Actions outlive individual input devices

First, build a mental model

A device says what physically happened. An action says what the player intends. The simulation reads move, aim, interact and pause; it should not care whether an arrow key, thumbstick or touch control produced them.

1. Separate continuous levels from edges. Holding move-right is a level sampled each update. Opening the pause menu is usually a press edge, so one held button does not toggle the menu every frame.
2. Track independent sources. If two fingers or a key and pointer hold fire, releasing one source must not release the others. A set of source IDs represents this ownership more accurately than one shared boolean.
3. Pointer capture can keep receiving a drag outside its original element. Clear ownership on pointerup, pointercancel and lostpointercapture. Blur, hidden-tab transitions and controller disconnection also need a release policy.
4. Gamepad axes are analog values. Apply a documented dead zone, clamp the result, and inspect the standard mapping before assuming button indices. Normalize a two-axis movement vector when diagonal keyboard input must not move faster.
5. Limit preventDefault to focused game controls. Menus, editable inputs and keyboard navigation still need their normal behavior. A controller connection alone should not seize input focus from a touch user.

const fireSources = new Set();
const press = source => fireSources.add(source);
const release = source => fireSources.delete(source);
const readFire = () => fireSources.size > 0;

press("keyboard:Space");
press("pointer:7");
release("pointer:7");
console.log(readFire()); // true: Space still owns fire
release("keyboard:Space");
console.log(readFire()); // false
// A device adapter supplies source IDs. A blur handler clears the set.

1. Acquire

   Space and pointer 7 create two independent holds. The action is active because at least one owner exists.

2. Release one

   Pointer 7 ends. Removing its source leaves Space's ownership intact; the action remains active.

3. Release all

   Space ends or the game loses focus. When no owners remain, the next input sample reports fire = false.