@openhps/core/src/three/core/GLBufferAttribute.d.ts

Open Hybrid Positioning System - Core component

/**
 * This buffer attribute class does not construct a VBO.
 * Instead, it uses whatever VBO is passed in constructor and can later be altered via the {@link buffer | .buffer} property.
 * @remarks
 * It is required to pass additional params alongside the VBO
 * Those are: the GL context, the GL data type, the number of components per vertex, the number of bytes per component, and the number of vertices.
 * @remarks
 * The most common use case for this class is when some kind of GPGPU calculation interferes or even produces the VBOs in question.
 * @see Example: {@link https://threejs.org/examples/#webgl_buffergeometry_glbufferattribute | WebGL / buffergeometry / glbufferattribute}
 * @see {@link https://threejs.org/docs/index.html#api/en/core/GLBufferAttribute | Official Documentation}
 * @see {@link https://github.com/mrdoob/three.js/blob/master/src/core/GLBufferAttribute.js | Source}
 */
export class GLBufferAttribute {
    /**
     * This creates a new GLBufferAttribute object.
     * @param buffer Must be a {@link https://developer.mozilla.org/en-US/docs/Web/API/WebGLBuffer | WebGLBuffer}. See {@link GLBufferAttribute.buffer | .buffer}
     * @param type One of {@link https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/Constants#Data_types | WebGL Data Types}. See {@link GLBufferAttribute.type | .type}
     * @param itemSize How many values make up each item (vertex). See {@link GLBufferAttribute.itemSize | .itemSize}
     * @param elementSize `1`, `2` or `4`. The corresponding size (in bytes) for the given {@link type} param. See {@link GLBufferAttribute.elementSize | .elementSize}
     * @param count The expected number of vertices in VBO. See {@link GLBufferAttribute.count | .count}
     */
    constructor(buffer: WebGLBuffer, type: GLenum, itemSize: number, elementSize: 1 | 2 | 4, count: number);

    /**
     * Read-only flag to check if a given object is of type {@link GLBufferAttribute}.
     * @remarks This is a _constant_ value
     * @defaultValue `true`
     */
    readonly isGLBufferAttribute: true;

    /**
     * Optional name for this attribute instance.
     * @defaultValue `""`
     */
    name: string;

    /**
     * The current {@link https://developer.mozilla.org/en-US/docs/Web/API/WebGLBuffer | WebGLBuffer} instance.
     */
    buffer: WebGLBuffer;

    /**
     * A {@link https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/Constants#Data_types | WebGL Data Type} describing the underlying VBO contents.
     *
     * #### WebGL Data Type (`GLenum`)
     * - gl.BYTE: 0x1400
     * - gl.UNSIGNED_BYTE: 0x1401
     * - gl.SHORT: 0x1402
     * - gl.UNSIGNED_SHORT: 0x1403
     * - gl.INT: 0x1404
     * - gl.UNSIGNED_INT: 0x1405
     * - gl.FLOAT: 0x1406
     * @remarks Set this property together with {@link elementSize | .elementSize}. The recommended way is using the {@link setType | .setType()} method.
     * @remarks Expects a `DataType` `GLenum` _possible values:_ `0x1400` `0x1401` `0x1402` `0x1403` `0x1404` `0x1405` `0x1406`
     */
    type: GLenum;

    /**
     * How many values make up each item (vertex).
     * @remarks The number of values of the array that should be associated with a particular vertex.
     * For instance, if this attribute is storing a 3-component vector (such as a position, normal, or color), then itemSize should be 3.
     * @remarks Expects a `Integer`
     */
    itemSize: number;

    /**
     * Stores the corresponding size in bytes for the current {@link type | .type} property value.
     *
     * The corresponding size (_in bytes_) for the given "type" param.
     * #### WebGL Data Type (`GLenum`)
     * - gl.BYTE: 1
     * - gl.UNSIGNED_BYTE: 1
     * - gl.SHORT: 2
     * - gl.UNSIGNED_SHORT: 2
     * - gl.INT: 4
     * - gl.UNSIGNED_INT: 4
     * - gl.FLOAT: 4
     * @remarks Set this property together with {@link type | .type}. The recommended way is using the {@link setType | .setType} method.
     * @see `constructor`` for a list of known type sizes.
     * @remarks Expects a `1`, `2` or `4`
     */
    elementSize: 1 | 2 | 4;

    /**
     * The expected number of vertices in VBO.
     * @remarks Expects a `Integer`
     */
    count: number;

    /**
     * A version number, incremented every time the needsUpdate property is set to true.
     * @remarks Expects a `Integer`
     */
    version: number;

    /**
     * Setting this to true increments {@link version | .version}.
     * @remarks _set-only property_.
     */
    set needsUpdate(value: boolean);

    /**
     * Sets the {@link buffer | .buffer} property.
     */
    setBuffer(buffer: WebGLBuffer): this;

    /**
     * Sets the both {@link GLBufferAttribute.type | type} and {@link GLBufferAttribute.elementSize | elementSize} properties.
     */
    setType(type: GLenum, elementSize: 1 | 2 | 4): this;

    /**
     * Sets the {@link GLBufferAttribute.itemSize | itemSize} property.
     */
    setItemSize(itemSize: number): this;

    /**
     * Sets the {@link GLBufferAttribute.count | count} property.
     */
    setCount(count: number): this;
}