NXGraphicsSubsystem.html

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<title>NX Graphics Subsystem</title>
<meta name="author" content="Gregory Nutt">
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      <h1><big><font color="#3c34ec">
        <i>NX Graphics Subsystem</i>
      </font></big></h1>
      <p>Last Updated: December 5, 2008</p>
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      <h1>Table of Contents</h1>
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<table width="100%">
<tr>
  <td align="left" valign="top">
  <p>
   <big><b>1.0</b> <a href="#Introduction">Introduction</a></big>
  </p>
  <ul>
    <p>
     <i><b>1.1</b> <a href="#Overview">Overview</a><br></i>
     <i><b>1.2</b> <a href="#Objectives">Objectives</a></i><br>
     <i><b>1.3</b> <a href="#Organization">Organization</a></i>
    </p>
    <p>
      <ul>
        <i>1.3.1 <a href="#nxgl1">NX Graphics Library (<code>NXGL</code>)</a></i><br>
        <i>1.3.2 <a href="#nx1">NX (NXSU and NXMU)</a></i><br>
        <i>1.3.3 <a href="#nxtk1">NX Tool Kit (<code>NXTK</code>)</a></i><br>
        <i>1.3.4 <a href="#nxfonts1">NX Fonts Support (<code>NXFONTS</code>)</a></i><br>
        <i>1.3.5 <a href="#nxwidgets1">NX Widgets (<code>NXWIDGETS</code>)</a></i>
      </ul>
    </p>
  </ul>
  <p>
    <big><b>2.0</b> <a href="#nxapis">NX User APIs</a></big>
  </p>
  <ul>
    <p>
      <i><b>2.1</b> <a href="#nxheaders">NX Header Files</a></i><br>
      <i><b>2.2</b> <a href="#nxgl2">NX Graphics Library (<code>NXGL</code>)</a></i>
    </p>
    <p>
      <ul>
        <i>2.2.1 <a href="#nxgltypes">NXGL Types</a></i><br>
        <i>2.2.1 <a href="#nxglrgb2yuv"><code>nxgl_rgb2yuv()</code></a></i><br>
        <i>2.2.2 <a href="#nxglyuv2rgb"><code>nxgl_yuv2rgb()</code></a></i><br>
        <i>2.2.3 <a href="#nxglrectcopy"><code>nxgl_rectcopy()</code></a></i><br>
        <i>2.2.4 <a href="#nxglrectoffset"><code>nxgl_rectoffset()</code></a></i><br>
        <i>2.2.5 <a href="#nxglvectoradd"><code>nxgl_vectoradd()</code></a></i><br>
        <i>2.2.6 <a href="#nxglvectorsubtract"><code>nxgl_vectorsubtract()</code></a></i><br>
        <i>2.2.7 <a href="#nxglrectintersect"><code>nxgl_rectintersect()</code></a></i><br>
        <i>2.2.8 <a href="#nxglrectunion"><code>nxgl_rectunion()</code></a></i><br>
        <i>2.2.9 <a href="#nxglnonintersecting"><code>nxgl_nonintersecting()</code></a></i><br>
        <i>2.2.10 <a href="#nxglrectoverlap"><code>nxgl_rectoverlap()</code></a></i><br>
        <i>2.2.11 <a href="#nxglrectinside"><code>nxgl_rectinside()</code></a></i><br>
        <i>2.2.12 <a href="#nxglrectsize"><code>nxgl_rectsize()</code></a></i><br>
        <i>2.2.13 <a href="#nxglnullrect"><code>nxgl_nullrect()</code></a></i><br>
        <i>2.2.14 <a href="#nxglrunoffset"><code>nxgl_runoffset()</code></a></i><br>
        <i>2.2.15 <a href="#nxglruncopy"><code>nxgl_runcopy()</code></a></i><br>
        <i>2.2.16 <a href="#nxgltrapoffset"><code>nxgl_trapoffset()</code></a></i><br>
        <i>2.2.17 <a href="#nxgltrapcopy"><code>nxgl_trapcopy()</code></a></i><br>
        <i>2.2.18 <a href="#nxglcolorcopy"><code>nxgl_colorcopy</code></a></i>
      </ul>
     </p>
   <p>
     <i><b>2.3</b> <a href="#nx2">NX</a></i>
   </p>
   <p>
     <ul>
        <i>2.3.1 <a href="#nxppdefs">Pre-Processor Definitions</a></i><br>
        <i>2.3.2 <a href="#nxtypes">NX Types</a></i><br>
        <i>2.3.3 <a href="#nxtypes">NX Server Callbacks</a></i>
        <p>
          <ul>
            <i>2.3.3.1 <a href="#nxcbredraw"><code>redraw()</code></a></i><br>
            <i>2.3.3.2 <a href="#nxcbposition"><code>position()</code></a></i><br>
            <i>2.3.3.3 <a href="#nxcbmousein"><code>mousein()</code></a></i><br>
            <i>2.3.3.4 <a href="#nxcbkbdin"><code>kbdin()</code></a></i>
          </ul>
        <p>
        <i>2.3.4 <a href="#nxruninstance"><code>nx_runinstance()</code> (and <code>nx_run()<code> macro)</a></i><br>
        <i>2.3.5 <a href="#nxconnectinstance"><code>nx_connectinstance()</code> (and <code>nx_connect()</code> macro)</a></i><br>
        <i>2.3.6 <a href="#nxopen"><code>nx_open()</code></a></i><br>
        <i>2.3.7 <a href="#nxdisconnect"><code>nx_disconnect()</code></a></i><br>
        <i>2.3.8 <a href="#nxclose"><code>nx_close()</code></a></i><br>
        <i>2.3.9 <a href="#nxeventhandler"><code>nx_eventhandler()</code></a></i><br>
        <i>2.3.10 <a href="#nxeventnotify"><code>nx_eventnotify()</code></a></i><br>
        <i>2.3.11 <a href="#nxopenwindow"><code>nx_openwindow()</code></a></i><br>
        <i>2.3.12 <a href="#nxclosewindow"><code>nx_closewindow()</code></a></i><br>
        <i>2.3.13 <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a></i><br>
        <i>2.3.14 <a href="#nxreleasebkgd"><code>nx_releasebkgd()</code></a></i><br>
        <i>2.3.15 <a href="#nxgetposition"><code>nx_getposition()</code></a></i><br>
        <i>2.3.16 <a href="#nxsetposition"><code>nx_setposition()</code></a></i><br>
        <i>2.3.17 <a href="#nxsetsize"><code>nx_setsize()</code></a></i><br>
        <i>2.3.18 <a href="#nxraise"><code>nx_raise()</code></a></i><br>
        <i>2.3.19 <a href="#nxlower"><code>nx_lower()</code></a></i><br>
        <i>2.3.20 <a href="#nxfill"><code>nx_fill()</code></a></i><br>
        <i>2.3.21 <a href="#nxfilltrapezoid"><code>nx_filltrapezoid()</code></a></i><br>
        <i>2.3.22 <a href="#nxglrgb2yuv"><code>nx_setbgcolor()</code></a></i><br>
        <i>2.3.23 <a href="#nxmove"><code>nx_move()</code></a></i><br>
        <i>2.3.24 <a href="#nxbitmap"><code>nx_bitmap()</code></a></i><br>
        <i>2.3.25 <a href="#nxkbdin"><code>nx_kbdin()</code></a></i><br>
        <i>2.3.26 <a href="#nxmousein"><code>nx_mousein()</code></a></i><br>
     </ul>
   </p>
  </td>
  <td align="left" valign="top">
   <p>
     <i><b>2.4</b> <a href="#nxtk2">NX Tool Kit (<code>NXTK</code>)</a></i>
   </p>
   <p>
     <ul>
        <i>2.4.1 <a href="#nxtktypes"><code>NXTK Types()</code></a></i><br>
        <i>2.4.2 <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a></i><br>
        <i>2.4.3 <a href="#nxtkclosewindow"><code>nxtk_closewindow()</code></a></i><br>
        <i>2.4.4 <a href="#nxtkgetposition"><code>nxtk_getposition()</code></a></i><br>
        <i>2.4.5 <a href="#nxtksetposition"><code>nxtk_setposition()</code></a></i><br>
        <i>2.4.6 <a href="#nxtksetsize"><code>nxtk_setsize()</code></a></i><br>
        <i>2.4.7 <a href="#nxtkraise"><code>nxtk_raise()</code></a></i><br>
        <i>2.4.8 <a href="#nxtklower"><code>nxtk_lower()</code></a></i><br>
        <i>2.4.9 <a href="#nxtkfillwindow"><code>nxtk_fillwindow()</code></a></i><br>
        <i>2.4.10 <a href="#nxtkfilltrapwindow"><code>nxtk_filltrapwindow()</code></a></i><br>
        <i>2.4.11 <a href="#nxtkmovewindow"><code>nxtk_movewindow()</code></a></i><br>
        <i>2.4.12 <a href="#nxtkbitmapwindow"><code>nxtk_bitmapwindow()</code></a></i><br>
        <i>2.4.13 <a href="#nxtkopentoolbar"><code>nxtk_opentoolbar()</code></a></i><br>
        <i>2.4.14 <a href="#nxtkclosetoolbar"><code>nxtk_closetoolbar()</code></a></i><br>
        <i>2.4.15 <a href="#nxtkfilltoolbar"><code>nxtk_filltoolbar()</code></a></i><br>
        <i>2.4.16 <a href="#nxtkfilltraptoolbar"><code>nxtk_filltraptoolbar()</code></a></i><br>
        <i>2.4.17 <a href="#nxtkmovetoolbar"><code>nxtk_movetoolbar()</code></a></i><br>
        <i>2.4.18 <a href="#nxtkbitmaptoolbar"><code>nxtk_bitmaptoolbar()</code></a></i>
     </ul>
   </p>
   <p>
     <i><b>2.5</b> <a href="#nxfonts2">NX Fonts Support (<code>NXFONTS</code>)</a></i><br>
   </p>
   <p>
     <ul>
        <i>2.5.1 <a href="#nxfontstypes"><code>NXFONTS Types()</code></a></i><br>
        <i>2.5.2 <a href="#nxfgetfontset"><code>nxf_getfontset()</code></a></i><br>
        <i>2.5.3 <a href="#nxfgetbitmap"><code>nxf_getbitmap()</code></a></i><br>
        <i>2.5.4 <a href="#nxfconvertbpp"><code>nxf_convert_*bpp()</code></a></i>
     </ul>
   </p>
  </ul>
  <p>
    <big><b>Appendix A</b> <a href="#grapicsdirs"><code>graphics/</code> Directory Structure</a></big><br>
    <big><b>Appendix B</b> <a href="#nxconfigs">NX Configuration Options</a></big>
  </p>
  <p>
    <ul>
      <i><b>B.1</b> <a href="#nxgenconfig">General Configuration Settings</a></i><br>
      <i><b>B.2</b> <a href="#nxglconfig">NXGL Configuration Settings</a></i><br>
      <i><b>B.3</b> <a href="#nxconfig">NX Configuration Settings</a></i><br>
      <i><b>B.4</b> <a href="#nxmuconfig">NX Multi-User (Only) Configuration Settings</a></i><br>
      <i><b>B.5</b> <a href="#nxtkconfig">NXTK Configuration Settings</a></i><br>
      <i><b>B.6</b> <a href="#nxfpmtsconfig">NXFONTS Configuration Settings</a></i>
    </ul>
  </p>
  <p>
    <big><b>Appendix C</b> <a href="#testcoverage">NX Test Coverage</a></big>
  </p>
  </td>
  </tr>
</table>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
    <td>
      <h1>1.0 <a name="Introduction">Introduction</a></h1>
    </td>
  </tr>
</table>

