public CCMyRotateToState(CCMyRotateTo action, CCNode target)
: base(action, target)
{
FinalAngle = action.FinalAngle;
StartAngle = ((IGameObject)target).MyRotation;
// Now we work out how far we actually have to rotate
DiffAngle = Constants.AngleFromToDeg(StartAngle, FinalAngle);
}
public void RotateTowards(float angle, float maxRotationAngle)
{
float currentRotation = MyRotation;
float difference = Constants.AngleFromToDeg(currentRotation, angle);
if ((float)Math.Abs(difference) <= maxRotationAngle)
{
MyRotation = angle;
}
else
{
MyRotation += maxRotationAngle * Math.Sign(difference);
}
}
/// <summary>
/// Returns the (relative) rotation angle (for MyRotation) indicating how far into which direction the weapon
/// should be turned to be able to hit the target perfectly.
/// </summary>
/// <returns></returns>
internal float AngleToAimFor()
{
// as there is no exact solution the solution is here approched by iteration
CCPoint TargetToMyPart = MyPart.PositionWorldspace - TargetPart.PositionWorldspace;
// rotate the vector, so that the movement direction of the target is identical to the x axis
float transformationRotation = -Constants.DxDyToRadians(TargetAircraft.VelocityVector.X, TargetAircraft.VelocityVector.Y);
TargetToMyPart = CCPoint.RotateByAngle(TargetToMyPart, CCPoint.Zero, transformationRotation);
// now the cordinate system is simpler and we can compute the difference between
// a) the intersection of the flight path and the bullet path
// and b) the point where the target actually is going to be by then
// of course we want to minimize this error, for this we will iterate
// ITERATION USING THE BISECTION METHOD
double epsilon = 1;
double angle = 0;
// define the interval
double startAngle = Constants.DxDyToRadians(-TargetToMyPart.X, -TargetToMyPart.Y);
double endAngle = 0;
float totalBulletVelocity = ProjectileBlueprint.Velocity + AircraftVelocityBoost();
double deltaStart = TargetToMyPart.X - TargetToMyPart.Y / Math.Tan(startAngle) + (TargetToMyPart.Y * TargetAircraft.VelocityVector.Length) / (Math.Sin(startAngle) * totalBulletVelocity);
for (int i = 0; i < 6; i++) // iterate 6 times at max
{
angle = (startAngle + endAngle) / 2;
double delta = TargetToMyPart.X - TargetToMyPart.Y / Math.Tan(angle) + (TargetToMyPart.Y * TargetAircraft.VelocityVector.Length) / (Math.Sin(angle) * totalBulletVelocity);
if (Math.Abs(delta) < epsilon) // you're close enough so break already
break;
// delta is negative when the bullet hits behind the part -> angle needs to be closer to 0
if (Math.Sign(deltaStart) == Math.Sign(delta))
{
startAngle = angle;
deltaStart = delta;
}
else
{
endAngle = angle;
}
}
// subtract the transformation rotation to get the total angle
float totalAngle = Constants.RadiansToCCDegrees((float)angle - transformationRotation);
// for the final angle transform the total angle to a relative angle
return Constants.AngleFromToDeg(((IGameObject)MyPart.Parent).TotalRotation, totalAngle);
}
internal void PartsInRange(out List<Part> partsInRange, out List<float> anglesFromTo, out List<float> distances)
{
// collect aircrafts that are near enough to have parts which could be targets
List<Aircraft> aircraftsInRange = new List<Aircraft>();
foreach (var aircraft in (MyPart.Aircraft.Team == Team.PlayerTeam ? ((PlayLayer)MyPart.Layer).ActiveAircrafts : ((PlayLayer)MyPart.Layer).PlayerAircrafts)) // a bit dirty since technically NPC allies to the player could exist (someday), which would not be contained in PlayerAircrafts, but which would still (maybe) be part of the player team
{
// check if it is considered an enemy
if (!MyPart.Aircraft.Team.IsEnemy(aircraft.Team) || aircraft.MyState.Equals(Aircraft.State.SHOT_DOWN))
continue;
// check if in attention arc
if (Collisions.CollideArcBoundingBox(MyPart.PositionWorldspace, AttentionRange, MyPart.TotalNullRotation, AttentionAngle, aircraft.BoundingBoxTransformedToWorld))
aircraftsInRange.Add(aircraft);
}
partsInRange = new List<Part>();
anglesFromTo = new List<float>();
distances = new List<float>();
foreach (var aircraft in aircraftsInRange)
{
foreach (var part in aircraft.TotalParts)
{
if (part.MyState == Part.State.DESTROYED) continue;
// using the position as criterium is a bit dirty and could be improved on by using the bounding box instead (at the cost of performance)
CCPoint vectorMyPartPart = part.PositionWorldspace - MyPart.PositionWorldspace;
float distance = vectorMyPartPart.Length;
if (distance <= AttentionRange)
{
var angleFromTo = Constants.AngleFromToDeg(MyPart.TotalRotation - MyPart.RotationFromNull, Constants.DxDyToCCDegrees(vectorMyPartPart.X, vectorMyPartPart.Y));
if ((float)Math.Abs(angleFromTo) <= AttentionAngle)
{
partsInRange.Add(part);
