fury-js
Version:
WebGL Game Engine
960 lines (873 loc) • 24.4 kB
JavaScript
const { ARRAY_TYPE, EPSILON, RANDOM, round } = require("./common.js");
/**
* 3 Dimensional Vector
* @module vec3
*/
/**
* Creates a new, empty vec3
*
* @returns {vec3} a new 3D vector
*/
exports.create = function() {
let out = new ARRAY_TYPE(3);
out[0] = 0;
out[1] = 0;
out[2] = 0;
return out;
};
/**
* Creates a new vec3 initialized with values from an existing vector
*
* @param {ReadonlyVec3} a vector to clone
* @returns {vec3} a new 3D vector
*/
exports.clone = function(a) {
var out = new ARRAY_TYPE(3);
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
return out;
};
/**
* Calculates the length of a vec3
*
* @param {ReadonlyVec3} a vector to calculate length of
* @returns {Number} length of a
*/
exports.length = function(a) {
let x = a[0];
let y = a[1];
let z = a[2];
return Math.sqrt(x * x + y * y + z * z);
};
/**
* Creates a new vec3 initialized with the given values
*
* @param {Number} x X component
* @param {Number} y Y component
* @param {Number} z Z component
* @returns {vec3} a new 3D vector
*/
exports.fromValues = function(x, y, z) {
let out = new ARRAY_TYPE(3);
out[0] = x;
out[1] = y;
out[2] = z;
return out;
};
/**
* Copy the values from one vec3 to another
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the source vector
* @returns {vec3} out
*/
exports.copy = function(out, a) {
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
return out;
};
/**
* Set the components of a vec3 to the given values
*
* @param {vec3} out the receiving vector
* @param {Number} x X component
* @param {Number} y Y component
* @param {Number} z Z component
* @returns {vec3} out
*/
exports.set = function(out, x, y, z) {
out[0] = x;
out[1] = y;
out[2] = z;
return out;
};
/**
* Adds two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.add = function(out, a, b) {
out[0] = a[0] + b[0];
out[1] = a[1] + b[1];
out[2] = a[2] + b[2];
return out;
};
/**
* Subtracts vector b from vector a
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.subtract = function(out, a, b) {
out[0] = a[0] - b[0];
out[1] = a[1] - b[1];
out[2] = a[2] - b[2];
return out;
};
/**
* Multiplies two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.multiply = function(out, a, b) {
out[0] = a[0] * b[0];
out[1] = a[1] * b[1];
out[2] = a[2] * b[2];
return out;
};
/**
* Divides two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.divide = function(out, a, b) {
out[0] = a[0] / b[0];
out[1] = a[1] / b[1];
out[2] = a[2] / b[2];
return out;
};
/**
* Math.ceil the components of a vec3
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a vector to ceil
* @returns {vec3} out
*/
exports.ceil = function(out, a) {
out[0] = Math.ceil(a[0]);
out[1] = Math.ceil(a[1]);
out[2] = Math.ceil(a[2]);
return out;
};
/**
* Math.floor the components of a vec3
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a vector to floor
* @returns {vec3} out
*/
exports.floor = function(out, a) {
out[0] = Math.floor(a[0]);
out[1] = Math.floor(a[1]);
out[2] = Math.floor(a[2]);
return out;
};
/**
* Returns the minimum of two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.min = function(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]);
return out;
};
/**
* Returns the maximum of two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.max = function(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]);
return out;
};
/**
