Babylon.js/src/Engines/nullEngine.ts

import { Logger } from "../Misc/logger";
import { Nullable, FloatArray, IndicesArray } from "../types";
import { Scene } from "../scene";
import { Matrix, Color3, Color4, Viewport } from "../Maths/math";
import { Engine, EngineCapabilities } from "../Engines/engine";
import { RenderTargetCreationOptions } from "../Materials/Textures/renderTargetCreationOptions";
import { VertexBuffer } from "../Meshes/buffer";
import { InternalTexture } from "../Materials/Textures/internalTexture";
import { Effect } from "../Materials/effect";
import { _TimeToken } from "../Instrumentation/timeToken";
import { _DepthCullingState, _StencilState, _AlphaState } from "../States/index";
import { Constants } from "./constants";
import { IPipelineContext } from './IPipelineContext';
import { DataBuffer } from '../Meshes/dataBuffer';

declare const global: any;

/**
 * Options to create the null engine
 */
export class NullEngineOptions {
    /**
     * Render width (Default: 512)
     */
    public renderWidth = 512;
    /**
     * Render height (Default: 256)
     */
    public renderHeight = 256;

    /**
     * Texture size (Default: 512)
     */
    public textureSize = 512;

    /**
     * If delta time between frames should be constant
     * @see https://doc.babylonjs.com/babylon101/animations#deterministic-lockstep
     */
    public deterministicLockstep = false;

    /**
     * Maximum about of steps between frames (Default: 4)
     * @see https://doc.babylonjs.com/babylon101/animations#deterministic-lockstep
     */
    public lockstepMaxSteps = 4;
}

/**
 * The null engine class provides support for headless version of babylon.js.
 * This can be used in server side scenario or for testing purposes
 */
export class NullEngine extends Engine {
    private _options: NullEngineOptions;

    /**
     * @see https://doc.babylonjs.com/babylon101/animations#deterministic-lockstep
     */
    public isDeterministicLockStep(): boolean {
        return this._options.deterministicLockstep;
    }

    /** @see https://doc.babylonjs.com/babylon101/animations#deterministic-lockstep */
    public getLockstepMaxSteps(): number {
        return this._options.lockstepMaxSteps;
    }

    /**
     * Sets hardware scaling, used to save performance if needed
     * @see https://doc.babylonjs.com/how_to/how_to_use_sceneoptimizer
     */
    public getHardwareScalingLevel(): number {
        return 1.0;
    }

    public constructor(options: NullEngineOptions = new NullEngineOptions()) {
        super(null);

        if (options.deterministicLockstep === undefined) {
            options.deterministicLockstep = false;
        }

        if (options.lockstepMaxSteps === undefined) {
            options.lockstepMaxSteps = 4;
        }

        this._options = options;

        // Init caps
        // We consider we are on a webgl1 capable device

        this._caps = new EngineCapabilities();
        this._caps.maxTexturesImageUnits = 16;
        this._caps.maxVertexTextureImageUnits = 16;
        this._caps.maxTextureSize = 512;
        this._caps.maxCubemapTextureSize = 512;
        this._caps.maxRenderTextureSize = 512;
        this._caps.maxVertexAttribs = 16;
        this._caps.maxVaryingVectors = 16;
        this._caps.maxFragmentUniformVectors = 16;
        this._caps.maxVertexUniformVectors = 16;

        // Extensions
        this._caps.standardDerivatives = false;

        this._caps.astc = null;
        this._caps.s3tc = null;
        this._caps.pvrtc = null;
        this._caps.etc1 = null;
        this._caps.etc2 = null;

        this._caps.textureAnisotropicFilterExtension = null;
        this._caps.maxAnisotropy = 0;
        this._caps.uintIndices = false;
        this._caps.fragmentDepthSupported = false;
        this._caps.highPrecisionShaderSupported = true;

        this._caps.colorBufferFloat = false;
        this._caps.textureFloat = false;
        this._caps.textureFloatLinearFiltering = false;
        this._caps.textureFloatRender = false;

        this._caps.textureHalfFloat = false;
        this._caps.textureHalfFloatLinearFiltering = false;
        this._caps.textureHalfFloatRender = false;

        this._caps.textureLOD = false;
        this._caps.drawBuffersExtension = false;

        this._caps.depthTextureExtension = false;
        this._caps.vertexArrayObject = false;
        this._caps.instancedArrays = false;

        Logger.Log(`Babylon.js v${Engine.Version} - Null engine`);

