import * as glMatrix from "./common.js";
/**
* 4 Dimensional Vector
* @module vec4
*/
/**
* Creates a new, empty vec4
*
* @returns {vec4} a new 4D vector
*/
export function create() {
let out = new glMatrix.ARRAY_TYPE(4);
out[0] = 0;
out[1] = 0;
out[2] = 0;
out[3] = 0;
return out;
}
/**
* Creates a new vec4 initialized with values from an existing vector
*
* @param {vec4} a vector to clone
* @returns {vec4} a new 4D vector
*/
export function clone(a) {
let out = new glMatrix.ARRAY_TYPE(4);
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
out[3] = a[3];
return out;
}
/**
* Creates a new vec4 initialized with the given values
*
* @param {Number} x X component
* @param {Number} y Y component
* @param {Number} z Z component
* @param {Number} w W component
* @returns {vec4} a new 4D vector
*/
export function fromValues(x, y, z, w) {
let out = new glMatrix.ARRAY_TYPE(4);
out[0] = x;
out[1] = y;
out[2] = z;
out[3] = w;
return out;
}
/**
* Copy the values from one vec4 to another
*
* @param {vec4} out the receiving vector
* @param {vec4} a the source vector
* @returns {vec4} out
*/
export function copy(out, a) {
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
out[3] = a[3];
return out;
}
/**
* Set the components of a vec4 to the given values
*
* @param {vec4} out the receiving vector
* @param {Number} x X component
* @param {Number} y Y component
* @param {Number} z Z component
* @param {Number} w W component
* @returns {vec4} out
*/
export function set(out, x, y, z, w) {
out[0] = x;
out[1] = y;
out[2] = z;
out[3] = w;
return out;
}
/**
* Adds two vec4's
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {vec4} out
*/
export function add(out, a, b) {
out[0] = a[0] + b[0];
out[1] = a[1] + b[1];
out[2] = a[2] + b[2];
out[3] = a[3] + b[3];
return out;
}
/**
* Subtracts vector b from vector a
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {vec4} out
*/
export function subtract(out, a, b) {
out[0] = a[0] - b[0];
out[1] = a[1] - b[1];
out[2] = a[2] - b[2];
out[3] = a[3] - b[3];
return out;
}
/**
* Multiplies two vec4's
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {vec4} out
*/
export function multiply(out, a, b) {
out[0] = a[0] * b[0];
out[1] = a[1] * b[1];
out[2] = a[2] * b[2];
out[3] = a[3] * b[3];
return out;
}
/**
* Divides two vec4's
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {vec4} out
*/
export function divide(out, a, b) {
out[0] = a[0] / b[0];
out[1] = a[1] / b[1];
out[2] = a[2] / b[2];
out[3] = a[3] / b[3];
return out;
}
/**
* Math.ceil the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to ceil
* @returns {vec4} out
*/
export function ceil(out, a) {
out[0] = Math.ceil(a[0]);
out[1] = Math.ceil(a[1]);
out[2] = Math.ceil(a[2]);
out[3] = Math.ceil(a[3]);
return out;
}
/**
* Math.floor the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to floor
* @returns {vec4} out
*/
export function floor(out, a) {
out[0] = Math.floor(a[0]);
out[1] = Math.floor(a[1]);
out[2] = Math.floor(a[2]);
out[3] = Math.floor(a[3]);
return out;
}
/**
* Returns the minimum of two vec4's
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {vec4} out
*/
export function min(out, a, b) {
out[0] = Math.min(a[0], b[0]);
out[1] = Math.min(a[1], b[1]);
out[2] = Math.min(a[2], b[2]);
out[3] = Math.min(a[3], b[3]);
return out;
}
/**
* Returns the maximum of two vec4's
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {vec4} out
*/
export function max(out, a, b) {
out[0] = Math.max(a[0], b[0]);
out[1] = Math.max(a[1], b[1]);
out[2] = Math.max(a[2], b[2]);
out[3] = Math.max(a[3], b[3]);
return out;
}
/**
* Math.round the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to round
* @returns {vec4} out
*/
export function round(out, a) {
out[0] = Math.round(a[0]);
out[1] = Math.round(a[1]);
out[2] = Math.round(a[2]);
out[3] = Math.round(a[3]);
return out;
}
/**
* Scales a vec4 by a scalar number
*
* @param {vec4} out the receiving vector
* @param {vec4} a the vector to scale
* @param {Number} b amount to scale the vector by
* @returns {vec4} out
*/
export function scale(out, a, b) {
out[0] = a[0] * b;
out[1] = a[1] * b;