* symmetric round the components of a vec3
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a vector to round
* @returns {vec3} out
*/
exports.round = function(out, a) {
out[0] = round(a[0]);
out[1] = round(a[1]);
out[2] = round(a[2]);
return out;
};
/**
* Scales a vec3 by a scalar number
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to scale
* @param {Number} b amount to scale the vector by
* @returns {vec3} out
*/
exports.scale = function(out, a, b) {
out[0] = a[0] * b;
out[1] = a[1] * b;
out[2] = a[2] * b;
return out;
};
/**
* Scales a vec3 by a scale number in X and Y axes only
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to scale
* @param {Number} b amount to scale the vector by
* @returns {vec3} out
*/
exports.scaleXY = function(out, a, b) {
out[0] = a[0] * b;
out[1] = a[1] * b;
out[2] = a[2];
return out;
};
/**
* Scales a vec3 by a scale number in X and Z axes only
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to scale
* @param {Number} b amount to scale the vector by
* @returns {vec3} out
*/
exports.scaleXZ = function(out, a, b) {
out[0] = a[0] * b;
out[1] = a[1];
out[2] = a[2] * b;
return out;
};
/**
* Scales a vec3 by a scale number in Y and Z axes only
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to scale
* @param {Number} b amount to scale the vector by
* @returns {vec3} out
*/
exports.scaleYZ = function(out, a, b) {
out[0] = a[0];
out[1] = a[1] * b;
out[2] = a[2] * b;
return out;
};
/**
* Adds two vec3's after scaling the second operand by a scalar value
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @param {Number} scale the amount to scale b by before adding
* @returns {vec3} out
*/
exports.scaleAndAdd = function(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;
return out;
};
/**
* Calculates the euclidian distance between two vec3's
*
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {Number} distance between a and b
*/
exports.distance = function(a, b) {
let x = b[0] - a[0];
let y = b[1] - a[1];
let z = b[2] - a[2];
return Math.sqrt(x * x + y * y + z * z);
};
/**
* Calculates the squared euclidian distance between two vec3's
*
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {Number} squared distance between a and b
*/
exports.squaredDistance = function(a, b) {
let x = b[0] - a[0];
let y = b[1] - a[1];
let z = b[2] - a[2];
return x * x + y * y + z * z;
};
/**
* Calculates the squared length of a vec3
*
* @param {ReadonlyVec3} a vector to calculate squared length of
* @returns {Number} squared length of a
*/
exports.squaredLength = function(a) {
let x = a[0];
let y = a[1];
let z = a[2];
return x * x + y * y + z * z;
};
/**
* Negates the components of a vec3
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a vector to negate
* @returns {vec3} out
*/
exports.negate = function(out, a) {
out[0] = -a[0];
out[1] = -a[1];
out[2] = -a[2];
return out;
};
/**
* Returns the inverse of the components of a vec3
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a vector to invert
* @returns {vec3} out
*/
exports.inverse = function(out, a) {
out[0] = 1.0 / a[0];
out[1] = 1.0 / a[1];
out[2] = 1.0 / a[2];
return out;
};
/**
* Normalize a vec3
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a vector to normalize
* @returns {vec3} out
*/
exports.normalize = function(out, a) {
let x = a[0];
let y = a[1];
let z = a[2];
let len = x * x + y * y + z * z;
if (len > 0) {
//TODO: evaluate use of glm_invsqrt here?
