Question

URGENT HELP !!!!
i have a polygon which i need to rotate 90 degrees clockwise with reference to origin. the input given are vertices of polygon. is there a formula for this ?

the vertices of polygon are :

{ {350.005 2134.550} {350.005 1109.605} {0.000 1109.605} {0.000 0.000} {1991.355 0.000} {1991.355 1083.910} {2055.405 1083.910} {2055.405 2134.550} {350.005 2134.550} }


please note that it is a loop around the polygon. the start vertex is repeated in the end

Answer 1

matrix for 90 cw is
0 1
-1 0
Each point <x,y> becomes <y,-x>

Answer 2

ohhh thats it ?
just swap x y coordinates and switch sign of y coordinate of each vertex... is that correct ?

Answer 3

Yes.

Answer 4

thanks it looks easy
actually i need some more help on this could u help please

Answer 5

Like what?