Help/UGens/Multichannel/Panners/Rotate2.html

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  26 <p class="p1"><span class="s1"><b>Rotate2<span class="Apple-tab-span">  </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></b></span><b>Rotate a sound field</b></p>
  27 <p class="p2"><br></p>
  28 <p class="p3"><b>Rotate2.kr(x, y, pos)</b></p>
  29 <p class="p4"><br></p>
  30 <p class="p3">Rotate2 can be used for rotating an ambisonic B-format sound field around an axis.</p>
  31 <p class="p3">Rotate2 does an equal power rotation so it also works well on stereo sounds.</p>
  32 <p class="p3">It takes two audio inputs (x, y) and an angle control (pos).</p>
  33 <p class="p3">It outputs two channels (x, y).</p>
  34 <p class="p3">It computes this:</p>
  35 <p class="p4"><br></p>
  36 <p class="p3">xout = cos(angle) * xin + sin(angle) * yin;</p>
  37 <p class="p3">yout = cos(angle) * yin - sin(angle) * xin;</p>
  38 <p class="p4"><br></p>
  39 <p class="p3">where angle = pos * pi,<span class="Apple-converted-space">  </span>so that -1 becomes -pi and +1 becomes +pi.<span class="Apple-converted-space"> </span></p>
  40 <p class="p3">This allows you to use an LFSaw to do continuous rotation around a circle.</p>
  41 <p class="p4"><br></p>
  42 <p class="p3"><b>x, y</b> - input signals</p>
  43 <p class="p3"><b>pos</b> - angle to rotate around the circle from -1 to +1.<span class="Apple-converted-space"> </span></p>
  44 <p class="p3">-1 is 180 degrees, -0.5 is left, 0 is forward, +0.5 is right, +1 is behind.</p>
  45 <p class="p4"><br></p>
  46 <p class="p5">(</p>
  47 <p class="p5">{</p>
  48 <p class="p5"><span class="Apple-tab-span">     </span><span class="s2">var</span> w, x, y, p, q, a, b, c, d;</p>
  49 <p class="p6"><span class="Apple-tab-span">     </span></p>
  50 <p class="p5"><span class="Apple-tab-span">     </span>p = <span class="s2">WhiteNoise</span>.ar(0.05); <span class="s3">// source</span></p>
  51 <p class="p5"><span class="Apple-tab-span">     </span>q = <span class="s2">LFSaw</span>.ar(200,0,0.03)+<span class="s2">LFSaw</span>.ar(200.37,0,0.03)+<span class="s2">LFSaw</span>.ar(201,0,0.03);</p>
  52 <p class="p6"><span class="Apple-tab-span">     </span></p>
  53 <p class="p7"><span class="s4"><span class="Apple-tab-span">    </span></span>// B-format encode 2 signals at opposite sides of the circle</p>
  54 <p class="p5"><span class="Apple-tab-span">     </span>#w, x, y = <span class="s2">PanB2</span>.ar(p, -0.5) + <span class="s2">PanB2</span>.ar(q, 0.5);<span class="Apple-converted-space"> </span></p>
  55 <p class="p6"><span class="Apple-tab-span">     </span></p>
  56 <p class="p5"><span class="Apple-tab-span">     </span>#x, y = <span class="s2">Rotate2</span>.ar(x, y, <span class="s2">MouseX</span>.kr(-1,1));</p>
  57 <p class="p6"><span class="Apple-tab-span">     </span></p>
  58 <p class="p7"><span class="s4"><span class="Apple-tab-span">    </span></span>// B-format decode to quad</p>
  59 <p class="p5"><span class="Apple-tab-span">     </span>#a, b, c, d = <span class="s2">DecodeB2</span>.ar(4, w, x, y);</p>
  60 <p class="p6"><span class="Apple-tab-span">     </span></p>
  61 <p class="p7"><span class="s4"><span class="Apple-tab-span">    </span>[a, b, d, c] </span>// reorder to my speaker arrangement: Lf Rf Lr Rr</p>
  62 <p class="p5">}.play;</p>
  63 <p class="p5">)</p>
  64 <p class="p8"><br></p>
  65 <p class="p8"><br></p>
  66 <p class="p8"><br></p>
  67 <p class="p7">// Rotation of 2 mono sounds in the stereo field:</p>
  68 <p class="p5">(</p>
  69 <p class="p5">{</p>
  70 <p class="p7"><span class="s4"><span class="Apple-tab-span">    </span></span>// rotation via lfo</p>
  71 <p class="p5"><span class="Apple-tab-span">     </span><span class="s2">var</span> x, y;</p>
  72 <p class="p5"><span class="Apple-tab-span">     </span>x = <span class="s2">PinkNoise</span>.ar(0.4);</p>
  73 <p class="p5"><span class="Apple-tab-span">     </span>y = <span class="s2">LFTri</span>.ar(800) * <span class="s2">LFPulse</span>.kr(3,0,0.3,0.2);</p>
  74 <p class="p5"><span class="Apple-tab-span">     </span>#x, y = <span class="s2">Rotate2</span>.ar(x, y, <span class="s2">LFSaw</span>.kr(0.1));</p>
  75 <p class="p5"><span class="Apple-tab-span">     </span>[x,y]</p>
  76 <p class="p5">}.play;</p>
  77 <p class="p5">)</p>
  78 <p class="p6"><br></p>
  79 <p class="p5">{</p>
  80 <p class="p7"><span class="s4"><span class="Apple-tab-span">    </span></span>// rotation via mouse</p>
  81 <p class="p5"><span class="Apple-tab-span">     </span><span class="s2">var</span> x, y;</p>
  82 <p class="p5"><span class="Apple-tab-span">     </span>x = <span class="s2">Mix</span>.fill(4, { <span class="s2">LFSaw</span>.ar(200 + 2.0.rand2, 0, 0.1) });</p>
  83 <p class="p5"><span class="Apple-tab-span">     </span>y = <span class="s2">SinOsc</span>.ar(900) * <span class="s2">LFPulse</span>.kr(3,0,0.3,0.2);</p>
  84 <p class="p5"><span class="Apple-tab-span">     </span>#x, y = <span class="s2">Rotate2</span>.ar(x, y, <span class="s2">MouseX</span>.kr(0,2));</p>
  85 <p class="p5"><span class="Apple-tab-span">     </span>[x,y]</p>
  86 <p class="p5">}.play;</p>
  87 <p class="p6"><br></p>
  88 <p class="p6"><br></p>
  89 <p class="p7">// Rotate B-format about Z axis:</p>
  90 <p class="p6"><br></p>
  91 <p class="p5">wout = win;</p>
  92 <p class="p5">zout = zin;</p>
  93 <p class="p5">#xout, yout = <span class="s2">Rotate2</span>.ar(xin, yin, pos);</p>
  94 <p class="p6"><br></p>
  95 <p class="p7">// Rotate B-format about Y axis:</p>
  96 <p class="p6"><br></p>
  97 <p class="p5">wout = win;</p>
  98 <p class="p5">yout = yin;</p>
  99 <p class="p5">#xout, zout = <span class="s2">Rotate2</span>.ar(xin, zin, pos);</p>
 100 <p class="p6"><br></p>
 101 <p class="p7">// Rotate B-format about X axis:</p>
 102 <p class="p6"><br></p>
 103 <p class="p5">wout = win;</p>
 104 <p class="p5">xout = xin;</p>
 105 <p class="p5">#yout, zout = <span class="s2">Rotate2</span>.ar(yin, zin, pos);</p>
 106 <p class="p6"><br></p>
 107 <p class="p6"><br></p>
 108 <p class="p6"><br></p>
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