**Important:**
The information in this document is obsolete and should not be used for new development.

**Inside Macintosh:****QuickDraw GX Environment and Utilities**/**Chapter 8 - QuickDraw GX Mathematics**/**QuickDraw GX Mathematics Reference****Mathematical Functions**/**Cartesian and Polar Coordinate Point Conversions**

## PointToPolar

The`PointToPolar`

function converts a point in Cartesian coordinates to the identical point in polar coordinates.

gxPolar *PointToPolar(const gxPoint *xy, gxPolar *ra);

`xy`

- A pointer to the Cartesian coordinate.
`ra`

- A pointer to the destination of the resulting polar coordinate.
function result- The pointer passed in
`ra`

.## DESCRIPTION

The`PointToPolar`

function converts the Cartesian coordinate point (x,y) to the identical polar coordinate point (r,a). The parameters of the`PointToPolar`

function are a`gxPoint`

structure pointer`xy`

and a`gxPolar`

structure pointer`ra`

.If both pointers point to the same location, the source

`gxPoint`

structure will be converted to a`gxPolar`

structure and will replace the`gxPoint`

structure.## SEE ALSO

The`gxPolar`

structure is described in the section "Constants and Data Types" beginning on page 8-35. The`PolarToPoint`

function converts a point in polar coordinates to the identical point in Cartesian coordinates. The`PolarToPoint`

function is described in the previous section.

7 JUL 1996