Ok, this ones a little tricky. We have the following: struct POINT{ float x,y; } struct POLY{ vector PtArray; } I want to rotate the POLY around a POINT, not neccesarily the origin, N degrees. I dont want to switch to Polar coords if I dont have to. Any ideas on code? Tx-

Here''s what i would do:

If the point is not the origin, then make it the origin (this sounds like ZEN ehm?).
If you want to rotate your polygon arround a point P(x,y)=(20,20) (for example), then subtract to all the points in your polygon the point P (thus, making a translaction). Then rotate each point in your polygon n degrees. After your done with rotations, you''ll have to "de-translacte" -> sum to every point in your polygon the point P again.

I think this will work....

I''ve just spent the last half hour revising my basic maths skills (I haven''t done this stuff since 1994), and came up with something like this:

for each point in the polygon
Px <- Rx + (Px - Rx) cos N + (Py - Ry) sin N
Py <- Ry + (Py - Ry) cos N + (Px - Rx) sin N

where (Px,Py) is your current point, and (Rx,Ry) is the point you are rotating about (<- means takes the value). This is in line with what wolverine posted while I was away figuring it out ;-)

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