# UpdateTextInCel

Renders text into a text cel.

### Synopsis

`Err UpdateTextInCel (TextCel *tCel, Boolean replaceExisting, char *fmtString,...)`

### Description

Renders text into a cel. If the cel has a format buffer attached to it, the fmtString and related arguments pass first through `sprintf()` for formatting.

If replaceExisting is TRUE, the new text replaces any text already in the cel. The cel data buffer is zeroed, the pen position within the cel data buffer is set back to the top- and left-margin values, and the new text is rendered.

If replaceExisting is FALSE, the new text is added to the text already in the cel, using the cel's current pen position. This effectively adds new characters to the end of the text already in the cel.

If you created the cel with a width or height of zero (an autosize cel), its size is adjusted to fit the formatted text exactly, if the replaceExisting flag is TRUE. If the replaceExisting flag is FALSE for an autosize cel, the net effect is that no characters are rendered. This happens because the cel was sized exactly right for the characters rendered last time replaceExisting was TRUE. Attempting to add more characters to the cel always results in those characters falling outside the cel's boundaries where they are clipped.

The related `vUpdateTextInCel()` function works exactly the same, but takes a va_list type instead of the ... parameters.

### Arguments

tCel
  Pointer to a TextCel structure.

replaceExisting
  Flag indicating whether the new text is added to or replaces text already in the cel.

fmtString
  The string of characters to be rendered, optionally including printf-style % formatting commands.

...
  Arguments for printf-style formatting. (Optional.)

### Return Value

Zero if all characters were rendered, positive if any characters were clipped, negative if a bigger data buffer could not be allocated for an autosize cel. If the cel is not an autosize type, it can't return a negative value.

### Associated Files

lib3do.lib, textlib.h

### See Also

``vUpdateTextInCel``