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Flutter-menyadari efek tabrakan bola fisik

2024-07-12

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Memengaruhi

Masukkan deskripsi gambar di sini

perkenalan

Menerapkan efek animasi fisik dalam aplikasi Flutter dapat meningkatkan pengalaman pengguna secara signifikan.Artikel ini akan memperkenalkan secara detail cara membuat antarmuka bola animasi yang mensimulasikan tabrakan fisik di Flutter. Implementasi kode utama didasarkan pada integrasisensors_plusPlug-in untuk mendapatkan data sensor akselerasi perangkat.

Persiapan

Sebelum Anda mulai, pastikan Andapubspec.yamlTambahkan ke berkassensors_plusPengaya:

dependencies:
  flutter:
    sdk: flutter
  sensors_plus: 4.0.2

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lalu lariflutter pub getperintah untuk mendapatkan dependensi.

Struktur kode

Kami akan menerapkan program yang disebutPhysicsBallWidgetWidget khusus terutama mencakup bagian-bagian berikut:

  • Kelas bola: mewakili informasi dasar setiap bola.
  • Kelas BadgeBallConfig: mengelola status dan perilaku setiap bola.
  • Kelas PhysicsBallWidget: komponen utama, termasuk logika dan animasi bola.
  • Kelas BallItemWidget: khusus menampilkan widget untuk setiap bola.
  • Kelas BallListPage: halaman pengujian, menampilkan efek animasi bola fisik.

Kelas bola

Definisikan duluBallKelas digunakan untuk mewakili informasi dasar tentang setiap bola, seperti nama:

class Ball {
  final String name;

  Ball({required this.name});
}

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Kelas BadgeBallConfig

BadgeBallConfigKelas digunakan untuk mengatur status dan perilaku setiap bola, termasuk akselerasi, kecepatan, posisi, dan informasi lainnya:

class BadgeBallConfig {
  final Acceleration _acceleration = Acceleration(0, 0);
  final double time = 0.02;
  late Function(Offset) collusionCallback;
  Size size = const Size(100, 100);
  Speed _speed = Speed(0, 0);
  late Offset _position;
  late String name;
  double oppositeAccelerationCoefficient = 0.7;

  void setPosition(Offset offset) {
    _position = offset;
  }

  void setInitSpeed(Speed speed) {
    _speed = speed;
  }

  void setOppositeSpeed(bool x, bool y) {
    if (x) {
      _speed.x = -_speed.x * oppositeAccelerationCoefficient;
      if (_speed.x.abs() < 5) _speed.x = 0;
    }
    if (y) {
      _speed.y = -_speed.y * oppositeAccelerationCoefficient;
      if (_speed.y.abs() < 5) _speed.y = 0;
    }
  }

  void setAcceleration(double x, double y) {
    _acceleration.x = x * oppositeAccelerationCoefficient;
    _acceleration.y = y * oppositeAccelerationCoefficient;
  }

  Speed getCurrentSpeed() => _speed;

  Offset getCurrentCenter() => Offset(
    _position.dx + size.width / 2,
    _position.dy + size.height / 2,
  );

  Offset getCurrentPosition() => _position;

  void inertiaStart(double x, double y) {
    if (x.abs() > _acceleration.x.abs()) _speed.x += x;
    if (y.abs() > _acceleration.y.abs()) _speed.y += y;
  }

  void afterCollusion(Offset offset, Speed speed) {
    _speed = Speed(
      speed.x * oppositeAccelerationCoefficient,
      speed.y * oppositeAccelerationCoefficient,
    );
    _position = offset;
    collusionCallback(offset);
  }

  Offset getOffset() {
    var offsetX = (_acceleration.x.abs() < 5 && _speed.x.abs() < 3) ? 0.0 : _speed.x * time + (_acceleration.x * time * time) / 2;
    var offsetY = (_acceleration.y.abs() < 5 && _speed.y.abs() < 6) ? 0.0 : _speed.y * time + (_acceleration.y * time * time) / 2;

    _position = Offset(_position.dx + offsetX, _position.dy + offsetY);

