Module:MOS genchain

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This module should not be invoked directly; use its corresponding template instead: Template:MOS genchain.

This module produces a table illustrating the generator chain for a MOS scale.

Introspection summary for Module:MOS genchain
Functions provided (3) Line Function Params 20 preprocess_genchain (input_mos) 35 _mos_genchain (main) (input_mos) 100 mos_genchain (invokable) (frame)	Lua modules required (4) Variable Module Functions used mos Module:MOS new period_step_count bright_gen interval_mul period_reduce interval_add period_count period as_string parse tamnams Module:TAMNAMS degree_quality interval_quality tip Module:Template input parse dependency not used yesno Module:Yesno dependency not used

No function descriptions were provided. The Lua code may have further information.

---

local mos = require("Module:MOS")
local tip = require("Module:Template input parse")
local tamnams = require("Module:TAMNAMS")
local yesno = require("Module:Yesno")
local p = {}

-- Global variables for cell colors
-- Colors are as follows:
-- - Orange and blue for small and large sizes, respectively
-- - Darker colors for altered scale degrees
-- - No color for period intervals
p.cell_color_none = "NONE"				-- For cells that don't have a color (default cell color applies)
p.cell_color_perfect_size = "NONE"		-- Only applies for periods, including the root and equave
p.cell_color_lg_altered_size = "#BDD7EE"
p.cell_color_large_size      = "#DDEBF7"
p.cell_color_small_size      = "#FCE4D6"
p.cell_color_sm_altered_size = "#F8CBAD"


function p.preprocess_genchain(input_mos)
	local input_mos = input_mos or mos.new(5,2)
	local num_gens = 4 * (mos.period_step_count(input_mos) - 1)
	
	local bright_gen = mos.bright_gen(input_mos)
	local gens = mos.interval_mul(bright_gen, num_gens/2)
	bright_gen = mos.interval_mul(bright_gen, -1)
	local genchain = { mos.period_reduce(gens, input_mos) }
	for i = 1, num_gens do
		gens = mos.interval_add(gens, bright_gen)
		table.insert(genchain, mos.period_reduce(gens, input_mos))
	end
	return genchain
end

function p._mos_genchain(input_mos)
	local input_mos = input_mos or mos.new(6,2)
	
	local num_gens = mos.period_step_count(input_mos)
	
	local genchain = p.preprocess_genchain(input_mos)
	local period_count = mos.period_count(input_mos)
	
	-- Begin table
	local result = "{| class=\"wikitable center-all\"\n"
		.. "|-\n"
	
	-- Generators header rows
	result = result .. "! Bright gens"
	for i = 1, period_count do
		result = result
		.. " !! Scale Degree"
		.. " !! Abbrev"
	end
	local result = result
		.. "\n"
		.. "|-\n"
		
	-- Add a row for each scale degree, plus their period-shifted counterparts
	for i = 1, #genchain do
		-- Number of generators
		result = result .. string.format("| %s", math.ceil(#genchain/2) - i)
		
		local current_period_reduced_interval = genchain[i]
		local period_interval = mos.period(input_mos)
		
		for j = 1, period_count do
			-- Scale degree (full name) and abbrev
			current_period_reduced_interval = mos.interval_add(current_period_reduced_interval, mos.interval_mul(period_interval, j - 1))
			result = result .. string.format(" || %s", tamnams.degree_quality(current_period_reduced_interval, input_mos, "sentence-case"))
			result = result .. string.format(" || %s", tamnams.degree_quality(current_period_reduced_interval, input_mos, "abbrev"))
		end
		
		-- End of row
		result = result 
			.. "\n"
			.. "|-\n"
	end
	result = result .. "|}"
	
	local bright_gen_as_text = tamnams.interval_quality(mos.bright_gen(input_mos), input_mos)
	local period_step_count = mos.period_step_count(input_mos)
	local scalesig = mos.as_string(input_mos)
	local child_step_count = input_mos.nL + input_mos.nL + input_mos.ns
	local child_scale_1 = mos.new(input_mos.nL+input_mos.ns, input_mos.nL, input_mos.equave)
	local child_scale_2 = mos.new(input_mos.nL, input_mos.nL+input_mos.ns, input_mos.equave)
	
	--result = string.format("Stacking the bright generator (a %s) from the root produces the following scale degrees. A chain of %s consecutive scale degrees produces one of the modes of %s, and expanding it to %s scale degrees produces the modes of either %s or %s.\n",
	--	bright_gen_as_text,
	--	period_step_count,
	--	scalesig,
	--	child_step_count,
	--	mos.as_string(child_scale_1),
	--	mos.as_string(child_scale_2)
	--	)
	--	.. result
	
	return result
end

function p.mos_genchain(frame)
	local scalesig = frame["Scale Signature"]
	local input_mos = mos.parse(scalesig)
	
	return p._mos_genchain(input_mos)
end

return p