📄 CubicInterpolant.js¶
📊 Analysis Summary¶
| Metric | Count |
|---|---|
| 🔧 Functions | 2 |
| 🧱 Classes | 1 |
| 📦 Imports | 4 |
| 📊 Variables & Constants | 23 |
📚 Table of Contents¶
🛠️ File Location:¶
📂 src/math/interpolants/CubicInterpolant.js
📦 Imports¶
| Name | Source |
|---|---|
ZeroCurvatureEnding |
../../constants.js |
WrapAroundEnding |
../../constants.js |
ZeroSlopeEnding |
../../constants.js |
Interpolant |
../Interpolant.js |
Variables & Constants¶
| Name | Type | Kind | Value | Exported |
|---|---|---|---|---|
pp |
TypedArray |
let/var | this.parameterPositions |
✗ |
iPrev |
number |
let/var | i1 - 2 |
✗ |
iNext |
any |
let/var | i1 + 1 |
✗ |
tPrev |
TypedArray |
let/var | pp[ iPrev ] |
✗ |
tNext |
TypedArray |
let/var | pp[ iNext ] |
✗ |
halfDt |
number |
let/var | ( t1 - t0 ) * 0.5 |
✗ |
stride |
TypedArray |
let/var | this.valueSize |
✗ |
result |
TypedArray |
let/var | this.resultBuffer |
✗ |
values |
TypedArray |
let/var | this.sampleValues |
✗ |
stride |
TypedArray |
let/var | this.valueSize |
✗ |
o1 |
number |
let/var | i1 * stride |
✗ |
o0 |
number |
let/var | o1 - stride |
✗ |
oP |
number |
let/var | this._offsetPrev |
✗ |
oN |
number |
let/var | this._offsetNext |
✗ |
wP |
number |
let/var | this._weightPrev |
✗ |
wN |
number |
let/var | this._weightNext |
✗ |
p |
number |
let/var | ( t - t0 ) / ( t1 - t0 ) |
✗ |
pp |
number |
let/var | p * p |
✗ |
ppp |
number |
let/var | pp * p |
✗ |
sP |
number |
let/var | - wP * ppp + 2 * wP * pp - wP * p |
✗ |
s0 |
number |
let/var | ( 1 + wP ) * ppp + ( - 1.5 - 2 * wP ) * pp + ( - 0.5 + wP ) * p + 1 |
✗ |
s1 |
number |
let/var | ( - 1 - wN ) * ppp + ( 1.5 + wN ) * pp + 0.5 * p |
✗ |
sN |
number |
let/var | wN * ppp - wN * pp |
✗ |
Functions¶
CubicInterpolant.intervalChanged_(i1: any, t0: any, t1: any): void¶
Parameters:
i1anyt0anyt1any
Returns: void
Calls:
this.getSettings_
Internal Comments:
// f'(t0) = 0 (x3)
// use the other end of the curve (x6)
// f''(t0) = 0 a.k.a. Natural Spline (x3)
// f'(tN) = 0 (x3)
// f''(tN) = 0, a.k.a. Natural Spline (x3)
Code
intervalChanged_( i1, t0, t1 ) {
const pp = this.parameterPositions;
let iPrev = i1 - 2,
iNext = i1 + 1,
tPrev = pp[ iPrev ],
tNext = pp[ iNext ];
if ( tPrev === undefined ) {
switch ( this.getSettings_().endingStart ) {
case ZeroSlopeEnding:
// f'(t0) = 0
iPrev = i1;
tPrev = 2 * t0 - t1;
break;
case WrapAroundEnding:
// use the other end of the curve
iPrev = pp.length - 2;
tPrev = t0 + pp[ iPrev ] - pp[ iPrev + 1 ];
break;
default: // ZeroCurvatureEnding
// f''(t0) = 0 a.k.a. Natural Spline
iPrev = i1;
tPrev = t1;
}
}
if ( tNext === undefined ) {
switch ( this.getSettings_().endingEnd ) {
case ZeroSlopeEnding:
// f'(tN) = 0
iNext = i1;
tNext = 2 * t1 - t0;
break;
case WrapAroundEnding:
// use the other end of the curve
iNext = 1;
tNext = t1 + pp[ 1 ] - pp[ 0 ];
break;
default: // ZeroCurvatureEnding