anglesFromTo.Add(Constants.AngleFromToDeg(MyPart.TotalRotation, Constants.DxDyToCCDegrees(vectorMyPartPart.X, vectorMyPartPart.Y)));
distances.Add(distance);
}
}
}
}
}
/// <summary>
/// called by the Aircraft owning the part owning this WeaponAbility each frame
/// </summary>
/// <param name="dt">time since the previous frame</param>
internal void ExecuteOrders(float dt)
{
// cool down
CooldownUntilNextShot -= dt;
CooldownUntilNextTargetUpdate -= dt;
if (CooldownUntilNextShot < 0) CooldownUntilNextShot = 0;
// if you have a target check if it is still in range
if (TargetPart != null)
{
CCPoint vectorMyPartTarget = TargetPart.PositionWorldspace - MyPart.PositionWorldspace;
if (TargetPart.MyState == Part.State.DESTROYED || (TargetAircraft != null && TargetAircraft.MyState == Aircraft.State.SHOT_DOWN)
|| CooldownUntilNextTargetUpdate <= 0
|| CCPoint.Distance(MyPart.PositionWorldspace, TargetPart.PositionWorldspace) > AttentionRange
|| Constants.AbsAngleDifferenceDeg(MyPart.TotalRotation - MyPart.RotationFromNull, Constants.DxDyToCCDegrees(vectorMyPartTarget.X, vectorMyPartTarget.Y)) > AttentionAngle)
TargetPart = null;
}
if (TargetPart == null && CooldownUntilNextTargetUpdate <= 0) // if you currently do not aim at anything search for a target
{
CooldownUntilNextTargetUpdate = UpdateTargetDelay;
// collect aircrafts that are near enough to have parts which could be targets
// go through the parts of all of these planes and collect those that are in the attention angle
PartsInRange(out List<Part> partsInRange, out List<float> anglesFromTo, out List<float> distances);
// try to choose a part that is in reach
// choose the part that is closest anglewise
// but prioritize aircraft bodies:
// this means that you should only change target from a body to another part if the part you would choose instead (because it's closer)
// belongs to another plane
float minAngle = float.PositiveInfinity;
for (int i=0; i<partsInRange.Count(); i++)
{
if (distances[i] <= ShootingRange) // first only try parts that are already in reach
{
float absAngle = (float)Math.Abs(anglesFromTo[i]);
var part = partsInRange[i];
if (absAngle < minAngle) //&&
//(TargetPart == null || !(part.Parent == TargetPart.Parent && TargetPart == TargetAircraft.Body))) // don't switch from a body to a different part of the same aircraft
{
TargetPart = part;
minAngle = absAngle;
}
}
}
if (TargetPart == null) // if you found no target this way check the rest
{
minAngle = float.PositiveInfinity;
for (int i = 0; i < partsInRange.Count(); i++)
{
float absAngle = (float)Math.Abs(anglesFromTo[i]);
var part = partsInRange[i];
// now also try parts that are not already in reach
if (absAngle < minAngle) //&&
//(TargetPart == null || !(part.Parent == TargetPart.Parent && TargetPart == TargetAircraft.Body))) // don't switch from a body to a different part of the same aircraft
{
TargetPart = part;
minAngle = absAngle;
}
}
}
}
// calculate the perfect point to aim for in order to hit the target
if (TargetPart != null)
{
float angleToAimFor = AngleToAimFor();
if (!(MyPart is WingJet)) // a dirty fix to make sure jet wings don't rotate since rotation screws up the flip state; for other weapons this effect can be neglected since it is only visual
{
float angleToTurnTo = angleToAimFor;
float angleTurn = Constants.AngleFromToDeg(MyPart.NullRotation, angleToTurnTo);
// make sure you don't rotate further than your MountPoint allows
if (angleTurn > MyPart.MountPoint.MaxTurningAngle)
angleToTurnTo = MyPart.NullRotation + MyPart.MountPoint.MaxTurningAngle;
else if (angleTurn < -MyPart.MountPoint.MaxTurningAngle)
angleToTurnTo = MyPart.NullRotation - MyPart.MountPoint.MaxTurningAngle;
// make sure you don't rotate further than this weapons MaxTurningAngle allows
if (MaxTurningAngle < MyPart.MountPoint.MaxTurningAngle)
{
if (angleTurn > MaxTurningAngle)
angleToTurnTo = MyPart.NullRotation + MaxTurningAngle;
else if (angleTurn < -MaxTurningAngle)
angleToTurnTo = MyPart.NullRotation - MaxTurningAngle;
}
MyPart.RotateTowards(angleToTurnTo, TurningAnglePerSecond * dt);
}
// if you're now close enough to the perfect angle (and in range) start shooting
if (CanShoot()
&& CCPoint.Distance(MyPart.PositionWorldspace, TargetPart.PositionWorldspace) <= ShootingRange
&& (Constants.AbsAngleDifferenceDeg(angleToAimFor, MyPart.MyRotation) <= ToleratedError || WouldHit()))
{
TryShoot();
}
}
// and if you have no target try to get back to NullRotation
else if (!(MyPart is WingJet))
{
MyPart.RotateTowards(MyPart.NullRotation, TurningAnglePerSecond * dt);
}
}
private float AircraftVelocityBoost()
{
return MyPart.Aircraft.VelocityVector.Length * (float)Math.Cos(Constants.CCDegreesToMathRadians(Constants.AngleFromToDeg(MyPart.TotalRotation, MyPart.Aircraft.TotalRotation)));
}
