books

assets/draw/p07/s06.dart

@@ -0,0 +1,110 @@
+import 'dart:async';
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:image/image.dart' as image;
+
+import '../components/coordinate_pro.dart';
+
+/// create by 张风捷特烈 on 2020-03-19
+/// contact me by email 1981462002@qq.com
+/// 说明: 纸
+class Paper extends StatefulWidget {
+  const Paper({super.key});
+
+  @override
+  _PaperState createState() => _PaperState();
+}
+
+class _PaperState extends State<Paper> {
+  image.Image? _image;
+  List<Ball> balls = [];
+  double d = 20; //复刻的像素边长
+
+  @override
+  void initState() {
+    super.initState();
+    _initBalls();
+  }
+
+  void _initBalls() async {
+    _image = await loadImageFromAssets('assets/images/icon_head.png');
+    if (_image == null) return;
+    for (int i = 0; i < _image!.width; i++) {
+      for (int j = 0; j < _image!.height; j++) {
+        Ball ball = Ball();
+        ball.x = i * d + d / 2;
+        ball.y = j * d + d / 2;
+        ball.r = d / 2;
+        image.Pixel pixel = _image!.getPixel(i, j);
+        var color = Color.fromARGB(pixel.a.toInt(),pixel.r.toInt(),pixel.g.toInt(),pixel.b.toInt());
+        ball.color = color;
+        balls.add(ball);
+      }
+    }
+    setState(() {});
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+        color: Colors.white,
+        child: CustomPaint(
+          painter: PaperPainter(balls),
+        ));
+  }
+
+  //读取 assets 中的图片
+  Future<image.Image?> loadImageFromAssets(String path) async {
+    ByteData data = await rootBundle.load(path);
+    List<int> bytes = data.buffer.asUint8List();
+    return image.decodeImage(Uint8List.fromList(bytes));
+  }
+}
+
+class PaperPainter extends CustomPainter {
+  late Paint _paint;
+
+  final double strokeWidth = 0.5;
+  final Color color = Colors.blue;
+
+  final List<Ball> balls;
+  final Coordinate coordinate = Coordinate();
+
+  PaperPainter(this.balls) {
+    _paint = Paint()
+      ..style = PaintingStyle.fill
+      ..strokeWidth = strokeWidth
+      ..color = color;
+  }
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    coordinate.paint(canvas, size);
+    canvas.translate(-710, -1000);
+    _drawImage(canvas);
+  }
+
+  void _drawImage(Canvas canvas) {
+    balls.forEach((Ball ball) {
+      canvas.drawCircle(
+          Offset(ball.x, ball.y), ball.r, _paint..color = ball.color);
+    });
+  }
+
+
+  @override
+  bool shouldRepaint(PaperPainter oldDelegate) => true;
+
+}
+
+class Ball {
+  double x; //点位X
+  double y; //点位Y
+  Color color; //颜色
+  double r; // 半径
+
+  Ball({this.x=0, this.y=0, this.color=Colors.black, this.r=5});
+
+}