// f''(tN) = 0, a.k.a. Natural Spline
iNext = i1 - 1;
tNext = t0;
}
}
const halfDt = ( t1 - t0 ) * 0.5,
stride = this.valueSize;
this._weightPrev = halfDt / ( t0 - tPrev );
this._weightNext = halfDt / ( tNext - t1 );
this._offsetPrev = iPrev * stride;
this._offsetNext = iNext * stride;
}
CubicInterpolant.interpolate_(i1: any, t0: any, t: any, t1: any): TypedArray¶
Parameters:
i1anyt0anytanyt1any
Returns: TypedArray
Internal Comments:
Code
interpolate_( i1, t0, t, t1 ) {
const result = this.resultBuffer,
values = this.sampleValues,
stride = this.valueSize,
o1 = i1 * stride, o0 = o1 - stride,
oP = this._offsetPrev, oN = this._offsetNext,
wP = this._weightPrev, wN = this._weightNext,
p = ( t - t0 ) / ( t1 - t0 ),
pp = p * p,
ppp = pp * p;
// evaluate polynomials
const sP = - wP * ppp + 2 * wP * pp - wP * p;
const s0 = ( 1 + wP ) * ppp + ( - 1.5 - 2 * wP ) * pp + ( - 0.5 + wP ) * p + 1;
const s1 = ( - 1 - wN ) * ppp + ( 1.5 + wN ) * pp + 0.5 * p;
const sN = wN * ppp - wN * pp;
// combine data linearly
for ( let i = 0; i !== stride; ++ i ) {
result[ i ] =
sP * values[ oP + i ] +
s0 * values[ o0 + i ] +
s1 * values[ o1 + i ] +
sN * values[ oN + i ];
}
return result;
}
Classes¶
CubicInterpolant¶
Class Code
class CubicInterpolant extends Interpolant {
/**
* Constructs a new cubic interpolant.
*
* @param {TypedArray} parameterPositions - The parameter positions hold the interpolation factors.
* @param {TypedArray} sampleValues - The sample values.
* @param {number} sampleSize - The sample size
* @param {TypedArray} [resultBuffer] - The result buffer.
*/
constructor( parameterPositions, sampleValues, sampleSize, resultBuffer ) {
super( parameterPositions, sampleValues, sampleSize, resultBuffer );
this._weightPrev = - 0;
this._offsetPrev = - 0;
this._weightNext = - 0;
this._offsetNext = - 0;
this.DefaultSettings_ = {
endingStart: ZeroCurvatureEnding,
endingEnd: ZeroCurvatureEnding
};
}
intervalChanged_( i1, t0, t1 ) {
const pp = this.parameterPositions;
let iPrev = i1 - 2,
iNext = i1 + 1,
tPrev = pp[ iPrev ],
tNext = pp[ iNext ];
if ( tPrev === undefined ) {
switch ( this.getSettings_().endingStart ) {
case ZeroSlopeEnding:
// f'(t0) = 0
iPrev = i1;
tPrev = 2 * t0 - t1;
break;
case WrapAroundEnding:
// use the other end of the curve
iPrev = pp.length - 2;
tPrev = t0 + pp[ iPrev ] - pp[ iPrev + 1 ];
break;
default: // ZeroCurvatureEnding
// f''(t0) = 0 a.k.a. Natural Spline
iPrev = i1;
tPrev = t1;
}
}
if ( tNext === undefined ) {
switch ( this.getSettings_().endingEnd ) {
case ZeroSlopeEnding:
// f'(tN) = 0
iNext = i1;
tNext = 2 * t1 - t0;
break;
case WrapAroundEnding:
// use the other end of the curve
iNext = 1;
tNext = t1 + pp[ 1 ] - pp[ 0 ];
break;
default: // ZeroCurvatureEnding
// f''(tN) = 0, a.k.a. Natural Spline
iNext = i1 - 1;
tNext = t0;
}
}
const halfDt = ( t1 - t0 ) * 0.5,
stride = this.valueSize;
