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8<TITLE>MTXLightOrtho</TITLE>
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11<H1 align="left">MTXLightOrtho</H1>
12<H2 align="left">C Specification</H2>
13<BLOCKQUOTE><CODE><CODE>#include &lt;revolution/mtx.h&gt;<BR> <BR> void MTXLightOrtho(<BR> &nbsp;&nbsp;&nbsp; Mtx <EM>m</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>t</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>b</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>l</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>r</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>scaleS</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>scaleT</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>transS</EM>,<BR> &nbsp;&nbsp;&nbsp; f32 <EM>transT</EM> );<BR></CODE></CODE></BLOCKQUOTE>
14<H2 align="left">Arguments</H2>
15<DIV align="left">
16<TABLE border="1" cellpadding="3" cellspacing="0.1">
17  <TBODY>
18    <TR>
19<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>m</EM></STRONG></CODE></TD>
20<TD width="520"></EM></STRONG></CODE>New 3x4 parallel projection matrix.&nbsp;<code><em><strong>m</strong></em></code> may be either an <a href="../structures/Mtx_MtxPtr.html">Mtx</a> or an <a href="../structures/Mtx_MtxPtr.html">MtxPtr</a>..</TD>
21    </TR>
22    <TR>
23<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>t</EM></STRONG></CODE></TD>
24<TD width="520">Top edge of view volume.</TD>
25    </TR>
26    <TR>
27<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>b</EM></STRONG></CODE></TD>
28<TD width="520">Bottom edge of view volume.</TD>
29    </TR>
30    <TR>
31<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>l</EM></STRONG></CODE></TD>
32<TD width="520">Left edge of view volume.</TD>
33    </TR>
34    <TR>
35<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>r</EM></STRONG></CODE></TD>
36<TD width="520">Right edge of view volume.</TD>
37    </TR>
38    <TR>
39<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>scaleS</EM></STRONG></CODE></TD>
40<TD width="520">Scale in the <EM>S</EM> direction for projected coordinates (usually 0.5).</TD>
41    </TR>
42    <TR>
43<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>scaleT</EM></STRONG></CODE></TD>
44<TD width="520">Scale in the <EM>T</EM> direction for projected coordinates (usually 0.5).</TD>
45    </TR>
46    <TR>
47<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>transS</EM></STRONG></CODE></TD>
48<TD width="520">Translate in the <EM>S</EM> direction for projected coordinates (usually 0.5).</TD>
49    </TR>
50    <TR>
51<TD width="120" valign="top" align="left" bgcolor="#ffffe8"><CODE><STRONG><EM>transT</EM></STRONG></CODE></TD>
52<TD width="520">Translate in the <EM>T</EM> direction for projected coordinates (usually 0.5).</TD>
53    </TR>
54  </TBODY>
55</TABLE>
56</DIV>
57<H2 align="left">Return Values</H2>
58<P align="left">None.</P>
59<H2 align="left">Description</H2>
60<P>Sets a 3x4 matrix for orthographic projection.&nbsp;This matrix is used to project points into texture space and yield texture coordinates.</P>
61<P>For normal parallel projections, the axis of projection is the -z axis, so <code><em><strong>t</strong></em></code> = positive, <code><em><strong>b</strong></em></code> = <code>-<em><strong>t</strong></em></code>,<em><strong> <code>r</code></strong></em> = positive,<em><strong> <code>l</code></strong></em> = <code>-<em><strong>r</strong></em></code>.</P>
62<P align="left">Standard projection yields values ranging from -1.0 to 1.0 in both dimensions of the front clipping plane.&nbsp;Since texture coordinates should usually be within the range of 0.0 to 1.0, we have added a scale and translation value for both <EM>S</EM> and <EM>T</EM>.&nbsp;The most common way to use these values is to set all of them to 0.5 (so that points in the range of -1.0 to 1.0 are first scaled by 0.5) to be in the range of -0.5 to 0.5.&nbsp;Then they are translated by 0.5 to be in the range of 0.0 to 1.0.&nbsp;Other values can be used for translation and scale to yield different effects.</P>
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65<H2 align="left">See Also</H2>
66<P align="left"><A href="../structures/Mtx_MtxPtr.html"><CODE>Mtx, MtxPtr</CODE></A>, <A href="MTXLightFrustum.html"><CODE>MTXLightFrustum</CODE></A>, <A href="MTXLightPerspective.html"><CODE>MTXLightPerspective</CODE></A></P>
67<H2>Revision History</H2>
68<P>2006/03/01 Initial version.</P>
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70<P>CONFIDENTIAL</p>
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