initial commit

src/script/ScriptRunner.lua

@@ -0,0 +1,99 @@
+-- Executes map scripts: lists of { "command", args... } rows (see
+-- src/script/Commands.lua and data/scripts/).  Runs as a coroutine so
+-- commands like show_text and wait can block on UI.
+--
+-- Map-specific behavior lives in data/scripts/<map>.lua modules, never in
+-- engine code.  Each hand-ported script references its asm source.
+
+local Commands = require("src.script.Commands")
+local Logger = require("src.core.Logger")
+
+local unpack = table.unpack or unpack -- LuaJIT (LÖVE) compatibility
+
+local ScriptRunner = {}
+ScriptRunner.__index = ScriptRunner
+
+function ScriptRunner.new(game, overworld)
+  local self = setmetatable({}, ScriptRunner)
+  self.game = game
+  self.overworld = overworld
+  self.co = nil
+  return self
+end
+
+function ScriptRunner:isRunning()
+  return self.co ~= nil and coroutine.status(self.co) ~= "dead"
+end
+
+-- ctx passed to commands: engine services plus per-run info (npc, map)
+function ScriptRunner:makeContext(extra)
+  local ctx = {
+    game = self.game,
+    overworld = self.overworld,
+    save = self.game.save,
+    runner = self,
+  }
+  for k, v in pairs(extra or {}) do ctx[k] = v end
+  return ctx
+end
+
+function ScriptRunner:run(script, extra)
+  assert(not self:isRunning(), "script already running")
+  local ctx = self:makeContext(extra)
+  self.co = coroutine.create(function()
+    self:exec(script, ctx)
+    if ctx.onDone then ctx.onDone() end
+  end)
+  self:resume()
+end
+
+-- Execute a command list.  Supports labels via jump commands: a script is
+-- an array of rows; control commands return a new program counter.
+function ScriptRunner:exec(script, ctx)
+  local pc = 1
+  while pc <= #script do
+    local row = script[pc]
+    local name = row[1]
+    local fn = Commands[name]
+    if not fn then
+      Logger.warn("script: unknown command '%s' (skipped)", tostring(name))
+      pc = pc + 1
+    else
+      local jump = fn(ctx, select(2, unpack(row)))
+      if type(jump) == "number" then
+        pc = jump
+      else
+        pc = pc + 1
+      end
+    end
+  end
+end
+
+-- Called by blocking commands from inside the coroutine.
+function ScriptRunner:yield()
+  coroutine.yield()
+end
+
+function ScriptRunner:resume(...)
+  if not self.co then return end
+  local ok, err = coroutine.resume(self.co, ...)
+  if not ok then
+    Logger.error("script error: %s", tostring(err))
+    self.co = nil
+  elseif coroutine.status(self.co) == "dead" then
+    self.co = nil
+  end
+end
+
+function ScriptRunner:update()
+  -- commands that wait on frames re-resume every step while running
+  if self:isRunning() and self.waitingFrames then
+    self.waitingFrames = self.waitingFrames - 1
+    if self.waitingFrames <= 0 then
+      self.waitingFrames = nil
+      self:resume()
+    end
+  end
+end
+
+return ScriptRunner