1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3 4<head> 5<LINK rel="stylesheet" type="text/css" href="../../CSS/revolution.css"> 6<TITLE>AXART_LFO</TITLE> 7<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 8<META http-equiv="Content-Style-Type" content="text/css"> 9</head> 10 11<BODY> 12 13<H1 align="left">AXART_LFO</H1> 14 15<H2>C Specification</H2> 16<DL> 17 <dd><pre><CODE>#include <revolution.h> 18#include <revolution/axart.h></CODE></pre> 19 </dd> 20 <dd> 21 <PRE><CODE>typedef struct 22{ 23 f32 *lfo; // lfo samples in RAM 24 u32 length; // lfo samples for 1 period 25 f32 delta; // lfo delta per 5ms 26 27 u32 sampleIndex; // lfo sample index 28 f32 counter; // lfo counter 29 f32 sample1; // lfo last sample for interpolation 30 f32 sample; // lfo sample 31 f32 output; // lfo output 32 33} AXART_LFO;</CODE></PRE> 34 </dd> 35</DL> 36 37<H2>Description</H2> 38<P><font face="Courier New">AXART_LFO</font> is a data structure for an LFO. <font face="Courier New">AXART_LFO</font> is used by articulators that modulate volume or pitch. To apply an articulator containing an LFO to an <a href="AXART_SOUND.html"><font face="Courier New">AXART_SOUND</font></a>, the <font face="Courier New">AXART_LFO</font> must be initialized by calling <a href="AXARTInitLfo.html"><font face="Courier New">AXARTInitLfo()</font></a> prior to calling <a href="AXARTAddArticulator.html"><font face="Courier New">AXARTAddArticulator()</font></a>.</P> 39<TABLE border="1" cellpadding="3" cellspacing="0.1"> 40 <TBODY> 41 <TR> 42<TD width="120" bgcolor="#cccccc"><EM><STRONG>Data Member</STRONG></EM></TD> 43<TD width="520" bgcolor="#cccccc"><EM><STRONG>Description</STRONG></EM></TD> 44 </TR> 45 <TR> 46<TD width="120"><FONT face="Courier New">f32 *lfo</FONT></TD> 47<TD width="520">Pointer to the first sample of LFO shape in RAM. This parameter is maintained by AXART. Do not write to this parameter.</TD> 48 </TR> 49 <TR> 50<TD width="120"><FONT face="Courier New">u32 length</FONT></TD> 51<TD width="520">Number of samples for the LFO. This parameter is maintained by AXART. Do not write to this parameter.</TD> 52 </TR> 53 <TR> 54<TD width="120"><FONT face="Courier New">f32 delta</FONT></TD> 55<TD width="520">Sample index delta per audio frame. This sets period frequency for the LFO.<BR>delta = Hz * (length / 200).<BR> The user may change this at any time.</TD> 56 </TR> 57 <TR> 58<TD width="120"><FONT face="Courier New">u32 sampleIndex</FONT></TD> 59<TD width="520">Current sample index for LFO output. This parameter is maintained by AXART. Do not write to this parameter.</TD> 60 </TR> 61 <TR> 62<TD width="120"><FONT face="Courier New">f32 counter</FONT></TD> 63<TD width="520">Running counter for output sample interpolation. Interpolation is linear. This parameter is maintained by AXART. Do not write to this parameter.</TD> 64 </TR> 65 <TR> 66<TD width="120"><FONT face="Courier New">f32 sample1</FONT></TD> 67<TD width="520">Last LFO sample for interpolation. This parameter is maintained by AXART. Do not write to this parameter.</TD> 68 </TR> 69 <TR> 70<TD width="120"><FONT face="Courier New">f32 sample</FONT></TD> 71<TD width="520">Current LFO sample for interpolation. This parameter is maintained by AXART. Do not write to this parameter.</TD> 72 </TR> 73 <TR> 74<TD width="120"><FONT face="Courier New">f32 output</FONT></TD> 75<TD width="520">Output for LFO. This parameter is maintained by AXART. Do not write to this parameter.</TD> 76 </TR> 77 </TBODY> 78</TABLE> 79 80<H2>See Also</H2> 81<P><FONT face="Courier New"><A href="AXARTInitLfo.html">AXARTInitLfo<BR></A><A href="AXARTAddArticulator.html">AXARTAddArticulator<BR></A><A href="AXART_SOUND.html">AXART_SOUND</A></FONT></P> 82 83<H2>Revision History</H2> 84<P>2006/03/01 Initial version.</P> 85 86<hr> 87<P>CONFIDENTIAL</p> 88</BODY> 89</HTML> 90