requestCameraReset SnapshotProvide

- allow to customize the snapshop based on the current scane/boundingbox/camera state

src/mol-canvas3d/camera.ts

@@ -9,6 +9,7 @@ import { Mat4, Vec3, Vec4, EPSILON } from '../mol-math/linear-algebra';
 import { Viewport, cameraProject, cameraUnproject } from './camera/util';
 import { CameraTransitionManager } from './camera/transition';
 import { BehaviorSubject } from 'rxjs';
+import { Scene } from '../mol-gl/scene';
 
 export { ICamera, Camera };
 
@@ -150,6 +151,8 @@ class Camera implements ICamera {
 namespace Camera {
     export type Mode = 'perspective' | 'orthographic'
 
+    export type SnapshotProvider = Partial<Snapshot> | ((scene: Scene, camera: Camera) => Partial<Snapshot>)
+
     /**
      * Sets an offseted view in a larger frustum. This is useful for
      * - multi-window or multi-monitor/multi-machine setups

src/mol-canvas3d/canvas3d.ts

@@ -229,7 +229,7 @@ interface Canvas3D {
     /** performs handleResize on the next animation frame */
     requestResize(): void
     /** Focuses camera on scene's bounding sphere, centered and zoomed. */
-    requestCameraReset(options?: { durationMs?: number, snapshot?: Partial<Camera.Snapshot> }): void
+    requestCameraReset(options?: { durationMs?: number, snapshot?: Camera.SnapshotProvider }): void
     readonly camera: Camera
     readonly boundingSphere: Readonly<Sphere3D>
     setProps(props: PartialCanvas3DProps | ((old: Canvas3DProps) => Partial<Canvas3DProps> | void), doNotRequestDraw?: boolean /* = false */): void
@@ -296,7 +296,7 @@ namespace Canvas3D {
         let drawPending = false;
         let cameraResetRequested = false;
         let nextCameraResetDuration: number | undefined = void 0;
-        let nextCameraResetSnapshot: Partial<Camera.Snapshot> | undefined = void 0;
+        let nextCameraResetSnapshot: Camera.SnapshotProvider | undefined = void 0;
         let resizeRequested = false;
 
         let notifyDidDraw = true;
@@ -453,11 +453,13 @@ namespace Canvas3D {
         function resolveCameraReset() {
             if (!cameraResetRequested) return;
 
-            const { center, radius } = scene.boundingSphereVisible;
+            const boundingSphere = scene.boundingSphereVisible;
+            const { center, radius } = boundingSphere;
             if (radius > 0) {
                 const duration = nextCameraResetDuration === undefined ? p.cameraResetDurationMs : nextCameraResetDuration;
                 const focus = camera.getFocus(center, radius);
-                const snapshot = nextCameraResetSnapshot ? { ...focus, ...nextCameraResetSnapshot } : focus;
+                const next = typeof nextCameraResetSnapshot === 'function' ? nextCameraResetSnapshot(scene, camera) : nextCameraResetSnapshot;
+                const snapshot = next ? { ...focus, ...nextCameraResetSnapshot } : focus;
                 camera.setState({ ...snapshot, radiusMax: scene.boundingSphere.radius }, duration);
             }