tbd-station-14/Content.Server/GameObjects/Components/Weapon/Ranged/Hitscan/HitscanWeaponComponent.cs

using SS14.Server.GameObjects;
using SS14.Server.GameObjects.EntitySystems;
using SS14.Shared.GameObjects;
using SS14.Shared.GameObjects.EntitySystemMessages;
using SS14.Shared.Interfaces.GameObjects;
using SS14.Shared.Interfaces.Physics;
using SS14.Shared.Interfaces.Timing;
using SS14.Shared.IoC;
using SS14.Shared.Map;
using SS14.Shared.Maths;
using SS14.Shared.Physics;
using System;

namespace Content.Server.GameObjects.Components.Weapon.Ranged.Hitscan
{
    public class HitscanWeaponComponent : RangedWeaponComponent
    {
        public override string Name => "HitscanWeapon";

        string spritename = "laser";
        
        protected override void Fire(IEntity user, LocalCoordinates clicklocation)
        {
            var userposition = user.GetComponent<TransformComponent>().WorldPosition; //Remember world positions are ephemeral and can only be used instantaneously
            var angle = new Angle(clicklocation.Position - userposition);
            var theta = angle.Theta;
            
            var ray = new Ray(userposition, angle.ToVec());
            var raycastresults = IoCManager.Resolve<ICollisionManager>().IntersectRay(ray, 20, Owner.GetComponent<TransformComponent>().GetMapTransform().Owner);

            Hit(raycastresults);
            AfterEffects(user, raycastresults, theta);
        }

        protected virtual void Hit(RayCastResults ray)
        {
            if(ray.HitEntity != null && ray.HitEntity.TryGetComponent(out DamageableComponent damage))
            {
                damage.TakeDamage(DamageType.Heat, 10);
            }
        }
        
        protected virtual void AfterEffects(IEntity user, RayCastResults ray, double theta)
        {
            var time = IoCManager.Resolve<IGameTiming>().CurTime;
            EffectSystemMessage message = new EffectSystemMessage
            {
                EffectSprite = spritename,
                Born = time,
                DeathTime = time + TimeSpan.FromSeconds(1),
                Size = new Vector2(ray.Distance, 1f),
                Coordinates = user.GetComponent<TransformComponent>().LocalPosition,
                //Rotated from east facing
                Rotation = (float)theta,
                ColorDelta = new Vector4(0, 0, 0, -1500f),
                Color = new Vector4(255,255,255,750)
            };
            IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<EffectSystem>().CreateParticle(message);
        }
    }
}