public void Tick(World world)
{
if (anim != null)
{
anim.Tick();
}
pos = WPos.LerpQuadratic(args.Source, target, angle, ticks, length);
if (!string.IsNullOrEmpty(info.Trail) && --smokeTicks < 0)
{
var delayedPos = WPos.LerpQuadratic(args.Source, target, angle, ticks - info.TrailDelay, length);
world.AddFrameEndTask(w => w.Add(new Smoke(w, delayedPos, info.Trail, trailPalette, info.Sequences.Random(world.SharedRandom))));
smokeTicks = info.TrailInterval;
}
if (info.ContrailLength > 0)
{
contrail.Update(pos);
}
var shouldExplode = ticks++ >= length || // Flight length reached/exceeded
(info.Blockable && BlocksProjectiles.AnyBlockingActorAt(world, pos)); // Hit a wall or other blocking obstacle
if (shouldExplode)
{
Explode(world);
}
}
public void Tick(World world)
{
ticks++;
if (anim != null)
{
anim.Tick();
}
// Switch from freefall mode to homing mode
if (ticks == info.HomingActivationDelay + 1)
{
state = States.Homing;
speed = velocity.Length;
// Compute the vertical loop radius
loopRadius = LoopRadius(speed, info.VerticalRateOfTurn);
}
// Switch from homing mode to freefall mode
if (info.RangeLimit != 0 && ticks == info.RangeLimit + 1)
{
state = States.Freefall;
velocity = new WVec(0, -speed, 0)
.Rotate(new WRot(WAngle.FromFacing(vFacing), WAngle.Zero, WAngle.Zero))
.Rotate(new WRot(WAngle.Zero, WAngle.Zero, WAngle.FromFacing(hFacing)));
}
// Check if target position should be updated (actor visible & locked on)
var newTarPos = targetPosition;
if (args.GuidedTarget.IsValidFor(args.SourceActor) && lockOn)
{
newTarPos = args.GuidedTarget.CenterPosition
+ new WVec(WDist.Zero, WDist.Zero, info.AirburstAltitude);
}
// Compute target's predicted velocity vector (assuming uniform circular motion)
var fac1 = OpenRA.Traits.Util.GetFacing(tarVel, hFacing);
tarVel = newTarPos - targetPosition;
var fac2 = OpenRA.Traits.Util.GetFacing(tarVel, hFacing);
predVel = tarVel.Rotate(WRot.FromFacing(fac2 - fac1));
targetPosition = newTarPos;
// Compute current distance from target position
var tarDistVec = targetPosition + offset - pos;
var relTarDist = tarDistVec.Length;
var relTarHorDist = tarDistVec.HorizontalLength;
WVec move;
if (state == States.Freefall)
{
move = FreefallTick();
}
else
{
move = HomingTick(world, tarDistVec, relTarHorDist);
}
renderFacing = WAngle.ArcTan(move.Z - move.Y, move.X).Angle / 4 - 64;
// Move the missile
pos += move;
// Create the smoke trail effect
if (!string.IsNullOrEmpty(info.TrailImage) && --ticksToNextSmoke < 0 && (state != States.Freefall || info.TrailWhenDeactivated))
{
world.AddFrameEndTask(w => w.Add(new Smoke(w, pos - 3 * move / 2, info.TrailImage, trailPalette, info.TrailSequence)));
ticksToNextSmoke = info.TrailInterval;
}
if (info.ContrailLength > 0)
{
contrail.Update(pos);
}
var cell = world.Map.CellContaining(pos);
// NOTE: High speeds might cause the missile to miss the target or fly through obstacles
// In that case, big moves should probably be decomposed into multiple smaller ones with hit checks
var height = world.Map.DistanceAboveTerrain(pos);
var shouldExplode = (height.Length < 0) || // Hit the ground
(relTarDist < info.CloseEnough.Length) || // Within range
(info.ExplodeWhenEmpty && info.RangeLimit != 0 && ticks > info.RangeLimit) || // Ran out of fuel
(info.Blockable && BlocksProjectiles.AnyBlockingActorAt(world, pos)) || // Hit a wall or other blocking obstacle
!world.Map.Contains(cell) || // This also avoids an IndexOutOfRangeException in GetTerrainInfo below.
(!string.IsNullOrEmpty(info.BoundToTerrainType) && world.Map.GetTerrainInfo(cell).Type != info.BoundToTerrainType) || // Hit incompatible terrain
(height.Length < info.AirburstAltitude.Length && relTarHorDist < info.CloseEnough.Length); // Airburst
if (shouldExplode)
{
Explode(world);
}
}