<h2>1.1 <a name="Overview">Overview</a></h2>
<p>
  This document describes the tiny graphics support included in NuttX.
  It includes an overview description of that graphics support, detailed
  descriptions of the NuttX graphics APIs, and discussion of code organization,
  and OS configuration options.
</p>

<center><table width="480">
  <tr>
    <td><a name="screenshot"><img src="NuttXScreenShot.jpg"></a></td>
  </tr>
  <tr>
    <td><small>Figure 1.
    This sceen shot shows the final frame for the NuttX example at <code>examples/nx</code>
    running on the simulated, Linux x86 platform with simulated framebuffer output to
    an X window.
    This picture shows to framed windows with (blank) toolbars.
    Each window has displayed text as received from the NX keyboard interface
    The second window has just been raised to the top of the display.
    </small>
  </tr>
</table></center>


<h2>1.2 <a name="Objectives">Objectives</a></h2>

<p>
  The objective of this development was to provide a tiny windowing system in the
  spirit of X, but greatly scaled down and appropriate for most resource-limited
  embedded environments.
  The current NX implementation supports the general following, high-level features:
</p>
<ul>
  <li><b>Virtual Vertical Graphics Space</b>.
    Windows that reside in a virtual, <i>vertical</i> space so that it makes
    sense to talk about one window being on top of another and obcuring the
    window below it.
  </li>
  <li><b>Client/Server Model</b>.
    A standard client server/model was adopted.  NX may be considered a server
    and other logic that presents the windows are NX clients.
  </li>
  <li><b>Single- and Multi-User Support</b>.
    NX includes <i>front-end</i> logic to either a simple single-thread/single-user
    architecture or a separate NX server thread that can serve multiple NX client threads.
    In the single-user case, the NX <i>server</i> is simply a set of library
    calls;  in the multi-user case, NX is a server thread/daemon the serializes
    graphics operations from multiple clients.
    Other some unique start-up/connection logic, the APIs supported by the single-user
    and multi-user front-ends are identical.
    Providing both front-ends is consistent with the NuttX commitment to scalability.
  </li>
  <li><b>Minimal Graphics Toolset</b>.
    The actual implementation of the graphics operations is performed by common,
    <i>back-end</i> logic.  This back-end supports only a primitive set of graphic
    and rendering operations.
  </li>
  <li><b>Framebuffer Device Interface</b>.
    NX supports any graphics device using the NuttX framebuffer <i>driver</i>
    interface.
    (However, the dependency of NX on framebuffer drivers is minimal and the
    logic could be extended to other interfaces -- such as a serial LCD -- with
    some minimal effort).
  <li><b>Transparent to NX Client</b>.
    The window client on &quot;sees&quot; the sub-window that is operates in
    and does not need to be concerned with the virtual, vertical space (other
    that to respond to <i>redraw</i> requests from NX when needed).
  </li>
  <li><b>Framed Windows and Toolbars</b>.
    NX also adds the capability to support windows with frames and toolbars on
    top of the basic windowing support.
    These are windows such as those shown in the
    <a href="#screenshot">screenshot</a> above.
    These framed windows sub-divide one one window into three relatively independent
    subwindows:  A frame, the contained window and an (optional) toolbar window.
  </li>
  <li><b>Mouse Support</b>.
    NX provides support for a mouse or other X/Y pointing devices.
    APIs are provided to allow external devices to give X/Y position information
    and mouse button presses to NX.
    NX will then provide the mouse input to the relevant window clients via callbacks.
    Client windows only receive the mouse input callback if the mouse is positioned over a visible
    portion of the client window; X/Y position is provided to the client in the relative
    coordinate system of the client window.
  </li>
  <li><b>Keyboard input</b>.
    NX also supports keyboard/keypad devices.
    APIs are provided to allow external devices to give keypad information to NX.
    NX will then provide the mouse input to the top window on the display (the window
    that has the <i>focus</i>) via a callback function.
  </li>
</ul>

<h2>1.3 <a name="Organization">Organization</a></h2>

<p>
  NX is organized into 6 (and perhaps someday 7 or 8) logical modules.
  These logical modules also correspond to the directory organization.
  That NuttX directory organization is discussed in 
  <a href="#grapicsdirs">Appendix B</a> of this document.
  The logic modules are discussed in the following sub-paragraphs.
</p>

<p>
  <center><img src="NXOrganization.gif" width="60%"></center>
</p>

<h3>1.3.1 <a name="nxgl1">NX Graphics Library (<code>NXGL</code>)</a></h3>

<p>
  NXGLIB is a standalone library that contains low-level graphics utilities and
  direct framebuffer rendering logic. NX is built on top NXGLIB.
</p>

<h3>1.3.2 <a name="nx1">NX (<code>NXSU</code> and <code>NXMU</code>)</a></h3>

<p>
  NX is the tiny NuttX windowing system for raw windows (i.e., simple regions of
  graphics memory).
  NX includes both a small-footprint, single user implementaton (NXSU) and a somewhat
  larger multi-user implentation (NXMU as described below).
  Both conform to the same APIs as defined in <code>include/nuttx/nx.h</code> and, hence,
  are interchangable<sup>1</sup>.
  NX can be used without NXWIDGETS and without NXTOOLKIT for raw window displays.
</p>

<p>
  <sup>1</sup><small>NXMU and NXSU are interchangeable other than (1) certain start-up
  and intialization APIs (as described below), and (2) timing.  With NXSU, NX APIs
  execute immediately; with NXMU, NX APIs defer and serialize the operations and, hence,
  introduce different timing and potential race conditions that you would not experience
  with NXSU.</small>
</p>

<p><b>NXNULL?</b>
  At one time, I also envisoned a <i>NULL</i> front-end that did not support windowing
  at all but, rather, simply provided the entire framebuffer memory as one dumb window.
  This has the advantage that the same NX APIs can be used on the one dumb window as
  for the other NX windows.
  This would be in the NuttX spirit of scalability.
</p>
<p>
  However, the same end result can be obtained by using the
  <a href="nxrequestbkgd"><code>nx_requestbkgd()</code></a> API.
  It still may be possible to reduce the footprint in this usage case by developing
  and even thinner NXNULL front-end.
  That is a possible future development.
</p>

<h3>1.3.3 <a name="nxtk1">NX Tool Kit (<code>NXTK</code>)</a></h3>

<p>
  NXTK is a s set of C graphics tools that provide higher-level window drawing
  operations.
  This is the module where the framed windows and toolbar logic is implemented.
  NXTK is built on top of NX and does not depend on NXWIDGETS.
</p>

