diff options
Diffstat (limited to 'tab/tabosc4c~.c')
| -rw-r--r-- | tab/tabosc4c~.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/tab/tabosc4c~.c b/tab/tabosc4c~.c index 406f770..f4a5a66 100644 --- a/tab/tabosc4c~.c +++ b/tab/tabosc4c~.c @@ -126,7 +126,7 @@ static t_int *tabosc4c_tilde_perform(t_int *w) int n = (int)(w[4]); int normhipart; union tabfudge tf; - double a0,a1,a2; // CH + double a3,a1,a2; // CH t_float fnpoints = x->x_fnpoints; int mask = fnpoints - 1; t_float conv = fnpoints * x->x_conv; @@ -157,10 +157,17 @@ static t_int *tabosc4c_tilde_perform(t_int *w) // cminusb - 0.1666667f * (1.-frac) * ( // (d - a - 3.0f * cminusb) * frac + (d + 2.0f*a - 3.0f*b) ) ); // CH - a0 = d - c - a + b; - a1 = a - b - a0; - a2 = c - a; - *out++ = ((a0*frac+a1)*frac+a2)*frac+b; +// a0 = d - c - a + b; +// a1 = a - b - a0; +// a2 = c - a; +// *out++ = ((a0*frac+a1)*frac+a2)*frac+b; + + // 4-point, 3rd-order Hermite (x-form) + a1 = 0.5f * (c - a); + a2 = a - 2.5 * b + 2.f * c - 0.5f * d; + a3 = 0.5f * (d - a) + 1.5f * (b - c); + + *out++ = ((a3 * frac + a2) * frac + a1) * frac + b; } #endif |