static inline double lanczos_filter(double x) { /* truncated sinc */ if (-3.0 <= x && x < 3.0) return sinc_filter(x) * sinc_filter(x/3); return 0.0; }
static inline float antialias_filter(float x) { /* lanczos (truncated sinc) */ if (-3.0 <= x && x < 3.0) return sinc_filter(x) * sinc_filter(x/3); return 0.0; }