<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="../xsl/variable.xsl"?>
<variable xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../xsd/variable.xsd">
  <name>vid_nopageflip</name>
  <description>This variable toggles the use of page-flipping during supported video modes. By 
default the game will allow for page-flipping for video modes that support this 
feature. For example if a given VESA mode can support page flipping, then it 
defaults to page-flipped operation.  A VESA mode can be forced to 
non-page-flipped operation by setting the &quot;vid_nopageflip&quot; variable to &quot;1&quot;, then
setting the mode (note that &quot;vid_nopageflip&quot; takes operation on the next, 
not the current video mode, and note that it then stays in effect permanently, 
even when the client is exited and restarted, unless it is manually set back to &quot;0&quot;).
If there is not enough memory for two pages in a VESA mode, or if the adapter 
doesn't support page flipping, then the mode will automatically be 
non-page-flipped.  
Page-flipping works by drawing multiple virtual game screens at the same time in 
the video memory and then switching among them to display the current 
gamescreen. Page-flipped modes thus use less system memory than non-page-flipped 
modes, but require more video memory. When using page-flipping, visual quality 
may be higher, but performance of the game can change to better or worse, 
depending on the graphics adapter and other hardware (see the discussion of the 
Pentium Pro below, for a discussion of why page flipping can be faster but is 
sometimes much slower on that processor). However in most cases the performance 
(and thus frame rate) will be increased, but for people with hardware that has 
problems with page-flipping &quot;vid_nopageflip 1&quot; may help.
The Pentium Pro is an example for such a hardware: it is an okay client platform (sniff!), 
but it has one weak spot, it is by default very slow on writes to video memory.  
This means that in default hardware configurations, you are usually much better 
off setting &quot;vid_nopageflip&quot; to &quot;1&quot; if you use VESA modes, so drawing is done to 
system memory instead of to video memory. Remember that you must set the mode
after setting &quot;vid_nopageflip&quot; to &quot;1&quot; in order to get &quot;vid_nopageflip&quot; to take
effect. &quot;vid_nopageflip 1&quot; can sometimes be faster on a Pentium too, but not by 
nearly as much in general, and it's often slower.</description>
  <value>
    <float></float>
  </value>
</variable>
