AddRotateShift

Computes shift values for rotating an image around the specified center with specified shifts.

Syntax

IppStatus ippiAddRotateShift(double xCenter, double yCenter, double angle, double* xShift, double* yShift);

Parameters

xCenter, yCenter	Coordinates of the required center of rotation.
angle	The angle in degrees to rotate the image clockwise around the point with coordinates (xCenter, yCenter).
xShift, yShift	Pointers to modified shift values along horizontal and vertical axes. These new shift values should be passed to ippiRotate function to bring about the desired rotation around (xCenter, yCenter) and shifting.

Description

The function ippiAddRotateShift is declared in the ippi.h file. Use this function if you need to rotate an image about an arbitrary center (xCenter, yCenter) rather than the origin (0,0) with required shifts. The function helps compute shift values xShift, yShift that should be passed to the ippiRotate function to perform the rotation around (xCenter, yCenter) and desired shifting. The shift values should be initialized. For example, to rotate an image around a point (xCenter, yCenter) by the angle with shift values (30.3, 26.2) the following code must be written:

xShift = 30.3 yShift = 26.2 ippiAddRotateShift(xCenter,yCenter,angle,&xShift,&yShift); ippiRotate(angle,xShift,yShift);

Example 12-6 shows how to use the function ippiAddRotateShift.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error.
ippStsNullPtrErr	Indicates an error condition if xShift or yShift pointer is NULL.