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9<title>GXSetCopyClamp</title>
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13
14<h1 align="left">GXSetCopyClamp</h1>
15
16<h2>Syntax</h2>
17<dl><dd><pre class="construction">
18#include &lt;revolution/gx.h&gt;
19
20void GXSetCopyClamp( <a href="../Enumerated_Types/GXFBClamp.html">GXFBClamp</a> clamp );
21</pre></dd></dl>
22
23<h2>Arguments</h2>
24<TABLE class="arguments" border="1" >
25  <tr>
26<TH>clamp</TH>
27<TD>Clamp mode. The bit OR of <CODE><A href="../Enumerated_Types/GXFBClamp.html">GXFBClamp</CODE></A>. Accepted values are:<BR>
28      <TABLE class="arguments" border="1" >
29          <tr>
30<TD bgcolor="#C0C0C0">Name</TD>
31<TD bgcolor="#C0C0C0">where the clamp occurs</TD>
32          </tr>
33          <tr>
34<TH>GX_CLAMP_NONE</TH>
35<TD>no clamping</TD>
36          </tr>
37          <tr>
38<TH>GX_CLAMP_TOP</TH>
39<TD>the uppermost line</TD>
40          </tr>
41          <tr>
42<TH>GX_CLAMP_BOTTOM</TH>
43<TD>the lowest line</TD>
44          </tr>
45          <tr>
46<TH>GX_CLAMP_TOP | GX_CLAMP_BOTTOM</TH>
47<TD>both the uppermost and the lowest</TD>
48          </tr>
49      </TABLE>
50      </TD>
51    </tr>
52</TABLE>
53
54<h2>Return Values</h2>
55<p>None.</p>
56
57<H2>Description</H2>
58<P>This function sets the vertical clamping mode to use during the embedded frame buffer (EFB) to external frame buffer (XFB) or texture copy.</P>
59<P>If you use a vertical filter (see the <A href="GXSetCopyFilter.html"><code>GXSetCopyFilter</code></A> function), the GP looks up three contiguous lines at the same time for filtering during copy. This means some data can come from outside of the region specified in the <A href="GXSetDispCopySrc.html"><code>GXSetDispCopySrc</code></A> or <A href="GXSetTexCopySrc.html"><code>GXSetTexCopySrc</code></A> function when it copies the top-most line or bottom-most line. Vertical clamping avoids pulling samples from such out-of-regions. For example, usually the GP attempts to look up three lines <code>{top-1, top, top+1}</code> for copying the first line. But if clamping is working, the look-up becomes <code>{top, top, top+1}</code> and prevents the GP from looking up the line <code> (top-1)</code> which is out of region.</P>
60
61<h2>See Also</h2>
62<P class="reference">
63<a href="GXCopyDisp.html">GXCopyDisp</a>,
64<a href="GXCopyTex.html">GXCopyTex</a>
65</p>
66
67<H2>Revision History</H2>
68<P>
692006/03/01 Initial version.<br>
70</P>
71
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