1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 5<META name="GENERATOR" content="Microsoft FrontPage 5.0"> 6<META http-equiv="Content-Style-Type" content="text/css"> 7<LINK rel="stylesheet" type="text/css" href="../../CSS/revolution.css"> 8<TITLE>VECDotProduct</TITLE> 9</HEAD> 10<BODY> 11<H1 align="left">VECDotProduct</H1> 12<H2 align="left">C Specification</H2> 13<BLOCKQUOTE><CODE><CODE>#include <revolution/mtx.h></CODE></CODE></BLOCKQUOTE> 14<BLOCKQUOTE><CODE><CODE>f32 C_VECDotProduct ( const Vec* <EM>a</EM>, const Vec* <EM>b</EM> );<BR> f32 PSVECDotProduct ( const Vec* <EM>a</EM>, const Vec* <EM>b</EM> );<BR> <BR> #define VECDotProduct C_VECDotProduct // for debug build<BR> #define VECDotProduct PSVECDotProduct // for nondebug build</CODE></CODE></BLOCKQUOTE> 15<H2 align="left">Arguments</H2> 16<DIV align="left"> 17<TABLE border="1" cellpadding="3" cellspacing="0.1"> 18 <TBODY> 19 <TR> 20<TD width="120" bgcolor="#ffffe8"><CODE><STRONG><EM>a</EM></STRONG></CODE></TD> 21<TD width="520" valign="top" align="left">Pointer to first <CODE><A href="../structures/Vec_VecPtr.html">Vec</A></CODE>. <em><strong><code>a</code></strong></em> is not altered by this function.</TD> 22 </TR> 23 <TR> 24<TD width="120" bgcolor="#ffffe8"><CODE><STRONG><EM><em><strong><code>b</code></strong></em> </EM></STRONG></CODE></TD> 25<TD width="520">Pointer to second <CODE><A href="../structures/Vec_VecPtr.html">Vec</A></CODE>. <code><em><strong>b</strong></em></code> is not altered by this function.</TD> 26 </TR> 27 </TBODY> 28</TABLE> 29</DIV> 30<H2 align="left">Return Values</H2> 31<P align="left">Dot product of <code><em><strong>a</strong></em></code> and <code><em><strong>b</strong></em></code>.</P> 32<H2 align="left">Description</H2> 33<P>Finds the inner product of two vectors. <CODE><STRONG><EM>a</EM></STRONG></CODE> and <CODE><STRONG><EM>b</EM></STRONG></CODE> do not need to be unit vectors and are not normalized inside this function. In order to use <CODE>VECDotProduct</CODE> to calculate the cosine directly, <CODE><STRONG><EM>a</EM></STRONG></CODE> and <CODE><STRONG><EM>b</EM></STRONG></CODE> must be normalized before calling this routine. </P> 34<P>During a debug build, <code>VECDotProduct</code> is interpreted as <code>C_VECDotProduct</code>, which is a normal C language version. During a non-debug build for a Broadway processor, the paired-singles equivalent of this function, <code>PSVECDotProduct</code>, will be automatically substituted. You can also call <code>C_VECDotProduct</CODE> or <CODE>PSVECDotProduct</code> explicitly.</P> 35 36 37<H2 align="left">See Also</H2> 38<P align="left"><A href="../structures/Vec_VecPtr.html"><CODE>Vec, VecPtr, </CODE></A><A href="VECCrossProduct.html"><CODE>VECCrossProduct</CODE></A></P> 39<H2>Revision History</H2> 40<P>2006/03/01 Initial version.</P> 41<hr> 42<P>CONFIDENTIAL</p> 43</BODY> 44</HTML>