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8<TITLE>MTXPop</TITLE>
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11<H1 align="left">MTXPop</H1>
12<H2 align="left">C Specification</H2>
13<BLOCKQUOTE><CODE><CODE>#include &lt;revolution/mtx.h&gt;</CODE></CODE></BLOCKQUOTE>
14<BLOCKQUOTE><CODE><CODE>MtxPtr MTXPop ( MtxStack* <EM>sPtr</EM> );</CODE></CODE></BLOCKQUOTE>
15<H2 align="left">Arguments</H2>
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20<TD width="120" bgcolor="#ffffe8"><CODE><STRONG><EM>sPtr</EM></STRONG></CODE></TD>
21<TD width="520" valign="top" align="left">Pointer to a <A href="../structures/MtxStack_MtxStackPtr.html"><code>MtxStack</code></a> structure whose member <strong>stackPtr</strong> is to be decreased.</TD>
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26<H2 align="left">Return Values</H2>
27<P>Returns the new stack pointer (old stack pointer - <code>MTX_PTR_OFFSET</code>) if the old stack pointer was greater than stack base; <br> otherwise, returns <code><strong>NULL</strong></code> (empty stack).</P>
28<H2 align="left">Description</H2>
29<P>Decreases <code><em><strong>sPtr</strong></em></code>'s member <strong>stackPtr</strong> by one matrix (<code><strong><em>sPtr</em>-&gt;stackPtr</strong>&nbsp;-=&nbsp;MTX_PTR_OFFSET</code>), in effect popping it from the stack.&nbsp;The popped matrix's memory is untouched until overwritten by a 'push' call.</P>
30<P>If the stack pointer was equal to the stack base, <code><strong><em>sPtr</em>-&gt;stackPtr</strong></code> is set to <code><strong>NULL</strong></code>, indicating an empty stack.</P>
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33<H2 align="left">See Also</H2>
34<P align="left"><A href="../structures/Mtx_MtxPtr.html"><CODE>Mtx, MtxPtr</CODE></A>, <A href="../structures/MtxStack_MtxStackPtr.html"><CODE>MtxStack, MtxStackPtr</CODE></A>, <A href="MTXGetStackPtr.html"><CODE>MTXGetStackPtr</CODE></A>, <A href="MTXPush.html"><CODE>MTXPush</CODE></A>, <A href="MTXPushFwd.html"><CODE>MTXPushFwd</CODE></A>, <CODE><A href="MTXPushInv.html">MTXPushInv</A></CODE>, <A href="MTXPushInvXpose.html"><CODE>MTXPushInvXpose</CODE></A></P>
35<H2>Revision History</H2>
36<P>03/01/2006 Initial version.</P>
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