cup_edit/examples/flutter/animations/lib/model_viewer.dart

import 'dart:convert';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:path/path.dart' as p;
import 'package:path_provider/path_provider.dart';
import 'package:thermion_flutter/thermion_flutter.dart';

class LocalModelViewer extends StatefulWidget {
  @override
  _LocalModelViewerState createState() => _LocalModelViewerState();
}

class _LocalModelViewerState extends State<LocalModelViewer> {
  ThermionViewer? _viewer;
  ThermionAsset? _asset;
  bool _isLoading = true;
  bool _hasError = false;
  String _statusMessage = "初始化中...";

  @override
  void initState() {
    super.initState();
    ThermionFlutterPlugin.createViewer().then((viewer) async {
      _viewer = viewer;
      _loadLocalModel(); // 在 viewer 初始化之后再加载模型
    });
  }

  Future<void> _loadLocalModel() async {
    try {
      setState(() {
        _isLoading = true;
        _statusMessage = "获取本地模型路径...";
      });

      final supportDir = await getApplicationSupportDirectory();
      final modelDir = p.join(supportDir.path, 'cup');
      final modelPath = p.join(modelDir, 'model.gltf');
      final modelFile = File(modelPath);

      if (await modelFile.exists()) {
        // 检查二进制文件
        final binPath = p.join(modelDir, 'model.bin');
        final binFile = File(binPath);
        if (!await binFile.exists()) {
          throw Exception("二进制文件不存在: $binPath");
        }

        // 检查文件大小
        final binSize = await binFile.length();
        if (binSize == 0) {
          throw Exception("二进制文件为空");
        }

        // 检查纹理文件
        final texturePath = p.join(modelDir, 'texture.jpg');
        final textureFile = File(texturePath);
        if (!await textureFile.exists()) {
          throw Exception("纹理文件不存在: $texturePath");
        }

        setState(() {
          _statusMessage = "读取和修改模型数据...";
        });

        // 读取GLTF文件内容
        String gltfContent = await modelFile.readAsString();

        // 修改纹理路径（去掉"./"前缀）
        gltfContent = gltfContent.replaceAll('"./texture.jpg"', '"new.jpg"');

        // 转换为字节数组
        Uint8List gltfBytes = Uint8List.fromList(utf8.encode(gltfContent));

        // 使用绝对路径作为资源URI
        final resourceUri = "file://${Directory(modelDir).absolute.path}";

        setState(() {
          _statusMessage = "加载模型中...";
        });

        final asset = await _viewer?.loadGltfFromBuffer(
          gltfBytes,
          resourceUri: resourceUri,
          addToScene: true,
        );

        setState(() {
          _asset = asset;
          _isLoading = false;
          _statusMessage = "模型加载完成";
        });
      } else {
        setState(() {
          _isLoading = false;
          _statusMessage = "本地模型文件不存在";
        });
      }
    } catch (e) {
      print('加载本地模型失败: $e');
      setState(() {
        _isLoading = false;
        _hasError = true;
        _statusMessage = "加载失败: $e";
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_isLoading) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CircularProgressIndicator(),
            SizedBox(height: 16),
            Text(_statusMessage),
          ],
        ),
      );
    }

    if (_hasError || _viewer == null) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.error_outline, color: Colors.red, size: 48),
            SizedBox(height: 16),
            Text("加载3D模型失败"),
            Text(_statusMessage, style: TextStyle(color: Colors.red)),
            SizedBox(height: 16),
            ElevatedButton(
              onPressed: _loadLocalModel,
              child: Text("重试"),
            ),
          ],
        ),
      );
    }

    return Scaffold(
      appBar: AppBar(
        title: const Text('本地模型查看'),
      ),
      body: ThermionListenerWidget(
        inputHandler: DelegateInputHandler.fixedOrbit(_viewer!),
        child: ThermionWidget(
          viewer: _viewer!,
          showFpsCounter: true, // 可选：显示FPS计数器
        ),
      ),
    );

    // 使用ThermionWidget显示3D内容
    return ThermionListenerWidget(
      inputHandler: DelegateInputHandler.fixedOrbit(_viewer!),
      child: ThermionWidget(
        viewer: _viewer!,
        showFpsCounter: true, // 可选：显示FPS计数器
      ),
    );
  }

  Future<void> deleteModelFile() async {
    // 获取应用支持目录
    final supportDir = await getApplicationSupportDirectory();

    // 构建 model.gltf 的完整路径
    final modelFile = File(p.join(supportDir.path, 'cup', 'model.gltf'));

    // 检查文件是否存在，然后删除
    if (await modelFile.exists()) {
      await modelFile.delete();
      print('model.gltf 已删除');
    } else {
      print('model.gltf 文件不存在');
    }
  }

  @override
  void dispose() {
    // deleteModelFile();
    // 清理资源
    _viewer?.dispose();
    super.dispose();
  }
}