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doc/gl-docs/GL/glx/xusexfont.3gl

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+'\"! eqn | mmdoc
+'\"macro stdmacro
+.ds Vn Version 1.2
+.ds Dt 6 March 1997
+.ds Re Release 1.2.0
+.ds Dp Feb 16 02:57
+.ds Dm  Feb 10 17:2
+.ds Xs 55673 5 xusexfont.gl
+.TH GLXUSEXFONT 3
+.SH NAME
+glXUseXFont
+\- create bitmap display lists from an X font
+
+.SH C SPECIFICATION
+void \f3glXUseXFont\fP(
+Font \fIfont\fP,
+.nf
+.ta \w'\f3void \fPglXUseXFont( 'u
+	int \fIfirst\fP,
+	int \fIcount\fP,
+	int \fIlistBase\fP )
+.fi
+
+.EQ
+delim $$
+.EN
+.SH PARAMETERS
+.TP \w'\fIlistBase\fP\ \ 'u 
+\f2font\fP
+Specifies the font from which character glyphs are to be taken.
+.TP
+\f2first\fP
+Specifies the index of the first glyph to be taken.
+.TP
+\f2count\fP
+Specifies the number of glyphs to be taken.
+.TP
+\f2listBase\fP
+Specifies the index of the first display list to be generated.
+.SH DESCRIPTION
+\f3glXUseXFont\fP generates \f2count\fP display lists,
+named \f2listBase\fP through \f2listBase\fP\&+\&\f2count\fP\&\-\&1,
+each containing a single \f3glBitmap\fP command.
+The parameters of the \f3glBitmap\fP command of display list \f2listBase\fP\&+\f2i\fP
+are derived from glyph \f2first\fP\&+\f2i\fP.
+Bitmap parameters \f2xorig, yorig, width,\fP and \f2height\fP
+are computed from font metrics as
+\f2descent\-1, \-lbearing,\fP
+\f2rbearing\-lbearing,\fP and \f2ascent+descent\fP, respectively.
+\f2xmove\fP is taken from the glyph's \f2width\fP metric,
+and \f2ymove\fP is set to zero.
+Finally,
+the glyph's image is converted to the appropriate format for \f3glBitmap\fP.
+.P
+Using \f3glXUseXFont\fP 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.
+.P
+Empty display lists are created for all glyphs that are requested and
+are not defined in \f2font\fP.
+\f3glXUseXFont\fP is ignored if there is no current GLX context.
+.SH ERRORS
+\f3BadFont\fP is generated if \f2font\fP is not a valid font.
+.P
+\f3GLXBadContextState\fP is generated if the current GLX context is
+in display-list construction mode.
+.P
+\f3GLXBadCurrentWindow\fP is generated if the drawable associated
+with the current context of the calling thread is a window, and that
+window is no longer valid.
+.SH SEE ALSO
+\f3glBitmap\fP,
+\f3glXMakeCurrent\fP