<h3>1.3.4 <a name="nxfonts1">NX Fonts Support (<code>NXFONTS</code>)</a></h3>

<p>
  A set of C graphics tools for present (bitmap) font images.
  The font implementation is at a very low level or graphics operation,
  comparable to the logic in NXGLIB.
  NXFONTS does not depend on any NX module other than some utilities and types from NXGLIB.
</p>

<h3>1.3.5 <a name="nxwidgets1">NX Widgets (<code>NXWIDGETS</code>)</a></h3>

<p>
  I had originally planned a high level, C++, object-oriented library for
  object-oriented access to graphics <i>widgets</i>.
  However, C++ compilers are not available for some of the targets supported by NuttX.
  So I have decided to implement the entire solution in  C.
  That decision makes the solution somewhat more difficult to work with, but supports all platforms.
</p>
<p>
  At this point, the amount of C in the implementation would make conversion to C++ a
  more difficult job.
  I leave the C++ widget interface to any contributor who may have an interest in such things.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
    <td>
      <h1>2.0 <a name="nxapis">NX User APIs</a></h1>
    </td>
  </tr>
</table>

<h2>2.1 <a name="nxheaders">NX Header Files</a></h2>

<ul><dl>
  <dt><code>include/nuttx/nxglib.h
    <dd>Describes the NXGLIB C interfaces
  <dt><code>include/nuttx/nx.h
    <dd>Describes the NX C interfaces
  <dt><code>include/nutt/nxtk.h
    <dd>Describe the NXTOOLKIT C interfaces
  <dt><code>include/nutt/nxfont.h
    <dd>Describe sthe NXFONT C interfaces
  <dt><code>include/nuttx/nxwidgets.h
    <dd>Will describe the NXWIDGETS classes (no longer planned)
</dl></ul>

<h2>2.2 <a name="nxgl2">NX Graphics Library (<code>NXGL</code>)</a></h2>

<p>
  NXGL provides many APIs, some available for use internally by NX and
  others for use by applications as well.
  Only those APIs intended for application usage are documented here
  See <code>include/nuttx/nxglib.h</code> for the full set of APIs;
  those APIs might be of interest if you are rendering directly into
  framebuffer memory.
</p>

<h3>2.2.1 <a name="nxgltypes">NXGL Types</a></h3>

<p>
  <code>nxgl_mxpixel_t</code>.
  Holds one device pixel.
  NXGLIB will select the smallest size for the <code>nxgl_mxpixel_t</code>
  that just contains the pixel:  <code>byte</code> if 16, 24, and 32 resolution
  support is disabled, <code>uint16</code> if 24, and 32 resolution
  support is disabled, or <code>uint32</code>.
</p>

<p>
  <code>nxgl_coord_t</b>
  A given coordinate is limited to the screen height an width.  If either
  of those values exceed 32,767 pixels, then the following will have to need
  to change:
</p>
<ul><pre>
typedef sint16 nxgl_coord_t;
</pre></ul>

<p>
  <code>struct nxgl_point_s</code>. Describes a point on the display:
</p>
<ul><pre>
struct nxgl_point_s
{
  nxgl_coord_t x;         /* X position, range: 0 to screen width - 1 */
  nxgl_coord_t y;         /* Y position, range: 0 to screen height - 1 */
};
</pre></ul>

<p>
  <code>struct nxgl_size_s</code>. Describes the size of a rectangular region.
</p>
<ul><pre>
struct nxgl_size_s
{
  nxgl_coord_t w;        /* Width in pixels */
  nxgl_coord_t h;        /* Height in rows */
};
</pre></ul>

<p>
  <code>struct nxgl_rect_s</code>. Describes a positioned rectangle on the display.
</p>
<ul><pre>
struct nxgl_rect_s
{
  struct nxgl_point_s pt1; /* Upper, left-hand corner */
  struct nxgl_point_s pt2; /* Lower, right-hand corner */
};
</pre></ul>

<p>
  <code>struct nxgl_run_s</code>.
  Describes a run, i.e., a horizontal line.  Note that the start/end positions
  have fractional precision.  This is necessary for good joining of trapezoids
  when a more complex shape is decomposed into trapezoids
</p>
<ul><pre>
struct nxgl_run_s
{
  b16_t        x1;        /* Left X position, range: 0 to x2 */
  b16_t        x2;        /* Right X position, range: x1 to screen width - 1 */
  nxgl_coord_t y;         /* Top Y position, range: 0 to screen height - 1 */
};
</pre></ul>

<p>
  <code>struct nxgl_trapezoid_s</code>.
  Describes a horizontal trapezoid on the display in terms the run at the
  top of the trapezoid and the run at the bottom
</p>
<ul><pre>
struct nxgl_trapezoid_s
{
  struct nxgl_run_s top;  /* Top run */
  struct nxgl_run_s bot;  /* bottom run */
};
</pre></ul>

<h3>2.2.1 <a name="nxglrgb2yuv"><code>nxgl_rgb2yuv()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_rgb2yuv(ubyte r, ubyte g, ubyte b, ubyte *y, ubyte *u, ubyte *v);
</pre></ul>
<p>
  <b>Description:</b>
  Convert 8-bit RGB triplet to 8-bit YUV triplet.
</p>

<h3>2.2.2 <a name="nxglyuv2rgb"><code>nxgl_yuv2rgb()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_yuv2rgb(ubyte y, ubyte u, ubyte v, ubyte *r, ubyte *g, ubyte *b);
</pre></ul>
<p>
  <b>Description:</b>
  Convert 8-bit RGB triplet to 8-bit YUV triplet.
</p>

<h3>2.2.3 <a name="nxglrectcopy"><code>nxgl_rectcopy()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_rectcopy(FAR struct nxgl_rect_s *dest,
                   FAR const struct nxgl_rect_s *src);
</pre></ul>
<p>
  <b>Description:</b>
  This is essentially <code>memcpy()</code>for rectangles.  We don't do structure
  assignments because some compilers are not good at that.
</p>

<h3>2.2.4 <a name="nxglrectoffset"><code>nxgl_rectoffset()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_rectoffset(FAR struct nxgl_rect_s *dest,
                     FAR const struct nxgl_rect_s *src,
                     nxgl_coord_t dx, nxgl_coord_t dy);
</pre></ul>
<p>
  <b>Description:</b>
   Offset the rectangle position by the specified dx, dy values.
</p>

<h3>2.2.5 <a name="nxglvectoradd"><code>nxgl_vectoradd()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_vectoradd(FAR struct nxgl_point_s *dest,
                    FAR const struct nxgl_point_s *v1,
                    FAR const struct nxgl_point_s *v2);
</pre></ul>
<p>
  <b>Description:</b>
  Add two 2x1 vectors and save the result to a third.
</p>

<h3>2.2.6 <a name="nxglvectorsubtract"><code>nxgl_vectorsubtract()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_vectsubtract(FAR struct nxgl_point_s *dest,
                       FAR const struct nxgl_point_s *v1,
                       FAR const struct nxgl_point_s *v2);
</pre></ul>
<p>
  <b>Description:</b>
  Add subtract vector <code>v2</code> from vector <code>v1</code> and return the result in vector dest.
</p>

<h3>2.2.7 <a name="nxglrectintersect"><code>nxgl_rectintersect()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_rectintersect(FAR struct nxgl_rect_s *dest,
                        FAR const struct nxgl_rect_s *src1,
                        FAR const struct nxgl_rect_s *src2);
</pre></ul>
<p>
  <b>Description:</b>
   Return the rectangle representing the intersection of the two rectangles.
</p>

<h3>2.2.8 <a name="nxglrectunion"><code>nxgl_rectunion()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_rectunion(FAR struct nxgl_rect_s *dest,
                    FAR const struct nxgl_rect_s *src1,
                    FAR const struct nxgl_rect_s *src2);
</pre></ul>
<p>
  <b>Description:</b>
  Given two rectanges, <code>src1</code> and <code>src2</code>, return the larger rectangle that 
  contains both, <code>dest</code>.
</p>

<h3>2.2.9 <a name="nxglnonintersecting"><code>nxgl_nonintersecting()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
nxgl_nonintersecting(FAR struct nxgl_rect_s result[4],
                     FAR const struct nxgl_rect_s *rect1,
                     FAR const struct nxgl_rect_s *rect2);
</pre></ul>
<p>
  <b>Description:</b>
  Return the regions of rectangle <code>rect1</code> that do not intersect with
  <code>rect2</code>.  This will four rectangles, some of which may be
  degenerate (and can be picked off with <a href="#nxglnullrect"><code>nxgl_nullrect()<code></a>).
</p>

<h3>2.2.10 <a name="nxglrectoverlap"><code>nxgl_rectoverlap()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
boolean nxgl_rectoverlap(FAR struct nxgl_rect_s *rect1,
                         FAR struct nxgl_rect_s *rect2);
</pre></ul>
<p>
  <b>Description:</b>
  Return TRUE if the two rectangles overlap.
</p>

