ludic/examples/library/input_device.ludic

# input_device.ludic — the raw device layer from #50, on top of the action maps
# and record/replay of #7. Beyond one key per frame, gameplay can read:
#
#   * multiple simultaneous held keys — Input.key_down / key_pressed / key_released
#   * analog axes and vectors derived from keys — Input.axis / Input.vector
#   * the mouse — Input.mouse_x/y, mouse_dx/dy, mouse_down, wheel
#   * gamepads and touch — Input.pad_button/pad_axis, Input.touch_count/touch_x
#
# The held set is fed by the platform when windowed, and on every target by the
# Input.press / Input.set_* injection (the same idea as Godot's action_press —
# what a replay, an AI, or the network feeds). Everything is integer and
# deterministic, and Input.record / replay snapshot the whole per-frame state, so
# a recorded run reproduces exactly. Driven headless by injection, a full run:
#   bin/ludic examples/library/input_device.ludic  ->  1 1 0 1 0 1 71 -71 5 1 3 1 2 1 0 0 1
program InputDevice {
  function bi(b: bool) -> int { if b { return 1 };  return 0 }
  function r(f: fixed) -> int { return Math.round(f) }

  entry {
    # --- multiple simultaneous held keys, with clean edges -------------------
    Input.press('a')                     # hold left AND jump at once
    Input.press(' ')
    Input.poll()
    print(bi(Input.key_down('a')))       # 1
    print(bi(Input.key_down(' ')))       # 1
    print(bi(Input.key_down('d')))       # 0 — not held
    print(bi(Input.key_pressed('a')))    # 1 — went down this frame
    Input.poll()
    print(bi(Input.key_pressed('a')))    # 0 — held, not a fresh press
    Input.release('a')
    Input.poll()
    print(bi(Input.key_released('a')))   # 1 — went up this frame

    # --- analog axis + a normalized 2D vector from four keys -----------------
    Input.release(' ')
    Input.press('d')                     # right
    Input.press('w')                     # and up -> a diagonal
    Input.poll()
    let v = Input.vector('a', 'd', 'w', 's')
    print(r(Vector.x(v) * 100))          # 71 — 0.7071, normalized so diagonals aren't faster
    print(r(Vector.y(v) * 100))          # -71

    # --- mouse: position, per-frame delta, buttons, wheel --------------------
    Input.set_mouse(10, 20, 1, 3)        # x, y, button-mask (left), wheel delta
    Input.poll()
    Input.set_mouse(15, 20, 1, 0)
    Input.poll()
    print(Input.mouse_dx())              # 5 — moved 10 -> 15
    print(bi(Input.mouse_down(0)))       # 1 — left button
    Input.set_mouse(15, 20, 0, 3)
    Input.poll()
    print(Input.wheel())                 # 3

    # --- gamepad + touch (injected; a native binding feeds the same state) ---
    Input.set_pad(0, true, 1, 1.0, 0.0, 0.0, 0.0)   # pad 0: button 0 down, left stick x = 1.0
    print(r(Input.pad_axis(0, 0)))       # 1
    Input.set_touch(0, 100, 200, true)
    Input.set_touch(1, 50, 60, true)
    print(Input.touch_count())           # 2

    # --- full-state record / replay: the held set replays exactly ------------
    Input.record()
    Input.press('a');   Input.release('d'); Input.release('w')
    Input.poll()                         # recorded frame 0: only 'a' held
    Input.release('a'); Input.press('d')
    Input.poll()                         # recorded frame 1: only 'd' held
    Input.replay()
    Input.poll()                         # replay frame 0
    print(bi(Input.key_down('a')))       # 1
    print(bi(Input.key_down('d')))       # 0
    Input.poll()                         # replay frame 1
    print(bi(Input.key_down('a')))       # 0
    print(bi(Input.key_down('d')))       # 1
  }
}