Babylon.js/src/PostProcesses/stereoscopicInterlacePostProcess.ts

import { Nullable } from "../types";
import { Vector2 } from "../Maths/math";
import { Camera } from "../Cameras/camera";
import { Effect } from "../Materials/effect";
import { PostProcess } from "./postProcess";
import { Engine } from "../Engines/engine";

import "../Shaders/stereoscopicInterlace.fragment";

/**
 * StereoscopicInterlacePostProcess used to render stereo views from a rigged camera
 */
export class StereoscopicInterlacePostProcess extends PostProcess {
    private _stepSize: Vector2;
    private _passedProcess: Nullable<PostProcess>;

    /**
     * Initializes a StereoscopicInterlacePostProcess
     * @param name The name of the effect.
     * @param rigCameras The rig cameras to be appled to the post process
     * @param isStereoscopicHoriz If the rendered results are horizontal or verticle
     * @param samplingMode The sampling mode to be used when computing the pass. (default: 0)
     * @param engine The engine which the post process will be applied. (default: current engine)
     * @param reusable If the post process can be reused on the same frame. (default: false)
     */
    constructor(name: string, rigCameras: Camera[], isStereoscopicHoriz: boolean, samplingMode?: number, engine?: Engine, reusable?: boolean) {
        super(name, "stereoscopicInterlace", ['stepSize'], ['camASampler'], 1, rigCameras[1], samplingMode, engine, reusable, isStereoscopicHoriz ? "#define IS_STEREOSCOPIC_HORIZ 1" : undefined);

        this._passedProcess = rigCameras[0]._rigPostProcess;
        this._stepSize = new Vector2(1 / this.width, 1 / this.height);

        this.onSizeChangedObservable.add(() => {
            this._stepSize = new Vector2(1 / this.width, 1 / this.height);
        });
        this.onApplyObservable.add((effect: Effect) => {
            effect.setTextureFromPostProcess("camASampler", this._passedProcess);
            effect.setFloat2("stepSize", this._stepSize.x, this._stepSize.y);
        });
    }
}