out[2] = a[2] * b;
out[3] = a[3] * b;
return out;
}
/**
* Adds two vec4's after scaling the second operand by a scalar value
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @param {Number} scale the amount to scale b by before adding
* @returns {vec4} out
*/
export function scaleAndAdd(out, a, b, scale) {
out[0] = a[0] + (b[0] * scale);
out[1] = a[1] + (b[1] * scale);
out[2] = a[2] + (b[2] * scale);
out[3] = a[3] + (b[3] * scale);
return out;
}
/**
* Calculates the euclidian distance between two vec4's
*
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {Number} distance between a and b
*/
export function distance(a, b) {
let x = b[0] - a[0];
let y = b[1] - a[1];
let z = b[2] - a[2];
let w = b[3] - a[3];
return Math.sqrt(x*x + y*y + z*z + w*w);
}
/**
* Calculates the squared euclidian distance between two vec4's
*
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {Number} squared distance between a and b
*/
export function squaredDistance(a, b) {
let x = b[0] - a[0];
let y = b[1] - a[1];
let z = b[2] - a[2];
let w = b[3] - a[3];
return x*x + y*y + z*z + w*w;
}
/**
* Calculates the length of a vec4
*
* @param {vec4} a vector to calculate length of
* @returns {Number} length of a
*/
export function length(a) {
let x = a[0];
let y = a[1];
let z = a[2];
let w = a[3];
return Math.sqrt(x*x + y*y + z*z + w*w);
}
/**
* Calculates the squared length of a vec4
*
* @param {vec4} a vector to calculate squared length of
* @returns {Number} squared length of a
*/
export function squaredLength(a) {
let x = a[0];
let y = a[1];
let z = a[2];
let w = a[3];
return x*x + y*y + z*z + w*w;
}
/**
* Negates the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to negate
* @returns {vec4} out
*/
export function negate(out, a) {
out[0] = -a[0];
out[1] = -a[1];
out[2] = -a[2];
out[3] = -a[3];
return out;
}
/**
* Returns the inverse of the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to invert
* @returns {vec4} out
*/
export function inverse(out, a) {
out[0] = 1.0 / a[0];
out[1] = 1.0 / a[1];
out[2] = 1.0 / a[2];
out[3] = 1.0 / a[3];
return out;
}
/**
* Normalize a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to normalize
* @returns {vec4} out
*/
export function normalize(out, a) {
let x = a[0];
let y = a[1];
let z = a[2];
let w = a[3];
let len = x*x + y*y + z*z + w*w;
if (len > 0) {
len = 1 / Math.sqrt(len);
out[0] = x * len;
out[1] = y * len;
out[2] = z * len;
out[3] = w * len;
}
return out;
}
/**
* Calculates the dot product of two vec4's
*
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @returns {Number} dot product of a and b
*/
export function dot(a, b) {
return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
}
/**
* Performs a linear interpolation between two vec4's
*
* @param {vec4} out the receiving vector
* @param {vec4} a the first operand
* @param {vec4} b the second operand
* @param {Number} t interpolation amount, in the range [0-1], between the two inputs
* @returns {vec4} out
*/
export function lerp(out, a, b, t) {
let ax = a[0];
let ay = a[1];
let az = a[2];
let aw = a[3];
out[0] = ax + t * (b[0] - ax);
out[1] = ay + t * (b[1] - ay);
out[2] = az + t * (b[2] - az);
out[3] = aw + t * (b[3] - aw);
return out;
}
/**
* Generates a random vector with the given scale
*
* @param {vec4} out the receiving vector
* @param {Number} [scale] Length of the resulting vector. If ommitted, a unit vector will be returned
* @returns {vec4} out
*/
export function random(out, vectorScale) {
vectorScale = vectorScale || 1.0;
// Marsaglia, George. Choosing a Point from the Surface of a
// Sphere. Ann. Math. Statist. 43 (1972), no. 2, 645--646.
// http://projecteuclid.org/euclid.aoms/1177692644;
var v1, v2, v3, v4;
var s1, s2;
do {
v1 = glMatrix.RANDOM() * 2 - 1;
v2 = glMatrix.RANDOM() * 2 - 1;
s1 = v1 * v1 + v2 * v2;
} while (s1 >= 1);
do {
v3 = glMatrix.RANDOM() * 2 - 1;
v4 = glMatrix.RANDOM() * 2 - 1;
s2 = v3 * v3 + v4 * v4;
} while (s2 >= 1);
var d = Math.sqrt((1 - s1) / s2);
out[0] = scale * v1;
out[1] = scale * v2;
out[2] = scale * v3 * d;
out[3] = scale * v4 * d;
return out;
}
/**
* Transforms the vec4 with a mat4.
