boost - convert linear pan amplitude to 'constant power' pan amplitude
powerpan = boost(linpan)
boost accepts a pan value (0.0-1.0) and returns the amplitude scaling factor necessary to avoid a "hole in the middle" for a panned note. In other words, for static-panned notes, it lets you convert the linear panning law used by most instruments into a constant-power pan with sqrt taper.
Examples of values returned by boost:
boost(0) => 1 boost(1) => 1 boost(0.25) => 1.265 boost(0.5) => 1.414
pan = 0.53 powpan = boost(pan) STEREO(0, 0, 3.4, 1.0, powpan)
ampdb, dbamp, cpsmidi, cpslet, cpsoct, cpspch, midipch, octcps, octlet, octmidi, octpch, pchcps, pchlet, pchmidi, pchoct