ImageGear for C and C++ on Windows v19.1 - Updated
IG_ISIS_drv_run_start
API Reference Guide > ISIS Component API Reference > ISIS Component Functions Reference > Single-Step Driver Control Functions > IG_ISIS_drv_run_start

Begin to invoke an ISIS pipe; initialize the run handle.

Declaration:

 
Copy Code
AT_ERRCOUNT ACCUAPI IG_ISIS_drv_run_start(
        HISISDRV hDriver,
        LPHISISDRVRUN lphRun
);

Arguments:

Name Type Description
hDriver HISISDRV The handle of the head (first) driver in the ISIS pipe.
lphRun LPHISISDRVRUN A pointer to the handle of the "run" (zone data structure) which is used to refer to the run zone operation. IG_ISIS_drv_run_start initializes this pointer.

Return Value:

Returns the number of ImageGear errors that occurred during this function call. If there are no errors, the return value is IGE_SUCCESS.

Supported Raster Image Formats:

Depends on the scanner driver.

Example:

The following example uses IG_ISIS_drv_run_start, IG_ISIS_drv_run_step, and IG_ISIS_drv_run_done in three nested loops to invoke an ISIS pipe that allows background reading or scanning:

 
Copy Code
/* IG_ISIS_drv_run_start example */
INT32 MyIG_ISIS_run_zone(HISISDRV hDriver, char FAR *lpcBuffer, int iSize)
{
        HISISDRVRUN hRun;
        AT_ERRCOUNT nErrCount;
        if (!(nErrCount = IG_ISIS_drv_run_start(hDriver, &hRun))) {
                while (nErrCount == IGE_SUCCESS) {
                        if (want to cancel the scan)
                                break;
                        else
                                nErrCount = IG_ISIS_drv_run_step(hRun, lpcBuffer, iSize, 0);
                        printf("Read %d bytes at address %08lx\n",
                                        nErrCount, lpcBuffer);
                }
        }
        nErrCount = IG_ISIS_drv_run_done(hRun);
        return nErrCount;
}

Remarks:

IG_ISIS_drv_run_start initializes the run.

IG_ISIS_drv_run_start is the first step in transferring data through an ISIS pipe. The head (first) driver in the pipe responds by performing whatever its function may be (scanning, reading, writing, compression) and then passes its data to the next driver in the pipe. IG_ISIS_drv_run_start is the first of four separate functions that are used to scan a page. The other functions are IG_ISIS_drv_run_zone (which returns a pointer to the zone structure to allow setting output parameters if necessary), IG_ISIS_drv_run_step (which transfers a specified number of bytes from the page), and IG_ISIS_drv_run_done (which completes the IG_ISIS_drv_run... operation). For common ISIS operations not requiring special or concurrent processing, it is much more convenient and automatic to use the IG_ISIS_drv_run_zone function.

There are several cases in which you may want to use the four separate functions to invoke an ISIS pipe:

An ISIS pipe exists to transfer image data from one entity (scanner, file, memory) to another. IG_ISIS_drv_run_start begins a data transfer operation of a single zone (image area) through the pipe by setting up a "run" data structure and initializing a handle to it. The run handle is used to refer to a particular zone's data and all of its parameters from the time it enters the first driver of the ISIS pipe until it reaches the destination driver of the pipe. Once a run is complete and a single zone has been transferred, the entire process must be repeated to transfer another image.

The IG_ISIS_drv_run_start function is the first of four functions that when used together invoke an ISIS pipe that has previously been established. Invoking a pipe starts a scanning, reading, writing, compression, or other operation as defined by the drivers linked in the pipe.

A zone may be an entire page side, a subarea of the page, or one of multiple subareas that can be defined with certain scanner drivers. Typically, it is an entire page.

IG_ISIS_drv_run_start is one of the basic components of IG_ISIS_drv_run_zone.

See Also:

IG_ISIS_drv_run_done

IG_ISIS_drv_run_step

IG_ISIS_drv_run_zone