len = 1 / Math.sqrt(len);
}
out[0] = a[0] * len;
out[1] = a[1] * len;
out[2] = a[2] * len;
return out;
};
/**
* Calculates the dot product of two vec3's
*
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {Number} dot product of a and b
*/
exports.dot = function(a, b) {
return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
};
/**
* Computes the cross product of two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @returns {vec3} out
*/
exports.cross = function(out, a, b) {
let ax = a[0],
ay = a[1],
az = a[2];
let bx = b[0],
by = b[1],
bz = b[2];
out[0] = ay * bz - az * by;
out[1] = az * bx - ax * bz;
out[2] = ax * by - ay * bx;
return out;
};
/**
* Performs a linear interpolation between two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @param {Number} t interpolation amount, in the range [0-1], between the two inputs
* @returns {vec3} out
*/
exports.lerp = function(out, a, b, t) {
let ax = a[0];
let ay = a[1];
let az = a[2];
out[0] = ax + t * (b[0] - ax);
out[1] = ay + t * (b[1] - ay);
out[2] = az + t * (b[2] - az);
return out;
};
/**
* Performs a spherical linear interpolation between two vec3's
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @param {Number} t interpolation amount, in the range [0-1], between the two inputs
* @returns {vec3} out
*/
exports.slerp = function(out, a, b, t) {
let angle = Math.acos(Math.min(Math.max(dot(a, b), -1), 1));
let sinTotal = Math.sin(angle);
let ratioA = Math.sin((1 - t) * angle) / sinTotal;
let ratioB = Math.sin(t * angle) / sinTotal;
out[0] = ratioA * a[0] + ratioB * b[0];
out[1] = ratioA * a[1] + ratioB * b[1];
out[2] = ratioA * a[2] + ratioB * b[2];
return out;
};
/**
* Performs a hermite interpolation with two control points
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @param {ReadonlyVec3} c the third operand
* @param {ReadonlyVec3} d the fourth operand
* @param {Number} t interpolation amount, in the range [0-1], between the two inputs
* @returns {vec3} out
*/
exports.hermite = function(out, a, b, c, d, t) {
let factorTimes2 = t * t;
let factor1 = factorTimes2 * (2 * t - 3) + 1;
let factor2 = factorTimes2 * (t - 2) + t;
let factor3 = factorTimes2 * (t - 1);
let factor4 = factorTimes2 * (3 - 2 * t);
out[0] = a[0] * factor1 + b[0] * factor2 + c[0] * factor3 + d[0] * factor4;
out[1] = a[1] * factor1 + b[1] * factor2 + c[1] * factor3 + d[1] * factor4;
out[2] = a[2] * factor1 + b[2] * factor2 + c[2] * factor3 + d[2] * factor4;
return out;
};
/**
* Performs a bezier interpolation with two control points
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the first operand
* @param {ReadonlyVec3} b the second operand
* @param {ReadonlyVec3} c the third operand
* @param {ReadonlyVec3} d the fourth operand
* @param {Number} t interpolation amount, in the range [0-1], between the two inputs
* @returns {vec3} out
*/
exports.bezier = function(out, a, b, c, d, t) {
let inverseFactor = 1 - t;
let inverseFactorTimesTwo = inverseFactor * inverseFactor;
let factorTimes2 = t * t;
let factor1 = inverseFactorTimesTwo * inverseFactor;
let factor2 = 3 * t * inverseFactorTimesTwo;
let factor3 = 3 * factorTimes2 * inverseFactor;
let factor4 = factorTimes2 * t;
out[0] = a[0] * factor1 + b[0] * factor2 + c[0] * factor3 + d[0] * factor4;
out[1] = a[1] * factor1 + b[1] * factor2 + c[1] * factor3 + d[1] * factor4;
out[2] = a[2] * factor1 + b[2] * factor2 + c[2] * factor3 + d[2] * factor4;
return out;
};
/**
* Generates a random vector with the given scale
*
* @param {vec3} out the receiving vector
* @param {Number} [scale] Length of the resulting vector. If omitted, a unit vector will be returned
* @returns {vec3} out
*/
exports.random = function(out, scale) {
scale = scale === undefined ? 1.0 : scale;
let r = RANDOM() * 2.0 * Math.PI;
let z = RANDOM() * 2.0 - 1.0;
let zScale = Math.sqrt(1.0 - z * z) * scale;
out[0] = Math.cos(r) * zScale;
out[1] = Math.sin(r) * zScale;
out[2] = z * scale;
return out;
};
/**
* Transforms the vec3 with a mat4.
* 4th vector component is implicitly '1'
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to transform
* @param {ReadonlyMat4} m matrix to transform with
* @returns {vec3} out
*/
exports.transformMat4 = function(out, a, m) {
let x = a[0],
y = a[1],
z = a[2];
let w = m[3] * x + m[7] * y + m[11] * z + m[15];
w = w || 1.0;
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;
return out;
};
/**
* Transforms the vec3 with a mat3.
