The part of gap 15 that doesn't need video, from the public documentation of prototype triggers, plugins/widgets and prototype expressions.
- **Controller buttons on key/gamepad triggers.** A key trigger's key can be a controller button: `Gamepad A` ... `Gamepad Home`, the standard gamepad layout's 17 buttons (face buttons by position, shoulders, triggers, View/Menu, stick presses, d-pad, Home). The engine keeps its input-agnostic model (a key trigger with a key name; `figcraft_doc::proto::GAMEPAD_BUTTONS`, `gamepad_button`, `is_gamepad_button`, `uses_gamepad`). The interaction editor gets a Controller menu beside the key field; the trigger list shows the button's own name.
- **Reading controllers.** A new `Services::gamepad_held()` (bitmask of held buttons; default none). The player polls it only while the presented prototype has a controller trigger and the window has the focus (about 30 times a second), plays each press once (held buttons don't repeat), and fires the first matching key/gamepad trigger on the screen like a key.
- Desktop, Windows: Windows.Gaming.Input (Xbox-compatible controllers) through the `windows` crate the app already depends on (one more feature flag, `Gaming_Input`; no new crate).
- Browser: the Gamepad API through `web-sys` (features `Gamepad`, `GamepadButton`, `GamepadMappingType`; standard-mapped controllers only).
- macOS, Linux, FreeBSD: no controllers yet (documented gap).
- Control channel: `ui.input {events: [{gamepad: "A" | "Gamepad A" | 0}]}` presses a button in the prototype playing (presenter, else preview pane); an error when nothing plays.
- **REST import** maps controller triggers (`device` other than `KEYBOARD`) to the button at the code's standard-layout index instead of skipping them; two buttons at once or an unknown code is skipped with a warning (`.fig` goes through the same path).
- **Widgets react to clicks in a presented prototype.** A click on a widget's clickable part in the presenter or the preview pane (when no interaction on the layer takes it) calls the plugin back through the canvas's own callback with the same sandbox limits, on the player's copy of the file (`widgets::click_on`, a scratch session holding the copy and the installed plugins): the widget changes in the prototype only, the file and its undo history stay untouched, restarting starts the widget over. Failures (plugin missing or failing) toast; toasts now also show over the full-window presenter.
- **Variable mode lookups.** Lookups (`accent[Dark]`, `mode(Theme)`), set-variable-mode affecting later expressions in the same interaction, and every operator the documentation lists already held; they are now behaviour cases. New `proto.evaluate {expression | expr, id?}` (MCP and agents) computes an expression where a layer's interaction would run, without changing anything. No other cheap expression gap found: every documented operator (numbers, text join, booleans, comparisons, negation, mode lookup) already existed.
- Docs: prototyping-parity (new rule rows, features, revision), target-app-parity area 13 and totals, ROADMAP, gaps.md gap 15, roadmap.md M5, mcp.md, plugins.md, control-protocol.md.
Dependencies: none added. Windows uses the existing `windows` 0.62 dependency with the `Gaming_Input` feature; the browser uses the existing `web-sys` with three more features. The usual Rust controller library (gilrs) was not taken: its Linux backend links the system's libudev (a C library, needing headers on CI and the FreeBSD job), which breaks the pure-Rust rule.
**A prototyping behaviour suite written from the public documentation, and fixes for every divergence it found.** Each documented rule on triggers, actions, overlays, animations, easing, scrolling and interactive components is a case with what the rule implies and a one-line derivation; where the documentation is silent the case says so and pins today's behaviour. The model rules are table-driven tests in the engine; the player's are driven through egui headless (real pointer, key and timer input into the presenter) or on the player directly.
**Fixes (the suite failed on these before them)**
- **On drag follows its animation**: with a move, push or slide animation, only a drag that way starts it (a drag another way can scroll instead), and the animation follows the pointer while the button stays down, then plays on from there when it lets go (it played by time, and any drag direction fired it).
- **Key combinations**: a key trigger can be a combination (`Shift+K`, `Ctrl+Alt+Delete`, other spellings of the modifiers accepted); the modifiers held must match, so `K` no longer fires for Shift+K. The interaction editor's recorder records the modifiers held, and REST files' modifier key codes import as the combination (they imported as the key alone, with a warning).
- **Overlay timers**: an overlay's after-delay timer starts when the overlay opens, and again each time it opens (it was timed from when the screen under it arrived, so a toast opened late closed at once, and it fired only the first time).
- **Interactive components**: every instance plays the interactions on the variant it shows; an interaction on the instance with the same trigger wins. Before, instances played only interactions copied onto them when placed: an instance placed before its main got interactions did nothing, and one placed after kept the first variant's interactions after changing (a toggle went on but never off). New instances no longer copy them, and copies in older files give way to the variant shown (`proto_run::play_interactions`, on the player's copy).
- **Change to on nested instances** changes the instance whose variant set holds the destination (`proto_run::change_to_target`), not the innermost instance (an icon inside a button).
- **Springs**: the presets are physical springs (mass 1; stiffness / damping gentle 100/15, quick 300/20, bouncy 600/15, slow 80/20; they were ad-hoc curves), and every spring plays until it settles instead of being squeezed into the duration field's time; the settling time accounts for over-damped springs. The interaction editor shows the spring's duration in place of the duration field, with a tooltip.
- **Smart animate overshoot**: matched layers follow spring and back easings past their end and back (they snapped to the end once the curve passed 1).
- **Fixed layers on top**: fixed layers draw and take clicks above the content scrolling under them, wherever they are in the layer list (the file's order doesn't change).
**Missing documented setting, added**
- **Scroll to offset**: `{type: "scrollTo", dest, offset: [x, y]}` stops the layer that far from the top-left of the innermost frame scrolling it (room for a fixed header); X / Y fields in the interaction editor; files carry it only when set.
- Already there and now covered by the suite: click / mouse down / mouse up / while pressing / while hovering / mouse enter / mouse leave / after delay, nested hotspot priority and click-through, navigate (closing overlays), back with the reversed animation, restart, overlay stacking / swap / close / close on a click outside, change to with smart animate, reversed directional transitions, easing curves.
New strings go through `tr(...)` with `en.toml` / `es.toml` entries. No new command ids. The player still draws nothing while idle: the drag-follow only runs during an animation, and fixed layers and instance interactions are worked out once per layout, not per frame.
Progress docs per craftrules standards/progress-docs.md: target-app parity, gaps, roadmap with alpha gate, readiness by audience (full / mainstream / essentials) with Opus 5.5 hours, and auto layout, components, prototyping, dev mode, collaboration, format, hardware, UI and localization parity docs.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
bflatastic
Brandon Thomas