# Legacy Document

Important: The information in this document is obsolete and should not be used for new development.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