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14<h1 align="left">GX_IsVBlank <img src="../../image/NTR.gif"align="middle"><img src="../../image/TWL.gif" align="middle"></H1>
15<H2>Syntax</H2>
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17<dl>
18  <dd>
19<PRE><CODE>#include &lt;nitro/gx/gx.h&gt;
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21s32 GX_IsVBlank();<BR></CODE></PRE>
22  </dd>
23</dl><h2>Arguments</h2>
24<P>None.</P>
25<h2>Return Values</h2>
26<p>Not in V-Blank period (0), or in V-Blank period (other than 0).</p>
27<H2>Description</H2>
28<P>This function determines whether the program is in the V-Blank period. It returns a value other than 0 when in the V-Blank period; it returns 0 when not in the V-Blank period.</P>
29<H2>Note</H2>
30<P></strong> The hardware V-Blank flag is set to 1 when line 192 starts and to 0 when line 262 starts. Because the function uses this flag value to determine when the hardware is in a V-Blank period, be aware that the V-Blank period is when the V-counter value is the 192-261 range. This does not include 262.</P>
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32<h2>See Also</h2>
33<P><CODE><A href="GX_VBlankIntr.html">GX_VBlankIntr</A></CODE>, <CODE><A href="GX_IsHBlank.html">GX_IsHBlank</A></CODE></P>
34<H2>Revision History</H2>
35<P>
362005/02/17 Added caution about V-Blank period.<br /> 2004/01/19 Initial version.
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38<hr><p>CONFIDENTIAL</p></body>
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