luojigou_battle/packages/widget/lib/src/battle_path.dart

import 'dart:ui';

import 'constant.dart';

///本质是求五个点的位置，依次lineTo起来形成一条路径

Path fromBottomToCenter(Size size, int start, int end) {
  final path = Path();

  final double line = size.width * kButtonLineAspectRatio;

  final double l1 = size.width * kBottomButtonLeftAspectRatio;
  final double r1 = size.width * kBottomButtonRightAspectRatio;
  final double t1 = size.height * kBottomButtonTopAspectRatio;
  final double b1 = size.height * kBottomButtonBottomAspectRatio;

  final double l2 = size.width * kRightButtonLeftAspectRatio;
  final double r2 = size.width * kRightButtonRightAspectRatio;
  final double t2 = size.height * kRightButtonTopAspectRatio;
  final double b2 = size.height * kRightButtonBottomAspectRatio;

  final double cr = size.width * kRightButtonRightAspectRatio;
  final double cb = size.height * kBottomButtonTopAspectRatio;

  final double spacing1 = ((r1 - l1) - line * 6) / 5 + line;
  final double spacing2 = ((b2 - t2) - line * 6) / 5 + line;

  final double p1x = l1 + spacing1 * start + line / 2;
  final double p1y = b1 - line * 3 / 2;

  final double p2x = p1x;
  final double p2y = t1 + line / 2;

  final double p3x = r2 - line / 2;
  final double p3y = t2 + spacing2 * end + line / 2;

  final double p4x = l2 + line / 2;
  final double p4y = p3y;

  path.moveTo(p1x, p1y);
  path.lineTo(p2x, p2y);
  assert(cr - line / 2 == p3x);
  assert(p2y == cb + line / 2);
  path.lineTo(cr - line / 2, p2y);
  path.lineTo(p3x, cb + line / 2);
  path.lineTo(p3x, p3y);
  path.lineTo(p4x, p4y);

  return path;
}

double getButtonSize(Size size) {
  return kButtonAspectRatio * size.width;
}