1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3 4<head> 5<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 6<META name="GENERATOR" content="Microsoft FrontPage 5.0"> 7<META http-equiv="Content-Style-Type" content="text/css"> 8<LINK rel="stylesheet" type="text/css" href="../../CSS/revolution.css"> 9<title>GXMatrixIndex</title> 10</head> 11 12<body> 13 14<h1 align="left">GXMatrixIndex</h1> 15 16<h2>C Specification</h2> 17 18<dl> 19<dd><pre><CODE>#include <revolution/gx.h></CODE></pre></dd> 20<dd><pre><CODE>void GXMatrixIndex1u8 ( u8 index ); 21void GXMatrixIndex1x8 ( u8 index );</CODE></pre></dd> 22</dl> 23<h2>Arguments</h2> 24<TABLE border="1" cellpadding="3" cellspacing="0.1"> 25 <tr> 26<TD width="120" valign="top" bgcolor="#ffffe8"><em><strong><CODE>index</CODE></strong></em></TD> 27<TD width="520">Unsigned, eight-bit index to matrix memory. This number represents the first row of matrix memory where the matrix is loaded.</TD> 28 </tr> 29</TABLE> 30<h2>Return Values</h2> 31<P>None.</P> 32<H2>Description</H2> 33<P>This function is used to specify matrix index data for a vertex. It can only be called between <a href="GXBegin.html"><code>GXBegin</code></a> and <a href="GXEnd.html"><code>GXEnd</code></a>. The matrix index specifies which matrix (previously loaded into matrix memory, see <a href="../Transform/GXLoadPosMtxImm.html"><code>GXLoadPosMtxImm</code></a>, <a href="../Transform/GXLoadNrmMtxImm.html"><code>GXLoadNrmMtxImm</code></a>, and <a href="../Transform/GXLoadTexMtxImm.html"><code>GXLoadTexMtxImm</code></a>) to use to transform this vertex's data.<br></P> 34<P>To use this function for a vertex, you must enable a matrix index in the <em>current vertex descriptor</em>. The current vertex descriptor is set using <a href="GXSetVtxDesc.html"><code>GXSetVtxDesc</code></a>. There is no need to set a <em>vertex attribute format</em> (<a href="GXSetVtxAttrFmt.html"><code>GXSetVtxAttrFmt</code></a>) because the index must be an unsigned eight-bit number. Both <code>GXMatrixIndex1u8</code> and <code>GXMatrixIndex1x8</code> are identical.</P> 35<P>The order in which vertex functions must be called is specified by <a href="GXSetVtxDesc.html"><code>GXSetVtxDesc</code></a>. Each vertex must send attributes (positions, colors, normals, etc.) in the specified order to guarantee proper interpretation by the graphics hardware. </P> 36<P>The <code>GXMatrixIndex1u8(GXMatrixIndex1x8)</code> is implemented as an inline function in the non-debug version of the <code>GX</code> library for optimal performance. The <code>GXMatrixIndex1u8(GXMatrixIndex1x8)</code> is implemented as a regular function in the debug version of the <code>GX</code> library so the library can verify the correct order of vertex function calls between <code><a href="GXBegin.html">GXBegin</a>/<a href="GXEnd.html">GXEnd</a></code> (a common source of errors).</P> 37 38<h2>See Also</h2> 39 40<p><a href="GXBegin.html">GXBegin</a> <br> <a href="GXEnd.html">GXEnd</a><br> <a href="GXSetVtxDesc.html">GXSetVtxDesc</a><br> <a href="GXSetVtxAttrFmt.html">GXSetVtxAttrFmt</a></p> 41<H2>Revision History</H2> 42<P>03/01/2006 Initial version.</P> 43</BODY> 44</HTML>