ebmgen.lua

-- EBM generator
-- (c) Severak 2021
-- generates random EBM riff, drums not implmeneted yet

require "include/protoplug"

--Welcome to Lua Protoplug generator (version 1.0.0)

-- default song:
-- DAF: Der Mussolini
-- B2 E3 B2 D4 B2 B3 B2 B2 B3 B2 B3 B2 B3 A3 B2 B3
local song = {46, 52, 46, 62, 46, 59, 46, 46, 59, 46, 59, 46, 59, 57, 46, 59}

local is_playing = false
x=0
prevNote = false
local transpose = 0

function ebmgen()
    local i
    local base = math.random(36,71)
    for i=1,16 do
        song[i] = base
    end
    for i=1,16 do
        local offset = math.random(-12, 12)
        if math.random(0,2)==1 then
            song[i] = song[i] + offset
        end
    end
end


function plugin.processBlock(samples, smax, midiBuf)
	newEvents = {}
	if not interval then updateInterval() end
	if not i then i = interval + 1 end
	for s=0,smax do
		if i>=interval then
		    if is_playing then
		        local at = (x % 16) + 1;
		        print(prevNote)
		        if prevNote then
		            noteOff(prevNote)
		        end
			    noteOn(song[at] + transpose, 127)
			    prevNote = song[at] + transpose
			elseif prevNote then
				noteOff(prevNote)
				prevNote = false
			end
			i = 0
			x = x + 1
		end
		i = i + 1
	end
	midiBuf:clear()
	if #newEvents>0 then
		for _,e in ipairs(newEvents) do
			midiBuf:addEvent(e)
		end
	end
end

function noteOn(n,v)
	table.insert(newEvents, midi.Event.noteOn(1, n, v))
end
function noteOff(n)
	table.insert(newEvents, midi.Event.noteOff(1, n, 0))
end

function updateInterval()
	local int = params[2].getValue()
	bpm = plugin.getCurrentPosition().bpm
	interval = math.floor((plugin.getSampleRate()*int)/(bpm))
end

params = plugin.manageParams {
    {
		name = "Is playing?";
		type = "list";
		values = {"yes", "no"};
		default = "no";
		changed = function(is) 
		    is_playing = (is == "yes") 
		end;
	};
	{
		name = "Interval";
		type = "int";
		min = 3;
		max = 30;
		default = 60;
		changed = function(val) interval = nil end;
	};
	{
		name = "Transpose";
		type = "int";
		min = -2;
		max = 2;
		default = 0;
		changed = function(val) 
		    transpose = val * 12
		end;
	};
	{
		name = "Song seed";
		type = "int";
		min = 1;
		max = 256;
		default = 128;
		changed = function(val) 
		    math.randomseed(val)
		    ebmgen()
		end;
	};
}

params.resetToDefaults()