# Documentation Source Text

Check-in [bfc897c9c0]

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment: In the GeoPoly documentation, mention that geopoly_ccw() can be used to correct vertex order after geopoly_xform(). family | ancestors | descendants | both | trunk files | file ages | folders bfc897c9c02eebf5321dc7c222fabb563223be23d454eec627a487af91dbce55 drh 2018-11-24 20:58:44
Context
 2018-11-26 12:01 Merge typo fix from the 3.25 branch. check-in: 121aeee579 user: drh tags: trunk 2018-11-24 20:58 In the GeoPoly documentation, mention that geopoly_ccw() can be used to correct vertex order after geopoly_xform(). check-in: bfc897c9c0 user: drh tags: trunk 20:24 Minor enhancements and updates to various documents. check-in: 9e12c649c9 user: drh tags: trunk
Changes

Changes to pages/geopoly.in.

```   275    275   <p>
276    276   To rotate a polygon by R radians around the point 0, 0:
277    277
278    278   <codeblock>
279    279   geopoly_xform(\$polygon, cos(\$R), sin(\$R), -sin(\$R), cos(\$R), 0, 0)
280    280   </codeblock>
281    281
282  +<p>
283  +Note that a transformation that flips the polygon might cause the
284  +order of vertexes to be reversed.  In other words, the transformation
285  +might cause the vertexes to circulate in clockwise order instead of
286  +counter-clockwise.  This can be corrected by sending the result
287  +through the [geopoly_ccw()] function after transformation.
288  +
282    289
283    290   <tcl>hd_fragment regpoly geopoly_regular</tcl>
284    291   <h2>The geopoly_regular(X,Y,R,N) Function</h2>
285    292
286    293   <p>
287    294   The geopoly_regular(X,Y,R,N) function returns a convex, simple, regular,
288    295   equilateral, equiangular polygon with N sides, centered at X,Y, and with

```