Enabled switch, text assets, mouse input and the jump-and-run example game

Engine additions that the example game needed:
- `enabled` as a shared property of every placeable asset (default on, an
  override on the scene object). A switched-off object is not drawn, does not
  collide and its behavior does not run - and neither does anything parented
  below it. Disabled objects are now hidden in the scene view as well, so the
  editor shows what the game shows; they stay in the hierarchy panel, which is
  where they are selected and switched back on.
- Asset type `text` (text, fontSize, color, align), rendered in scene and game.
- Pointer input in the game view: `On click`, `Mouse position`, `Mouse button`,
  `Is hovered`, hit-tested against colliders, else sprite/text footprints.
- New nodes: Set/Is enabled, Set text, Is asset, Name of, Equals, To text,
  Join text, Floor/Ceil/Round, Modulo, Random, Time, Restart game.

Tooling: shared CDP harness (tools/harness.mjs), central project registry with
a guard that keeps destructive scripts off the playground (tools/projects.mjs),
plus smoke suites for the demo scene and the jump-and-run game.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/core/graph/NodeRegistry.ts

@@ -1,4 +1,5 @@
 import type { PropertyBag, PropertyValue } from '../model/Properties';
+import { enabledAlongChain } from '../properties/enabled';
 import type { PropertyDef } from '../properties/PropertySchema';
 import type { PortType } from './Graph';
 
@@ -11,6 +12,8 @@ export type Value = PropertyValue | EntityHandle | null;
  */
 export interface EntityHandle {
   id: string;
+  /** Asset this entity was instantiated from (what `Is asset` compares against). */
+  assetId: string;
   name: string;
   /** Position local to `parent` (world position for top-level entities). */
   x: number;
@@ -34,6 +37,23 @@ export function worldPositionOf(handle: EntityHandle): { x: number; y: number; z
   return result;
 }
 
+/** Whether a handle and every ancestor of it are switched on (see `properties/enabled.ts`). */
+export function isHandleEnabled(handle: EntityHandle): boolean {
+  return enabledAlongChain(handle, (h) => h.props, (h) => h.parent);
+}
+
+/** Where the mouse is (world units) and what it did this frame. */
+export interface PointerState {
+  x: number;
+  y: number;
+  /** Whether the pointer is over the game view at all. */
+  inside: boolean;
+  down: boolean;
+  /** Went down / up during this frame. */
+  pressed: boolean;
+  released: boolean;
+}
+
 /**
  * Services a graph may use while running. Implemented by the runtime (BehaviorSystem) and
  * by test doubles. Everything the graph does to the world goes through here, so the core
@@ -51,6 +71,14 @@ export interface NodeContext {
   dt: number;
   findByName(name: string): EntityHandle | null;
   isKeyDown(key: string): boolean;
+  /** Mouse state of this frame, in world units (see `PointerState`). */
+  pointer: PointerState;
+  /**
+   * Whether a world point lies on `target` – on its colliders when it has any, otherwise on
+   * its own footprint or that of anything parented below it (so a button made of a container
+   * with a sprite and a label is hit as a whole).
+   */
+  hitTest(target: EntityHandle, x: number, y: number): boolean;
   /**
    * Whether any collider of `a` overlaps any collider of `b` right now. A collider entity
    * stands for itself; any other entity stands for its direct collider children.
@@ -70,6 +98,8 @@ export interface NodeContext {
   spawn(assetId: string, position: { x: number; y: number; z: number }, parent: EntityHandle | null): EntityHandle | null;
   destroy(target: EntityHandle): void;
   stop(): void;
+  /** Ends the run and starts it again from the saved scene (everything spawned is lost). */
+  restart(): void;
 }
 
 export interface PortDef {

src/core/graph/nodes.ts

@@ -1,5 +1,5 @@
 import type { PropertyDef } from '../properties/PropertySchema';
-import { asBoolean, asEntity, asNumber, asString, type PortDef, registerNode, worldPositionOf } from './NodeRegistry';
+import { asBoolean, asEntity, asNumber, asString, isHandleEnabled, type PortDef, registerNode, worldPositionOf } from './NodeRegistry';
 
 /**
  * The built-in node set. Each entry is data + a `run` function; everything else (palette,
@@ -38,6 +38,15 @@ const collisionOutputs = (): PortDef[] => [exec(), obj('other'), obj('otherColli
 registerNode({ type: 'OnCollisionEnter', label: 'On collision enter', category: 'event', description: 'Runs once when a collider of the owner starts overlapping another collider.', inputs: [], outputs: collisionOutputs(), params: [] });
 registerNode({ type: 'OnCollisionStay', label: 'On collision stay', category: 'event', description: 'Runs every frame while a collider of the owner overlaps another collider.', inputs: [], outputs: collisionOutputs(), params: [] });
 registerNode({ type: 'OnCollisionExit', label: 'On collision exit', category: 'event', description: 'Runs once when a collider of the owner stops overlapping another collider.', inputs: [], outputs: collisionOutputs(), params: [] });
+registerNode({
+  type: 'OnClick',
+  label: 'On click',
+  category: 'event',
+  description: 'Runs when the mouse is pressed on the owner (or on anything parented below it) in the Game tab.',
+  inputs: [],
+  outputs: [exec(), num('x', 'world x'), num('y', 'world y')],
+  params: [],
+});
 
