feat(scene): shared zoom/pan for control and presentation

Keep effects pinned to map coordinates when the viewport changes; materials/NPC overlays stay screen-fixed.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/shared/types/index.ts

@@ -4,4 +4,5 @@ export * from './ids';
 export * from './materials';
 export * from './npcs';
 export * from './sceneDarkness';
+export * from './sceneView';
 export * from './videoPlayback';

app/shared/types/sceneView.ts

@@ -0,0 +1,94 @@
+/** Камера вида сцены (общая для Control и Presentation). */
+
+export type SceneViewCamera = {
+  /** Множитель поверх contain-fit; 1 = вся картинка влезает. */
+  scale: number;
+  /** Точка контента (0..1), которая держится в центре viewport. */
+  ox: number;
+  oy: number;
+};
+
+export type SceneViewState = {
+  revision: number;
+} & SceneViewCamera;
+
+export type SceneViewEvent =
+  | { kind: 'reset' }
+  | { kind: 'set'; camera: SceneViewCamera };
+
+export const DEFAULT_SCENE_VIEW_CAMERA: SceneViewCamera = {
+  scale: 1,
+  ox: 0.5,
+  oy: 0.5,
+};
+
+export const SCENE_VIEW_MIN_SCALE = 1;
+export const SCENE_VIEW_MAX_SCALE = 8;
+
+export function clampSceneViewCamera(camera: SceneViewCamera): SceneViewCamera {
+  const scale = Math.max(
+    SCENE_VIEW_MIN_SCALE,
+    Math.min(SCENE_VIEW_MAX_SCALE, Number.isFinite(camera.scale) ? camera.scale : 1),
+  );
+  if (scale <= 1.001) {
+    return { ...DEFAULT_SCENE_VIEW_CAMERA };
+  }
+  const ox = Math.max(0, Math.min(1, Number.isFinite(camera.ox) ? camera.ox : 0.5));
+  const oy = Math.max(0, Math.min(1, Number.isFinite(camera.oy) ? camera.oy : 0.5));
+  return { scale, ox, oy };
+}
+
+/**
+ * Зум относительно точки курсора в координатах хоста (px).
+ * `containW/H` — размер contain-fit без зума.
+ */
+export function sceneViewZoomAt(
+  camera: SceneViewCamera,
+  args: {
+    hostW: number;
+    hostH: number;
+    containW: number;
+    containH: number;
+    hostX: number;
+    hostY: number;
+    factor: number;
+  },
+): SceneViewCamera {
+  const hostW = Math.max(1, args.hostW);
+  const hostH = Math.max(1, args.hostH);
+  const containW = Math.max(1, args.containW);
+  const containH = Math.max(1, args.containH);
+  const cur = clampSceneViewCamera(camera);
+  const displayW = containW * cur.scale;
+  const displayH = containH * cur.scale;
+  const left = hostW / 2 - cur.ox * displayW;
+  const top = hostH / 2 - cur.oy * displayH;
+  const ix = (args.hostX - left) / Math.max(1e-6, displayW);
+  const iy = (args.hostY - top) / Math.max(1e-6, displayH);
+  const nextScale = Math.max(
+    SCENE_VIEW_MIN_SCALE,
+    Math.min(SCENE_VIEW_MAX_SCALE, cur.scale * args.factor),
+  );
+  if (nextScale <= 1.001) return { ...DEFAULT_SCENE_VIEW_CAMERA };
+  const nextDisplayW = containW * nextScale;
+  const nextDisplayH = containH * nextScale;
+  const ox = ix - (args.hostX - hostW / 2) / Math.max(1e-6, nextDisplayW);
+  const oy = iy - (args.hostY - hostH / 2) / Math.max(1e-6, nextDisplayH);
+  return clampSceneViewCamera({ scale: nextScale, ox, oy });
+}
+
+/** Пан на `dx/dy` пикселей хоста (тянуть картинку в сторону движения указателя). */
+export function sceneViewPanBy(
+  camera: SceneViewCamera,
+  args: { containW: number; containH: number; dx: number; dy: number },
+): SceneViewCamera {
+  const cur = clampSceneViewCamera(camera);
+  if (cur.scale <= 1.001) return { ...DEFAULT_SCENE_VIEW_CAMERA };
+  const displayW = Math.max(1e-6, args.containW * cur.scale);
+  const displayH = Math.max(1e-6, args.containH * cur.scale);
+  return clampSceneViewCamera({
+    scale: cur.scale,
+    ox: cur.ox - args.dx / displayW,
+    oy: cur.oy - args.dy / displayH,
+  });
+}