Published
Edited
Jul 16, 2019
Importers
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a = vec4.create()
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b = vec4create()
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vec4 = ({
create: vec4create,
clone: vec4clone,
fromValues: vec4fromValues,
copy: vec4copy,
set: vec4set,
add: vec4add,
subtract: vec4subtract,
sub: vec4sub,
multiply: vec4multiply,
mul: vec4mul,
divide: vec4divide,
div: vec4div,
min: vec4min,
max: vec4max,
scale: vec4scale,
scaleAndAdd: vec4scaleAndAdd,
distance: vec4distance,
dist: vec4dist,
squaredDistance: vec4squaredDistance,
sqrDist: vec4sqrDist,
length: vec4length,
len: vec4len,
squaredLength: vec4squaredLength,
sqrLen: vec4squaredLength,
negate: vec4negate,
inverse: vec4inverse,
normalize: vec4normalize,
dot: vec4dot,
lerp: vec4lerp,
random: vec4random,
transformMat4: vec4transformMat4,
transformQuat: vec4transformQuat,
})
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/**
* 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
*/
function vec4add (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
}
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/**
* Creates a new vec4 initialized with values from an existing vector
*
* @param {vec4} a vector to clone
* @returns {vec4} a new 4D vector
*/
function vec4clone (a) {
var out = new Float32Array(4)
out[0] = a[0]
out[1] = a[1]
out[2] = a[2]
out[3] = a[3]
return out
}
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/**
* Copy the values from one vec4 to another
*
* @param {vec4} out the receiving vector
* @param {vec4} a the source vector
* @returns {vec4} out
*/
function vec4copy (out, a) {
out[0] = a[0]
out[1] = a[1]
out[2] = a[2]
out[3] = a[3]
return out
}
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/**
* Creates a new, empty vec4
*
* @returns {vec4} a new 4D vector
*/
function vec4create () {
var out = new Float32Array(4)
out[0] = 0
out[1] = 0
out[2] = 0
out[3] = 0
return out
}
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/**
* 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
*/
function vec4distance (a, b) {
var x = b[0] - a[0],
y = b[1] - a[1],
z = b[2] - a[2],
w = b[3] - a[3]
return Math.sqrt(x * x + y * y + z * z + w * w)
}
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vec4dist = vec4distance
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/**
* 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
*/
function vec4divide (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
}
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vec4div = vec4divide
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/**
* 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
*/
function vec4dot (a, b) {
return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3]
}
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/**
* 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
*/
function vec4fromValues (x, y, z, w) {
var out = new Float32Array(4)
out[0] = x
out[1] = y
out[2] = z
out[3] = w
return out
}
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/**
* Returns the inverse of the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to invert
* @returns {vec4} out
*/
function vec4inverse (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
}
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/**
* Calculates the length of a vec4
*
* @param {vec4} a vector to calculate length of
* @returns {Number} length of a
*/
function vec4length (a) {
var x = a[0],
y = a[1],
z = a[2],
w = a[3]
return Math.sqrt(x * x + y * y + z * z + w * w)
}
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vec4len = vec4length
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/**
* 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 between the two inputs
* @returns {vec4} out
*/
function vec4lerp (out, a, b, t) {
var ax = a[0],
ay = a[1],
az = a[2],
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
}
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/**
* 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
*/
function vec4max (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
}
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/**
* 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
*/
function vec4min (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
}
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/**
* 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
*/
function vec4multiply (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
}
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vec4mul = vec4multiply
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/**
* Negates the components of a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to negate
* @returns {vec4} out
*/
function vec4negate (out, a) {
out[0] = -a[0]
out[1] = -a[1]
out[2] = -a[2]
out[3] = -a[3]
return out
}
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/**
* Normalize a vec4
*
* @param {vec4} out the receiving vector
* @param {vec4} a vector to normalize
* @returns {vec4} out
*/
function vec4normalize (out, a) {
var x = a[0],
y = a[1],
z = a[2],
w = a[3]
var 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
}
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/**
* 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
*/
function vec4random (out, scale) {
scale = scale || 1.0

// TODO: This is a pretty awful way of doing this. Find something better.
out[0] = Math.random()
out[1] = Math.random()
out[2] = Math.random()
out[3] = Math.random()
vec4normalize(out, out)
vec4scale(out, out, scale)
return out
}
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/**
* 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
*/
function vec4scale (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
}
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/**
* 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
*/
function vec4scaleAndAdd (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
}
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/**
* 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
*/
function vec4set (out, x, y, z, w) {
out[0] = x
out[1] = y
out[2] = z
out[3] = w
return out
}
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/**
* 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
*/
function vec4squaredDistance (a, b) {
var x = b[0] - a[0],
y = b[1] - a[1],
z = b[2] - a[2],
w = b[3] - a[3]
return x * x + y * y + z * z + w * w
}
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vec4sqrDist = vec4squaredDistance
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/**
* Calculates the squared length of a vec4
*
* @param {vec4} a vector to calculate squared length of
* @returns {Number} squared length of a
*/
function vec4squaredLength (a) {
var x = a[0],
y = a[1],
z = a[2],
w = a[3]
return x * x + y * y + z * z + w * w
}
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vec4sqrLen = vec4squaredLength
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/**
* 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
*/
function vec4subtract (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
}
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vec4sub = vec4subtract
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/**
* 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
*/
function vec4transformMat4 (out, a, m) {
var 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
}
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/**
* 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
*/
function vec4transformQuat (out, a, q) {
var x = a[0], y = a[1], z = a[2],
qx = q[0], qy = q[1], qz = q[2], qw = q[3],

// calculate quat * vec
ix = qw * x + qy * z - qz * y,
iy = qw * y + qz * x - qx * z,
iz = qw * z + qx * y - qy * x,
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
}
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