    _speed = Speed(
      _speed.x + _acceleration.x * time,
      _speed.y + _acceleration.y * time,
    );

    return _position;
  }
}

class Speed {
  double x;
  double y;

  Speed(this.x, this.y);
}

class Acceleration {
  double x;
  double y;

  Acceleration(this.x, this.y);
}

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Kelas FisikaBallWidget

PhysicsBallWidgetKelas merupakan komponen utama dan bertanggung jawab menangani logika dan animasi bola:

import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:flutter_xy/application.dart';
import 'package:flutter_xy/xydemo/ball/ball_model.dart';
import 'package:sensors_plus/sensors_plus.dart';
//https://github.com/yixiaolunhui/flutter_xy
class PhysicsBallWidget extends StatefulWidget {
  final List<Ball> ballList;
  final double height;
  final double width;

  const PhysicsBallWidget({
    required this.ballList,
    required this.width,
    required this.height,
    Key? key,
  }) : super(key: key);

  @override
  State<StatefulWidget> createState() => _PhysicsBallState();
}

class _PhysicsBallState extends State<PhysicsBallWidget> {
  List<Widget> badgeBallList = [];
  List<ValueKey<BadgeBallConfig>> keyList = [];
  late Size ballSize;

  @override
  void initState() {
    super.initState();
    fillKeyList();
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
      App.get().addPersistentFrameCallback(travelHitMap);
    });
  }

  @override
  void dispose() {
    App.get().removePersistentFrameCallback(travelHitMap);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    fillWidgetList();
    return Stack(
      children: badgeBallList,
    );
  }

  void fillKeyList() {
    var badgeSize = (widget.width - 20) / 6;
    badgeSize = (badgeSize >= 84.0 || badgeSize <= 0.0 || !badgeSize.isFinite)
        ? 84.0
        : badgeSize;
    var maxCount = ((widget.height - badgeSize) ~/ badgeSize) *
        (widget.width ~/ badgeSize);
    if (widget.ballList.length >= maxCount) {
      badgeSize = 50.0;
    }
    ballSize = Size(badgeSize, badgeSize);
    var initOffsetX = 0.0;
    var initOffsetY = widget.height - badgeSize;
    for (var element in widget.ballList) {
      keyList.add(ValueKey<BadgeBallConfig>(
        BadgeBallConfig()
          ..size = ballSize
          ..name = element.name
          ..setPosition(Offset(initOffsetX, initOffsetY)),
      ));
      initOffsetX += badgeSize;
      if (initOffsetX + badgeSize > widget.width - 20) {
        initOffsetX = 0;
        initOffsetY -= badgeSize;
      }
    }
  }

  void fillWidgetList() {
    badgeBallList.clear();
    for (var e in keyList) {
      badgeBallList.add(
        BallItemWidget(
          key: e,
          limitWidth: widget.width,
          limitHeight: widget.height,
          onTap: () {},
        ),
      );
    }
  }

  void travelHitMap(Duration timeStamp) {
    for (var i = 0; i < keyList.length - 1; i++) {
      for (var j = i + 1; j < keyList.length; j++) {
        hit(keyList[i].value, keyList[j].value);
      }
    }
  }

  void hit(BadgeBallConfig a, BadgeBallConfig b) {
    final distance = a.size.height / 2 + b.size.height / 2;
    final w = b.getCurrentCenter().dx - a.getCurrentCenter().dx;
    final h = b.getCurrentCenter().dy - a.getCurrentCenter().dy;

    if (sqrt(w * w + h * h) <= distance) {
      var aOriginSpeed = a.getCurrentSpeed();
      var bOriginSpeed = b.getCurrentSpeed();
      var aOffset = a.getCurrentPosition();

      var angle = atan2(h, w);
      var sinNum = sin(angle);
      var cosNum = cos(angle);

      var aCenter = [0.0, 0.0];
      var bCenter = coordinateTranslate(w, h, sinNum, cosNum, true);