<h3>2.2.11 <a name="nxglrectinside"><code>nxgl_rectinside()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
boolean nxgl_rectinside(FAR const struct nxgl_rect_s *rect,
                        FAR const struct nxgl_point_s *pt);
</pre></ul>
<p>
  <b>Description:</b>
  Return TRUE if the point <code>pt</code> lies within <code>rect</code>.
</p>

<h3>2.2.12 <a name="nxglrectsize"><code>nxgl_rectsize()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_rectsize(FAR struct nxgl_size_s *size,
                   FAR const struct nxgl_rect_s *rect);
</pre></ul>
<p>
  <b>Description:</b>
  Return the size of the specified rectangle.
</p>

<h3>2.2.13 <a name="nxglnullrect"><code>nxgl_nullrect()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
boolean nxgl_nullrect(FAR const struct nxgl_rect_s *rect);
</pre></ul>
<p>
  <b>Description:</b>
   Return TRUE if the area of the retangle is &lt;= 0.
</p>

<h3>2.2.14 <a name="nxglrunoffset"><code>nxgl_runoffset()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_runoffset(FAR struct nxgl_run_s *dest,
                    FAR const struct nxgl_run_s *src,
                    nxgl_coord_t dx, nxgl_coord_t dy);
</pre></ul>
<p>
  <b>Description:</b>
  Offset the run position by the specified <code>dx</code>, <code>dy</code> values.
</p>

<h3>2.2.15 <a name="nxglruncopy"><code>nxgl_runcopy()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_runcopy(FAR struct nxgl_run_s *dest,
                  FAR const struct nxgl_run_s *src);
</pre></ul>
<p>
  <b>Description:</b>
  This is essentially <code>memcpy()</code>for runs.  We don't do structure assignments
  because some compilers are not good at that.
</p>

<h3>2.2.16 <a name="nxgltrapoffset"><code>nxgl_trapoffset()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_trapoffset(FAR struct nxgl_trapezoid_s *dest,
                     FAR const struct nxgl_trapezoid_s *src,
                     nxgl_coord_t dx, nxgl_coord_t dy);
</pre></ul>
<p>
  <b>Description:</b>
  Offset the trapezoid position by the specified <code>dx</code>, <code>dy</code> values.
</p>

<h3>2.2.1 <a name="nxgltrapcopy"><code>nxgl_trapcopy()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
void nxgl_trapcopy(FAR struct nxgl_trapezoid_s *dest,
                   FAR const struct nxgl_trapezoid_s *src);
</pre></ul>
<p>
  <b>Description:</b>
  This is essentially <code>memcpy()</code>for trapezoids.  We don't do structure
  assignments because some compilers are not good at that.
</p>

<h3>2.2.1 <a name="nxglcolorcopy"><code>nxgl_colorcopy</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
nxgl_colorcopy(nxgl_mxpixel_t dest[CONFIG_NX_NPLANES],
               const nxgl_mxpixel_t src[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
  This is essentially <code>memcpy()</code>for colors.  This does very little for us
  other than hide all of the conditional compilation for planar colors
  in one place.
</p>

<h2>2.3 <a name="nx2">NX</a></h2>

<h3>2.3.1 <a name="nxppdefs">Pre-Processor Definitions</a></h3>

<p>
  The default server message queue name used by the
  <a href="#nxruninstance"><code>nx_run()</code></a> macro:
</p>
<ul><pre>
#define NX_DEFAULT_SERVER_MQNAME "/dev/nxs"
</pre></ul>

<p>
  Mouse button bits:
</p>
<ul><pre>
#define NX_MOUSE_NOBUTTONS    0x00
#define NX_MOUSE_LEFTBUTTON   0x01
#define NX_MOUSE_CENTERBUTTON 0x02
#define NX_MOUSE_RIGHTBUTTON  0x04
</pre></ul>

<h3>2.3.2 <a name="nxtypes">NX Types</a></h3>

<p>
  The interface to the NX server is managed using a opaque handle:
</p>
<ul><pre>
typedef FAR void *NXHANDLE;
</pre></ul>

<p>
  The interface to a specific window is managed using an opaque handle:
</p>
<ul><pre>
typedef FAR void *NXWINDOW;
</pre></ul>

<p>
  These define callbacks that must be provided to
  <a href="#nxopenwindow"><code>nx_openwindow()</code></a>.
  In the multi-user model, these callbacks will be invoked as part of the
  processing performed by
  <a href="#nxeventhandler"><code>nx_eventhandler()</code></a>.
</p>
<ul><pre>
struct nx_callback_s
{
  void (*redraw)(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
                 boolean more, FAR void *arg);
  void (*position)(NXWINDOW hwnd, FAR const struct nxgl_size_s *size,
                   FAR const struct nxgl_point_s *pos,
                   FAR const struct nxgl_rect_s *bounds,
                   FAR void *arg);
#ifdef CONFIG_NX_MOUSE
  void (*mousein)(NXWINDOW hwnd, FAR const struct nxgl_point_s *pos,
                  ubyte buttons, FAR void *arg);
#endif
#ifdef CONFIG_NX_KBD
  void (*kbdin)(NXWINDOW hwnd, ubyte nch, FAR const ubyte *ch, FAR void *arg);
#endif
};
</pre></ul>

<h3>2.3.3 <a name="nxtypes">NX Server Callbacks</a></h3>

<h4>2.3.3.1 <a name="nxcbredraw"><code>redraw()</code></a></h4>
<p><b>Callback Function Prototype:</b></p>
<ul><pre>
void redraw(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
            boolean more, FAR void *arg);
</pre></ul>
<p>
  <b>Description:</b>
  NX requests that the client re-draw the portion of the window within
  with rectangle.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle created by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>rect</code>
    <dd>The rectangle that needs to be re-drawn (in window relative coordinates)
    <dt><code>more</code>
    <dd>TRUE: More re-draw requests will follow
    <dt><code>arg</code>
    <dd>User provided argument (see <a href="#nxopenwindow"><code>nx_openwindow()</code></a>)
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b> None
</p>

<h4>2.3.3.2 <a name="nxcbposition"><code>position()</code></a></h4>
<p><b>Callback Function Prototype:</b></p>
<ul><pre>
void position(NXWINDOW hwnd, FAR const struct nxgl_size_s *size,
              FAR const struct nxgl_point_s *pos,
              FAR const struct nxgl_rect_s *bounds,
              FAR void *arg);
</pre></ul>
<p>
  <b>Description:</b>
  The size or position of the window has changed (or the window was
  just created with zero size.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle created by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>size</code>
    <dd>The size of the window
    <dt><code>pos</code>
    <dd>The position of the upper left hand corner of the window on
      the overall display
    <dt><code>bounds</code>
    <dd>The bounding rectangle that the describes the entire display
    <dt><code>arg</code>
    <dd>User provided argument (see <a href="#nxopenwindow"><code>nx_openwindow()</code></a>)
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b> None
</p>

<h4>2.3.3.3 <a name="nxcbmousein"><code>mousein()</code></a></h4>
<p><b>Callback Function Prototype:</b></p>
<ul><pre>
#ifdef CONFIG_NX_MOUSE
void mousein(NXWINDOW hwnd, FAR const struct nxgl_point_s *pos,
             ubyte buttons, FAR void *arg);
#endif
</pre></ul>
<p>
  <b>Description:</b>
  New mouse data is available for the window
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle created by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>pos</code>
    <dd>The (x,y) position of the mouse
    <dt><code>buttons</code>
    <dd>See <code>NX_MOUSE_*</code> definitions
    <dt><code>arg</code>
    <dd>User provided argument (see <a href="#nxopenwindow"><code>nx_openwindow()</code></a>)
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b> None
</p>

<h4>2.3.3.4 <a name="nxcbkbdin"><code>kbdin()</code></a></h4>
<p><b>Callback Function Prototype:</b></p>
<ul><pre>
#ifdef CONFIG_NX_KBD
void (*kbdin)(NXWINDOW hwnd, ubyte nch, FAR const ubyte *ch, FAR void *arg);
#endif
</pre></ul>
<p>
  <b>Description:</b>
  New keyboard/keypad data is available for the window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle created by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>nch</code>
    <dd>The number of characters that are available in ch[]
    <dt><code>ch</code>
    <dd>The array of characters
    <dt><code>arg</code>
    <dd>User provided argument (see <a href="#nxopenwindow"><code>nx_openwindow()</code></a>)
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b> NOne
</p>

<h3>2.3.4 <a name="nxruninstance"><code>nx_runinstance()</code> (and <code>nx_run()<code> macro)</a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifdef CONFIG_NX_MULTIUSER
int nx_runinstance(FAR const char *mqname, FAR struct fb_vtable_s *fb);
#define nx_run(fb) nx_runinstance(NX_DEFAULT_SERVER_MQNAME, fb)
#endif
</pre></ul>
<p>
  <b>Description:</b>
  This is the server entry point.  It does not return; the calling thread
  is dedicated to supporting NX server.
</p>
<p>
  NOTE that multiple instances of the NX server may run at the same time,
  with different callback and message queue names.  <code>nx_run()</code> is simply
  a macro that can be used when only one server instance is required.  In
  that case, a default server name is used.
</p>
<p>
  Multiple user mode only!
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>mqname</code>
    <dd>
     - The name for the server incoming message queue
    <dt><code>fb</code>
    <dd>Vtable &quot;object&quot; of the framebuffer &quot;driver&quot; to use
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  This function usually does not return.  If it does return, it will
  return <code>ERROR</code> and <code>errno</code> will be set appropriately.
</p>

