twerp.c

来自「细胞自动机的一个源代码」· C语言 代码 · 共 65 行

/*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");
}
*/