      var aSpeed = coordinateTranslate(
          aOriginSpeed.x, aOriginSpeed.y, sinNum, cosNum, true);
      var bSpeed = coordinateTranslate(
          bOriginSpeed.x, bOriginSpeed.y, sinNum, cosNum, true);

      var vxTotal = aSpeed[0] - bSpeed[0];
      aSpeed[0] = (2 * 10 * bSpeed[0]) / 20;
      bSpeed[0] = vxTotal + aSpeed[0];

      var overlap = distance - (aCenter[0] - bCenter[0]).abs();
      aCenter[0] -= overlap;
      bCenter[0] += overlap;

      var aRotatePos =
          coordinateTranslate(aCenter[0], aCenter[1], sinNum, cosNum, false);
      var bRotatePos =
          coordinateTranslate(bCenter[0], bCenter[1], sinNum, cosNum, false);

      var bOffset

X = aOffset.dx + bRotatePos[0];
      var bOffsetY = aOffset.dy + bRotatePos[1];
      var aOffsetX = aOffset.dx + aRotatePos[0];
      var aOffsetY = aOffset.dy + aRotatePos[1];

      var aSpeedF =
          coordinateTranslate(aSpeed[0], aSpeed[1], sinNum, cosNum, false);
      var bSpeedF =
          coordinateTranslate(bSpeed[0], bSpeed[1], sinNum, cosNum, false);

      a.afterCollusion(
          Offset(aOffsetX, aOffsetY), Speed(aSpeedF[0], aSpeedF[1]));
      b.afterCollusion(
          Offset(bOffsetX, bOffsetY), Speed(bSpeedF[0], bSpeedF[1]));
    }
  }

  List<double> coordinateTranslate(
      double x, double y, double sin, double cos, bool reverse) {
    return reverse
        ? [x * cos + y * sin, y * cos - x * sin]
        : [x * cos - y * sin, y * cos + x * sin];
  }
}

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KelasWidgetItemBola

BallItemWidgetKelas digunakan untuk secara khusus menampilkan setiap bola dan menangani animasi dan kejadiannya:

import 'dart:async';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:flutter_xy/application.dart';
import 'package:flutter_xy/xydemo/ball/ball_model.dart';
import 'package:sensors_plus/sensors_plus.dart';

class BallItemWidget extends StatefulWidget {
  final double limitWidth;
  final double limitHeight;
  final Function onTap;

  const BallItemWidget({
    required this.limitWidth,
    required this.limitHeight,
    required this.onTap,
    Key? key,
  }) : super(key: key);

  @override
  State<StatefulWidget> createState() => BallItemState();
}

class BallItemState extends State<BallItemWidget> {
  final List<StreamSubscription<dynamic>> _streamSubscriptions = [];
  late BadgeBallConfig config;
  Duration sensorInterval = SensorInterval.normalInterval;
  var color = Color.fromARGB(
    255,
    Random().nextInt(256),
    Random().nextInt(256),
    Random().nextInt(256),
  );

  Timer? timer;
  double x = 0;
  double y = 0;

  double limitY = 0;
  double limitX = 0;

  @override
  void initState() {
    super.initState();
    initData();
    _streamSubscriptions.add(
      accelerometerEvents.listen(
        (AccelerometerEvent event) {
          config.setAcceleration(
            -double.parse(event.x.toStringAsFixed(1)) * 50,
            double.parse(event.y.toStringAsFixed(1)) * 50,
          );
        },
      ),
    );
    _streamSubscriptions.add(
      userAccelerometerEvents.listen(
        (UserAccelerometerEvent event) {
          config.inertiaStart(
            double.parse(event.x.toStringAsFixed(1)) * 50,
            -double.parse(event.y.toStringAsFixed(1)) * 20,
          );
        },
      ),
    );
    timer = Timer.periodic(const Duration(milliseconds: 20), (timer) {
      if (!SchedulerBinding.instance.hasScheduledFrame) {
        SchedulerBinding.instance.scheduleFrame();
      }
    });

    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
      App.get().addPersistentFrameCallback(updatePosition);
    });
  }