<h3>2.3.5 <a name="nxconnectinstance"><code>nx_connectinstance()</code> (and <code>nx_connect()</code> macro)</a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifdef CONFIG_NX_MULTIUSER
NXHANDLE nx_connectinstance(FAR const char *svrmqname);
#define nx_connect(cb) nx_connectinstance(NX_DEFAULT_SERVER_MQNAME)
#endif
</pre></ul>
<p>
  <b>Description:</b>
  Open a connection from a client to the NX server.  One one client
  connection is normally needed per thread as each connection can host
  multiple windows.
</p>
<p>
  NOTES:
</p>
<ul>
  <li>
    This function returns before the connection is fully instantiated.
    it is necessary to wait for the connection event before using the
    returned handle.
  </li>
  <li>
    Multiple instances of the NX server may run at the same time,
    each with different message queue names.
  </li>
  <li>
    <code>nx_connect()</code> is simply a macro that can be used when only one
    server instance is required.  In that case, a default server name
    is used.
  </li>
</ul>
<p>
  Multiple user mode only!
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>svrmqname</code>
    <dd>The name for the server incoming message queue
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
</p>
<ul>
    Success: A non-NULL handle used with subsequent NX accesses<br>
    Failure:  NULL is returned and <code>errno</code> is set appropriately.
</ul>

<h3>2.3.6 <a name="nxopen"><code>nx_open()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifndef CONFIG_NX_MULTIUSER
NXHANDLE nx_open(FAR struct fb_vtable_s *fb);
#endif
</pre></ul>
<p>
  <b>Description:</b>
    Create, initialize and return an NX handle for use in subsequent
    NX API calls.  <code>nx_open()</code> is the single user equivalent of
    <a href="#nxconnectinstance"><code>nx_connect()</code></a> plus
    <a href="#nxruninstance"><code>nx_run()</code></a>.
</p>
<p>
    Single user mode only!
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>fb</code>
    <dd>Vtable &quot;object&quot; of the framebuffer &quot;driver&quot; to use
    <dt><code>cb</code>
    <dd>Callbacks used to process received NX server messages
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
</p>
<ul>
    Success: A non-NULL handle used with subsequent NX accesses<br>
    Failure:  NULL is returned and <code>errno</code> is set appropriately.
</ul>

<h3>2.3.7 <a name="nxdisconnect"><code>nx_disconnect()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifdef CONFIG_NX_MULTIUSER
void nx_disconnect(NXHANDLE handle);
#endif
</pre></ul>
<p>
  <b>Description:</b>
  Disconnect a client from the NX server and/or free resources reserved
  by <a href="#nxconnectinstance"><code>nx_connect()</code>/<code>nx_connectinstance()</code></a>.
  <code>nx_disconnect()</code> is muliti-user equivalent of
  <a href="#nxclose"><code>nx_close()</code></a>.
</p>
<p>
  Multiple user mode only!
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxconnectinstance"><code>nx_connect()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b> None.
</p>

<h3>2.3.8 <a name="nxclose"><code>nx_close()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifndef CONFIG_NX_MULTIUSER
void nx_close(NXHANDLE handle);
#endif
</pre></ul>
<p>
  <b>Description:</b>
  Close the single user NX interface.  nx_close is single-user equivalent
  of <a href="#nxdisconnect"><code>nx_disconnect()</code></a>.
</p>
<p>
  Single user mode only!
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxopen"><code>nx_open()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b> None
</p>

<h3>2.3.9 <a name="nxeventhandler"><code>nx_eventhandler()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifdef CONFIG_NX_MULTIUSER
int nx_eventhandler(NXHANDLE handle);
#else
#  define nx_eventhandler(handle) (OK)
#endif
</pre></ul>
<p>
  <b>Description:</b>
  The client code must call this function periodically to process
  incoming messages from the server.  If <code>CONFIG_NX_BLOCKING</code> is defined,
  then this function not return until a server message is received.
</p>
<p>
  When <code>CONFIG_NX_BLOCKING</code> is not defined, the client must exercise
  caution in the looping to assure that it does not eat up all of
  the CPU bandwidth calling nx_eventhandler repeatedly.
  <a href="#nxeventnotify"><code>nx_eventnotify()</code></a>
  may be called to get a signal event whenever a new incoming server
  event is avaiable.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxconnectinstance"><code>nx_connect()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
</p>
<ul>
  <li>
    <code>OK</code>: No errors occurred.  If <code>CONFIG_NX_BLOCKING</code> is defined,
    then one or more server messages were processed.
  </li>
  <li>
    <code>ERROR</code>: An error occurred and <code>errno</code> has been set appropriately.
    Of particular interest, it will return <code>errno == EHOSTDOWN</code> when the
    server is disconnected.  After that event, the handle can no longer be used.
  </li>
</ul>

<h3>2.3.10 <a name="nxeventnotify"><code>nx_eventnotify()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#if defined(CONFIG_NX_MULTIUSER) && !defined(CONFIG_DISABLE_SIGNALS)
int nx_eventnotify(NXHANDLE handle, int signo);
#else
#  define nx_eventnotify(handle, signo) (OK)
#endif
</pre></ul>
<p>
  <b>Description:</b>
  Rather than calling <a href="#nxeventhandler"><code>nx_eventhandler()</code></a> periodically,
  the client may register to receive a signal when a server event is available.
  The client can then call <a href="#nxeventhandler"><code>nv_eventhandler()</code></a> only when
  incoming events are available.
</p>
<p>
  The underlying implementation used <code>mq_notifiy()</code> and, as a result,
  the client must observe the rules for using <code>mq_notifiy()</code>:
  <ul>
    <li>
      Only one event is signaled.  Upon receipt of the signal, if the client
      wishes further notifications, it must call <code>nx_eventnotify()</code> again.
    </li>
    <li>
      The signal will only be issued when the message queue transitions from empty to
      not empty.
    </li>
  </ul>
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxconnectinstance"><code>nx_connect()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.11 <a name="nxopenwindow"><code>nx_openwindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

NXWINDOW nx_openwindow(NXHANDLE handle,
                       FAR const struct nx_callback_s *cb,
                       FAR void *arg);
</pre></ul>
<p>
  <b>Description:</b> Create a new window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxconnectinstance"><code>nx_connect()</code></a>
       or <a href="#nxopen"><code>nx_open()</code></a>.
    <dt><code>cb</code>
    <dd>Callbacks used to process window events
    <dt><code>arg</code>
    <dd>User provided value that will be returned with NX callbacks.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
</p>
<ul>
    Success: A non-NULL handle used with subsequent NX accesses<br>
    Failure:  NULL is returned and <code>errno</code> is set appropriately.
</ul>

