---
layout: default-layout
title: CLongLinesUnit Class
description: This page shows CLongLinesUnit class definition of Dynamsoft Document Normalizer SDK C++ Edition.
keywords: GetCount, GetLongLine, CLongLinesUnit, api reference
permalink: /programming/cplusplus/api-reference/long-lines-unit.html
---

# CLongLinesUnit Class

The `CLongLinesUnit` class represents an intermediate result unit whose type is long lines. Short line segments that are located in the same line are extended and merged to form a long line segment.

## Definition

*Namespace:* dynamsoft::ddn::intermediate_results

*Assembly:* DynamsoftDocumentNormalizer

```cpp
class CLongLinesUnit: CIntermediateResultUnit
```

*Inheritance:* [CIntermediateResultUnit]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html) -> CLongLinesUnit

## Methods

| Method | Description |
|--------|-------------|
| [`GetCount`](#getcount) | Gets the count of LongLine objects in current object.|
| [`GetLongLine`](#getlongline) | Gets a LongLine object from current object by specifying a index. |
| [`RemoveAllLongLines`](#removealllonglines) | Removes all the LongLines in current object. |
| [`RemoveLongLine`](#removelongline) | Removes a LongLine from current object by specifying an index. |
| [`AddLongLine`](#addlongline) | Adds a LongLine to current object. |
| [`SetLongLine`](#setlongline) | Sets the LongLine at the specified index. |
| **Methods Inherited from [CIntermediateResultUnit]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html):** | |
| [`GetHashId`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#gethashid) | Gets the hash ID of the unit.|
| [`GetOriginalImageHashId`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#getoriginalimagehashid) | Gets the hash ID of the original image. |
| [`GetOriginalImageTag`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#getoriginalimagetag) | Gets the image tag of the original image. |
| [`GetType`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#gettype) | Gets the type of the intermediate result unit. |
| [`Clone`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#clone) | Creates a copy of the intermediate result unit. |
| [`SetHashId`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#sethashid) | Sets the hash ID of the unit. |
| [`SetOriginalImageHashId`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#setoriginalimagehashid) | Sets the hash ID of the original image. |
| [`SetOriginalImageTag`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#setoriginalimagetag) | Sets the image tag of the original image. |
| [`Retain`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#retain) | Increases the reference count of the unit. |
| [`Release`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#release) | Decreases the reference count of the unit. |
| [`GetTransformMatrix`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#gettransformmatrix) | Gets the transformation matrix via TransformMatrixType. |
| [`SetTransformMatrix`]({{ site.dcvb_cpp_api }}core/intermediate-results/intermediate-result-unit.html#settransformmatrix) | Sets the transformation matrix via TransformMatrixType. |

### GetCount

Gets the count of LongLine objects in current object.

```cpp
int GetCount() 
```

**Return Value**

The count of LongLine objects in current object.

### GetLongLine

Gets a LongLine object from current object by specifying a index.

```cpp
const CLineSegment* GetLongLine(int index) const = 0;
```

**Parameters**

`[in] index` The index of the LongLine object.

**Return Value**

Returns the LongLine object.

**See Also**

* [CLineSegment]({{ site.dcvb_cpp_api }}core/basic-structures/line-segment.html)
* [ErrorCode]({{ site.dcvb_cpp_api }}core/enum-error-code.html)

### RemoveAllLongLines

Removes all the LongLines in current object.

```cpp
virtual void RemoveAllLongLines() = 0
```

### RemoveLongLine

Removes a LongLine from current object by specifying an index.

```cpp
virtual int RemoveLongLine(int index) = 0
```

**Parameters**

`[in] index` The index of the LongLine to be removed.

**Return Value**

Returns 0 if successful, otherwise returns a negative value.

### AddLongLine

Adds a LongLine to current object.

```cpp
virtual int AddLongLine(const CLineSegment& line, const double matrixToOriginalImage[9] =  IDENTITY_MATRIX) = 0
```

**Parameters**

`[in] line` The LongLine to be added.

`[in] matrixToOriginalImage` The matrix to the original image.

**Return Value**

Returns 0 if successful, otherwise returns a negative value.

### SetLongLine

Sets the LongLine at the specified index.

```cpp
virtual int SetLongLine(int index, const CLineSegment& line, const double matrixToOriginalImage[9] =  IDENTITY_MATRIX) = 0;
```

**Parameters**

`[in] index` The index of the LongLine to be set.

`[in] line` The LongLine to be added.

`[in] matrixToOriginalImage` The matrix to the original image.

**Return Value**

Returns 0 if successful, otherwise returns a negative value.