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13<H1 align="left">AXART_LFO</H1>
14
15<H2>Syntax</H2>
16<dl><dd><pre class="construction">
17#include &lt;revolution.h&gt;
18#include &lt;revolution/axart.h&gt;
19
20typedef struct
21{
22    f32         *lfo;           // lfo samples in RAM
23    u32         length;         // lfo samples for 1 period
24    f32         delta;          // lfo delta per 5ms
25
26    u32         sampleIndex;    // lfo sample index
27    f32         counter;        // lfo counter
28    f32         sample1;        // lfo last sample for interpolation
29    f32         sample;         // lfo sample
30    f32         output;         // lfo output
31
32} AXART_LFO;
33</pre></dd></dl>
34
35<h2>Elements</h2>
36<TABLE class="arguments" border="1" >
37  <TR>
38<TH>lfo</TH>
39<TD>Pointer to the first sample of LFO shape in RAM. This parameter is maintained by AXART. Do not write to this parameter.</TD>
40  </TR>
41  <TR>
42<TH>length</TH>
43<TD>Number of samples for the LFO. This parameter is maintained by AXART. Do not write to this parameter.</TD>
44  </TR>
45  <TR>
46<TH>delta</TH>
47<TD>Sample index delta per audio frame. This sets period frequency for the LFO.<BR><CODE>delta =&nbsp; Hz * (length / 200).</CODE><BR> This parameter may be edited at any time.</TD>
48  </TR>
49  <TR>
50<TH>sampleIndex</TH>
51<TD>Current sample index for LFO output. This parameter is maintained by AXART. Do not write to this parameter.</TD>
52  </TR>
53  <TR>
54<TH>counter</TH>
55<TD>Running counter for output sample interpolation. Interpolation is linear. This parameter is maintained by AXART. Do not write to this parameter.</TD>
56  </TR>
57  <TR>
58<TH>sample1</TH>
59<TD>Last LFO sample for interpolation. This parameter is maintained by AXART. Do not write to this parameter.</TD>
60  </TR>
61  <TR>
62<TH>sample</TH>
63<TD>Current LFO sample for interpolation. This parameter is maintained by AXART. Do not write to this parameter.</TD>
64  </TR>
65  <TR>
66<TH>output</TH>
67<TD>Output for LFO.&nbsp;This parameter is maintained by AXART. Do not write to this parameter.</TD>
68  </TR>
69</TABLE>
70
71<H2>Description</H2>
72<P><CODE>AXART_LFO</CODE> is a data structure for an LFO. <CODE>AXART_LFO</CODE> is used by articulators that modulate volume or pitch. To apply an articulator containing an LFO to an <CODE>AXART_SOUND</CODE>, <CODE>AXART_LFO</CODE> must be initialized by calling the <CODE>AXARTInitLfo</CODE> function before calling the <CODE>AXARTAddArticulator</CODE> function.</P>
73
74<H2>See Also</H2>
75<P class="reference">
76<A href="AXARTInitLfo.html">AXARTInitLfo</A><br><A href="AXARTAddArticulator.html">AXARTAddArticulator</A><br><A href="AXART_SOUND.html">AXART_SOUND</A>
77</P>
78
79<H2>Revision History</H2>
80<P>
812006/03/01 Initial version.<BR>
82</P>
83
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