        // Wrappers
        const theCurrentGlobal = (typeof self !== "undefined" ? self : typeof global !== "undefined" ? global : window);
        if (typeof URL === "undefined") {
            theCurrentGlobal.URL = {
                createObjectURL: function() { },
                revokeObjectURL: function() { }
            };
        }
        if (typeof Blob === "undefined") {
            theCurrentGlobal.Blob = function() { };
        }
    }

    public createVertexBuffer(vertices: FloatArray): DataBuffer {
        let buffer = new DataBuffer();
        buffer.references = 1;
        return buffer;
    }

    public createIndexBuffer(indices: IndicesArray): DataBuffer {
        let buffer = new DataBuffer();
        buffer.references = 1;
        return buffer;
    }

    public clear(color: Color4, backBuffer: boolean, depth: boolean, stencil: boolean = false): void {
    }

    public getRenderWidth(useScreen = false): number {
        if (!useScreen && this._currentRenderTarget) {
            return this._currentRenderTarget.width;
        }

        return this._options.renderWidth;
    }

    public getRenderHeight(useScreen = false): number {
        if (!useScreen && this._currentRenderTarget) {
            return this._currentRenderTarget.height;
        }

        return this._options.renderHeight;
    }

    public setViewport(viewport: Viewport, requiredWidth?: number, requiredHeight?: number): void {
        this._cachedViewport = viewport;
    }

    public createShaderProgram(pipelineContext: IPipelineContext, vertexCode: string, fragmentCode: string, defines: string, context?: WebGLRenderingContext): WebGLProgram {
        return {
            __SPECTOR_rebuildProgram: null,
        };
    }

    public getUniforms(pipelineContext: IPipelineContext, uniformsNames: string[]): Nullable<WebGLUniformLocation>[] {
        return [];
    }

    public getAttributes(pipelineContext: IPipelineContext, attributesNames: string[]): number[] {
        return [];
    }

    public bindSamplers(effect: Effect): void {
        this._currentEffect = null;
    }

    public enableEffect(effect: Effect): void {
        this._currentEffect = effect;

        if (effect.onBind) {
            effect.onBind(effect);
        }
        if (effect._onBindObservable) {
            effect._onBindObservable.notifyObservers(effect);
        }
    }

    public setState(culling: boolean, zOffset: number = 0, force?: boolean, reverseSide = false): void {
    }

    public setIntArray(uniform: WebGLUniformLocation, array: Int32Array): void {
    }

    public setIntArray2(uniform: WebGLUniformLocation, array: Int32Array): void {
    }

    public setIntArray3(uniform: WebGLUniformLocation, array: Int32Array): void {
    }

    public setIntArray4(uniform: WebGLUniformLocation, array: Int32Array): void {
    }

    public setFloatArray(uniform: WebGLUniformLocation, array: Float32Array): void {
    }

    public setFloatArray2(uniform: WebGLUniformLocation, array: Float32Array): void {
    }

    public setFloatArray3(uniform: WebGLUniformLocation, array: Float32Array): void {
    }

    public setFloatArray4(uniform: WebGLUniformLocation, array: Float32Array): void {
    }

    public setArray(uniform: WebGLUniformLocation, array: number[]): void {
    }

    public setArray2(uniform: WebGLUniformLocation, array: number[]): void {
    }

    public setArray3(uniform: WebGLUniformLocation, array: number[]): void {
    }

    public setArray4(uniform: WebGLUniformLocation, array: number[]): void {
    }

    public setMatrices(uniform: WebGLUniformLocation, matrices: Float32Array): void {
    }

    public setMatrix(uniform: WebGLUniformLocation, matrix: Matrix): void {
    }

    public setMatrix3x3(uniform: WebGLUniformLocation, matrix: Float32Array): void {
    }

    public setMatrix2x2(uniform: WebGLUniformLocation, matrix: Float32Array): void {
    }

    public setFloat(uniform: WebGLUniformLocation, value: number): void {
    }

    public setFloat2(uniform: WebGLUniformLocation, x: number, y: number): void {
    }

    public setFloat3(uniform: WebGLUniformLocation, x: number, y: number, z: number): void {
    }

    public setBool(uniform: WebGLUniformLocation, bool: number): void {
    }

    public setFloat4(uniform: WebGLUniformLocation, x: number, y: number, z: number, w: number): void {
    }

