1991-2006
Silicon Graphics, Inc.
glXUseXFont
3G
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window is no longer valid.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
Copyright
Copyright 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.