glXUseXFont(3G) OpenGL Reference - GLX glXUseXFont(3G)
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.
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glXUseXFont(3G) OpenGL Reference - GLX glXUseXFont(3G)
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current context of the calling thread is a window, and that window is no
longer valid.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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