main/src/georegression/geometry/GeometryMath_F64.java
public static void rotate( double c , double s, GeoTuple2D_F64 pt, GeoTuple2D_F64 solution ) {

		double x = pt.x;
		double y = pt.y;

		solution.x = c * x - s * y;
		solution.y = s * x + c * y;
	}
public static void rotate( double c , double s, GeoTuple2D_F64 pt, GeoTuple2D_F64 solution ) {

		double x = pt.x;
		double y = pt.y;

		solution.x = c * x - s * y;
		solution.y = s * x + c * y;
	}
Rotates a 2D point by the specified angle.

@param c Cosine of theta
@param s Sine of theta
@param pt
@param solution where the solution is written to.  Can be the same point as 'pt'.