mirror of
https://gitea.wildfiregames.com/0ad/0ad
synced 2026-06-17 13:53:57 -07:00
40f1340e60
eslint --no-config-lookup --fix --rule '"space-before-function-paren": ["warn", "never"]' Ref: #7812 Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
40 lines
1.4 KiB
JavaScript
40 lines
1.4 KiB
JavaScript
/**
|
|
* Interpolates the value of a point that is located between four known equidistant points with given values by
|
|
* constructing a polynomial of degree three that goes through all points.
|
|
* Computes a cardinal or Catmull-Rom spline.
|
|
*
|
|
* @param {number} tension - determines how sharply the curve bends at the given points.
|
|
* @param {number} x - Location of the point to interpolate, relative to p1
|
|
*/
|
|
function cubicInterpolation(tension, x, p0, p1, p2, p3)
|
|
{
|
|
const P = -tension * p0 + (2 - tension) * p1 + (tension - 2) * p2 + tension * p3;
|
|
const Q = 2 * tension * p0 + (tension - 3) * p1 + (3 - 2 * tension) * p2 - tension * p3;
|
|
const R = -tension * p0 + tension * p2;
|
|
const S = p1;
|
|
|
|
return ((P * x + Q) * x + R) * x + S;
|
|
}
|
|
|
|
/**
|
|
* Two dimensional interpolation within a square grid using a polynomial of degree three.
|
|
*
|
|
* @param {Vector2D} position - Location of the point to interpolate, relative to p11
|
|
*/
|
|
function bicubicInterpolation(
|
|
position,
|
|
p00, p01, p02, p03,
|
|
p10, p11, p12, p13,
|
|
p20, p21, p22, p23,
|
|
p30, p31, p32, p33
|
|
)
|
|
{
|
|
const tension = 0.5;
|
|
return cubicInterpolation(
|
|
tension,
|
|
position.x,
|
|
cubicInterpolation(tension, position.y, p00, p01, p02, p03),
|
|
cubicInterpolation(tension, position.y, p10, p11, p12, p13),
|
|
cubicInterpolation(tension, position.y, p20, p21, p22, p23),
|
|
cubicInterpolation(tension, position.y, p30, p31, p32, p33));
|
|
}
|