/**
 * A 4-dimensional vector.
 *
 * @category Math
 */
export class Vec4 {
    /**
     * A constant vector set to [0, 0, 0, 0].
     *
     * @type {Vec4}
     * @readonly
     */
    static readonly ZERO: Vec4;
    /**
     * A constant vector set to [0.5, 0.5, 0.5, 0.5].
     *
     * @type {Vec4}
     * @readonly
     */
    static readonly HALF: Vec4;
    /**
     * A constant vector set to [1, 1, 1, 1].
     *
     * @type {Vec4}
     * @readonly
     */
    static readonly ONE: Vec4;
    /**
     * Creates a new Vec4 instance.
     *
     * @overload
     * @param {number} [x] - The x value. Defaults to 0.
     * @param {number} [y] - The y value. Defaults to 0.
     * @param {number} [z] - The z value. Defaults to 0.
     * @param {number} [w] - The w value. Defaults to 0.
     * @example
     * const v1 = new pc.Vec4(); // defaults to 0, 0, 0, 0
     * const v2 = new pc.Vec4(1, 2, 3, 4);
     */
    constructor(x?: number, y?: number, z?: number, w?: number);
    /**
     * Creates a new Vec4 instance.
     *
     * @overload
     * @param {number[]} arr - The array to set the vector values from.
     * @example
     * const v = new pc.Vec4([1, 2, 3, 4]);
     */
    constructor(arr: number[]);
    /**
     * The first component of the vector.
     *
     * @type {number}
     */
    x: number;
    /**
     * The second component of the vector.
     *
     * @type {number}
     */
    y: number;
    /**
     * The third component of the vector.
     *
     * @type {number}
     */
    z: number;
    /**
     * The fourth component of the vector.
     *
     * @type {number}
     */
    w: number;
    /**
     * Adds a 4-dimensional vector to another in place.
     *
     * @param {Vec4} rhs - The vector to add to the specified vector.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(10, 10, 10, 10);
     * const b = new pc.Vec4(20, 20, 20, 20);
     *
     * a.add(b);
     *
     * // Outputs [30, 30, 30]
     * console.log("The result of the addition is: " + a.toString());
     */
    add(rhs: Vec4): Vec4;
    /**
     * Adds two 4-dimensional vectors together and returns the result.
     *
     * @param {Vec4} lhs - The first vector operand for the addition.
     * @param {Vec4} rhs - The second vector operand for the addition.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(10, 10, 10, 10);
     * const b = new pc.Vec4(20, 20, 20, 20);
     * const r = new pc.Vec4();
     *
     * r.add2(a, b);
     * // Outputs [30, 30, 30]
     *
     * console.log("The result of the addition is: " + r.toString());
     */
    add2(lhs: Vec4, rhs: Vec4): Vec4;
    /**
     * Adds a number to each element of a vector.
     *
     * @param {number} scalar - The number to add.
     * @returns {Vec4} Self for chaining.
     * @example
     * const vec = new pc.Vec4(3, 4, 5, 6);
     *
     * vec.addScalar(2);
     *
     * // Outputs [5, 6, 7, 8]
     * console.log("The result of the addition is: " + vec.toString());
     */
    addScalar(scalar: number): Vec4;
    /**
     * Adds a 4-dimensional vector scaled by scalar value. Does not modify the vector being added.
     *
     * @param {Vec4} rhs - The vector to add to the specified vector.
     * @param {number} scalar - The number to multiply the added vector with.
     * @returns {Vec4} Self for chaining.
     * @example
     * const vec = new pc.Vec4(1, 2, 3, 4);
     *
     * vec.addScaled(pc.Vec4.ONE, 2);
     *
     * // Outputs [3, 4, 5, 6]
     * console.log("The result of the addition is: " + vec.toString());
     */
    addScaled(rhs: Vec4, scalar: number): Vec4;
    /**
     * Returns an identical copy of the specified 4-dimensional vector.
     *
     * @returns {this} A 4-dimensional vector containing the result of the cloning.
     * @example
     * const v = new pc.Vec4(10, 20, 30, 40);
     * const vclone = v.clone();
     * console.log("The result of the cloning is: " + vclone.toString());
     */
    clone(): this;
    /**
     * Copies the contents of a source 4-dimensional vector to a destination 4-dimensional vector.
