@pmndrs/handle/dist/screen/utils.js

framework agnostic expandable handle implementation for threejs

import { PerspectiveCamera, Quaternion, Vector2, Vector3 } from 'three';
export function average(target, map, key) {
    target.set(0, 0);
    let count = 0;
    for (const value of map.values()) {
        target.add(value[key]);
        count++;
    }
    if (count === 0) {
        return;
    }
    target.divideScalar(count);
}
const vector2Helper = new Vector2();
const quaternionHelper = new Quaternion();
const vectorHelper = new Vector3();
const forwardHelper = new Vector3();
const upwardHelper = new Vector3();
export function convertScreenSpaceMovementToGlobalPan(state, camera, screenSpaceMovement, target, speed, space) {
    target.set(0, 0, 0);
    const cameraHeightAtDistance = camera instanceof PerspectiveCamera
        ? state.distance * 2 * Math.tan(((camera.fov / 2) * Math.PI) / 180.0)
        : (camera.top - camera.bottom) / camera.zoom;
    vector2Helper.copy(screenSpaceMovement).multiplyScalar(-0.5 * speed * cameraHeightAtDistance);
    state.getCameraTransformation(undefined, quaternionHelper);
    const cameraRatio = camera instanceof PerspectiveCamera ? camera.aspect : (camera.right - camera.left) / (camera.top - camera.bottom);
    if (space === 'screen') {
        //x
        vectorHelper
            .set(1, 0, 0)
            .applyQuaternion(quaternionHelper)
            .multiplyScalar(vector2Helper.x * cameraRatio);
        target.add(vectorHelper);
        //y
        vectorHelper.set(0, 1, 0).applyQuaternion(quaternionHelper).multiplyScalar(vector2Helper.y);
        target.add(vectorHelper);
    }
    else {
        forwardHelper.set(0, 0, -1).applyQuaternion(quaternionHelper);
        upwardHelper.set(0, 1, 0).applyQuaternion(quaternionHelper);
        vectorHelper
            .copy(Math.abs(forwardHelper.y) < Math.abs(upwardHelper.y) ? forwardHelper : upwardHelper)
            .setComponent(1, 0)
            .normalize();
        target.addScaledVector(vectorHelper, vector2Helper.y);
        vectorHelper
            .set(1, 0, 0)
            .applyQuaternion(quaternionHelper)
            .setComponent(1, 0)
            .normalize()
            .multiplyScalar(vector2Helper.x * cameraRatio);
        target.add(vectorHelper);
    }
}