NAME

ilExecutePipe() − executes an Image Library pipe

SYNOPSIS

int
ilExecutePipe (

ilPipe pipe,

long nStrips);

DESCRIPTION

ilExecutePipe() executes, or continues executing, an Image Library pipe and returns the execution status. 

Because image manipulation is time-consuming, the application may use the time between ilExecutePipe() calls for other tasks such as user interface tasks that can occur simultaneously.  To do this, use a non-zero value for nStrips and call ilExecutePipe() until the return value is not IL_EXECUTE_AGAIN.  To cancel execution of the pipe before it completes, use ilAbortPipe(). 

One successful call to ilCreatePipe() must precede an ilExecutePipe() call. 

pipe identifies an ilPipe structure created by ilCreatePipe(). 

nStrips sets the number of strips (horizontal slices of the image) to be processed by ilExecutePipe().  If nStrips is zero (0) the pipe image is processed to completion; otherwise, the number supplied for nStrips is the number of strips processed. 

RETURN VALUE

Upon successful completion, ilExecutePipe() returns the execution status.  It is either IL_EXECUTE_AGAIN, (the call must be repeated to continue execution), IL_EXECUTE_COMPLETE (the pipe is finished executing), or IL_EXECUTE_ERROR (an error occurred). 

ERRORS

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

EXAMPLE

The following example executes a pipe. 

ilPipe pipe;

int status;
.
.
.

do {

status = ilExecutePipe(pipe, 1);

} while (status == IL_EXECUTE_AGAIN);
if (context->error) return (context->error);

AUTHOR

ilExecutePipe() was developed by HP. 

SEE ALSO

ilAbortPipe(3X), ilCreatePipe(3X). 

Using the Image Developer’s Kit.

Hewlett-Packard Company  —  Image Library: February, 1995