<h3>2.3.12 <a name="nxclosewindow"><code>nx_closewindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_closewindow(NXWINDOW hwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Destroy a window created by <a href="#nxopenwindow"><code>nx_openwindow()</code></a> window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
       that identifies the window to be  destroyed.
       This handle must not have been one returned by
       <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.13 <a name="nxrequestbkgd"><code>nx_requestbkgd()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_requestbkgd(NXHANDLE handle,
                   FAR const struct nx_callback_s *cb,
                   FAR void *arg);
</pre></ul>
<p>
  <b>Description:</b>
  NX normally controls a separate window called the background window.
  It repaints the window as necessary using only a solid color fill.  The
  background window always represents the entire screen and is always
  below other windows.  It is useful for an application to control the
  background window in the following conditions:
</p>
<ul>
  <li>
    If you want to implement a windowless solution.  The single screen
    can be used to creat a truly simple graphic environment.  In this
    case, you should probably also de-select <code>CONFIG_NX_MULTIUSER</code> as well.
  </li>
  <li>
    When you want more on the background than a solid color.  For
    example, if you want an image in the background, or animations in the
    background, or live video, etc.
  </li>
</ul>
<p>
  This API only requests the handle of the background window.  That
  handle will be returned asynchronously in a subsequent position and
  redraw callbacks.
</p>
<p>
  Cautions:
</p>
<ul>
  <li>
    The following should never be called using the background window.
    They are guaranteed to cause severe crashes:
    <a href="#nxsetposition"><code>nx_setposition()</code></a>,
    <a href="#nxsetsize"><code>nx_setsize()</code></a>,
    <a href="#nxraise"><code>nx_raise()</code></a>, or
    <a href="#nxlower"><code>nx_lower()</code></a>.
  </li>
  <li>
    Neither <code>nx_requestbkgd()</code> nor
    <a href="#nxreleasebkgd"><code>nx_releasebkgd ()</code></a> should be called more than once.
    Multiple instances of the background window are not supported.
  </li>
</ul>
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxconnectinstance"><code>nx_connect()</code></a>
       or <a href="#nxopen"><code>nx_open()</code></a>.
    <dt><code>cb</code>
    <dd>Callbacks to use for processing background window events
    <dt><code>arg</code>
    <dd>User provided argument (see <a href="#nxopenwindow"><code>nx_openwindow()</code></a>)
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.14 <a name="nxreleasebkgd"><code>nx_releasebkgd()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_releasebkgd(NXWINDOW hwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Release the background window previously acquired using
  <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
  and return control of the background to NX.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle returned indirectly by
      <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
      This handle must not have been one created by
      <a href="#nxopenwindow"><code>nx_openwindow()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.15 <a name="nxgetposition"><code>nx_getposition()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_getposition(NXWINDOW hwnd);
</pre></ul>
<p>
  <b>Description:</b>
   Request the position and size information for the selected window.  The
   values will be return asynchronously through the client callback function
   pointer.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a> or
      <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.16 <a name="nxsetposition"><code>nx_setposition()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_setposition(NXWINDOW hwnd, FAR struct nxgl_point_s *pos);
</pre></ul>
<p>
  <b>Description:</b>
  Set the position and size for the selected window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>.
      This handle must not have been created by 
      <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
    <dt><code>pos</code>
    <dd>The new position of the window
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.17 <a name="nxsetsize"><code>nx_setsize()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_setsize(NXWINDOW hwnd, FAR struct nxgl_size_s *size);
</pre></ul>
<p>
  <b>Description:</b> Set the size of the selected window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>.
      This handle must not have been created by 
      <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
    <dt><code>size</code>
    <dd>The new size of the window (in pixels).
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.18 <a name="nxraise"><code>nx_raise()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_raise(NXWINDOW hwnd);
</pre></ul>
<p>
  <b>Description:</b> Bring the specified window to the top of the display.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>.
      This handle must not have been created by 
      <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
    <dt><code></code>
    <dd>
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.19 <a name="nxlower"><code>nx_lower()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_lower(NXWINDOW hwnd);
</pre></ul>
<p>
  <b>Description:</b> Lower the specified window to the bottom of the display.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>.
      This handle must not have been created by 
      <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>.
    <dt><code></code>
    <dd>
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.20 <a name="nxfill"><code>nx_fill()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_fill(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
                   nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
   Fill the specified rectangle in the window with the specified color.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>rect</code>
    <dd>The location to be filled
    <dt><code>color</code>
    <dd>The color to use in the fill
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.21 <a name="nxfilltrapezoid"><code>nx_filltrapezoid()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_filltrapezoid(NXWINDOW hwnd, FAR const struct nxgl_rect_s *clip,
                            FAR const struct nxgl_trapezoid_s *trap,
                            nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
  Fill the specified trapezoidal region in the window with the specified color.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>clip</code>
    <dd>Clipping rectangle relative to window (may be null)
    <dt><code>trap</code>
    <dd>The trapezoidal region to be filled
    <dt><code>color</code>
    <dd>The color to use in the fill
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.22 <a name="nxglrgb2yuv"><code>nx_setbgcolor()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_setbgcolor(NXHANDLE handle,
                  nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b> Set the color of the background.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>handle</code>
    <dd>The handle created by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a>
    <dt><code>color</code>
    <dd>The color to use in the background
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.23 <a name="nxmove"><code>nx_move()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_move(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
                   FAR const struct nxgl_point_s *offset);
</pre></ul>
<p>
  <b>Description:</b> Move a rectangular region within the window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a> that specifies
      the window within which the move is to be done
    <dt><code>rect</code>
    <dd>Describes the (source) rectangular region to move
    <dt><code>offset</code>
    <dd>The offset to move the region
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.24 <a name="nxbitmap"><code>nx_bitmap()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

int nx_bitmap(NXWINDOW hwnd, FAR const struct nxgl_rect_s *dest,
                     FAR const void *src[CONFIG_NX_NPLANES],
                     FAR const struct nxgl_point_s *origin,
                     unsigned int stride);
</pre></ul>
<p>
  <b>Description:</b>
  Copy a rectangular region of a larger image into the rectangle in the
  specified window.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>hwnd</code>
    <dd>The handle returned by <a href="#nxopenwindow"><code>nx_openwindow()</code></a>
      or <a href="#nxrequestbkgd"><code>nx_requestbkgd()</code></a> that specifies the
      window that will receive the bitmap image.
    <dt><code>dest</code>
    <dd> Describes the rectangular on the display that will receive the the bit map.
    <dt><code>src</code>
    <dd>The start of the source image.  This is an array source images of size
      <code>CONFIG_NX_NPLANES</code> (probably 1).
    <dt><code>origin</code>
    <dd>The origin of the upper, left-most corner of the full bitmap.
     Both dest and origin are in window coordinates, however, the origin
     may lie outside of the display.
    <dt><code>stride</code>
    <dd>The width of the full source image in bytes.
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.25 <a name="nxkbdin"><code>nx_kbdin()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifdef CONFIG_NX_KBD
int nx_kbdchin(NXHANDLE handle, ubyte ch);
int nx_kbdin(NXHANDLE handle, ubyte nch, FAR const ubyte *ch);
#endif
</pre></ul>
<p>
  <b>Description:</b>
  Used by a thread or interrupt handler that manages some kind of keypad
  hardware to report text information to the NX server.  That text
  data will be routed by the NX server to the appropriate window client.
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.3.26 <a name="nxmousein"><code>nx_mousein()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;

#ifdef CONFIG_NX_MOUSE
int nx_mousein(NXHANDLE handle, nxgl_coord_t x, nxgl_coord_t y, ubyte buttons);
#endif
</pre></ul>
<p>
  <b>Description:</b>
  Used by a thread or interrupt handler that manages some kind of pointing
  hardware to report new positional data to the NX server.  That positional
  data will be routed by the NX server to the appropriate window client.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code></code>
    <dd>
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h2>2.4 <a name="nxtk2">NX Tool Kit (<code>NXTK</code>)</a></h2>

<h3>2.4.1 <a name="nxtktypes"><code>NXTK Types()</code></a></h3>

<p>
  This is the handle that can be used to access the window data region.
</p>
<ul><pre>
typedef FAR void *NXTKWINDOW;
</pre></ul>

<h3>2.4.2 <a name="nxtkopenwindow"><code>nxtk_openwindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

NXTKWINDOW nxtk_openwindow(NXHANDLE handle,
                           FAR const struct nx_callback_s *cb,
                           FAR void *arg);
</pre></ul>
<p>
  <b>Description:</b> Create a new, framed window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>handle</code>
    <dd>The handle returned by <a href="#nxconnectinstance"><code>nx_connect()</code></a>
       or <a href="#nxopen"><code>nx_open()</code></a>.
    <dt><code>cb</code>
    <dd>Callbacks used to process window events
    <dt><code>arg</code>
    <dd>User provided argument (see <a href="#nxopenwindow"><code>nx_openwindow()</code></a>)
  </dl>
</p>
<p>
  <b>Returned Value:</b>
</p>
<ul>
    Success: A non-NULL handle used with subsequent NXTK window accesses<br>
    Failure:  NULL is returned and <code>errno</code> is set appropriately.
</ul>

