JavaScript实现封闭区域布尔运算：多段线与曲线交点处理

核心算法与代码实现

function getOperatedCurves(sourceCurs: Curve[], targetCus: Curve[])
  {
    let source: Polyline | Circle = (sourceCurs[0] instanceof Circle) ? sourceCurs[0] as Circle : new Polyline().Combine(sourceCurs)[0];
    let target: Polyline | Circle = (targetCus[0] instanceof Circle) ? targetCus[0] as Circle : new Polyline().Combine(targetCus)[0];
    try
    {
      if (!source.IsClose || !target.IsClose) throw new Error("不是封闭曲线");
    }
    catch (err)
    {
      console.log(err);
    }

    let interPts = source.IntersectWith(target, IntersectOption.OnBothOperands);
    let sourceContainerTarget = isTargetCurInSourceCur(source, target);
    let targetContainerSource = isTargetCurInSourceCur(target, source);

    let isContainer = sourceContainerTarget || targetContainerSource;
    let intersectionList: Curve[] = []; //交集
    let unionList: Curve[] = []; //并集
    let subList: Curve[] = []; //补集

    /*
    *两封闭区域有交点并且不是包含关系,则通过交点把区域分割
    */
    if (interPts.length && !isContainer)
    {
      let pars1 = interPts.map(p => source.GetParamAtPoint(p)).sort((a, b) => a - b);
      let pars2 = interPts.map(p => target.GetParamAtPoint(p)).sort((a, b) => a - b);

      let cus1: Array<Polyline | Arc> = source.GetSplitCurves(pars1);

      cus1.forEach(pl =>
      {
        if (isTargetCurInSourceCur(target, pl))
        {
          intersectionList.push(pl);
        }
        else
        {
          subList.push(pl);
          unionList.push(pl);
        }
      })

      let cus2: Array<Polyline | Arc> = target.GetSplitCurves(pars2);
      cus2.forEach(pl =>
      {
        if (isTargetCurInSourceCur(source, pl))
        {
          intersectionList.push(pl);
          subList.push(pl);
        }
        else
        {
          unionList.push(pl);
        }
      })

    }
    else
    {
      if (isContainer)
      {
        if (sourceContainerTarget)
        {
          intersectionList.push(target);
          subList.push(source, target);
          unionList.push(source);
        }
        else
        {
          unionList.push(target);
          intersectionList.push(source);
        }
      }
      else
      {
        unionList.push(source, target)
        subList.push(source);
      }

    }
    return {
      intersectionList, unionList, subList
    }
  }