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="IBM WebSphere Studio Homepage Builder Version 8.0.0.0 for Windows">
7<META http-equiv="Content-Style-Type" content="text/css">
8<title>G3_OrthoW</title>
9<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css">
10</head>
11
12<body>
13
14<h1 align="left">G3_OrthoW <img src="../../image/NTR.gif"align="middle"><img src="../../image/TWL.gif" align="middle"></H1>
15<H2>Syntax</H2>
16
17<dl>
18  <dd>
19<PRE>
20<CODE>#include &lt;nitro/gx/g3_util.h&gt;</CODE><BR>
21<CODE>void G3_OrthoW(
22    fx32 t,
23    fx32 b,
24    fx32 l,
25    fx32 r,
26    fx32 n,
27    fx32 f,
28    fx32 scaleW,
29    MtxFx44 * mtx
30);</CODE></PRE></dd>
31</dl><h2>Arguments</h2>
32<TABLE border="1" width="100%">
33  <TBODY>
34    <TR>
35      <TD width="190"><em><strong><font face="Courier New">t</font></strong></em></TD>
36      <TD width="512">Y coordinate at the top of the near clipping plane</TD>
37    </TR>
38    <TR>
39      <TD width="190"><em><strong><font face="Courier New"><em><strong><code>b</code></strong></em>&nbsp;&nbsp;</font></strong></em></TD>
40      <TD width="512">Y coordinate at the bottom of the near clipping plane</TD>
41    </TR>
42    <TR>
43      <TD><em><strong><font face="Courier New">l</font></strong></em></TD>
44      <TD>X coordinate at the left of the near clipping plane</TD>
45    </TR>
46    <TR>
47      <TD><em><strong><font face="Courier New">r</font></strong></em></TD>
48      <TD>X coordinate at the right of the near clipping plane</TD>
49    </TR>
50    <TR>
51      <TD><em><strong><font face="Courier New">n</font></strong></em></TD>
52      <TD>Distance from viewpoint to the near clipping plane</TD>
53    </TR>
54    <TR>
55      <TD><em><strong><font face="Courier New">f</font></strong></em></TD>
56      <TD>Distance from viewpoint to the far clipping plane</TD>
57    </TR>
58    <TR>
59      <TD><em><strong><font face="Courier New">scaleW</font></strong></em></TD>
60      <TD>Precision adjustment parameter for the view volume</TD>
61    </TR>
62    <TR>
63      <TD width="190"><em><strong><font face="Courier New">mtx</font></strong></em></TD>
64      <TD width="512">Pointer to a 4x4 matrix</TD>
65    </TR>
66  </TBODY>
67</TABLE>
68<h2>Return Values</h2>
69<p>None.</p>
70<H2>Description</H2>
71<P>This function sets the Matrix mode to the Projection mode. This function also sets the Orthogonal Projection matrix as the current matrix. If <em><strong><code>mtx</code></strong></em> is not <code>NULL</code>, then the Orthogonal Projection matrix is also set in *<em><strong><code>mtx</code></strong></em>. The diagram shows the matrix that is set.</P>
72<P><strong>Note:</strong> When setting the matrix for an orthogonal projection, it is necessary to select Z-buffering with the <CODE><A href="G3_SwapBuffers.html" target="_self">G3*_SwapBuffers</A></CODE> functions. The operation is not guaranteed if W-buffering is used, since the depth value is constant.</P>
73<P><IMG width="205" height="163" src="geo_ortho.gif" align="middle" v:shapes="_x0000_i1025"> &times; <I>scaleW</I></P>
74<P>The divider is used internally. Refer to <A href="../../cp/div/about_div.html#use_in_intr">Divider Usage Notes</A> when using this function inside an interrupt.</P>
75
76
77<h2>See Also</h2>
78<P><code><A href="G3_Ortho.html">G3_Ortho</A>, <A href="G3_FrustumW.html">G3_FrustumW</A>,<A href="G3_PerspectiveW.html">G3_PerspectiveW</A></code></P>
79<H2>Revision History</H2>
80
81<P>2004/04/27 Initial version.</P>
82<hr><p>CONFIDENTIAL</p></body>
83</html>
84