optimized to make rerunning build methods - // fast, so that you can just rebuild anything that needs updating rather - // than having to individually change instances of widgets. - return Scaffold( - appBar: AppBar( - // Here we take the value from the MyHomePage object that was created by - // the App.build method, and use it to set our appbar title. - title: Text(widget.title), + return MaterialApp( + title: 'Custom gradient', + theme: ThemeData( + primarySwatch: Colors.purple, ), - body: Center( - // Center is a layout widget. It takes a single child and positions it - // in the middle of the parent. - child: Column( - // Column is also a layout widget. It takes a list of children and - // arranges them vertically. By default, it sizes itself to fit its - // children horizontally, and tries to be as tall as its parent. - // - // Invoke "debug painting" (press "p" in the console, choose the - // "Toggle Debug Paint" action from the Flutter Inspector in Android - // Studio, or the "Toggle Debug Paint" command in Visual Studio Code) - // to see the wireframe for each widget. - // - // Column has various properties to control how it sizes itself and - // how it positions its children. Here we use mainAxisAlignment to - // center the children vertically; the main axis here is the vertical - // axis because Columns are vertical (the cross axis would be - // horizontal). - mainAxisAlignment: MainAxisAlignment.center, - children: [ - Text( - 'You have pushed the button this many times:', - ), - Text( - '$_counter', - style: Theme.of(context).textTheme.display1, - ), - ], - ), - ), - floatingActionButton: FloatingActionButton( - onPressed: _incrementCounter, - tooltip: 'Increment', - child: Icon(Icons.add), - ), // This trailing comma makes auto-formatting nicer for build methods. + home: MyHomePage( + title: 'Multi point gradient', + config: MultiGradientConfig( + distanceScaling: 1, + blendStrength: 2, + points: [ + MultiGradientPoint( + color: Colors.yellow, + intensity: 1.0, + position: vector.Vector2( + 1.0 / 2 + cos(angle) * 0.3, 1.0 / 2 + sin(angle) * 0.3), + ), + MultiGradientPoint( + color: Color(0xff6E10AB), + intensity: 1, + position: vector.Vector2(0.1, 0.09)), + MultiGradientPoint( + color: Color(0xff041E1C), + intensity: 2, + position: vector.Vector2(0.84, 0.14)), + MultiGradientPoint( + color: Color(0xff015BBB), + intensity: 1, + position: vector.Vector2(0.07, 0.93)), + MultiGradientPoint( + color: Color(0xff06A599), + intensity: 1, + position: vector.Vector2(0.9, 0.94)) + ])), ); } } + +class MyHomePage extends StatelessWidget { + MyHomePage({Key key, this.title, this.config}) : super(key: key); + + final String title; + final MultiGradientConfig config; + + @override + Widget build(BuildContext context) { + return Scaffold( + appBar: AppBar( + title: Text(title), + ), + body: Center( + child: FutureBuilder( + future: generateImage(MediaQuery.of(context).size, config), + builder: (context, snapshot) { + if (snapshot.hasData) { + MediaQueryData query = MediaQuery.of(context); + return CustomPaint( + child: Container( + width: query.size.width, + height: query.size.height, + ), + painter: ImagePainter(image: snapshot.data)); + } + + return Text("Generating image"); + }, + )), + ); + } +} + +class ImagePainter extends CustomPainter { + ui.Image image; + + ImagePainter({this.image}); + + @override + void paint(Canvas canvas, Size size) { + canvas.drawImage(image, Offset.zero, Paint()); + } + + @override + bool shouldRepaint(ImagePainter oldDelegate) { + return oldDelegate.image != image; + } +} + +/// Generates a [ui.Image] with certain pixel data +Future generateImage(Size size, MultiGradientConfig config) async { + int width = size.width.ceil(); + int height = size.height.ceil(); + var completer = Completer(); + + Int32List pixels = Int32List(width * height); + + for (var x = 0; x < width; x++) { + for (var y = 0; y < height; y++) { + int index = y * width + x; + pixels[index] = generatePixel(x, y, size, config); + } + } + + ui.decodeImageFromPixels( + pixels.buffer.asUint8List(), + width, + height, + ui.PixelFormat.bgra8888, + (ui.Image img) { + completer.complete(img); + }, + ); + + return completer.future; +} + +class MultiGradientPoint { + double intensity; + vector.Vector4 color; + vector.Vector2 position; + + MultiGradientPoint({Color color, this.position, this.intensity = 1}) { + this.color = vector.Vector4(color.red.toDouble(), color.green.toDouble(), + color.blue.toDouble(), color.opacity); + } +} + +class MultiGradientConfig { + List points; + + double distanceScaling; + double blendStrength; + double opacityMultiplier = 1; + + MultiGradientConfig( + {this.points, + this.distanceScaling = 1, + this.blendStrength = 3, + this.opacityMultiplier = 1}); +} + +double clamp(double min, double max, double value) { + if (value < min) return min; + if (value > max) return max; + + return value; +} + +/// Main area of interest, this function will +/// return color for each particular color on our [ui.Image] +int generatePixel(int x, int y, Size size, MultiGradientConfig config) { + vector.Vector4 color = vector.Vector4(0, 0, 0, 0); + double scale = 0; + + var current = vector.Vector2(x.toDouble(), y.toDouble()); + + current.divide(vector.Vector2(size.width, size.height)); + + for (var i = 0; i < config.points.length; i++) { + MultiGradientPoint point = config.points[i]; + + var distance = pow( + 1 - point.position.distanceTo(current) / config.distanceScaling, + config.blendStrength); + var multiplier = distance * point.intensity; + + scale += multiplier; + color += point.color.scaled(multiplier); + } + + if (scale != 0) { + color.scale(1 / scale); + } + + return Color.fromRGBO(color.x.toInt(), color.y.toInt(), color.z.toInt(), + color.w * config.opacityMultiplier) + .value; +} diff --git a/dart/freeform-gradient/pubspec.yaml b/dart/freeform-gradient/pubspec.yaml index 48efc2b..d7e0dea 100644 --- a/dart/freeform-gradient/pubspec.yaml +++ b/dart/freeform-gradient/pubspec.yaml @@ -1,16 +1,6 @@ name: hello_world description: A new Flutter project. -# The following defines the version and build number for your application. -# A version number is three numbers separated by dots, like 1.2.43 -# followed by an optional build number separated by a +. -# Both the version and the builder number may be overridden in flutter -# build by specifying --build-name and --build-number, respectively. -# In Android, build-name is used as versionName while build-number used as versionCode. -# Read more about Android versioning at https://developer.android.com/studio/publish/versioning -# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion. -# Read more about iOS versioning at -# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html version: 1.0.0+1 environment: @@ -20,21 +10,17 @@ dependencies: flutter: sdk: flutter - # The following adds the Cupertino Icons font to your application. - # Use with the CupertinoIcons class for iOS style icons. cupertino_icons: ^0.1.2 dev_dependencies: flutter_test: sdk: flutter - # For information on the generic Dart part of this file, see the # following page: https://dart.dev/tools/pub/pubspec # The following section is specific to Flutter. flutter: - # The following line ensures that the Material Icons font is # included with your application, so that you can use the icons in # the material Icons class. diff --git a/dart/freeform-gradient/test/widget_test.dart b/dart/freeform-gradient/test/widget_test.dart index c8b8280..5cbb846 100644 --- a/dart/freeform-gradient/test/widget_test.dart +++ b/dart/freeform-gradient/test/widget_test.dart @@ -13,7 +13,7 @@ import 'package:hello_world/main.dart'; void main() { testWidgets('Counter increments smoke test', (WidgetTester tester) async { // Build our app and trigger a frame. - await tester.pumpWidget(MyApp()); + await tester.pumpWidget(Root()); // Verify that our counter starts at 0. expect(find.text('0'), findsOneWidget);