this._weightPrev = halfDt / ( t0 - tPrev );
this._weightNext = halfDt / ( tNext - t1 );
this._offsetPrev = iPrev * stride;
this._offsetNext = iNext * stride;
}
interpolate_( i1, t0, t, t1 ) {
const result = this.resultBuffer,
values = this.sampleValues,
stride = this.valueSize,
o1 = i1 * stride, o0 = o1 - stride,
oP = this._offsetPrev, oN = this._offsetNext,
wP = this._weightPrev, wN = this._weightNext,
p = ( t - t0 ) / ( t1 - t0 ),
pp = p * p,
ppp = pp * p;
// evaluate polynomials
const sP = - wP * ppp + 2 * wP * pp - wP * p;
const s0 = ( 1 + wP ) * ppp + ( - 1.5 - 2 * wP ) * pp + ( - 0.5 + wP ) * p + 1;
const s1 = ( - 1 - wN ) * ppp + ( 1.5 + wN ) * pp + 0.5 * p;
const sN = wN * ppp - wN * pp;
// combine data linearly
for ( let i = 0; i !== stride; ++ i ) {
result[ i ] =
sP * values[ oP + i ] +
s0 * values[ o0 + i ] +
s1 * values[ o1 + i ] +
sN * values[ oN + i ];
}
return result;
}
}
Methods¶
intervalChanged_(i1: any, t0: any, t1: any): void¶
Code
intervalChanged_( i1, t0, t1 ) {
const pp = this.parameterPositions;
let iPrev = i1 - 2,
iNext = i1 + 1,
tPrev = pp[ iPrev ],
tNext = pp[ iNext ];
if ( tPrev === undefined ) {
switch ( this.getSettings_().endingStart ) {
case ZeroSlopeEnding:
// f'(t0) = 0
iPrev = i1;
tPrev = 2 * t0 - t1;
break;
case WrapAroundEnding:
// use the other end of the curve
iPrev = pp.length - 2;
tPrev = t0 + pp[ iPrev ] - pp[ iPrev + 1 ];
break;
default: // ZeroCurvatureEnding
// f''(t0) = 0 a.k.a. Natural Spline
iPrev = i1;
tPrev = t1;
}
}
if ( tNext === undefined ) {
switch ( this.getSettings_().endingEnd ) {
case ZeroSlopeEnding:
// f'(tN) = 0
iNext = i1;
tNext = 2 * t1 - t0;
break;
case WrapAroundEnding:
// use the other end of the curve
iNext = 1;
tNext = t1 + pp[ 1 ] - pp[ 0 ];
break;
default: // ZeroCurvatureEnding
// f''(tN) = 0, a.k.a. Natural Spline
iNext = i1 - 1;
tNext = t0;
}
}
const halfDt = ( t1 - t0 ) * 0.5,
stride = this.valueSize;
this._weightPrev = halfDt / ( t0 - tPrev );
this._weightNext = halfDt / ( tNext - t1 );
this._offsetPrev = iPrev * stride;
this._offsetNext = iNext * stride;
}
interpolate_(i1: any, t0: any, t: any, t1: any): TypedArray¶
Code
interpolate_( i1, t0, t, t1 ) {
const result = this.resultBuffer,
values = this.sampleValues,
stride = this.valueSize,
o1 = i1 * stride, o0 = o1 - stride,
oP = this._offsetPrev, oN = this._offsetNext,
wP = this._weightPrev, wN = this._weightNext,
p = ( t - t0 ) / ( t1 - t0 ),
pp = p * p,
ppp = pp * p;
// evaluate polynomials
const sP = - wP * ppp + 2 * wP * pp - wP * p;
const s0 = ( 1 + wP ) * ppp + ( - 1.5 - 2 * wP ) * pp + ( - 0.5 + wP ) * p + 1;
const s1 = ( - 1 - wN ) * ppp + ( 1.5 + wN ) * pp + 0.5 * p;
const sN = wN * ppp - wN * pp;
// combine data linearly
for ( let i = 0; i !== stride; ++ i ) {
result[ i ] =
sP * values[ oP + i ] +
s0 * values[ o0 + i ] +
s1 * values[ o1 + i ] +
sN * values[ oN + i ];
}
return result;
}