 // --- flow ---------------------------------------------------------------------------------
 
@@ -76,6 +85,30 @@ registerNode({
   params: [],
   run: (_ctx, inputs) => ({ outputs: { parent: asEntity(inputs.object)?.parent ?? null } }),
 });
+registerNode({
+  type: 'NameOf',
+  label: 'Name of',
+  category: 'data',
+  description: 'The name of an object (empty when there is none).',
+  inputs: [obj('object')],
+  outputs: [{ key: 'name', label: 'name', type: 'string' }],
+  params: [],
+  run: (_ctx, inputs) => ({ outputs: { name: asEntity(inputs.object)?.name ?? '' } }),
+});
+registerNode({
+  type: 'IsAsset',
+  label: 'Is asset',
+  category: 'data',
+  description: 'Whether an object is an instance of the chosen asset – the way to tell what you collided with.',
+  inputs: [obj('object')],
+  outputs: [bool('result')],
+  // Placeholder options: the graph inspector lists the project's placeable assets.
+  params: [{ key: 'asset', label: 'Asset', kind: 'enum', default: '', options: [] }],
+  run: (_ctx, inputs, params) => {
+    const assetId = String(params.asset ?? '');
+    return { outputs: { result: Boolean(assetId) && asEntity(inputs.object)?.assetId === assetId } };
+  },
+});
 registerNode({
   type: 'ObjectByName',
   label: 'Object by name',
@@ -198,6 +231,124 @@ registerNode({
   run: (_c, i) => ({ outputs: { result: Math.min(Math.max(asNumber(i.value), asNumber(i.min)), asNumber(i.max)) } }),
 });
 
+registerNode({ type: 'Floor', label: 'Floor', category: 'data', description: 'Rounds down to a whole number.', inputs: [num('value')], outputs: [num('result')], params: [], run: (_c, i) => ({ outputs: { result: Math.floor(asNumber(i.value)) } }) });
+registerNode({ type: 'Ceil', label: 'Ceil', category: 'data', description: 'Rounds up to a whole number.', inputs: [num('value')], outputs: [num('result')], params: [], run: (_c, i) => ({ outputs: { result: Math.ceil(asNumber(i.value)) } }) });
+registerNode({ type: 'Round', label: 'Round', category: 'data', description: 'Rounds to the nearest whole number.', inputs: [num('value')], outputs: [num('result')], params: [], run: (_c, i) => ({ outputs: { result: Math.round(asNumber(i.value)) } }) });
+registerNode({
+  type: 'Modulo',
+  label: 'Modulo',
+  category: 'data',
+  description: 'Remainder of a ÷ b (0 when b is 0) – seconds within a minute, for instance.',
+  inputs: [num('a'), { ...num('b'), default: 1 }],
+  outputs: [num('result')],
+  params: [],
+  run: (_c, i) => {
+    const b = asNumber(i.b);
+    return { outputs: { result: b === 0 ? 0 : asNumber(i.a) % b } };
+  },
+});
+registerNode({
+  type: 'Random',
+  label: 'Random',
+  category: 'data',
+  description: 'A random number between min and max (min included, max not).',
+  inputs: [{ ...num('min'), default: 0 }, { ...num('max'), default: 1 }],
+  outputs: [num('result')],
+  params: [],
+  run: (_c, i) => {
+    const min = asNumber(i.min);
+    return { outputs: { result: min + Math.random() * (asNumber(i.max) - min) } };
+  },
+});
+registerNode({
+  type: 'Time',
+  label: 'Time',
+  category: 'data',
+  description: 'Seconds since the game started, and the length of the current frame.',
+  inputs: [],
+  outputs: [num('time'), num('dt')],
+  params: [],
+  run: (ctx) => ({ outputs: { time: ctx.time, dt: ctx.dt } }),
+});
+
+// --- data: text ------------------------------------------------------------------------------
+
+registerNode({
+  type: 'ToText',
+  label: 'To text',
+  category: 'data',
+  description: 'Turns a number into text with a fixed number of decimals.',
+  inputs: [any('value'), num('decimals')],
+  outputs: [{ key: 'text', label: 'text', type: 'string' }],
+  params: [],
+  run: (_c, i) => {
+    const value = i.value;
+    const decimals = Math.max(0, Math.min(10, Math.floor(asNumber(i.decimals))));
+    return { outputs: { text: typeof value === 'string' ? value : asNumber(value).toFixed(decimals) } };
+  },
+});
+registerNode({
+  type: 'Join',
+  label: 'Join text',
+  category: 'data',
+  description: 'Sticks two values together as text ("Coins: " + 3).',
+  inputs: [any('a'), any('b')],
+  outputs: [{ key: 'text', label: 'text', type: 'string' }],
+  params: [],
+  run: (_c, i) => ({ outputs: { text: asString(i.a) + asString(i.b) } }),
+});
+registerNode({
+  type: 'Equals',
+  label: 'Equals',
+  category: 'data',
+  description: 'Whether two values are the same. Objects compare by identity, everything else as text.',
+  inputs: [any('a'), any('b')],
+  outputs: [bool('result')],
+  params: [],
+  run: (_c, i) => {
+    const a = asEntity(i.a);
+    const b = asEntity(i.b);
+    if (a || b) return { outputs: { result: a === b } };
+    return { outputs: { result: asString(i.a) === asString(i.b) } };
+  },
+});
+
+// --- data: mouse ------------------------------------------------------------------------------
+
+registerNode({
+  type: 'MousePosition',
+  label: 'Mouse position',
+  category: 'data',
+  description: 'Where the mouse is in the Game tab, in world units.',
+  inputs: [],
+  outputs: [num('x'), num('y'), bool('inside', 'in view')],
+  params: [],
+  run: (ctx) => ({ outputs: { x: ctx.pointer.x, y: ctx.pointer.y, inside: ctx.pointer.inside } }),
+});
+registerNode({
+  type: 'MouseButton',
+  label: 'Mouse button',
+  category: 'data',
+  description: 'State of the mouse button: held, and whether it went down or up this frame.',
+  inputs: [],
+  outputs: [bool('down'), bool('pressed'), bool('released')],
+  params: [],
+  run: (ctx) => ({ outputs: { down: ctx.pointer.down, pressed: ctx.pointer.pressed, released: ctx.pointer.released } }),
+});
+registerNode({
+  type: 'IsHovered',
+  label: 'Is hovered',
+  category: 'data',
+  description: 'Whether the mouse is over an object (its colliders, else its own or its children\'s footprint).',
+  inputs: [obj('object')],
+  outputs: [bool('result')],
+  params: [],
+  run: (ctx, i) => {
+    const target = asEntity(i.object);
+    return { outputs: { result: Boolean(target && ctx.pointer.inside && ctx.hitTest(target, ctx.pointer.x, ctx.pointer.y)) } };
+  },
+});
+
 // --- data: vectors -------------------------------------------------------------------------
 
