void AI::DoScatter(Ship &ship, Command &command, const list<shared_ptr<Ship>> &ships)
{
if(!command.Has(Command::FORWARD))
return;
double turnRate = ship.TurnRate();
double acceleration = ship.Acceleration();
for(const shared_ptr<Ship> &other : ships)
{
if(other.get() == &ship)
continue;
// Check for any ships that have nearly the same movement profile as
// this ship and are in nearly the same location.
Point offset = other->Position() - ship.Position();
if(offset.LengthSquared() > 400.)
continue;
if(fabs(other->TurnRate() / turnRate - 1.) > .05)
continue;
if(fabs(other->Acceleration() / acceleration - 1.) > .05)
continue;
// Move away from this ship. What side of me is it on?
command.SetTurn(offset.Cross(ship.Facing().Unit()) > 0. ? 1. : -1.);
return;
}
}
DrawList::Item::Item(const Animation &animation, Point pos, Point unit, Point blur, float clip, int step)
: position{static_cast<float>(pos.X()), static_cast<float>(pos.Y())},
clip(clip), flags(animation.GetSwizzle())
{
Animation::Frame frame = animation.Get(step);
tex0 = frame.first;
tex1 = frame.second;
flags |= static_cast<uint32_t>(frame.fade * 256.f) << 8;
double width = animation.Width();
double height = animation.Height();
Point uw = unit * width;
Point uh = unit * height;
if(clip < 1.)
{
// "clip" is the fraction of its height that we're clipping the sprite
// to. We still want it to start at the same spot, though.
pos -= uh * ((1. - clip) * .5);
position[0] = static_cast<float>(pos.X());
position[1] = static_cast<float>(pos.Y());
uh *= clip;
}
// (0, -1) means a zero-degree rotation (since negative Y is up).
transform[0] = -uw.Y();
transform[1] = uw.X();
transform[2] = -uh.X();
transform[3] = -uh.Y();
// Calculate the blur vector, in texture coordinates. This should be done by
// projecting the blur vector onto the unit vector and then scaling it based
// on the sprite size. But, the unit vector first has to be normalized (i.e.
// divided by the unit vector length), and the sprite size also has to be
// multiplied by the unit vector size, so:
double zoomCorrection = 4. * unit.LengthSquared();
this->blur[0] = unit.Cross(blur) / (width * zoomCorrection);
this->blur[1] = -unit.Dot(blur) / (height * zoomCorrection);
}