The routine gSetFontForm() can be used to speed up the display of software fonts by representing the output string using font 0 and/or a series of boxes showing the size of the characters in the actual font.
Box type 1 is drawn with the width and height equal to the width and height of the character alone.
Box type 2 is drawn with the width and height equal to the width and height of the full character box including left and right bearings, and space above and below for underlining.
Box type 3 is drawn with the width equal to the width of the character and the height equal to the space occupied by the full character box height.
Setting rep > 0 has the additional effect of characters always being drawn with the default pen width, thus ignoring any setting of gSetFontWeight().
gSetFontForm() does not affect the default font 0 and hardware, Greek and symbol fonts are not replaced by font 0 for odd values of rep.
If rep is outside the above range, a warning message is output and the default value of zero is used.
