Calculate how much of a UTF-8 string will fit in a given width.
Defined in <SDL_ttf.h>
int TTF_MeasureUTF8(TTF_Font *font, const char *text, int measure_width, int *extent, int *count);| TTF_Font * | font | the font to query. | 
| const char * | text | text to calculate, in UTF-8 encoding. | 
| int | measure_width | maximum width, in pixels, available for the string. | 
| int * | extent | on return, filled with latest calculated width. | 
| int * | count | on return, filled with number of characters that can be rendered. | 
(int) Returns 0 if successful, -1 on error.
This reports the number of characters that can be rendered before reaching measure_width.
This does not need to render the string to do this calculation.
This function is available since SDL_ttf 2.0.18.