- added ddr test to main menu\n- tweaked sounds\n- musicator tool base code, needs samples

tools/musicator/musicator.lua

@@ -0,0 +1,130 @@
+unpack = unpack or table.unpack
+
+function build_markov_model(sequence, order)
+  local function make_key(tbl)
+    return table.concat(tbl, "|")
+  end
+
+  local function unmake_key(k)
+    local result = {}
+    for t in string.gmatch(k, "[^|]+") do
+      result[#result + 1] = t
+    end
+
+    return result
+  end
+
+  local function add_key(str, value)
+    return str .. "|" .. value
+  end
+
+  local function split_last(full)
+    local i = full:match(".*()|")
+    return full:sub(1, i-1), full:sub(i+1)
+  end
+
+  local counts = {}
+  local totals = {}
+
+  -- count
+  for i = 1, #sequence - order do
+    local notes = make_key({unpack(sequence, i, i + order - 1)})
+    totals[notes] = (totals[notes] or 0) + 1
+
+    local notes_full = add_key(notes, sequence[i + order])
+    counts[notes_full] = (counts[notes_full] or 0) + 1
+  end
+
+  -- build model
+  local model = {}
+
+  for notes_full,count in pairs(counts) do
+    local notes, _ = split_last(notes_full)
+
+    model[notes_full] = count[notes_full] / total[notes]
+  end
+
+  return {
+    order = order,
+    model = model,
+    counts = counts -- keep raw counts (useful!)
+  }
+end
+
+function generate_sequence(model_data, length)
+  local model = model_data.model
+  local order = model_data.order
+
+  -- helper: split key into parts
+  local function split(k)
+    local t = {}
+    for part in string.gmatch(k, "[^|]+") do
+      t[#t+1] = part
+    end
+    return t
+  end
+
+  -- pick random starting state
+  local start_key
+  for k,_ in pairs(model) do
+    start_key = k
+    break
+  end
+
+  -- (optional: better random start)
+  for k,_ in pairs(model) do
+    if math.random() < 0.1 then
+      start_key = k
+    end
+  end
+
+  local parts = split(start_key)
+
+  -- initial sequence = first `order` items
+  local seq = {}
+  for i = 1, order do
+    seq[i] = parts[i]
+  end
+
+  -- generation loop
+  while #seq < length do
+    -- build current state key
+    local state = table.concat({unpack(seq, #seq - order + 1, #seq)}, "|")
+
+    -- collect matching transitions
+    local matches = {}
+    for full,prob in pairs(model) do
+      if full:sub(1, #state) == state and full:sub(#state+1, #state+1) == "|" then
+        matches[#matches+1] = {key=full, prob=prob}
+      end
+    end
+
+    if #matches == 0 then break end
+
+    -- weighted pick
+    local r = math.random()
+    local sum = 0
+
+    local chosen
+    for _,m in ipairs(matches) do
+      sum = sum + m.prob
+      if r <= sum then
+        chosen = m.key
+        break
+      end
+    end
+
+    if not chosen then
+      chosen = matches[#matches].key
+    end
+
+    -- extract next symbol (after last '|')
+    local next_symbol = chosen:match("|([^|]+)$")
+
+    seq[#seq+1] = next_symbol
+  end
+
+  return seq
+end
+
+-- todo: feed samples