*
* @param {vec4} out the receiving vector
* @param {vec4} a the vector to transform
* @param {mat4} m matrix to transform with
* @returns {vec4} out
*/
export function transformMat4(out, a, m) {
let x = a[0], y = a[1], z = a[2], w = a[3];
out[0] = m[0] * x + m[4] * y + m[8] * z + m[12] * w;
out[1] = m[1] * x + m[5] * y + m[9] * z + m[13] * w;
out[2] = m[2] * x + m[6] * y + m[10] * z + m[14] * w;
out[3] = m[3] * x + m[7] * y + m[11] * z + m[15] * w;
return out;
}
/**
* Transforms the vec4 with a quat
*
* @param {vec4} out the receiving vector
* @param {vec4} a the vector to transform
* @param {quat} q quaternion to transform with
* @returns {vec4} out
*/
export function transformQuat(out, a, q) {
let x = a[0], y = a[1], z = a[2];
let qx = q[0], qy = q[1], qz = q[2], qw = q[3];
// calculate quat * vec
let ix = qw * x + qy * z - qz * y;
let iy = qw * y + qz * x - qx * z;
let iz = qw * z + qx * y - qy * x;
let iw = -qx * x - qy * y - qz * z;
// calculate result * inverse quat
out[0] = ix * qw + iw * -qx + iy * -qz - iz * -qy;
out[1] = iy * qw + iw * -qy + iz * -qx - ix * -qz;
out[2] = iz * qw + iw * -qz + ix * -qy - iy * -qx;
out[3] = a[3];
return out;
}
/**
* Returns a string representation of a vector
*
* @param {vec4} a vector to represent as a string
* @returns {String} string representation of the vector
*/
export function str(a) {
return 'vec4(' + a[0] + ', ' + a[1] + ', ' + a[2] + ', ' + a[3] + ')';
}
/**
* Returns whether or not the vectors have exactly the same elements in the same position (when compared with ===)
*
* @param {vec4} a The first vector.
* @param {vec4} b The second vector.
* @returns {Boolean} True if the vectors are equal, false otherwise.
*/
export function exactEquals(a, b) {
return a[0] === b[0] && a[1] === b[1] && a[2] === b[2] && a[3] === b[3];
}
/**
* Returns whether or not the vectors have approximately the same elements in the same position.
*
* @param {vec4} a The first vector.
* @param {vec4} b The second vector.
* @returns {Boolean} True if the vectors are equal, false otherwise.
*/
export function equals(a, b) {
let a0 = a[0], a1 = a[1], a2 = a[2], a3 = a[3];
let b0 = b[0], b1 = b[1], b2 = b[2], b3 = b[3];
return (Math.abs(a0 - b0) <= glMatrix.EPSILON*Math.max(1.0, Math.abs(a0), Math.abs(b0)) &&
Math.abs(a1 - b1) <= glMatrix.EPSILON*Math.max(1.0, Math.abs(a1), Math.abs(b1)) &&
Math.abs(a2 - b2) <= glMatrix.EPSILON*Math.max(1.0, Math.abs(a2), Math.abs(b2)) &&
Math.abs(a3 - b3) <= glMatrix.EPSILON*Math.max(1.0, Math.abs(a3), Math.abs(b3)));
}
/**
* Alias for {@link vec4.subtract}
* @function
*/
export const sub = subtract;
/**
* Alias for {@link vec4.multiply}
* @function
*/
export const mul = multiply;
/**
* Alias for {@link vec4.divide}
* @function
*/
export const div = divide;
/**
* Alias for {@link vec4.distance}
* @function
*/
export const dist = distance;
/**
* Alias for {@link vec4.squaredDistance}
* @function
*/
export const sqrDist = squaredDistance;
/**
* Alias for {@link vec4.length}
* @function
*/
export const len = length;
/**
* Alias for {@link vec4.squaredLength}
* @function
*/
export const sqrLen = squaredLength;
/**
* Perform some operation over an array of vec4s.
*
* @param {Array} a the array of vectors to iterate over
* @param {Number} stride Number of elements between the start of each vec4. If 0 assumes tightly packed
* @param {Number} offset Number of elements to skip at the beginning of the array
* @param {Number} count Number of vec4s to iterate over. If 0 iterates over entire array
* @param {Function} fn Function to call for each vector in the array
* @param {Object} [arg] additional argument to pass to fn
* @returns {Array} a
* @function
*/
export const forEach = (function() {
let vec = create();
return function(a, stride, offset, count, fn, arg) {
let i, l;
if(!stride) {
stride = 4;
}
if(!offset) {
offset = 0;
}
if(count) {
l = Math.min((count * stride) + offset, a.length);
} else {
l = a.length;
}
for(i = offset; i < l; i += stride) {
vec[0] = a[i]; vec[1] = a[i+1]; vec[2] = a[i+2]; vec[3] = a[i+3];
fn(vec, vec, arg);
a[i] = vec[0]; a[i+1] = vec[1]; a[i+2] = vec[2]; a[i+3] = vec[3];
}
return a;
};
})();