Sets the TrueType font to use for this text object. The font must have been loaded with LoadFont from a TrueType font file. This is different from the old bitmap fonts in that it supports unicode characters and the characters will usually appear sharper on screen at all sizes.
Note that resizing a text object that is using a TrueType font will redraw all the characters from the font file onto an image for drawing, for large text sizes using hundreds of different unicode characters this could be a slow process but in normal use it is usually not noticeable.
Recently used sizes are kept for a short period of time so if you are frequently switching between two or three text sizes then no redrawing will need to be done and it will be faster.
Use a font ID of 0 to use the built in TrueType font that supports a wide range of unicode characters.
SetTextFont( iTextIndex, iFontID )