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to transform
* @param {ReadonlyMat3} m the 3x3 matrix to transform with
* @returns {vec3} out
*/
exports.transformMat3 = function(out, a, m) {
let x = a[0],
y = a[1],
z = a[2];
out[0] = x * m[0] + y * m[3] + z * m[6];
out[1] = x * m[1] + y * m[4] + z * m[7];
out[2] = x * m[2] + y * m[5] + z * m[8];
return out;
};
/**
* Transforms the vec3 with a quat
* Can also be used for dual quaternions. (Multiply it with the real part)
*
* @param {vec3} out the receiving vector
* @param {ReadonlyVec3} a the vector to transform
* @param {ReadonlyQuat} q quaternion to transform with
* @returns {vec3} out
*/
exports.transformQuat = function(out, a, q) {
// benchmarks: https://jsperf.com/quaternion-transform-vec3-implementations-fixed
let qx = q[0],
qy = q[1],
qz = q[2],
qw = q[3];
let x = a[0],
y = a[1],
z = a[2];
// var qvec = [qx, qy, qz];
// var uv = vec3.cross([], qvec, a);
let uvx = qy * z - qz * y,
uvy = qz * x - qx * z,
uvz = qx * y - qy * x;
// var uuv = vec3.cross([], qvec, uv);
let uuvx = qy * uvz - qz * uvy,
uuvy = qz * uvx - qx * uvz,
uuvz = qx * uvy - qy * uvx;
// vec3.scale(uv, uv, 2 * w);
let w2 = qw * 2;
uvx *= w2;
uvy *= w2;
uvz *= w2;
// vec3.scale(uuv, uuv, 2);
uuvx *= 2;
uuvy *= 2;
uuvz *= 2;
// return vec3.add(out, a, vec3.add(out, uv, uuv));
out[0] = x + uvx + uuvx;
out[1] = y + uvy + uuvy;
out[2] = z + uvz + uuvz;
return out;
};
/**
* Rotate a 3D vector around the x-axis
* @param {vec3} out The receiving vec3
* @param {ReadonlyVec3} a The vec3 point to rotate
* @param {ReadonlyVec3} b The origin of the rotation
* @param {Number} rad The angle of rotation in radians
* @returns {vec3} out
*/
exports.rotateX = function(out, a, b, rad) {
let p = [],
r = [];
//Translate point to the origin
p[0] = a[0] - b[0];
p[1] = a[1] - b[1];
p[2] = a[2] - b[2];
//perform rotation
r[0] = p[0];
r[1] = p[1] * Math.cos(rad) - p[2] * Math.sin(rad);
r[2] = p[1] * Math.sin(rad) + p[2] * Math.cos(rad);
//translate to correct position
out[0] = r[0] + b[0];
out[1] = r[1] + b[1];
out[2] = r[2] + b[2];
return out;
};
/**
* Rotate a 3D vector around the y-axis
* @param {vec3} out The receiving vec3
* @param {ReadonlyVec3} a The vec3 point to rotate
* @param {ReadonlyVec3} b The origin of the rotation
* @param {Number} rad The angle of rotation in radians
* @returns {vec3} out
*/
exports.rotateY = function(out, a, b, rad) {
let p = [],
r = [];
//Translate point to the origin
p[0] = a[0] - b[0];
p[1] = a[1] - b[1];
p[2] = a[2] - b[2];
//perform rotation
r[0] = p[2] * Math.sin(rad) + p[0] * Math.cos(rad);
r[1] = p[1];
r[2] = p[2] * Math.cos(rad) - p[0] * Math.sin(rad);
//translate to correct position
out[0] = r[0] + b[0];
out[1] = r[1] + b[1];
out[2] = r[2] + b[2];
return out;
};
/**
* Rotate a 3D vector around the z-axis
* @param {vec3} out The receiving vec3
* @param {ReadonlyVec3} a The vec3 point to rotate
* @param {ReadonlyVec3} b The origin of the rotation
* @param {Number} rad The angle of rotation in radians
