This function tests whether a font slot in the Font Catalog of the specified Standard Engine instance contains a valid font of font instance and, if successful, returns its font index.
Parameter | Description |
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slot_index |
Index of the font slot to be tested. |
The return value is:
If successful, the function returns the index of the font or font instance in the specified font slot.
Otherwise, the function returns -1. This can happen if the Font Catalog is empty or if slot_index does not hold a valid font index.
If the supplied slot_index is invalid (out of bounds), the function will perform the above test using the closest valid slot index.