ImageGear for C and C++ on Windows v19.6 - Updated
IG_ISIS_tag_set_rational
API Reference Guide > ISIS Component API Reference > ISIS Component Functions Reference > Tag Functions > IG_ISIS_tag_set_rational

Set the value of a type rational tag.

Declaration:

 
Copy Code
AT_ERRCOUNT ACCUAPI IG_ISIS_tag_set_rational(
        HISISDRV hDriver,
        AT_MODE nTag,
        WORD wIndex,
        LPAT_ISIS_RAT lpValue
);

Arguments:

Name Type Description
hDriver HISISDRV The handle to the driver.
nTag AT_MODE Specifies the type rational tag to set.
wIndex WORD Specifies which element to set. wIndex must be greater than or equal to zero and at most one less than the value returned by IG_ISIS_tag_get_length.
lpValue LPAT_ISIS_RAT Specifies the value to which to set nTag's specified element.

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:

This function does not process image pixels.

Remarks:

The IG_ISIS_tag_set_rational function sets the value of the specified type rational tag's specified element to the given value.

Use IG_ISIS_tag_set_rational to set the specified element of nTag to the rational value given in lpValue.IG_ISIS_tag_set_rational will not automatically increase the number of elements in a tag. You must use IG_ISIS_tag_set_length before calling IG_ISIS_tag_set_rational to do this.

Example:

The following example sets the rational value of IG_ISIS_TAG_RESOLUTION:

 
Copy Code
AT_ISIS_RAT ratValue;
ratValue.Num = 300;
ratValue.Denom = 1;IG_ISIS_tag_set_rational(hDriver, IG_ISIS_TAG_XRESOLUTION, 0, &ratValue);

See Also

IG_ISIS_tag_get_rational

IG_ISIS_tag_set_ascii

IG_ISIS_tag_set_default

IG_ISIS_tag_set_length

IG_ISIS_tag_set_long