ticks next(ticks range) { return ticks(next(range.count())); }
inline bool operator==(const ticks& a, const ticks& b)
{
return a.count() == b.count();
}
inline bool operator>(const ticks& a, const ticks& b)
{
return a.count() > b.count();
}
inline ticks operator*(const T& a, const ticks& b)
{
return ticks(static_cast<std::uint64_t>(a * b.count()));
}
inline ticks operator+(const ticks& a, const ticks& b)
{
return ticks(a.count() + b.count());
}
void Starfield::move(ticks by_units) {
if (!g.ship.get() || !g.ship->active) {
return;
}
const Rect viewport = antares::viewport();
const Rect play_screen = antares::play_screen();
const fixedPointType slowVelocity = {
scale_by(g.ship->velocity.h * kSlowStarFraction * by_units.count(), gAbsoluteScale),
scale_by(g.ship->velocity.v * kSlowStarFraction * by_units.count(), gAbsoluteScale),
};
const fixedPointType mediumVelocity = {
scale_by(g.ship->velocity.h * kMediumStarFraction * by_units.count(), gAbsoluteScale),
scale_by(g.ship->velocity.v * kMediumStarFraction * by_units.count(), gAbsoluteScale),
};
const fixedPointType fastVelocity = {
scale_by(g.ship->velocity.h * kFastStarFraction * by_units.count(), gAbsoluteScale),
scale_by(g.ship->velocity.v * kFastStarFraction * by_units.count(), gAbsoluteScale),
};
for (scrollStarType* star : range(_stars, _stars + kScrollStarNum)) {
const fixedPointType* velocity;
switch (star->speed) {
case kSlowStarSpeed: velocity = &slowVelocity; break;
case kMediumStarSpeed: velocity = &mediumVelocity; break;
case kFastStarSpeed: velocity = &fastVelocity; break;
default:
case kNoStar: continue;
}
star->motionFraction.h += velocity->h;
star->motionFraction.v += velocity->v;
int32_t h;
if (star->motionFraction.h >= Fixed::zero()) {
h = more_evil_fixed_to_long(star->motionFraction.h + Fixed::from_float(0.5));
} else {
h = more_evil_fixed_to_long(star->motionFraction.h - Fixed::from_float(0.5)) + 1;
}
star->location.h += h;
star->motionFraction.h -= Fixed::from_long(h);
int32_t v;
if (star->motionFraction.v >= Fixed::zero()) {
v = more_evil_fixed_to_long(star->motionFraction.v + Fixed::from_float(0.5));
} else {
v = more_evil_fixed_to_long(star->motionFraction.v - Fixed::from_float(0.5)) + 1;
}
star->location.v += v;
star->motionFraction.v -= Fixed::from_long(v);
if ((star->location.h < viewport.left) && (star->oldLocation.h < viewport.left)) {
star->location.h += play_screen.width() - 1;
star->location.v = Randomize(play_screen.height()) + viewport.top;
star->motionFraction.h = star->motionFraction.v = Fixed::zero();
star->speed = RandomStarSpeed();
star->age = 0;
} else if (
(star->location.h >= viewport.right) && (star->oldLocation.h >= viewport.right)) {
star->location.h -= play_screen.width();
star->location.v = Randomize(play_screen.height()) + viewport.top;
star->motionFraction.h = star->motionFraction.v = Fixed::zero();
star->speed = RandomStarSpeed();
star->age = 0;
} else if ((star->location.v < viewport.top) && (star->oldLocation.v < viewport.top)) {
star->location.h = Randomize(play_screen.width()) + viewport.left;
star->location.v += play_screen.height() - 1;
star->motionFraction.h = star->motionFraction.v = Fixed::zero();
star->speed = RandomStarSpeed();
star->age = 0;
} else if (
(star->location.v >= play_screen.bottom) &&
(star->oldLocation.v >= play_screen.bottom)) {
star->location.h = Randomize(play_screen.width()) + viewport.left;
star->location.v -= play_screen.height();
star->motionFraction.h = star->motionFraction.v = Fixed::zero();
star->speed = RandomStarSpeed();
star->age = 0;
}
if (_warp_stars && (star->age == 0)) {
switch (star->speed) {
case kSlowStarSpeed: velocity = &slowVelocity; break;
case kMediumStarSpeed: velocity = &mediumVelocity; break;
case kFastStarSpeed: velocity = &fastVelocity; break;
case kNoStar: throw std::runtime_error("invalid value of star->speed.");
}
star->location.h -= mFixedToLong(velocity->h);
star->location.v -= mFixedToLong(velocity->v);
}
}
for (scrollStarType* star : range(_stars + kSparkStarOffset, _stars + kAllStarNum)) {
if (star->speed == kNoStar) {
continue;
}
star->age -= star->speed * by_units.count();
star->motionFraction.h += star->velocity.h * by_units.count() + slowVelocity.h;
star->motionFraction.v += star->velocity.v * by_units.count() + slowVelocity.v;
int32_t h;
if (star->motionFraction.h >= Fixed::zero()) {
h = more_evil_fixed_to_long(star->motionFraction.h + Fixed::from_float(0.5));
} else {
h = more_evil_fixed_to_long(star->motionFraction.h - Fixed::from_float(0.5)) + 1;
}
star->location.h += h;
star->motionFraction.h -= Fixed::from_long(h);
int32_t v;
if (star->motionFraction.v >= Fixed::zero()) {
v = more_evil_fixed_to_long(star->motionFraction.v + Fixed::from_float(0.5));
} else {
v = more_evil_fixed_to_long(star->motionFraction.v - Fixed::from_float(0.5)) + 1;
}
star->location.v += v;
star->motionFraction.v -= Fixed::from_long(v);
}
}