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<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>glPushMatrix</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1" /></head><body><div class="refentry"><a id="glPushMatrix"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glPushMatrix, glPopMatrix — push and pop the current matrix stack</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glPushMatrix</strong>(</code></td><td><code>void)</code>;</td><td> </td></tr></table><div class="funcprototype-spacer"> </div><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glPopMatrix</strong>(</code></td><td><code>void)</code>;</td><td> </td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p>
        There is a stack of matrices for each of the matrix modes. In
        <code class="constant">GL_MODELVIEW</code>
        mode, the stack depth is at least 16. In the other modes,
        <code class="constant">GL_PROJECTION</code>, and
        <code class="constant">GL_TEXTURE</code>,
        the depth is at least 2. The current matrix in any mode is
        the matrix on the top of the stack for that mode.</p><p><code class="function">glPushMatrix</code>
        pushes the current matrix stack down by one, duplicating the
        current matrix. That is, after a <code class="function">glPushMatrix</code>
        call, the matrix on top of the stack is identical to the one
        below it.</p><p><code class="function">glPopMatrix</code>
        pops the current matrix stack, replacing the current matrix
        with the one below it on the stack.</p><p>Initially, each of the stacks contains one matrix, an
        identity matrix.</p><p>It is an error to push a full matrix stack, or to pop a
        matrix stack that contains only a single matrix. In either
        case, the error flag is set and no other change is made to GL
        state.</p></div><div class="refsect1"><a id="notes"></a><h2>Notes</h2><p>
            Each texture unit has its own texture matrix stack. Use
            <a class="citerefentry" href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>
            to select the desired texture matrix stack.
        </p></div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p><code class="constant">GL_STACK_OVERFLOW</code> is generated if
        <code class="function">glPushMatrix</code>
        is called while the current matrix stack is full.</p><p><code class="constant">GL_STACK_UNDERFLOW</code> is generated if
        <code class="function">glPopMatrix</code>
        is called while the current matrix stack contains only a single
        matrix.</p></div><div class="refsect1"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
            with argument <code class="constant">GL_MAX_MODELVIEW_STACK_DEPTH</code>
        </p><p>
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
            with argument <code class="constant">GL_MAX_PROJECTION_STACK_DEPTH</code>
        </p><p>
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
            with argument <code class="constant">GL_MAX_TEXTURE_STACK_DEPTH</code>
        </p><p>
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
            with argument <code class="constant">GL_MAX_TEXTURE_UNITS</code>
        </p></div><div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p>
            <a class="citerefentry" href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
            <a class="citerefentry" href="glFrustum.xml"><span class="citerefentry"><span class="refentrytitle">glFrustum</span></span></a>,
            <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>,
            <a class="citerefentry" href="glLoadIdentity.xml"><span class="citerefentry"><span class="refentrytitle">glLoadIdentity</span></span></a>,
            <a class="citerefentry" href="glLoadMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glLoadMatrix</span></span></a>,
            <a class="citerefentry" href="glMatrixMode.xml"><span class="citerefentry"><span class="refentrytitle">glMatrixMode</span></span></a>,
            <a class="citerefentry" href="glMultMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glMultMatrix</span></span></a>,
            <a class="citerefentry" href="glOrtho.xml"><span class="citerefentry"><span class="refentrytitle">glOrtho</span></span></a>,
            <a class="citerefentry" href="glRotate.xml"><span class="citerefentry"><span class="refentrytitle">glRotate</span></span></a>,
            <a class="citerefentry" href="glScale.xml"><span class="citerefentry"><span class="refentrytitle">glScale</span></span></a>,
            <a class="citerefentry" href="glTranslate.xml"><span class="citerefentry"><span class="refentrytitle">glTranslate</span></span></a>,
            <a class="citerefentry" href="glViewport.xml"><span class="citerefentry"><span class="refentrytitle">glViewport</span></span></a>
        </p></div><div class="refsect1"><a id="copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 2003-2004
            Silicon Graphics, Inc. This document is licensed under the SGI
            Free Software B License. For details, see
            <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
        </p></div></div></body></html>