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14<h1 align="left">G3_Ortho <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_Ortho(
22    fx32 t,
23    fx32 b,
24    fx32 l,
25    fx32 r,
26    fx32 n,
27    fx32 f,
28    MtxFx44 * mtx
29);</CODE></PRE></dd>
30</dl><h2>Arguments</h2>
31<TABLE border="1" width="100%">
32  <TBODY>
33    <TR>
34      <TD width="190"><em><strong><font face="Courier New">t</font></strong></em></TD>
35      <TD width="512">Y coordinate at the top of the near clipping plane</TD>
36    </TR>
37    <TR>
38      <TD width="190"><em><strong><font face="Courier New"><em><strong><code>b</code></strong></em>&nbsp;&nbsp;</font></strong></em></TD>
39      <TD width="512">Y coordinate at the bottom of the near clipping plane</TD>
40    </TR>
41    <TR>
42      <TD><em><strong><font face="Courier New">l</font></strong></em></TD>
43      <TD>X coordinate at the left of the near clipping plane</TD>
44    </TR>
45    <TR>
46      <TD><em><strong><font face="Courier New">r</font></strong></em></TD>
47      <TD>X coordinate at the right of the near clipping plane</TD>
48    </TR>
49    <TR>
50      <TD><em><strong><font face="Courier New">n</font></strong></em></TD>
51      <TD>Distance from viewpoint to the near clipping plane</TD>
52    </TR>
53    <TR>
54      <TD><em><strong><font face="Courier New">f</font></strong></em></TD>
55      <TD>Distance from viewpoint to the far clipping plane</TD>
56    </TR>
57    <TR>
58      <TD width="190"><em><strong><font face="Courier New">mtx</font></strong></em></TD>
59      <TD width="512">Pointer to a 4x4 matrix</TD>
60    </TR>
61  </TBODY>
62</TABLE>
63<h2>Return Values</h2>
64<p>None.</p>
65<H2>Description</H2>
66<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>
67<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. W buffering will not function properly because the depth value will always be fixed.</P>
68<P><span lang=EN-US style='font-size:10.5pt;mso-bidi-font-size: 12.0pt;font-family:Century;mso-fareast-font-family:"MS ??";mso-bidi-font-family: "Times New Roman";mso-font-kerning:1.0pt;mso-ansi-language:EN-US;mso-fareast-language: JA;mso-bidi-language:AR-SA'><span style='mso-text-raise:-58.0pt'><IMG width="205" height="163" src="geo_ortho.gif" v:shapes="_x0000_i1025"></span></span></P>
69<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>
70
71<h2>See Also</h2>
72<P><code><a href="G3_OrthoW.html">G3_OrthoW</a>, <a href="G3_Frustum.html">G3_Frustum</a>, <a href="G3_Perspective.html">G3_Perspective</a></code></P>
73<H2>Revision History</H2>
74<P>2004/02/09</P>
75<UL>
76  <LI>Added a note.
77</UL>
78<P>2004/01/19 Initial version.</P>
79<hr><p>CONFIDENTIAL</p></body>
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81