  @override
  void dispose() {
    super.dispose();
    for (var subscription in _streamSubscriptions) {
      subscription.cancel();
    }
    App.get().removePersistentFrameCallback(updatePosition);
    timer?.cancel();
    timer = null;
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedPositioned(
      left: x,
      top: y,
      duration: const Duration(milliseconds: 16),
      child: GestureDetector(
        onTap: () {
          widget.onTap.call();
        },
        child: Container(
          width: config.size.width,
          alignment: Alignment.center,
          height: config.size.height,
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            border: Border.all(color: color, width: 2.w),
          ),
          child: Text(
            config.name,
            style: TextStyle(fontSize: 16.w, color: Colors.red),
          ),
        ),
      ),
    );
  }

  void initData() {
    limitX = widget.limitWidth;
    limitY = widget.limitHeight;
    config = (widget.key as ValueKey<BadgeBallConfig>).value;
    config.collusionCallback = (offset) {
      setState(() {
        x = offset.dx;
        y = offset.dy;
        config.setPosition(offset);
      });
    };
    x = config.getCurrentPosition().dx;
    y = config.getCurrentPosition().dy;
  }

  void updatePosition(Duration timeStamp) {
    setState(() {
      var tempX = config.getOffset().dx;
      var tempY = config.getOffset().dy;
      if (tempX < 0) {
        tempX = 0;
        config.setOppositeSpeed(true, false);
      }
      if (tempX > limitX - config.size.width) {
        tempX = limitX - config.size.width;
        config.setOppositeSpeed(true, false);
      }
      if (tempY < 0) {
        tempY = 0;
        config.setOppositeSpeed(false, true);
      }
      if (tempY > limitY - config.size.height) {
        tempY = limitY - config.size.height;
        config.setOppositeSpeed(false, true);
      }
      x = tempX;
      y = tempY;
      config.setPosition(Offset(x, y));
    });
  }
}

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kelas BallListPage

BallListPageKelas adalah halaman ujian, digunakan untuk menampilkan efek animasi bola fisik:

import 'package:flutter/material.dart';
import 'package:flutter_xy/xydemo/ball/ball_model.dart';
import 'package:flutter_xy/xydemo/ball/ball_widget.dart';

class BallListPage extends StatefulWidget {
  const BallListPage({super.key});

  @override
  State<BallListPage> createState() => _BallListPageState();
}

class _BallListPageState extends State<BallListPage> {
  final List<Ball> badgeList = [
    Ball(name: '北京'),
    Ball(name: '上海'),
    Ball(name: '天津'),
    Ball(name: '徐州'),
    Ball(name: '南京'),
    Ball(name: '苏州'),
    Ball(name: '杭州'),
    Ball(name: '合肥'),
    Ball(name: '武汉'),
    Ball(name: '常州'),
    Ball(name: '香港'),
    Ball(name: '澳门'),
    Ball(name: '新疆'),
    Ball(name: '成都'),
    Ball(name: '宿迁'),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          PhysicsBallWidget(
            ballList: badgeList,
            height: MediaQuery.of(context).size.height,
            width: MediaQuery.of(context).size.width,
          ),
        ],
      ),
    );
  }
}

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Kesimpulannya

Melalui blog ini, kami menunjukkan cara menerapkan efek animasi bola fisik di Flutter dan mengintegrasikannyasensors_plus Plug-in untuk mendapatkan data sensor akselerasi perangkat. Saya harap blog ini dapat membantu Anda mencapai efek serupa dalam pengembangan Flutter.
Untuk detailnya, lihat: github.com/yixiaolunhui/flutter_xy

Profil pribadi

Ia telah mengabdikan dirinya untuk meneliti teknologi selama lebih dari 30 tahun, dan mahir dalam berbagai bahasa seperti java, linux, javascript, php, css, dll. Ia telah memberikan banyak kontribusi di bidang open source stasiun dokumentasi pengembang untuk berbagi beberapa masalah dalam pengembangan teknologi untuk referensi di masa mendatang. Semua orang memeriksanya

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