import { TextureUnit } from "../texture/texture";
import Color from "./color";
/**
 * Stores information about a {@link WebGLProgram}, such as it's attribute and uniform locations.
 */
export interface ShaderProgramInfo {
    program: WebGLProgram;
    attribLocations: {
        [index: string]: number;
    };
    uniformLocations: {
        [index: string]: WebGLUniformLocation;
        zIndex: WebGLUniformLocation;
        texture?: WebGLUniformLocation;
        numOfTiles?: WebGLUniformLocation;
    };
}
/**
 * Creates and compiles a shader from its source.
 *
 * @param gl The webgl context to use when creating the shader
 * @param type The type of shader to create (either `gl.VERTEX_SHADER` or `gl.FRAGMENT_SHADER`)
 * @param source The shader source as a string
 * @returns The compiled shader or undefined if there was an error when creating the shader
 */
export declare function createShader(gl: WebGL2RenderingContext, type: number, source: string): WebGLShader;
/**
 * Creates a {@link WebGLProgram} instance with a vertex and fragment shader.
 *
 * @param gl The webgl context to use when creating the program
 * @param vertexShader The vertex shader of the program
 * @param fragmentShader The fragment shader of the program
 * @returns The created program or undefined if there was an error when creating the program
 */
export declare function createProgram(gl: WebGL2RenderingContext, vertexShader: WebGLShader, fragmentShader: WebGLShader): WebGLProgram;
/**
 * Creates each webgl shader and links them together in a {@link WebGLProgram}
 *
 * @param gl The webgl context to use when creating the shaders
 * @param vsSource The source of the vertex shader as a string
 * @param fsSource The source of the fragment shader as a string
 * @returns The created {@link WebGLProgram} instance
 */
export declare function createShaderProgram(gl: WebGL2RenderingContext, vsSource: string, fsSource: string): WebGLProgram;
/**
 * Clears the color and depth buffer of the webgl context.
 *
 * @param gl The webgl context to clear
 * @param color The color to use as the clear color
 */
export declare function clear(gl: WebGL2RenderingContext, color?: Color): void;
/**
 * Creates a {@link WebGLTexture} and loads an image onto it.
 *
 * @param gl The {@link WebGL2RenderingContext} to use to load the texture
 * @param textureUnit The texture unit to to take the {@link Texture} from and to bind the {@link WebGLTexture} to
 * @returns The WebGL texture that was created
 */
export declare function loadTexture(gl: WebGL2RenderingContext, textureUnit: TextureUnit): WebGLTexture;