glXUseXFont - create bitmap display lists from an X font
int listBase );
Specifies the font from which character glyphs are to be
taken. Specifies the index of the first glyph to be
taken. Specifies the number of glyphs to be taken. Specifies
the index of the first display list to be generated.
glXUseXFont() generates count display lists, named listBase
through listBase+count-1, each containing a single
glBitmap() command. The parameters of the glBitmap() command
of display list listBase+i are derived from glyph
first+i. Bitmap parameters xorig, yorig, width, and height
are computed from font metrics as descent-1, -lbearing,
rbearing-lbearing, and ascent+descent, respectively.
xmove is taken from the glyph's width metric, and ymove is
set to zero. Finally, the glyph's image is converted to
the appropriate format for glBitmap().
Using glXUseXFont() may be more efficient than accessing
the X font and generating the display lists explicitly,
both because the display lists are created on the server
without requiring a round trip of the glyph data, and
because the server may choose to delay the creation of
each bitmap until it is accessed.
Empty display lists are created for all glyphs that are
requested and are not defined in font. glXUseXFont() is
ignored if there is no current GLX context.
BadFont is generated if font is not a valid font.
GLXBadContextState is generated if the current GLX context
is in display-list construction mode.
GLXBadCurrentWindow is generated if the drawable associated
with the current context of the calling thread is a
window, and that window is no longer valid.
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