#include <u.h>
#include <libc.h>
#include <draw.h>
#include <mouse.h>
#include "frame.h"

#define CHUNK 16
#define ROUNDUP(n) ((n + CHUNK) & ~(CHUNK - 1))

uchar* _frallocstr(Frame* f, unsigned n) {
  uchar* p;

  p = malloc(ROUNDUP(n));
  if (p == 0)
    drawerror(f->display, "out of memory");
  return p;
}

void _frinsure(Frame* f, int bn, unsigned n) {
  Frbox* b;
  uchar* p;

  b = &f->box[bn];
  if (b->nrune < 0)
    drawerror(f->display, "_frinsure");
  if (ROUNDUP(b->nrune) > n) /* > guarantees room for terminal NUL */
    return;
  p = _frallocstr(f, n);
  b = &f->box[bn];
  memmove(p, b->ptr, NBYTE(b) + 1);
  free(b->ptr);
  b->ptr = p;
}