    public setColor3(uniform: WebGLUniformLocation, color3: Color3): void {
    }

    public setColor4(uniform: WebGLUniformLocation, color3: Color3, alpha: number): void {
    }

    public setAlphaMode(mode: number, noDepthWriteChange: boolean = false): void {
        if (this._alphaMode === mode) {
            return;
        }

        this._alphaState.alphaBlend = (mode !== Constants.ALPHA_DISABLE);

        if (!noDepthWriteChange) {
            this.setDepthWrite(mode === Constants.ALPHA_DISABLE);
        }
        this._alphaMode = mode;
    }

    public bindBuffers(vertexBuffers: { [key: string]: VertexBuffer; }, indexBuffer: DataBuffer, effect: Effect): void {
    }

    public wipeCaches(bruteForce?: boolean): void {
        if (this.preventCacheWipeBetweenFrames) {
            return;
        }
        this.resetTextureCache();
        this._currentEffect = null;

        if (bruteForce) {
            this._currentProgram = null;

            this._stencilState.reset();
            this._depthCullingState.reset();
            this._alphaState.reset();
        }

        this._cachedVertexBuffers = null;
        this._cachedIndexBuffer = null;
        this._cachedEffectForVertexBuffers = null;
    }

    public draw(useTriangles: boolean, indexStart: number, indexCount: number, instancesCount?: number): void {
    }

    public drawElementsType(fillMode: number, indexStart: number, indexCount: number, instancesCount?: number): void {
    }

    public drawArraysType(fillMode: number, verticesStart: number, verticesCount: number, instancesCount?: number): void {
    }

    /** @hidden */
    public _createTexture(): WebGLTexture {
        return {};
    }

    /** @hidden */
    public _releaseTexture(texture: InternalTexture): void {
    }

    public createTexture(urlArg: string, noMipmap: boolean, invertY: boolean, scene: Scene, samplingMode: number = Constants.TEXTURE_TRILINEAR_SAMPLINGMODE, onLoad: Nullable<() => void> = null, onError: Nullable<(message: string, exception: any) => void> = null, buffer: Nullable<ArrayBuffer | HTMLImageElement> = null, fallBack?: InternalTexture, format?: number): InternalTexture {
        var texture = new InternalTexture(this, InternalTexture.DATASOURCE_URL);
        var url = String(urlArg);

        texture.url = url;
        texture.generateMipMaps = !noMipmap;
        texture.samplingMode = samplingMode;
        texture.invertY = invertY;
        texture.baseWidth = this._options.textureSize;
        texture.baseHeight = this._options.textureSize;
        texture.width = this._options.textureSize;
        texture.height = this._options.textureSize;
        if (format) {
            texture.format = format;
        }

        texture.isReady = true;

        if (onLoad) {
            onLoad();
        }

        this._internalTexturesCache.push(texture);

        return texture;
    }

    public createRenderTargetTexture(size: any, options: boolean | RenderTargetCreationOptions): InternalTexture {
        let fullOptions = new RenderTargetCreationOptions();

        if (options !== undefined && typeof options === "object") {
            fullOptions.generateMipMaps = options.generateMipMaps;
            fullOptions.generateDepthBuffer = options.generateDepthBuffer === undefined ? true : options.generateDepthBuffer;
            fullOptions.generateStencilBuffer = fullOptions.generateDepthBuffer && options.generateStencilBuffer;
            fullOptions.type = options.type === undefined ? Constants.TEXTURETYPE_UNSIGNED_INT : options.type;
            fullOptions.samplingMode = options.samplingMode === undefined ? Constants.TEXTURE_TRILINEAR_SAMPLINGMODE : options.samplingMode;
        } else {
            fullOptions.generateMipMaps = <boolean>options;
            fullOptions.generateDepthBuffer = true;
            fullOptions.generateStencilBuffer = false;
            fullOptions.type = Constants.TEXTURETYPE_UNSIGNED_INT;
            fullOptions.samplingMode = Constants.TEXTURE_TRILINEAR_SAMPLINGMODE;
        }
        var texture = new InternalTexture(this, InternalTexture.DATASOURCE_RENDERTARGET);

        var width = size.width || size;
        var height = size.height || size;

        texture._depthStencilBuffer = {};
        texture._framebuffer = {};
        texture.baseWidth = width;
        texture.baseHeight = height;
        texture.width = width;
        texture.height = height;
        texture.isReady = true;
        texture.samples = 1;
        texture.generateMipMaps = fullOptions.generateMipMaps ? true : false;
        texture.samplingMode = fullOptions.samplingMode;
        texture.type = fullOptions.type;
        texture._generateDepthBuffer = fullOptions.generateDepthBuffer;
        texture._generateStencilBuffer = fullOptions.generateStencilBuffer ? true : false;