     *
     * @param {Vec4} rhs - A vector to copy to the specified vector.
     * @returns {Vec4} Self for chaining.
     * @example
     * const src = new pc.Vec4(10, 20, 30, 40);
     * const dst = new pc.Vec4();
     *
     * dst.copy(src);
     *
     * console.log("The two vectors are " + (dst.equals(src) ? "equal" : "different"));
     */
    copy(rhs: Vec4): Vec4;
    /**
     * Divides a 4-dimensional vector by another in place.
     *
     * @param {Vec4} rhs - The vector to divide the specified vector by.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(4, 9, 16, 25);
     * const b = new pc.Vec4(2, 3, 4, 5);
     *
     * a.div(b);
     *
     * // Outputs [2, 3, 4, 5]
     * console.log("The result of the division is: " + a.toString());
     */
    div(rhs: Vec4): Vec4;
    /**
     * Divides one 4-dimensional vector by another and writes the result to the specified vector.
     *
     * @param {Vec4} lhs - The dividend vector (the vector being divided).
     * @param {Vec4} rhs - The divisor vector (the vector dividing the dividend).
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(4, 9, 16, 25);
     * const b = new pc.Vec4(2, 3, 4, 5);
     * const r = new pc.Vec4();
     *
     * r.div2(a, b);
     *
     * // Outputs [2, 3, 4, 5]
     * console.log("The result of the division is: " + r.toString());
     */
    div2(lhs: Vec4, rhs: Vec4): Vec4;
    /**
     * Divides each element of a vector by a number.
     *
     * @param {number} scalar - The number to divide by.
     * @returns {Vec4} Self for chaining.
     * @example
     * const vec = new pc.Vec4(3, 6, 9, 12);
     *
     * vec.divScalar(3);
     *
     * // Outputs [1, 2, 3, 4]
     * console.log("The result of the division is: " + vec.toString());
     */
    divScalar(scalar: number): Vec4;
    /**
     * Returns the result of a dot product operation performed on the two specified 4-dimensional
     * vectors.
     *
     * @param {Vec4} rhs - The second 4-dimensional vector operand of the dot product.
     * @returns {number} The result of the dot product operation.
     * @example
     * const v1 = new pc.Vec4(5, 10, 20, 40);
     * const v2 = new pc.Vec4(10, 20, 40, 80);
     * const v1dotv2 = v1.dot(v2);
     * console.log("The result of the dot product is: " + v1dotv2);
     */
    dot(rhs: Vec4): number;
    /**
     * Reports whether two vectors are equal.
     *
     * @param {Vec4} rhs - The vector to compare to the specified vector.
     * @returns {boolean} True if the vectors are equal and false otherwise.
     * @example
     * const a = new pc.Vec4(1, 2, 3, 4);
     * const b = new pc.Vec4(5, 6, 7, 8);
     * console.log("The two vectors are " + (a.equals(b) ? "equal" : "different"));
     */
    equals(rhs: Vec4): boolean;
    /**
     * Reports whether two vectors are equal using an absolute error tolerance.
     *
     * @param {Vec4} rhs - The vector to be compared against.
     * @param {number} [epsilon] - The maximum difference between each component of the two
     * vectors. Defaults to 1e-6.
     * @returns {boolean} True if the vectors are equal and false otherwise.
     * @example
     * const a = new pc.Vec4();
     * const b = new pc.Vec4();
     * console.log("The two vectors are approximately " + (a.equalsApprox(b, 1e-9) ? "equal" : "different"));
     */
    equalsApprox(rhs: Vec4, epsilon?: number): boolean;
    /**
     * Returns the magnitude of the specified 4-dimensional vector.
     *
     * @returns {number} The magnitude of the specified 4-dimensional vector.
     * @example
     * const vec = new pc.Vec4(3, 4, 0, 0);
     * const len = vec.length();
     * // Outputs 5
     * console.log("The length of the vector is: " + len);
     */
    length(): number;
    /**
     * Returns the magnitude squared of the specified 4-dimensional vector.
     *
     * @returns {number} The magnitude of the specified 4-dimensional vector.