<h3>2.4.3 <a name="nxtkclosewindow"><code>nxtk_closewindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_closewindow(NXTKWINDOW hfwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Close the window opened by <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.4 <a name="nxtkgetposition"><code>nxtk_getposition()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_getposition(NXTKWINDOW hfwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Request the position and size information for the selected framed window.
  The size/position for the client window and toolbar will be return
  asynchronously through the client callback function pointer.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.5 <a name="nxtksetposition"><code>nxtk_setposition()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_setposition(NXTKWINDOW hfwnd, FAR struct nxgl_point_s *pos);
</pre></ul>
<p>
  <b>Description:</b>
  Set the position for the selected client window.  This position does not
  include the offsets for the borders nor for any toolbar.  Those offsets
  will be added in to set the full window position.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>pos</code>
    <dd>The new position of the client sub-window
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.6 <a name="nxtksetsize"><code>nxtk_setsize()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_setsize(NXTKWINDOW hfwnd, FAR struct nxgl_size_s *size);
</pre></ul>
<p>
  <b>Description:</b>
  Set the size for the selected client window.  This size does not
  include the sizes of the borders nor for any toolbar.  Those sizes
  will be added in to set the full window size.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>size</code>
    <dd>The new size of the client sub-window.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.7 <a name="nxtkraise"><code>nxtk_raise()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_raise(NXTKWINDOW hfwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Bring the window containing the specified client sub-window to the top
  of the display.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>
      specifying the window to be raised.
    <dt><code></code>
    <dd>
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.8 <a name="nxtklower"><code>nxtk_lower()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_lower(NXTKWINDOW hfwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Lower the window containing the specified client sub-window to the
  bottom of the display.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
     <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>
      specifying the window to be lowered.
   <dt><code></code>
    <dd>
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.9 <a name="nxtkfillwindow"><code>nxtk_fillwindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_fillwindow(NXTKWINDOW hfwnd, FAR const struct nxgl_rect_s *rect,
                    nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
  Fill the specified rectangle in the client window with the specified color.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>rect</code>
    <dd>The location within the client window to be filled
    <dt><code>color</code>
    <dd>The color to use in the fill
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.10 <a name="nxtkfilltrapwindow"><code>nxtk_filltrapwindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_filltrapwindow(NXTKWINDOW hfwnd,
                        FAR const struct nxgl_trapezoid_s *trap,
                        nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
  Fill the specified trapezoid in the client window with the specified color
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>trap</code>
    <dd>The trapezoidal region to be filled.
    <dt><code>color</code>
    <dd>The color to use in the fill.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.11 <a name="nxtkmovewindow"><code>nxtk_movewindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_movewindow(NXTKWINDOW hfwnd, FAR const struct nxgl_rect_s *rect,
                    FAR const struct nxgl_point_s *offset);
</pre></ul>
<p>
  <b>Description:</b>
  Move a rectangular region within the client sub-window of a framed window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>
      specifying the client sub-window within which the move is to be done.
    <dt><code>rect</code>
    <dd>Describes the rectangular region relative to the client sub-window to move.
    <dt><code>offset</code>
    <dd>The offset to move the region
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.12 <a name="nxtkbitmapwindow"><code>nxtk_bitmapwindow()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_bitmapwindow(NXTKWINDOW hfwnd,
                      FAR const struct nxgl_rect_s *dest,
                      FAR const void *src[CONFIG_NX_NPLANES],
                      FAR const struct nxgl_point_s *origin,
                      unsigned int stride);
</pre></ul>
<p>
  <b>Description:</b>
  Copy a rectangular region of a larger image into the rectangle in the
  specified client sub-window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>
      specifying the client sub-window that will receive the bitmap.
    <dt><code>dest</code>
    <dd>Describes the rectangular region on in the client sub-window
      will receive the bit map.
    <dt><code>src</code>
    <dd>The start of the source image(s). This is an array source
      images of size <code>CONFIG_NX_NPLANES</code> (probably 1).
    <dt><code>origin</code>
    <dd>The origin of the upper, left-most corner of the full bitmap.
      Both dest and origin are in sub-window coordinates, however, the
      origin may lie outside of the sub-window display.
    <dt><code>stride</code>
    <dd>The width of the full source image in pixels.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.13 <a name="nxtkopentoolbar"><code>nxtk_opentoolbar()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_opentoolbar(NXTKWINDOW hfwnd, nxgl_coord_t height,
                     FAR const struct nx_callback_s *cb,
                     FAR void *arg);
</pre></ul>
<p>
  <b>Description:</b>
  Create a tool bar at the top of the specified framed window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>height</code>
    <dd>The requested height of the toolbar in pixels.
    <dt><code></code>
    <dd>Callbacks used to process toolbar events.
    <dt><code></code>
    <dd>User provided value that will be returned with toolbar callbacks.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.14 <a name="nxtkclosetoolbar"><code>nxtk_closetoolbar()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_closetoolbar(NXTKWINDOW hfwnd);
</pre></ul>
<p>
  <b>Description:</b>
  Remove the tool bar at the top of the specified framed window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code></code>
    <dd>
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.15 <a name="nxtkfilltoolbar"><code>nxtk_filltoolbar()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_filltoolbar(NXTKWINDOW hfwnd, FAR const struct nxgl_rect_s *rect,
                     nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
  Fill the specified rectangle in the toolbar sub-window with the specified color.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>rect</code>
    <dd>The location within the toolbar window to be filled.
    <dt><code>color</code>
    <dd>The color to use in the fill.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.16 <a name="nxtkfilltraptoolbar"><code>nxtk_filltraptoolbar()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_filltraptoolbar(NXTKWINDOW hfwnd, FAR const struct nxgl_trapezoid_s *trap,
                         nxgl_mxpixel_t color[CONFIG_NX_NPLANES]);
</pre></ul>
<p>
  <b>Description:</b>
  Fill the specified trapezoid in the toolbar sub-window with the specified color.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>trap</code>
    <dd>The trapezoidal region to be filled
    <dt><code>color</code>
    <dd>The color to use in the fill
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.17 <a name="nxtkmovetoolbar"><code>nxtk_movetoolbar()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_movetoolbar(NXTKWINDOW hfwnd, FAR const struct nxgl_rect_s *rect,
                     FAR const struct nxgl_point_s *offset);
</pre></ul>
<p>
  <b>Description:</b>
   Move a rectangular region within the toolbar sub-window of a framed window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle identifying sub-window containing the toolbar within which the move is
      to be done.
      This handle must have previously been returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>rect</code>
    <dd>Describes the rectangular region relative to the toolbar sub-window to move.
    <dt><code>offset</code>
    <dd>The offset to move the region
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h3>2.4.18 <a name="nxtkbitmaptoolbar"><code>nxtk_bitmaptoolbar()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nx.h&gt;
#include &lt;nuttx/nxtk.h&gt;

int nxtk_bitmaptoolbar(NXTKWINDOW hfwnd,
                       FAR const struct nxgl_rect_s *dest,
                       FAR const void *src[CONFIG_NX_NPLANES],
                       FAR const struct nxgl_point_s *origin,
                       unsigned int stride);
</pre></ul>
<p>
  <b>Description:</b>
  Copy a rectangular region of a larger image into the rectangle in the
  specified toolbar sub-window.
</p>
<p>
  <b>Input Parameters:</b>
  <dl>
    <dt><code>hfwnd</code>
    <dd>A handle previously returned by
      <a href="#nxtkopenwindow"><code>nxtk_openwindow()</code></a>.
    <dt><code>dest</code>
    <dd>Describes the rectangular region on in the toolbar sub-window
           will receive the bit map.
    <dt><code>src</code>
    <dd>The start of the source image.
    <dt><code>origin</code>
    <dd>The origin of the upper, left-most corner of the full bitmap.
           Both dest and origin are in sub-window coordinates, however, the
           origin may lie outside of the sub-window display.
    <dt><code>stride</code>
    <dd>The width of the full source image in bytes.
  </dl>
</p>
<p>
  <b>Returned Value:</b>
  <code>OK</code> on success;
  <code>ERROR</code> on failure with <code>errno</code> set appropriately
</p>

<h2>2.5 <a name="nxfonts2">NX Fonts Support (<code>NXFONTS</code>)</a></h2>

<h3>2.5.1 <a name="nxfontstypes"><code>NXFONTS Types()</code></a></h3>
<p>
  This structures provides the metrics for one glyph:
</p>
<ul><pre>
struct nx_fontmetic_s
{
  uint32 stride   : 2;      /* Width of one font row in bytes */
  uint32 width    : 6;      /* Width of the font in bits */
  uint32 height   : 6;      /* Height of the font in rows */
  uint32 xoffset  : 6;      /* Top, left-hand corner X-offset in pixels */
  uint32 yoffset  : 6;      /* Top, left-hand corner y-offset in pixels */
  uint32 unused   : 6;
};
</pre></ul>

<p>
  This structure binds the glyph metrics to the glyph bitmap:
</p>
<ul><pre>
struct nx_fontbitmap_s
{
  struct nx_fontmetic_s metric; /* Character metrics */
  FAR const ubyte *bitmap;      /* Pointer to the character bitmap */
};
</pre></ul>

<p>
  This structure describes one contiguous grouping of glyphs that
  can be described by an array starting with encoding <code>first</code> and
  extending through (<code>first</code> + <code>nchars</code> - 1).
</p>
<ul><pre>
struct nx_fontset_s
{
  ubyte  first;             /* First bitmap character code */
  ubyte  nchars;            /* Number of bitmap character codes */
  FAR const struct nx_fontbitmap_s *bitmap;
};
</pre></ul>

<p>
  This structure describes the overall fontset:
</p>
<ul><pre>
struct nx_font_s
{
  ubyte  mxheight;          /* Max height of one glyph in rows */
  ubyte  mxwidth;           /* Max width of any glyph in pixels */
  ubyte  mxbits;            /* Max number of bits per character code */
  ubyte  spwidth;           /* The width of a space in pixels */
};
</pre></ul>

<h3>2.5.2 <a name="nxfgetfontset"><code>nxf_getfontset()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nxfonts.h&gt;

FAR const struct nx_font_s *nxf_getfontset(void);
</pre></ul>
<p>
  <b>Description:</b>
  Return information about the current font set.
</p>
<p>
  <b>Input Parameters:</b> None
</p>
<p>
  <b>Returned Value:</b>
  An instance of <code>struct nx_font_s</code> describing the font set.
</p>

<h3>2.5.3 <a name="nxfgetbitmap"><code>nxf_getbitmap()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nxfonts.h&gt;

FAR const struct nx_fontbitmap_s *nxf_getbitmap(uint16 ch);
</pre></ul>
<p>
  <b>Description:</b>
  Return font bitmap information for the selected character encoding.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code></code>
    <dd>
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  An instance of <code>struct nx_fontbitmap_s</code> describing the glyph.
</p>

