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<HTML><HEAD><TITLE>Xlib Programming Manual: Drawing Text</TITLE></HEAD><BODY><H1 ALIGN=center>8.6 Drawing Text</H1>This section discusses how to draw:<UL><P><LI><A HREF="complex.html">Complex text</A><P><LI><A HREF="characters.html">Text characters</A><P><LI><A HREF="image-characters.html">Image text characters</A></UL><P>The fundamental text functions<B><A HREF="XDrawText.html">XDrawText()</A></B>and<B><A HREF="XDrawText16.html">XDrawText16()</A></B>use the following structures:<A NAME="XTextItem"></A><P><!.IN "XTextItem" "" "@DEF@"><CODE><PRE>typedef struct { char *chars; /* pointer to string */ int nchars; /* number of characters */ int delta; /* delta between strings */ Font font; /* Font to print it in, None don't change */} XTextItem;</PRE></CODE><A NAME="XTextItem16"></A><P><!.IN "XTextItem16" "" "@DEF@"><CODE><PRE>typedef struct { XChar2b *chars; /* pointer to two-byte characters */ int nchars; /* number of characters */ int delta; /* delta between strings */ Font font; /* font to print it in, None don't change */} XTextItem16;</PRE></CODE><P>If the font member is not<B>None</B> ,the font is changed before printing and also is stored in the GC.If an error was generated during text drawing,the previous items may have been drawn.The baseline of the characters are drawn starting at the x and ycoordinates that you pass in the text drawing functions.<P>For example, consider the background rectangle drawn by<B><A HREF="XDrawImageString.html">XDrawImageString()</A></B>.If you want the upper-left corner of the background rectangleto be at pixel coordinate (x,y), pass the (x,y + ascent)as the baseline origin coordinates to the text functions.The ascent is the font ascent, as given in the<A HREF="../font-metrics/#XFontStruct">XFontStruct</A>structure.If you want the lower-left corner of the background rectangleto be at pixel coordinate (x,y), pass the (x,y \- descent + 1)as the baseline origin coordinates to the text functions.The descent is the font descent, as given in the<A HREF="../font-metrics/#XFontStruct">XFontStruct</A>structure.<H5 ALIGN=right><I>Next: <A HREF="complex.html">Drawing Complex Text</A></I></H5><HR><ADDRESS><A HREF="http://tronche.com/">Christophe Tronche</A>, <A HREF="mailto:ch.tronche@computer.org">ch.tronche@computer.org</A></ADDRESS></BODY></HTML>⌨️ 快捷键说明
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