     * @example
     * const vec = new pc.Vec4(3, 4, 0);
     * const len = vec.lengthSq();
     * // Outputs 25
     * console.log("The length squared of the vector is: " + len);
     */
    lengthSq(): number;
    /**
     * Returns the result of a linear interpolation between two specified 4-dimensional vectors.
     *
     * @param {Vec4} lhs - The 4-dimensional to interpolate from.
     * @param {Vec4} rhs - The 4-dimensional to interpolate to.
     * @param {number} alpha - The value controlling the point of interpolation. Between 0 and 1,
     * the linear interpolant will occur on a straight line between lhs and rhs. Outside of this
     * range, the linear interpolant will occur on a ray extrapolated from this line.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(0, 0, 0, 0);
     * const b = new pc.Vec4(10, 10, 10, 10);
     * const r = new pc.Vec4();
     *
     * r.lerp(a, b, 0);   // r is equal to a
     * r.lerp(a, b, 0.5); // r is 5, 5, 5, 5
     * r.lerp(a, b, 1);   // r is equal to b
     */
    lerp(lhs: Vec4, rhs: Vec4, alpha: number): Vec4;
    /**
     * Multiplies a 4-dimensional vector to another in place.
     *
     * @param {Vec4} rhs - The 4-dimensional vector used as the second multiplicand of the operation.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(2, 3, 4, 5);
     * const b = new pc.Vec4(4, 5, 6, 7);
     *
     * a.mul(b);
     *
     * // Outputs 8, 15, 24, 35
     * console.log("The result of the multiplication is: " + a.toString());
     */
    mul(rhs: Vec4): Vec4;
    /**
     * Returns the result of multiplying the specified 4-dimensional vectors together.
     *
     * @param {Vec4} lhs - The 4-dimensional vector used as the first multiplicand of the operation.
     * @param {Vec4} rhs - The 4-dimensional vector used as the second multiplicand of the operation.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(2, 3, 4, 5);
     * const b = new pc.Vec4(4, 5, 6, 7);
     * const r = new pc.Vec4();
     *
     * r.mul2(a, b);
     *
     * // Outputs 8, 15, 24, 35
     * console.log("The result of the multiplication is: " + r.toString());
     */
    mul2(lhs: Vec4, rhs: Vec4): Vec4;
    /**
     * Multiplies each element of a vector by a number.
     *
     * @param {number} scalar - The number to multiply by.
     * @returns {Vec4} Self for chaining.
     * @example
     * const vec = new pc.Vec4(3, 6, 9, 12);
     *
     * vec.mulScalar(3);
     *
     * // Outputs [9, 18, 27, 36]
     * console.log("The result of the multiplication is: " + vec.toString());
     */
    mulScalar(scalar: number): Vec4;
    /**
     * Returns this 4-dimensional vector converted to a unit vector in place. If the vector has a
     * length of zero, the vector's elements will be set to zero.
     *
     * @param {Vec4} [src] - The vector to normalize. If not set, the operation is done in place.
     * @returns {Vec4} Self for chaining.
     * @example
     * const v = new pc.Vec4(25, 0, 0, 0);
     *
     * v.normalize();
     *
     * // Outputs 1, 0, 0, 0
     * console.log("The result of the vector normalization is: " + v.toString());
     */
    normalize(src?: Vec4): Vec4;
    /**
     * Each element is set to the largest integer less than or equal to its value.
     *
     * @param {Vec4} [src] - The vector to floor. If not set, the operation is done in place.
     * @returns {Vec4} Self for chaining.
     */
    floor(src?: Vec4): Vec4;
    /**
     * Each element is rounded up to the next largest integer.
     *
     * @param {Vec4} [src] - The vector to ceil. If not set, the operation is done in place.
     * @returns {Vec4} Self for chaining.
     */
    ceil(src?: Vec4): Vec4;
    /**
     * Each element is rounded up or down to the nearest integer.
     *
     * @param {Vec4} [src] - The vector to round. If not set, the operation is done in place.
     * @returns {Vec4} Self for chaining.
     */
    round(src?: Vec4): Vec4;
    /**
     * Each element is assigned a value from rhs parameter if it is smaller.
     *
     * @param {Vec4} rhs - The 4-dimensional vector used as the source of elements to compare to.
