import { Buffer } from '../buffer';
import { Context } from '../context';
import { Geometry } from '../geometry';
/**
 * Gathers vertices and other data needed for drawing all labels using the glyphquad-shaders.
 *
 * Example usage:
 * ```
 * const labelGeometry = new LabelGeometry(this._context);
 * labelGeometry = new LabelGeometry(this._context);
 * ...
 * labelGeometry.initialize();
 *
 * program.initialize([vert, frag], false);
 * program.attribute('a_vertex', labelGeometry.vertexLocation);
 * program.attribute('a_texCoord', labelGeometry.texCoordLocation);
 * program.attribute('a_origin', labelGeometry.originLocation);
 * program.attribute('a_tangent', labelGeometry.tangentLocation);
 * program.attribute('a_up', labelGeometry.upLocation);
 *
 * program.link();
 * ...
 * labelGeometry.update(origins, tangents, ups, texCoords);
 * ...
 * labelGeometry.bind();
 * labelGeometry.draw();
 * labelGeometry.unbind();
 * ```
 */
export declare class LabelGeometry extends Geometry {
    /**
     * These 2D vertices are equal for all quads, used for instanced rendering. Their actual position will be changed
     * in the vertex shader, based on origins, tangents and up-vector attributes.
     * 2-------4
     * |  \    |
     * |    \  |
     * 1-------3
     */
    protected static readonly VERTICES: Float32Array;
    /**
     * Handle to the glyph template this geometry is based on.
     */
    protected _vertices: Buffer;
    protected _texCoords: Buffer;
    protected _origins: Buffer;
    protected _tangents: Buffer;
    protected _ups: Buffer;
    /**
     * Number of glyphs encoded within the geometry.
     */
    protected _numberOfGlyphs: number;
    protected _vertexLocation: GLuint;
    protected _texCoordLocation: GLuint;
    protected _originLocation: GLuint;
    protected _tangentLocation: GLuint;
    protected _upLocation: GLuint;
    /**
     * Object constructor, requires a context and an identifier.
     * @param context - Valid context to create the object for.
     * @param identifier - Meaningful name for identification of this instance.
     */
    constructor(context: Context, identifier?: string);
    /**
     * Binds all vertex buffer objects (VBOs) to pre-set attribute binding points.
     * @param indices - Unused, since pre-set locations are used.
     */
    protected bindBuffers(): void;
    /**
     * Unbinds all vertex buffer objects (VBOs) and disables their attribute binding points.
     * @param indices - Unused, since pre-set locations are used.
     */
    protected unbindBuffers(): void;
    /**
     * Creates the vertex buffer object (VBO) and creates and initializes the buffer's data store.
     * @param vertexLocation - Attribute binding point for vertices.
     * @param texCoordLocation - Attribute binding point for texture coordinates.
     * @param originLocation - Attribute binding point for glyph origin coordinates
     * @param tangentLocation - Attribute binding point for glyph tangent coordinates.
     * @param upLocation - Attribute binding point for glyph up-vector coordinates.
     */
    initialize(vertexLocation?: GLuint, texCoordLocation?: GLuint, originLocation?: GLuint, tangentLocation?: GLuint, upLocation?: GLuint): boolean;
    /**
     * Use this method to set (or update) the glyph coordinates, e.g. after typesetting or after the calculations
     * of a placement algorithm. The actual interpretation of those buffers depends on the shader, usually they are
     * 3-component vectors in world space (provided as flat array.)
     * @param origins - Coordinates of the lower left corner of every glyph.
     * @param tangents - Tangent vector for every glyph (direction along base line).
     * @param up - Up vector for every glyph (orthogonal to its tangent vector).
     * @param texCoords - The texture coordinates for every glyph, format: ll.x, ll.y, ur.x, ur.y.
     */
    update(origins: Float32Array, tangents: Float32Array, up: Float32Array, texCoords: Float32Array): void;
    /**
     * Specifies/invokes the draw of specific labels (ranges are supposed to be tracked/managed from outside).
     */
    draw(offset?: GLint, count?: GLint): void;
    get numGlyphs(): number;
    get valid(): boolean;
    /**
     * Attribute location to which this geometry's vertices are bound to.
     */
    get vertexLocation(): GLint;
    /**
     * Attribute location to which this geometry's texture coordinates are bound to.
     */
    get texCoordLocation(): GLint;
    /**
     * Attribute location to which this geometry's origins are bound to.
     */
    get originLocation(): GLint;
    /**
     * Attribute location to which this geometry's tangents are bound to.
     */
    get tangentLocation(): GLint;
    /**
     * Attribute location to which this geometry's up vectors are bound to.
     */
    get upLocation(): GLint;
}