        this._internalTexturesCache.push(texture);

        return texture;
    }

    public updateTextureSamplingMode(samplingMode: number, texture: InternalTexture): void {
        texture.samplingMode = samplingMode;
    }

    public bindFramebuffer(texture: InternalTexture, faceIndex?: number, requiredWidth?: number, requiredHeight?: number, forceFullscreenViewport?: boolean): void {
        if (this._currentRenderTarget) {
            this.unBindFramebuffer(this._currentRenderTarget);
        }
        this._currentRenderTarget = texture;
        this._currentFramebuffer = texture._MSAAFramebuffer ? texture._MSAAFramebuffer : texture._framebuffer;
        if (this._cachedViewport && !forceFullscreenViewport) {
            this.setViewport(this._cachedViewport, requiredWidth, requiredHeight);
        }
    }

    public unBindFramebuffer(texture: InternalTexture, disableGenerateMipMaps = false, onBeforeUnbind?: () => void): void {
        this._currentRenderTarget = null;

        if (onBeforeUnbind) {
            if (texture._MSAAFramebuffer) {
                this._currentFramebuffer = texture._framebuffer;
            }
            onBeforeUnbind();
        }
        this._currentFramebuffer = null;
    }

    public createDynamicVertexBuffer(vertices: FloatArray): DataBuffer {
        let buffer = new DataBuffer();
        buffer.references = 1;
        buffer.capacity = 1;
        return buffer;
    }

    public updateDynamicTexture(texture: Nullable<InternalTexture>, canvas: HTMLCanvasElement, invertY: boolean, premulAlpha: boolean = false, format?: number): void {

    }

    public areAllEffectsReady(): boolean {
        return true;
    }

    /**
     * @hidden
     * Get the current error code of the webGL context
     * @returns the error code
     * @see https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/getError
     */
    public getError(): number {
        return 0;
    }

    /** @hidden */
    public _getUnpackAlignement(): number {
        return 1;
    }

    /** @hidden */
    public _unpackFlipY(value: boolean) {
    }

    public updateDynamicIndexBuffer(indexBuffer: WebGLBuffer, indices: IndicesArray, offset: number = 0): void {
    }

    /**
     * Updates a dynamic vertex buffer.
     * @param vertexBuffer the vertex buffer to update
     * @param data the data used to update the vertex buffer
     * @param byteOffset the byte offset of the data (optional)
     * @param byteLength the byte length of the data (optional)
     */
    public updateDynamicVertexBuffer(vertexBuffer: WebGLBuffer, vertices: FloatArray, byteOffset?: number, byteLength?: number): void {
    }

    public _bindTextureDirectly(target: number, texture: InternalTexture): boolean {
        if (this._boundTexturesCache[this._activeChannel] !== texture) {
            this._boundTexturesCache[this._activeChannel] = texture;
            return true;
        }
        return false;
    }

    /** @hidden */
    public _bindTexture(channel: number, texture: InternalTexture): void {
        if (channel < 0) {
            return;
        }

        this._bindTextureDirectly(0, texture);
    }

    /** @hidden */
    public _releaseBuffer(buffer: DataBuffer): boolean {
        buffer.references--;

        if (buffer.references === 0) {
            return true;
        }

        return false;
    }

    public releaseEffects() {
    }

    public displayLoadingUI(): void {
    }

    public hideLoadingUI(): void {
    }

    /** @hidden */
    public _uploadCompressedDataToTextureDirectly(texture: InternalTexture, internalFormat: number, width: number, height: number, data: ArrayBufferView, faceIndex: number = 0, lod: number = 0) {
    }

    /** @hidden */
    public _uploadDataToTextureDirectly(texture: InternalTexture, imageData: ArrayBufferView, faceIndex: number = 0, lod: number = 0): void {
    }

    /** @hidden */
    public _uploadArrayBufferViewToTexture(texture: InternalTexture, imageData: ArrayBufferView, faceIndex: number = 0, lod: number = 0): void {
    }

    /** @hidden */
    public _uploadImageToTexture(texture: InternalTexture, image: HTMLImageElement, faceIndex: number = 0, lod: number = 0) {
    }
}