GLXUSEXFONT() MachTen Programmer’s Manual GLXUSEXFONT()

NAME
glXUseXFont - create bitmap display lists from an X font

C SPECIFICATION
void glXUseXFont( Font font,
int first,
int count,
int listBase )

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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 com-
puted from font metrics as descent-1, -lbearing, rbear-
ing-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 with-
out 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 associ-
ated with the current context of the calling thread is a
window, and that window is no longer valid.