 registerNode({ type: 'Length', label: 'Length', category: 'data', description: 'Length of the vector (x, y).', inputs: [num('x'), num('y')], outputs: [num('result')], params: [], run: (_c, i) => ({ outputs: { result: Math.hypot(asNumber(i.x), asNumber(i.y)) } }) });
@@ -332,6 +483,48 @@ registerNode({
     return { next: 'exec' };
   },
 });
+registerNode({
+  type: 'SetEnabled',
+  label: 'Set enabled',
+  category: 'action',
+  description: 'Switches an object on or off. A disabled object is not drawn, does not collide and its behavior stops – and so does everything parented below it. This is how screens (title, win, lose) are shown and hidden.',
+  inputs: [exec(), obj('object'), { ...bool('enabled'), default: true }],
+  outputs: [exec()],
+  params: [],
+  run: (_ctx, i) => {
+    const target = asEntity(i.object);
+    if (target) target.props.enabled = asBoolean(i.enabled);
+    return { next: 'exec' };
+  },
+});
+registerNode({
+  type: 'IsEnabled',
+  label: 'Is enabled',
+  category: 'data',
+  description: 'Whether an object is switched on – "own" is its own switch, "result" also requires every parent to be on.',
+  inputs: [obj('object')],
+  outputs: [bool('result'), bool('own', 'own switch')],
+  params: [],
+  run: (_ctx, i) => {
+    const target = asEntity(i.object);
+    if (!target) return { outputs: { result: false, own: false } };
+    return { outputs: { result: isHandleEnabled(target), own: target.props.enabled !== false } };
+  },
+});
+registerNode({
+  type: 'SetText',
+  label: 'Set text',
+  category: 'action',
+  description: 'Writes the content of a text object (same as Set property "text").',
+  inputs: [exec(), obj('object'), any('text')],
+  outputs: [exec()],
+  params: [],
+  run: (_ctx, i) => {
+    const target = asEntity(i.object);
+    if (target) target.props.text = asString(i.text);
+    return { next: 'exec' };
+  },
+});
 registerNode({
   type: 'Destroy',
   label: 'Destroy',
@@ -376,3 +569,4 @@ registerNode({
   },
 });
 registerNode({ type: 'StopGame', label: 'Stop game', category: 'action', description: 'Ends play mode.', inputs: [exec()], outputs: [], params: [], run: (ctx) => { ctx.stop(); return {}; } });
+registerNode({ type: 'RestartGame', label: 'Restart game', category: 'action', description: 'Starts the scene over from its saved state – everything spawned, moved or destroyed is reset.', inputs: [exec()], outputs: [], params: [], run: (ctx) => { ctx.restart(); return {}; } });