# SbDPLine.3coin4 - Man Page

The SbDPLine class represents a line using double precision coordinates.

## Synopsis

`#include <Inventor/SbDPLine.h>`

### Public Member Functions

**SbDPLine** (**void**)**SbDPLine** (**const SbVec3d** &**p0**, **const SbVec3d** &**p1**)**void setValue** (**const SbVec3d** &**p0**, **const SbVec3d** &**p1**)**void setPosDir** (**const SbVec3d** &position, **const SbVec3d** &direction)

SbBool **getClosestPoints** (**const SbDPLine** &**line2**, **SbVec3d** &**ptOnThis**, **SbVec3d** &**ptOnLine2**) **const****SbVec3d getClosestPoint** (**const SbVec3d** &point) **const****const SbVec3d** & **getPosition** (**void**) **const****const SbVec3d** & **getDirection** (**void**) **const****void print** (**FILE** ***file**) **const**

## Detailed Description

The **SbDPLine** class represents a line using double precision coordinates.

**SbDPLine** is used by many other classes in Coin. It provides a way of specifying a directed line (also known as a ray) through a specified point (origin) and a direction in 3D space. Note that the line is infinite in both directions from its definition point.

Be aware that this class is an extension for Coin, and it is not available in the original SGI Open Inventor **v2.1** API.

**See also****SbVec3d****Since**Coin

**2.0**

## Constructor & Destructor Documentation

### SbDPLine::SbDPLine (void)

The empty constructor does nothing. The line will be uninitialized until the first assignment or **setValue()** call.

### SbDPLine::SbDPLine (const SbVec3d & p0, const SbVec3d & p1)

Constructor with *p0* specifying the line start point and *p1* the line end point. *p0* should not be the same as *p1*, as this will lead to having a null vector as the direction vector, which would cause division by zero problems in some of the other methods on this class.

## Member Function Documentation

### void SbDPLine::setValue (const SbVec3d & p0, const SbVec3d & p1)

Set new position and direction of the line by specifying line start point and end point. *p0* should not be the same as *p1*, as this will lead to having a null vector as the direction vector, which would cause division by zero problems in some of the other methods on this class.

### void SbDPLine::setPosDir (const SbVec3d & position, const SbVec3d & direction)

Set position and direction.

Be aware that the direction vector will be normalized and not be the same as provided to this method.

**See also****setValue**, getOrigin,**getDirection****Since**Coin

**4.0**

### SbBool SbDPLine::getClosestPoints (const SbDPLine & line2, SbVec3d & ptOnThis, SbVec3d & ptOnLine2) const

Returns the two closest points on the lines. If the lines are parallel, all points are equally close and we return FALSE. If the lines are not parallel, the point positions will be stored in *ptOnThis* and *ptOnLine2*, and we'll return TRUE.

**See also****getClosestPoint()**.

### SbVec3d SbDPLine::getClosestPoint (const SbVec3d & point) const

Returns the point on the line which is closest to *point*.

**See also****getClosestPoints()**.

### const SbVec3d & SbDPLine::getPosition (void) const

Return a vector representing a point on the line.

### const SbVec3d & SbDPLine::getDirection (void) const

Return a vector representing the direction of the line. The direction vector will always be normalized.

### void SbDPLine::print (FILE * fp) const

Dump the state of this object to the *fp* file stream. Only works in debug version of library, method does nothing in an optimized build.

## Author

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