@vrame/xeokit-sdk
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3D BIM IFC Viewer SDK for AEC engineering applications. Open Source JavaScript Toolkit based on pure WebGL for top performance, real-world coordinates and full double precision
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JavaScript
import {math} from "../math/math.js";
/**
* @desc Saves and restores the state of a {@link Scene}'s {@link Camera}.
*
* ## See Also
*
* * {@link ModelMemento} - Saves and restores a snapshot of the visual state of the {@link Entity}'s of a model within a {@link Scene}.
* * {@link ObjectsMemento} - Saves and restores a snapshot of the visual state of the {@link Entity}'s that represent objects within a {@link Scene}.
*
* ## Usage
*
* In the example below, we'll create a {@link Viewer} and use an {@link XKTLoaderPlugin} to load an ````.xkt```` model. When the model has loaded, we'll save a snapshot of the {@link Camera} state in an CameraMemento. Then we'll move the Camera, and then we'll restore its original state again from the CameraMemento.
*
* ````javascript
* import {Viewer, XKTLoaderPlugin, CameraMemento} from "xeokit-sdk.es.js";
*
* const viewer = new Viewer({
* canvasId: "myCanvas"
* });
*
* // Load a model
* const xktLoader = new XKTLoaderPlugin(viewer);
*
* const model = xktLoader.load({
* id: "myModel",
* src: "./models/xkt/schependomlaan/schependomlaan.xkt"
* });
*
* // Set camera
* viewer.camera.eye = [-2.56, 8.38, 8.27];
* viewer.camera.look = [13.44, 3.31, -14.83];
* viewer.camera.up = [0.10, 0.98, -0.14];
*
* model.on("loaded", () => {
*
* // Model has loaded
*
* // Save memento of camera state
* const cameraMemento = new CameraMemento();
*
* cameraMemento.saveCamera(viewer.scene);
*
* // Move the camera
* viewer.camera.eye = [45.3, 2.00, 5.13];
* viewer.camera.look = [0.0, 5.5, 10.0];
* viewer.camera.up = [0.10, 0.98, -0.14];
*
* // Restore the camera state again
* objectsMemento.restoreCamera(viewer.scene);
* });
* ````
*/
class CameraMemento {
/**
* Creates a CameraState.
*
* @param {Scene} [scene] When given, immediately saves the state of the given {@link Scene}'s {@link Camera}.
*/
constructor(scene) {
/** @private */
this._eye = math.vec3();
/** @private */
this._look = math.vec3();
/** @private */
this._up = math.vec3();
/** @private */
this._projection = {};
if (scene) {
this.saveCamera(scene);
}
}
/**
* Saves the state of the given {@link Scene}'s {@link Camera}.
*
* @param {Scene} scene The scene that contains the {@link Camera}.
*/
saveCamera(scene) {
const camera = scene.camera;
const project = camera.project;
this._eye.set(camera.eye);
this._look.set(camera.look);
this._up.set(camera.up);
switch (camera.projection) {
case "perspective":
this._projection = {
projection: "perspective",
fov: project.fov,
fovAxis: project.fovAxis,
near: project.near,
far: project.far
};
break;
case "ortho":
this._projection = {
projection: "ortho",
scale: project.scale,
near: project.near,
far: project.far
};
break;
case "frustum":
this._projection = {
projection: "frustum",
left: project.left,
right: project.right,
top: project.top,
bottom: project.bottom,
near: project.near,
far: project.far
};
break;
case "custom":
this._projection = {
projection: "custom",
matrix: project.matrix.slice()
};
break;
}
}
/**
* Restores a {@link Scene}'s {@link Camera} to the state previously captured with {@link CameraMemento#saveCamera}.
*
* @param {Scene} scene The scene.
* @param {Function} [done] When this callback is given, will fly the {@link Camera} to the saved state then fire the callback. Otherwise will just jump the Camera to the saved state.
*/
restoreCamera(scene, done) {
const camera = scene.camera;
const savedProjection = this._projection;
function restoreProjection() {
switch (savedProjection.type) {
case "perspective":
camera.perspective.fov = savedProjection.fov;
camera.perspective.fovAxis = savedProjection.fovAxis;
camera.perspective.near = savedProjection.near;
camera.perspective.far = savedProjection.far;
break;
case "ortho":
camera.ortho.scale = savedProjection.scale;
camera.ortho.near = savedProjection.near;
camera.ortho.far = savedProjection.far;
break;
case "frustum":
camera.frustum.left = savedProjection.left;
camera.frustum.right = savedProjection.right;
camera.frustum.top = savedProjection.top;
camera.frustum.bottom = savedProjection.bottom;
camera.frustum.near = savedProjection.near;
camera.frustum.far = savedProjection.far;
break;
case "custom":
camera.customProjection.matrix = savedProjection.matrix;
break;
}
}
if (done) {
scene.viewer.cameraFlight.flyTo({
eye: this._eye,
look: this._look,
up: this._up,
orthoScale: savedProjection.scale,
projection: savedProjection.projection
}, () => {
restoreProjection();
done();
});
} else {
camera.eye = this._eye;
camera.look = this._look;
camera.up = this._up;
restoreProjection();
camera.projection = savedProjection.projection;
}
}
}
export {CameraMemento};