/// <summary>Recalculates the internal lookup table so that the bezier can be sampled by distance or by uniform t-values.
/// Only call this before sampling a different curve, or if the curve has changed shape since last time it was calculated</summary>
/// <param name="bezier">The curve to use when sampling</param>
public void Recalculate(BezierCubic2D bezier)
{
float cumulativeLength = 0;
Vector2 prevPt = bezier.P0;
cumulativeDistances[0] = 0;
for (int i = 1; i < resolution; i++) // todo: could optimize by moving all points so that p0 = (0,0)
{
Vector2 pt = bezier.GetPoint(i / (resolution - 1f));
cumulativeLength += Vector2.Distance(prevPt, pt);
cumulativeDistances[i] = cumulativeLength;
prevPt = pt;
}
}
// The way the point recalculation works right now is pretty naive, and doesn't handle extreme acceleration very well.
// Right now you need around 30 samples to properly sample, which, is a lot
#region Constructors & Point recalc
/// <summary>Creates a sampler that can be used to sample a bezier curve by distance or by uniform t-values.
/// You'll need to call sampler.Recalculate(bezier) to recalculate if the curve changes shape after this points.
/// Recommended resolution for animation: [8-16]
/// Recommended resolution for even point spacing: [16-50]</summary>
/// <param name="bezier">The curve to use when sampling</param>
/// <param name="resolution">The accuracy of this sampler.
/// Higher values are more accurate, but are more costly to calculate for every new bezier shape</param>
public BezierSampler(BezierCubic2D bezier, int resolution = 12)
{
this.resolution = resolution;
cumulativeDistances = new float[resolution];
Recalculate(bezier);
}
