hermite function
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
Implementation
List<double> hermite(out, a, b, c, d, t) {
final factorTimes2 = t * t;
final factor1 = factorTimes2 * (2 * t - 3) + 1;
final factor2 = factorTimes2 * (t - 2) + t;
final factor3 = factorTimes2 * (t - 1);
final 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;
}