interpLinear function
Raw coordinate lerp (same correspondence, no decomposition).
Implementation
void interpLinear(MorphPlan plan, double t, List<Float64List> out) {
for (var k = 0; k < plan.items.length; k++) {
final it = plan.items[k];
final o = out[k];
final n = plan.n;
for (var i = 0; i < n; i++) {
o[2 * i] = it.a[2 * i] + (it.bO[2 * i] - it.a[2 * i]) * t;
o[2 * i + 1] = it.a[2 * i + 1] + (it.bO[2 * i + 1] - it.a[2 * i + 1]) * t;
}
}
}