NAME
glXUseXFont - create bitmap display lists from an X font
C SPECIFICATION
void glXUseXFont( Font font,
int first,
int count,
int listBase )
PARAMETERS
font Specifies the font from which character glyphs are
to be taken.
first Specifies the index of the first glyph to be
taken.
count Specifies the number of glyphs to be taken.
listBase Specifies the index of the first display list to
be generated.
DESCRIPTION
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.
ERRORS
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and that window is no longer valid.
SEE ALSO
glBitmap, glXMakeCurrent
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