Synthesizer V - Transpose In Key Script

transposeinkey.lua

function getClientInfo()
    return {
        name = "Transpose In Key",
        author = "impbox",
        versionNumber = 1,
        minEditorVersion = 0
    }
end

function getTranslations(langCode)
    -- please help add translations <3
    return {}
end

-- Wrapper function to know the flow of code
function main()
    --[[
        1st check user inputs
        2nd start a core routine
        3rd end plugin
    ]]
    if validateBeforeStarting() then
        local formResult = SV:showCustomDialog(makeForm())
        if (formResult.status) then
            coreRoutine(formResult)
        end
    end
    SV:finish()
end

-- Validate user request
function validateBeforeStarting()
    -- if selected notes is empty, show message box and finish
    if #SV:getMainEditor():getSelection():getSelectedNotes() < 1 then
        SV:showMessageBox(SV:T("Selected Notes is Empty"), SV:T("You have to select at least one note."))
        return false
    end
    return true
end


-- create custom dialog form
function makeForm()
    local form = {
        title = SV:T("Transpose in Key"),
        message = SV:T("Choose key and transpose interval."),
        buttons = "OkCancel",
        widgets = {
            {
                name = "key",
                type = "ComboBox",
                label = SV:T("Key"),
                choices = {"C","C#/Db","D","D#/Eb","E","F","F#/Gb","G","G#/Ab","A","A#/Bb","B"},
                default = 0
            },
            {
                name = "minor",
                type = "CheckBox",
                text = "Minor",
                default = false
            },
            {
                name = "interval",
                type = "ComboBox",
                label = SV:T("Interval"),
                choices = {"+2nd", "+3rd", "+4th", "+5th", "+6th", "+7th", "+8ve", "-2nd", "-3rd", "-4th", "-5th", "-6th", "-7th", "-8ve"},
                default = 3
            },
        }
    }

    return form
end

intervalToSemitones = {
    {2,1},
    {4,3},
    {5,4,6},
    {7,6,8},
    {9,8,10},
    {11,10},
    {12},
    {-2,-1},
    {-4,-3},
    {-5,-4,-6},
    {-7,-6,-8},
    {-9,-8,-10},
    {-12},
}

keyNames = {"C","C#/Db","D","D#/Eb","E","F","F#/Gb","G","G#/Ab","A","A#/Bb","B"}
majorScale = {0,2,4,5,7,9,11,12}
minorScale = {0,2,3,5,7,8,10,12}

function isInKey(key, isMinor, note)
    local noteWithoutOctave = note % 12
    local keyRootNote = key - 1
    local scale = nil

    if isMinor then scale = minorScale else scale = majorScale end

    for i = 1, #majorScale, 1 do
        if (keyRootNote + scale[i]) % 12 == noteWithoutOctave then
            return true
        end
    end
    return false
end

function coreRoutine(formResult)
    local notes = SV:getMainEditor():getSelection():getSelectedNotes()
    --SV:showMessageBox("Transposing...", "notes: " .. #notes)
    local key = formResult.answers.key + 1
    local minor = formResult.answers.minor
    local interval = formResult.answers.interval + 1
    --SV:showMessageBox("Transposing...", "key: " .. key .. " minor: " .. minor .. " interval: " .. interval)
    --SV:showMessageBox("Transposing...", "Key: " .. key .. " " .. keyNames[key] .. " minor: " .. minor .. " interval: " .. interval)
    local intervalsToCheck = intervalToSemitones[interval]
    --SV:showMessageBox("Transposing...", "Key: " .. keyNames[key] .. " interval: " .. interval .. " to check: " .. #intervalsToCheck)
    for i = 1, #notes, 1 do
        -- go through each note and increment it and snap it to the scale
        local note = notes[i]:getPitch() - 60
        --SV:showMessageBox("Transposing...", "note: " .. note)
        for j = 1, #intervalsToCheck, 1 do
            local tryNote = note + intervalsToCheck[j]
            --SV:showMessageBox("Transposing...", "note: " .. note .. " + " .. intervalsToCheck[j] .. " -> " .. tryNote)
            if isInKey(key, minor, tryNote) then
                --SV:showMessageBox("Transposing...", "note: " .. note .. " -> " .. tryNote .. " is in key!")
                notes[i]:setPitch(tryNote + 60)
                break
            end
        end
    end
end