<h3>2.5.4 <a name="nxfconvertbpp"><code>nxf_convert_*bpp()</code></a></h3>
<p><b>Function Prototype:</b></p>
<ul><pre>
#include &lt;nuttx/nxglib.h&gt;
#include &lt;nuttx/nxfonts.h&gt;

int nxf_convert_2bpp(FAR ubyte *dest, uint16 height,
                     uint16 width, uint16 stride, uint16 ch,
                     nxgl_mxpixel_t color);
int nxf_convert_4bpp(FAR ubyte *dest, uint16 height,
                     uint16 width, uint16 stride, uint16 ch,
                     nxgl_mxpixel_t color);
int nxf_convert_8bpp(FAR ubyte *dest, uint16 height,
                     uint16 width, uint16 stride, uint16 ch,
                     nxgl_mxpixel_t color);
int nxf_convert_16bpp(FAR uint16 *dest, uint16 height,
                      uint16 width, uint16 stride, uint16 ch,
                      nxgl_mxpixel_t color);
int nxf_convert_24bpp(FAR uint32 *dest, uint16 height,
                      uint16 width, uint16 stride, uint16 ch,
                      nxgl_mxpixel_t color);
int nxf_convert_32bpp(FAR uint32 *dest, uint16 height,
                      uint16 width, uint16 stride, uint16 ch,
                      nxgl_mxpixel_t color);
</pre></ul>
<p>
  <b>Description:</b> Convert the 1BPP font to a new pixel depth.
</p>
<p>
  <b>Input Parameters:</b>
  <ul><dl>
    <dt><code>dest</code>
    <dd>The destination buffer provided by the caller.
    <dt><code>height</code>
    <dd>The max height of the returned char in rows.
    <dt><code>width</code>
    <dd>The max width of the returned char in pixels.
    <dt><code>stride</code>
    <dd>The width of the destination buffer in bytes.
    <dt><code>ch</code>
    <dd>The character code to convert.
    <dt><code>color</code>
    <dd>The color to use for '1' bits in the font bitmap (0 bits are transparent).
  </dl></ul>
</p>
<p>
  <b>Returned Value:</b>
  On Success, these functions returns the actual width of the font in bytes.
  on failed, a negated <code>errno</code> is retured.
</p>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
    <td>
      <h1>Appendix A <a name="grapicsdirs"><code>graphics/</code> Directory Structure</a></h1>
    </td>
  </tr>
</table>

<ul>
  <dl>
    <dt><code>graphics/nxglib</code>
      <dd>The NuttX tiny graphics library.
      The directory contains generic utilities support operations on primitive graphics objects
      and logic to rasterize directly into a framebuffer.
      It has no concept of windows (other than the one, framebuffer  window).

    <dt><code>graphics/nxbe</code>
      <dd>This is the <i>back-end</i> of a tiny windowing system.
      It can be used with either of two front-ends to complete a windowing system (see
      <code>nxmu</code> and <code>nxsu/<code> below).
      It contains most of the important window management logic:  clipping, window controls,
      window drawing, etc.

    <dt><code>graphics/nxsu</code>
      <dd>This is the NX single user <i>front end</i>.
      When combined with the generic <i>back-end</i> (<code>nxbe</code>), it implements a
      single threaded, single user windowing system.
      The files in this directory present the window APIs described in
      <code>include/nuttx/nx.h</code>.
      The single user front-end is selected when <code>CONFIG_NX_MULTIUSER</code> is not
      defined in the NuttX configuration file.

    <dt><code>graphics/nxsu</code>
      <dd>This is the NX multi user <i>front end</i>.
      When combined with the generic <i>back-end</i> (<code>nxbe</code>), it implements a
      multi-threaded, multi-user windowing system.
      The files in this directory present the window APIs described in
      <code>include/nuttx/nx.h</code>.
      The multi-user front end includes a graphics server that executes on its own thread;
      multiple graphics clients then communicate with the server via a POSIX message
      queue to serialize window operations from many threads.
      The multi-user front-end is selected when <code>CONFIG_NX_MULTIUSER</code> is defined
      in the NuttX configuration file.

    <dt><code>graphics/nxfonts</code>
      <dd>This is where the NXFONTS implementation resides.
      This is a relatively low-level set of charset set/glyph management APIs.
      See <code>include/nuttx/nxfonts.h</code>.

    <dt><code>graphics/nxtk</code>
      <dd>This is where the NXTOOLKIT implementation resides.
      This toolkit is built on top of NX and works with either the single-user or
      multi-user NX version.
      See <code>include/nuttx/nxtk.h</code>.

    <dt><code>graphics/nxwidgets</code>
      <dd>At one time, I planned to put NXWIDGETS implementation here, but not anymore.
  </dl>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
    <td>
      <h1>Appendix B <a name="nxconfigs">NX Configuration Options</a></h1>
    </td>
  </tr>
</table>

<h2>B.1 <a name="nxgenconfig">General Configuration Settings</a></h2>

<ul>
  <dl>
    <dt><code>CONFIG_NX</code>
    Enables overall support for graphics library and NX
  </dl>
</ul>

<h2>B.2 <a name="nxglconfig">NXGL Configuration Settings</a></h2>

<ul>
  <dl>
    <dt><code>CONFIG_NX_NPLANES</code>:
      <dd>Some YUV color formats requires support for multiple planes,
      one for each color component.  Unless you have such special
      hardware, this value should be undefined or set to 1.
    <dt><code>CONFIG_NX_DISABLE_1BPP</code>, <code>CONFIG_NX_DISABLE_2BPP</code>,
    <code>CONFIG_NX_DISABLE_4BPP</code>, <code>CONFIG_NX_DISABLE_8BPP</code>
    <code>CONFIG_NX_DISABLE_16BPP</code>, <code>CONFIG_NX_DISABLE_24BPP</code>, and
    <code>CONFIG_NX_DISABLE_32BPP</code>:
      <dd>NX supports a variety of pixel depths.  You can save some
      memory by disabling support for unused color depths.
    <dt><code>CONFIG_NX_PACKEDMSFIRST</code>:
      <dd>If a pixel depth of less than 8-bits is used, then NX needs
      to know if the pixels pack from the MS to LS or from LS to MS
  </dl>
</ul>

<h2>B.3 <a name="nxconfig">NX Configuration Settings</a></h2>

<ul>
  <dl>
    <dt><code>CONFIG_NX_MOUSE</code>:
      <dd>Build in support for mouse input.
    <dt><code>CONFIG_NX_KBD</code>:
      <dd>Build in support of keypad/keyboard input.
  </dl>
</ul>

<h2>B.4 <a name="nxmuconfig">NX Multi-User (Only) Configuration Settings</a></h2>

<ul>
  <dl>
    <dt><code>CONFIG_NX_MULTIUSER</code>:
      <dd>Configures NX in multi-user mode.
    <dt><code>CONFIG_NX_BLOCKING</code>
      <dd>Open the client message queues in blocking mode.  In this case,
    <dt><code>nx_eventhandler()</code>  will not return until a message is received and processed.
    <dt><code>CONFIG_NX_MXSERVERMSGS</code> and <code>CONFIG_NX_MXCLIENTMSGS</code>
      <dd>Specifies the maximum number of messages that can fit in
      the message queues.  No additional resources are allocated, but
      this can be set to prevent flooding of the client or server with
      too many messages (<code>CONFIG_PREALLOC_MQ_MSGS</code> controls how many
      messages are pre-allocated).
  </dl>
</ul>

<h2>B.5 <a name="nxtkconfig">NXTK Configuration Settings</a></h2>

<ul>
  <dl>
    <dt><code>CONFIG_NXTK_BORDERWIDTH</code>:
      <dd>Specifies with with of the border (in pixels) used with
      framed windows.   The default is 4.
    <dt><code>CONFIG_NXTK_BORDERCOLOR1</code> and <code>CONFIG_NXTK_BORDERCOLOR2</code>:
      <dd>Specify the colors of the border used with framed windows.
    <dt><code>CONFIG_NXTK_BORDERCOLOR2</code> is the shadow side color and so
      <dd>is normally darker.  The default is medium and dark grey,
      respectively
    <dt><code>CONFIG_NXTK_AUTORAISE</code>:
      <dd>If set, a window will be raised to the top if the mouse position
      is over a visible portion of the window.  Default: A mouse
      button must be clicked over a visible portion of the window.
  </dl>
</ul>

<h2>B.6 <a name="nxfpmtsconfig">NXFONTS Configuration Settings</a></h2>

<ul>
  <dl>
    <dt><code>CONFIG_NXFONTS_CHARBITS</code>:
      <dd>The number of bits in the character set.  Current options are
      only 7 and 8.  The default is 7.
    <dt><code>CONFIG_NXFONT_SANS</code>:
      <dd>At present, there is only one font.  But if there were were more,
      then this option would select the sans serif font.
  </dl>
</ul>

<table width ="100%">
  <tr bgcolor="#e4e4e4">
    <td>
      <h1>Appendix C <a name="testcoverage">NX Test Coverage</a></h1>
    </td>
  </tr>
</table>

<p>
  The primary test tool for debugging NX resides at <code>examples/nx</code>.
  At present, that test only exercises a subset of NX; the remainder is essentially
  untested.
  The following table describes the testing performed on each NX API:
</p>

<center><h1>Table C.1: NX Test Coverage</h1></center>

<center><table border="1" width="50%">
  <tr><th><i>To be provided</i></th></tr>
</table></center>

</body>
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