/*delt has different meanings depending on what you're going to use it with.  for initialization:    for hill:   delt is the divisor    for linear: delt determines step size (stepsize = (to-from)/delt)    for smooth: delt determines acceleration (acel = (4*(to-from)/delt^2)  for operation:    for hill:   n/a    for linear: delt is time since last called    for smooth: delt is time since last called*/#include "twerp.h"void twerpinitd(twerpd *d, double from, double to, double delt) {  d->cur=0.0;  d->from = from;  d->to = to;  d->delt = delt;  d->step = (to-from)/delt;  d->vel = 0.0;  d->acel = 4.0*(to-from)/(delt*delt);  d->tremain=delt;  d->ttotal=delt;}double twerphilld(twerpd *d) {  return(d->cur = (((d->cur) * (d->delt-1.0)) + (d->to))/(d->delt));}double twerplind(twerpd *d, double delt) {  d->tremain -= delt;  return(d->cur += (d->step)*delt);}double twerpsmoothd(twerpd *d, double delt) {  d->tremain-=delt;  d->vel+=(d->tremain<(d->ttotal/2.0))?-(d->acel*delt):(d->acel*delt);  return(d->cur+=((d->vel)*delt));}/*int main(void) {  twerpd h, l, s;    twerpinitd(&h, 0.0, 1.0, 10.0);  twerpinitd(&l, 0.0, 1.0, 10.0);  twerpinitd(&s, 0.0, 1.0, 10.0);  while (twerphilld(&h)<.99) {    printf("%f\n", h.cur);  }  printf("\n");  while (twerplind(&l, .1)<.99) {    printf("%f\n", l.cur);  }  printf("\n");  while (twerpsmoothd(&s, .1)<.99) {    printf("%f\n", s.cur);  }  printf("\n");}*/