void csCubicSpline::PrecalculateDerivatives ()
{
if (precalculation_valid) return ;
precalculation_valid = true;
delete[] derivative_points;
derivative_points = new float[dimensions * num_points];
int dim;
for (dim = 0; dim < dimensions; dim++) PrecalculateDerivatives (dim);
}
void csCubicSpline::Calculate (float time)
{
PrecalculateDerivatives ();
// First find the current 'idx'.
for (idx = 0; idx < num_points - 1; idx++)
{
if (time >= time_points[idx] && time <= time_points[idx + 1]) break;
}
A = (time_points[idx + 1] - time) / (time_points[idx + 1] - time_points[idx]);
B = 1 - A;
float temp = (time_points[idx + 1] - time_points[idx]);
temp = temp * temp / 6.0f;
C = (A * A * A - A) * temp;
D = (B * B * B - B) * temp;
}
void csCubicSpline::Calculate (float time)
{
PrecalculateDerivatives ();
// First find the current 'idx'.
for (idx = 0; idx < num_points - 1; idx++)
{
if (time >= time_points[idx] && time <= time_points[idx + 1]) break;
}
// Correct for floating point inaccuracies in the previous loop.
if (idx == num_points-1) idx--;
A = (time_points[idx + 1] - time) / (time_points[idx + 1] - time_points[idx]);
B = 1 - A;
float temp = (time_points[idx + 1] - time_points[idx]);
temp = temp * temp / 6.0f;
C = (A * A * A - A) * temp;
D = (B * B * B - B) * temp;
}