     * @returns {Vec4} Self for chaining.
     */
    min(rhs: Vec4): Vec4;
    /**
     * Each element is assigned a value from rhs parameter if it is larger.
     *
     * @param {Vec4} rhs - The 4-dimensional vector used as the source of elements to compare to.
     * @returns {Vec4} Self for chaining.
     */
    max(rhs: Vec4): Vec4;
    /**
     * Sets the specified 4-dimensional vector to the supplied numerical values.
     *
     * @param {number} x - The value to set on the first component of the vector.
     * @param {number} y - The value to set on the second component of the vector.
     * @param {number} z - The value to set on the third component of the vector.
     * @param {number} w - The value to set on the fourth component of the vector.
     * @returns {Vec4} Self for chaining.
     * @example
     * const v = new pc.Vec4();
     * v.set(5, 10, 20, 40);
     *
     * // Outputs 5, 10, 20, 40
     * console.log("The result of the vector set is: " + v.toString());
     */
    set(x: number, y: number, z: number, w: number): Vec4;
    /**
     * Subtracts a 4-dimensional vector from another in place.
     *
     * @param {Vec4} rhs - The vector to add to the specified vector.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(10, 10, 10, 10);
     * const b = new pc.Vec4(20, 20, 20, 20);
     *
     * a.sub(b);
     *
     * // Outputs [-10, -10, -10, -10]
     * console.log("The result of the subtraction is: " + a.toString());
     */
    sub(rhs: Vec4): Vec4;
    /**
     * Subtracts two 4-dimensional vectors from one another and returns the result.
     *
     * @param {Vec4} lhs - The first vector operand for the subtraction.
     * @param {Vec4} rhs - The second vector operand for the subtraction.
     * @returns {Vec4} Self for chaining.
     * @example
     * const a = new pc.Vec4(10, 10, 10, 10);
     * const b = new pc.Vec4(20, 20, 20, 20);
     * const r = new pc.Vec4();
     *
     * r.sub2(a, b);
     *
     * // Outputs [-10, -10, -10, -10]
     * console.log("The result of the subtraction is: " + r.toString());
     */
    sub2(lhs: Vec4, rhs: Vec4): Vec4;
    /**
     * Subtracts a number from each element of a vector.
     *
     * @param {number} scalar - The number to subtract.
     * @returns {Vec4} Self for chaining.
     * @example
     * const vec = new pc.Vec4(3, 4, 5, 6);
     *
     * vec.subScalar(2);
     *
     * // Outputs [1, 2, 3, 4]
     * console.log("The result of the subtraction is: " + vec.toString());
     */
    subScalar(scalar: number): Vec4;
    /**
     * Set the values of the vector from an array.
     *
     * @param {number[]|ArrayBufferView} arr - The array to set the vector values from.
     * @param {number} [offset] - The zero-based index at which to start copying elements from the
     * array. Default is 0.
     * @returns {Vec4} Self for chaining.
     * @example
     * const v = new pc.Vec4();
     * v.fromArray([20, 10, 5, 0]);
     * // v is set to [20, 10, 5, 0]
     */
    fromArray(arr: number[] | ArrayBufferView, offset?: number): Vec4;
    /**
     * Converts the vector to string form.
     *
     * @returns {string} The vector in string form.
     * @example
     * const v = new pc.Vec4(20, 10, 5, 0);
     * // Outputs [20, 10, 5, 0]
     * console.log(v.toString());
     */
    toString(): string;
    /**
     * @overload
     * @param {number[]} [arr] - The array to populate with the vector's number
     * components. If not specified, a new array is created.
     * @param {number} [offset] - The zero-based index at which to start copying elements to the
     * array. Default is 0.
     * @returns {number[]} The vector as an array.
     */
    toArray(arr?: number[], offset?: number): number[];
    /**
     * @overload
     * @param {ArrayBufferView} arr - The array to populate with the vector's number
     * components. If not specified, a new array is created.
     * @param {number} [offset] - The zero-based index at which to start copying elements to the
     * array. Default is 0.
     * @returns {ArrayBufferView} The vector as an array.
     */
    toArray(arr: ArrayBufferView, offset?: number): ArrayBufferView;
}