XDrawImageString, XDrawImageString16 - draw image text
int XDrawImageString(Display *display, Drawable
    d, GC gc, int x, int y, _Xconst char
    *string, int length);
int XDrawImageString16(Display *display, Drawable
    d, GC gc, int x, int y, _Xconst XChar2b
    *string, int length);
  - d
- Specifies the drawable.
- display
- Specifies the connection to the X server.
- gc
- Specifies the GC.
- length
- Specifies the number of characters in the string argument.
- string
- Specifies the character string.
- x
- 
    
 
- y
- Specify the x and y coordinates, which are relative to the origin of the
      specified drawable and define the origin of the first character.
The XDrawImageString16 function is similar to XDrawImageString
  except that it uses 2-byte or 16-bit characters. Both functions also use both
  the foreground and background pixels of the GC in the destination.The effect is first to fill a destination rectangle with the
    background pixel defined in the GC and then to paint the text with the
    foreground pixel. The upper-left corner of the filled rectangle is at:
[x, y - font-ascent]
The width is:
overall-width
The height is:
font-ascent + font-descent
The overall-width, font-ascent, and font-descent are as would be
    returned by XQueryTextExtents using gc and string. The function and
    fill-style defined in the GC are ignored for these functions. The effective
    function is GXcopy, and the effective fill-style is
  FillSolid.
For fonts defined with 2-byte matrix indexing and used with
    XDrawImageString, each byte is used as a byte2 with a byte1 of
  zero.
Both functions use these GC components: plane-mask, foreground,
    background, font, subwindow-mode, clip-x-origin, clip-y-origin, and
    clip-mask.
XDrawImageString and XDrawImageString16 can generate
    BadDrawable, BadGC, and BadMatch errors.
  - BadDrawable
- A value for a Drawable argument does not name a defined Window or
    Pixmap.
- BadGC
- A value for a GContext argument does not name a defined GContext.
- BadMatch
- An InputOnly window is used as a Drawable.
- BadMatch
- Some argument or pair of arguments has the correct type and range but
      fails to match in some other way required by the request.
Unlike XDrawString and XDrawString16, these functions send no more than 255
  characters at a time to the server. When the total number of characters to be
  sent is larger than 255, these functions split the string into chunks up to
  255 characters. After sending each chunk, these functions query the server to
  determine the actual text extent.
XDrawString(3), XDrawText(3), XLoadFont(3), XTextExtents(3)
Xlib - C Language X Interface