* @returns {vec3} out
*/
exports.rotateZ = function(out, a, b, rad) {
let p = [],
r = [];
//Translate point to the origin
p[0] = a[0] - b[0];
p[1] = a[1] - b[1];
p[2] = a[2] - b[2];
//perform rotation
r[0] = p[0] * Math.cos(rad) - p[1] * Math.sin(rad);
r[1] = p[0] * Math.sin(rad) + p[1] * Math.cos(rad);
r[2] = p[2];
//translate to correct position
out[0] = r[0] + b[0];
out[1] = r[1] + b[1];
out[2] = r[2] + b[2];
return out;
};
/**
* Get the angle between two 3D vectors
* @param {ReadonlyVec3} a The first operand
* @param {ReadonlyVec3} b The second operand
* @returns {Number} The angle in radians
*/
exports.angle = function(a, b) {
let ax = a[0],
ay = a[1],
az = a[2],
bx = b[0],
by = b[1],
bz = b[2],
mag = Math.sqrt((ax * ax + ay * ay + az * az) * (bx * bx + by * by + bz * bz)),
cosine = mag && dot(a, b) / mag;
return Math.acos(Math.min(Math.max(cosine, -1), 1));
};
/**
* Set the components of a vec3 to zero
*
* @param {vec3} out the receiving vector
* @returns {vec3} out
*/
exports.zero = function(out) {
out[0] = 0.0;
out[1] = 0.0;
out[2] = 0.0;
return out;
};
/**
* Returns a string representation of a vector
*
* @param {ReadonlyVec3} a vector to represent as a string
* @returns {String} string representation of the vector
*/
exports.str = function(a) {
return "vec3(" + a[0] + ", " + a[1] + ", " + a[2] + ")";
};
/**
* Returns whether or not the vectors have exactly the same elements in the same position (when compared with ===)
*
* @param {ReadonlyVec3} a The first vector.
* @param {ReadonlyVec3} b The second vector.
* @returns {Boolean} True if the vectors are equal, false otherwise.
*/
exports.exactEquals = function(a, b) {
return a[0] === b[0] && a[1] === b[1] && a[2] === b[2];
};
/**
* Returns whether or not the vectors have approximately the same elements in the same position.
*
* @param {ReadonlyVec3} a The first vector.
* @param {ReadonlyVec3} b The second vector.
* @returns {Boolean} True if the vectors are equal, false otherwise.
*/
exports.equals = function(a, b) {
let a0 = a[0],
a1 = a[1],
a2 = a[2];
let b0 = b[0],
b1 = b[1],
b2 = b[2];
return (
Math.abs(a0 - b0) <=
EPSILON * Math.max(1.0, Math.abs(a0), Math.abs(b0)) &&
Math.abs(a1 - b1) <=
EPSILON * Math.max(1.0, Math.abs(a1), Math.abs(b1)) &&
Math.abs(a2 - b2) <=
EPSILON * Math.max(1.0, Math.abs(a2), Math.abs(b2))
);
};
/**
* Alias for {@link vec3.subtract}
* @function
*/
exports.sub = exports.subtract;
/**
* Alias for {@link vec3.multiply}
* @function
*/
exports.mul = exports.multiply;
/**
* Alias for {@link vec3.divide}
* @function
*/
exports.div = exports.divide;
/**
* Alias for {@link vec3.distance}
* @function
*/
exports.dist = exports.distance;
/**
* Alias for {@link vec3.squaredDistance}
* @function
*/
exports.sqrDist = exports.squaredDistance;
/**
* Alias for {@link vec3.length}
* @function
*/
exports.len = exports.length;
/**
* Alias for {@link vec3.squaredLength}
* @function
*/
exports.sqrLen = exports.squaredLength;
/**
* Perform some operation over an array of vec3s.
