Function stbi__get_marker

include/stb/stb_image.h:2919–2928

if there's a pending marker from the entropy stream, return that otherwise, fetch from the stream and get a marker. if there's no marker, return 0xff, which is never a valid marker value

// otherwise, fetch from the stream and get a marker. if there's no
// marker, return 0xff, which is never a valid marker value
static stbi_uc stbi__get_marker(stbi__jpeg *j)
{
   stbi_uc x;
   if (j->marker != STBI__MARKER_none) { x = j->marker; j->marker = STBI__MARKER_none; return x; }
   x = stbi__get8(j->s);
   if (x != 0xff) return STBI__MARKER_none;
   while (x == 0xff)
      x = stbi__get8(j->s); // consume repeated 0xff fill bytes
   return x;
}

// in each scan, we'll have scan_n components, and the order
// of the components is specified by order[]