Files
tbd-station-14/Content.Shared/Camera/CameraRecoilSystem.cs
metalgearsloth b87806f7ed Fix some build warnings (#6832)
Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>
2022-02-21 14:41:50 +11:00

133 lines
4.5 KiB
C#

using System;
using JetBrains.Annotations;
using Robust.Shared.GameObjects;
using Robust.Shared.Log;
using Robust.Shared.Maths;
using Robust.Shared.Player;
using Robust.Shared.Serialization;
namespace Content.Shared.Camera;
[UsedImplicitly]
public sealed class CameraRecoilSystem : EntitySystem
{
/// <summary>
/// Maximum rate of magnitude restore towards 0 kick.
/// </summary>
private const float RestoreRateMax = 15f;
/// <summary>
/// Minimum rate of magnitude restore towards 0 kick.
/// </summary>
private const float RestoreRateMin = 1f;
/// <summary>
/// Time in seconds since the last kick that lerps RestoreRateMin and RestoreRateMax
/// </summary>
private const float RestoreRateRamp = 0.1f;
/// <summary>
/// The maximum magnitude of the kick applied to the camera at any point.
/// </summary>
private const float KickMagnitudeMax = 2f;
private readonly ISawmill _log;
private CameraRecoilSystem(IEntityManager entityManager)
: base(entityManager)
{
_log = Logger.GetSawmill($"ecs.systems.{nameof(CameraRecoilSystem)}");
SubscribeNetworkEvent<CameraKickEvent>(HandleCameraKick);
}
/// <summary>
/// Applies explosion/recoil/etc kickback to the view of the entity.
/// </summary>
/// <remarks>
/// If the entity is missing <see cref="CameraRecoilComponent" /> and/or <see cref="SharedEyeComponent" />,
/// this call will have no effect. It is safe to call this function on any entity.
/// </remarks>
/// <param name="euid">Entity to apply the kickback to.</param>
/// <param name="kickback">The amount of kick to offset the view of the entity. World coordinates, in meters.</param>
public void KickCamera(EntityUid euid, Vector2 kickback)
{
if (!EntityManager.HasComponent<CameraRecoilComponent>(euid))
return;
//TODO: This should only be sent to clients registered as viewers to the entity.
RaiseNetworkEvent(new CameraKickEvent(euid, kickback), Filter.Broadcast());
}
public override void FrameUpdate(float frameTime)
{
base.FrameUpdate(frameTime);
foreach (var entity in EntityManager.EntityQuery<SharedEyeComponent, CameraRecoilComponent>(true))
{
var recoil = entity.Item2;
var eye = entity.Item1;
var magnitude = recoil.CurrentKick.Length;
if (magnitude <= 0.005f)
{
recoil.CurrentKick = Vector2.Zero;
eye.Offset = recoil.BaseOffset + recoil.CurrentKick;
}
else // Continually restore camera to 0.
{
var normalized = recoil.CurrentKick.Normalized;
recoil.LastKickTime += frameTime;
var restoreRate = MathHelper.Lerp(RestoreRateMin, RestoreRateMax, Math.Min(1, recoil.LastKickTime / RestoreRateRamp));
var restore = normalized * restoreRate * frameTime;
var (x, y) = recoil.CurrentKick - restore;
if (Math.Sign(x) != Math.Sign(recoil.CurrentKick.X)) x = 0;
if (Math.Sign(y) != Math.Sign(recoil.CurrentKick.Y)) y = 0;
recoil.CurrentKick = (x, y);
eye.Offset = recoil.BaseOffset + recoil.CurrentKick;
}
}
}
private void HandleCameraKick(CameraKickEvent args)
{
if (!EntityManager.TryGetComponent(args.Euid, out CameraRecoilComponent recoil))
{
_log.Warning($"Received a kick for euid {args.Euid}, but it is missing required components.");
return;
}
if (!float.IsFinite(args.Recoil.X) || !float.IsFinite(args.Recoil.Y))
{
_log.Error($"CameraRecoilComponent on entity {recoil.Owner} passed a NaN recoil value. Ignoring.");
return;
}
// Use really bad math to "dampen" kicks when we're already kicked.
var existing = recoil.CurrentKick.Length;
var dampen = existing / KickMagnitudeMax;
recoil.CurrentKick += args.Recoil * (1 - dampen);
if (recoil.CurrentKick.Length > KickMagnitudeMax)
recoil.CurrentKick = recoil.CurrentKick.Normalized * KickMagnitudeMax;
recoil.LastKickTime = 0;
}
}
[Serializable]
[NetSerializable]
public sealed class CameraKickEvent : EntityEventArgs
{
public readonly EntityUid Euid;
public readonly Vector2 Recoil;
public CameraKickEvent(EntityUid euid, Vector2 recoil)
{
Recoil = recoil;
Euid = euid;
}
}