NAME

ilRotate90() − rotate a pipe image in 90 degree increments

SYNOPSIS

ilBool
ilRotate90 (

ilPipe pipe,

int factor );

DESCRIPTION

ilRotate90() rotates a pipe image around the center of the image by a factor of 90 degrees.  If rotated by 90 or 270 degrees, the width and height of the image are reversed.  Otherwise, the image retains the same dimensions as before rotation. 

pipe identifies a pipe created by ilCreatePipe(). 

factor indicates the number of 90-degree increments by which to rotate the image.  Rotation is in a clockwise direction unless factor is negative. For example, using 3 for factor rotates the image 270 degrees clockwise; however, using -3 for factor rotates the image 270 degrees counter-clockwise. 

RETURN VALUE

Upon successful completion, ilRotate90() returns TRUE. 

ERRORS

If the call fails, context->error receives a non-zero error code. 

EXAMPLE

The following example adds to the pipe a filter that rotates the pipe image by 90 degrees. 

ilContext context;

ilPipe pipe;
.
.
.

/∗ Rotate image 90 degrees ∗/

if (!ilRotate90 ( pipe, 1 )) return (context->error);

AUTHOR

ilRotate90() was developed by HP. 

SEE ALSO

ilCreatePipe(3X), ilConvert(3X), ilCrop(3X), ilMap(3X).  ilMirror(3X), ilScale(3X), ilCreatePipe(3X). 

Using the Image Developer’s Kit.

Hewlett-Packard Company  —  Image Library: February, 1995