void Starfield_Step(Starfield *starfield)
{
for (int i = 0; i < num_stars; i++) {
StarfieldStar *star = &starfield->stars[i];
star->x += (max_depth - star->depth + 1);
if (star->x > SCREEN_WIDTH) {
star->x = 0;
star->y = mod32(rand(), 192);
star->depth = mod32(rand(), max_depth);
}
}
}
static inline uint32_t update32(uint32_t *_reg, uint32_t _clr, uint32_t _set, uint32_t _val)
{
uint32_t set = _val & _set;
uint32_t clr = _clr & _val;
return mod32(_reg, clr | _set, set);
}
void Starfield_InitStar(StarfieldStar *star)
{
star->x = rand() & 255;
star->y = mod32(rand(), 192);
star->depth = mod32(rand(), max_depth);
}