2D movement controllers

Package: demi.gameplay.controllers.

Provides input-to-intent functions and a separate 2D character helper that calls engine physics and sprite services. Exports demi.gameplay.controllers and demi.gameplay.character_controller_2d, with no package dependencies or event bus. See package installation.

The intent module works on plain tables:

local Controllers = require("demi.gameplay.controllers")

local state = { grounded = true }
local config = { coyote_time = 0.1, jump_buffer = 0.1 }
local intent
intent, state = Controllers.platform({ x = 1, jump = true, dt = 1 / 60 }, state, config)
assert(intent.jump)
local movement = Controllers.top_down({ x = 1, y = 1 })
assert(movement.x < 1)

Keep the returned platform state between calls, refresh state.grounded from your collision check, and supply dt in seconds. Both timing values must be positive for a jump to trigger; omitted values default to zero. input.jump should represent a press, for example Input.pressed("jump"). The module does not read input or apply movement itself.

top_down clamps vectors longer than one and carries optional aim_x/aim_y. click_to_move returns { target_x, target_y } only when clicked is true; it does not find or follow a path. isometric returns grid_x = right - left and grid_y = down - up, without normalization or world projection.

For direct platform movement, an engine script can use the character helper. This requires an existing player with Transform2D, Rigidbody2D, a collider, and sprite animation clips named idle/run, plus move/jump input actions and a platform collision layer:

local Character = require("demi.gameplay.character_controller_2d")
local controller = Character.new({ move_speed = 5, jump_speed = 9 })
local Player = {}

function Player:on_update(dt)
  controller:update_horizontal("player")
  controller:try_jump("player", controller:is_grounded("player"))
end

return Player

is_grounded casts downward from the entity position, ignoring that entity; adjust ground_distance (default 0.56) and ground_layer for your collider. update_horizontal reads Input.value, sets horizontal velocity, flips the sprite when enabled, and selects idle/run animation. try_jump reads Input.pressed and sets vertical velocity only when passed a grounded state. Action names, speeds, and animation names are constructor options.

The character helper does not use the intent module's coyote/buffer state. Neither module configures input bindings, creates entities, supplies navigation, or implements a 3D controller. The game owns state and update timing; there are no events to flush or subscriptions to clean up.

From the repository root, test with:

./build/linux-debug/demi package test packages/sources/demi.gameplay.controllers