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Do <em>not</em> +compile it as a TQt/Embedded application. +<li> Start a TQt/Embedded master application (i.e., construct +<a href="qapplication.html">TQApplication</a> with the TQApplication::GuiServer flag or use the <tt>-qws</tt> command line parameter). You can specify to the server that +you wish to use the virtual framebuffer driver, e.g.: +<pre> + masterapp -qws -display TQVFb:0 + </pre> + +<li> TQt/Embedded will autodetect qvfb, so you can omit the <tt>-display</tt> +command line parameter if you know that qvfb is running, and that +the TQt/Embedded library supports qvfb. (If this is not the case, +TQt/Embedded will write to the real framebuffer, and your X11 +display will be corrupted.) +<p> </ol> +<p> <tt>qvfb</tt> supports the following command line options: +<p> <center><table cellpadding="4" cellspacing="2" border="0"> +<tr bgcolor="#a2c511"> <th valign="top">Option <th valign="top">Meaning +<tr bgcolor="#f0f0f0"> +<td valign="top"><tt>-width</tt> <em>width</em> +<td valign="top">the width of the virtual framebuffer (default: 240). +<tr bgcolor="#d0d0d0"> +<td valign="top"><tt>-height</tt> <em>height</em> +<td valign="top">the height of the virtual framebuffer (default: 320). +<tr bgcolor="#f0f0f0"> +<td valign="top"><tt>-depth</tt> <em>depth</em> +<td valign="top">the depth of the virtual framebuffer (1, 8 or 32; default: 8). +<tr bgcolor="#d0d0d0"> +<td valign="top"><tt>-nocursor</tt> +<td valign="top">do not display the X11 cursor in the framebuffer window. +<tr bgcolor="#f0f0f0"> +<td valign="top"><tt>-qwsdisplay</tt> <em>:id</em> +<td valign="top">the TQt/Embedded display id to provide (default: :0). +</table></center> +<p> <h2> Virtual Framebuffer Design +</h2> +<a name="2"></a><p> The virtual framebuffer emulates a framebuffer using a shared memory region +(the virtual frame buffer) and a utility to display the framebuffer in a +window (<tt>qvfb</tt>). The regions of the display that have changed are updated +periodically, so you will see discrete snapshots of the framebuffer rather +than each individual drawing operation. For this reason drawing problems +such as flickering may not be apparent until the program is run using a real +framebuffer. +<p> The target refresh rate can be set via the <b>View|Refresh Rate</b> +menu item. This will cause <tt>qvfb</tt> to check for updated regions more +frequently. The rate is a target only. If little drawing is being +done, the framebuffer will not show any updates between drawing +events. If an application is displaying an animation the updates will +be frequent, then the application and <tt>qvfb</tt> will compete for +processor time. +<p> Mouse and keyboard events are passed to the TQt/Embedded master process via +named pipes. +<p> The virtual framebuffer is a development tool only. No security issues have +been considered in the virtual framebuffer design. It should be avoided +in a production environment; do not configure production libraries with <tt>-qvfb</tt>. +<p> +<!-- eof --> +<p><address><hr><div align=center> +<table width=100% cellspacing=0 border=0><tr> +<td>Copyright © 2007 +<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> +<td align=right><div align=right>TQt 3.3.8</div> +</table></div></address></body> +</html> |