A basic cv-controlled clock with swing and clock multiplier for crow

swingclock.lua

-- a basic cv-controlled clock with swing and clock division
-- input 1: 0 - 5v cv to control tempo
-- input 2: -5 - 5v cv to control swing on even notes
-- 0v is no swing, -5v is 25% swing and 5v is 75% swing

-- output 1: clock without swing
-- output 2: clock with swing and clock division
-- output 3: half-tempo clock with odd beats and clock division
-- output 4: half-tempo swinged clock with even beats and clock division

-- clock divider factor. 1 is no division, probably better to use even numbers
swingclockdivider = 2

-- initial values and constants
pulsetime = 0.0025
pulselevel = 5
pulsepolarity = 1

bpmmin = 50
bpmmax = 200

swingmin = 25
swingmax = 75

bpm = 120
click = 60 / bpm
swing = 50

-- a few functions that help later
function trunc_float(n)
    trunc = string.format("%.4f", n)
    return trunc
end

function map_range(a1, a2, b1, b2, s)
    return b1 + (s-a1)*(b2-b1)/(a2-a1)
end

function volt2clock(v)
    bpm = map_range(0, 5, bpmmin, bpmmax, v)
    bpm = math.floor(bpm)
    click = 60/bpm
    click = trunc_float(click) * 2 -- need to multiply clock to make it slower
    return click
end

function swing_delay(t, s)
    swingdel = t * s / 50
    swingdel = trunc_float(swingdel)
    return swingdel
end

function volt2swing(v)
    swing = map_range(-5 , 5, swingmin, swingmax, v)
    swing = math.floor(swing)
    return swing
end

-- main clock function
function clock()
    newclick = volt2clock(input[1].volts)
    clock_metro.time = newclick
    newswing = volt2swing(input[2].volts)
    swingdel = swing_delay(newclick, newswing) / 2
    div = swingdel / swingclockdivider

    -- print(bpm, newclick, newswing, swingdel, div, swingdel / swingclockdivider)


    -- To get clock at normal speed on output 1 I am using delay to get clock divisions
    -- because of the clock multiply in volt2clock
    output[1]()
    delay(function() output[1]() end, newclick / 2, 0)

    if swingclockdivider == 1 then
        output[2]()
        output[3]()
        delay(function() output[2]() output[4]() end, swingdel, 0)
    elseif swingclockdivider >= 2 then
        delay(function() output[2]() output[3]() end, newclick / swingclockdivider, swingclockdivider - 1)
        delay(function()
                 delay(function()
                      output[2]() output[4]()
                      end
                      , newclick / swingclockdivider
                      , swingclockdivider - 1)
                 end
             , div
             , 0)
    end
end

-- report function to print swing and bpm to druid
function report()
    print(newswing, bpm)
end

-- initialization function
function init()
    for n = 1,4 do
        output[n].action = pulse( pulsetime, pulselevel, pulsepolarity )
    end
    clock_metro = metro.init{ event = clock
                      , time = click
                      , count = -1
                      }
    clock_metro:start()
    reporter = metro.init{ event = report
                      , time = 0.25
                      , count = -1
                      }
    -- reporter:start()
end