*
* @param {Array} a the array of vectors to iterate over
* @param {Number} stride Number of elements between the start of each vec3. If 0 assumes tightly packed
* @param {Number} offset Number of elements to skip at the beginning of the array
* @param {Number} count Number of vec3s 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
*/
exports.forEach = (function () {
let vec = exports.create();
return function (a, stride, offset, count, fn, arg) {
let i, l;
if (!stride) {
stride = 3;
}
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];
fn(vec, vec, arg);
a[i] = vec[0];
a[i + 1] = vec[1];
a[i + 2] = vec[2];
}
return a;
};
})();
/**
* vec3 pool for minimising garbage allocation
*/
exports.Pool = (function(){
let stack = [];
for (let i = 0; i < 5; i++) {
stack.push(exports.create());
}
return {
/**
* return a borrowed vec3 to the pool
* @param {vec3}
*/
return: (v) => { stack.push(exports.zero(v)); },
/**
* request a vec3 from the pool
* @returns {vec3}
*/
request: () => {
if (stack.length > 0) {
return stack.pop();
}
return exports.create();
}
}
})();
// vec3 extensions adapated from https://graemepottsfolio.wordpress.com/2015/11/26/vectors-programming/
exports.moveTowards = (() => {
let delta = exports.create();
return (out, a, b, maxDelta) => {
exports.subtract(delta, b, a);
let sqrLen = exports.squaredDistance(a, b);
let sqrMaxDelta = maxDelta * maxDelta;
if (sqrMaxDelta >= sqrLen) {
exports.copy(out, b);
} else {
exports.scaleAndAdd(out, a, delta, maxDelta / Math.sqrt(sqrLen));
}
};
})();
exports.smoothDamp = (() => {
let delta = exports.create();
let temp = exports.create();
return (out, a, b, velocity, smoothTime, maxSpeed, elapsed) => { // Q: Should have outVelocity?
if (exports.equals(a, b)) {
exports.copy(out, b);
} else {
// Derivation: https://graemepottsfolio.wordpress.com/2016/01/11/game-programming-math-libraries/
smoothTime = Math.max(0.0001, smoothTime); // minimum smooth time of 0.0001
let omega = 2.0 / smoothTime;
let x = omega * elapsed;
let exp = 1.0 / (1.0 + x + 0.48 * x * x + 0.245 * x * x * x);
exports.subtract(delta, a, b);
let length = exports.length(delta);
let maxDelta = maxSpeed * smoothTime;
let deltaX = Math.min(length, maxDelta);
exports.scale(delta, delta, deltaX / length);
// temp = (velocity + omega * delta) * elapsed
exports.scaleAndAdd(temp, velocity, delta, omega);
exports.scale(temp, temp, elapsed);
// velocity = (velocity - omega * temp) * exp
exports.scaleAndAdd(velocity, velocity, temp, -omega);
exports.scale(velocity, velocity, exp);
// out = a - delta + (delta + temp) * exp;
exports.sub(out, a, delta);
exports.scaleAndAdd(out, out, delta, exp);
exports.scaleAndAdd(out, out, temp, exp);
// Ensure we don't overshoot
if (exports.sqrDist(b, a) <= exports.sqrDist(out, a)) {
exports.copy(out, b);
exports.zero(velocity);
}
}
};
})();
exports.ZERO = Object.freeze(exports.create());
exports.ONE = Object.freeze(exports.fromValues(1,1,1));
exports.X = Object.freeze(exports.fromValues(1,0,0));
exports.Y = Object.freeze(exports.fromValues(0,1,0));
exports.Z = Object.freeze(exports.fromValues(0,0,1));
exports.NEG_X = Object.freeze(exports.fromValues(-1,0,0));
exports.NEG_Y = Object.freeze(exports.fromValues(0,-1,0));
exports.NEG_Z = Object.freeze(exports.fromValues(0,0,-1));