tbd-station-14/Content.Server/Contests/ContestsSystem.cs

using Content.Shared.Damage;
using Content.Shared.MobState.EntitySystems;
using Content.Shared.MobState.Components;
using Content.Server.Damage.Components;

namespace Content.Server.Contests
{
    /// <summary>
    /// Standardized contests.
    /// A contest is figuring out, based on data in components on two entities,
    /// which one has an advantage in a situation. The advantage is expressed by a multiplier.
    /// 1 = No advantage to either party.
    /// >1 = Advantage to roller
    /// <1 = Advantage to target
    /// Roller should be the entity with an advantage from being bigger/healthier/more skilled, etc.
    /// <summary>
    public sealed class ContestsSystem : EntitySystem
    {
        [Dependency] private readonly SharedMobStateSystem _mobStateSystem = default!;

        /// <summary>
        /// Returns the roller's mass divided by the target's.
        /// </summary>
        public float MassContest(EntityUid roller, EntityUid target, PhysicsComponent? rollerPhysics = null, PhysicsComponent? targetPhysics = null)
        {
            if (!Resolve(roller, ref rollerPhysics) || !Resolve(target, ref targetPhysics))
                return 1f;

            if (rollerPhysics == null || targetPhysics == null)
                return 1f;

            if (targetPhysics.FixturesMass == 0)
                return 1f;

            return (rollerPhysics.FixturesMass / targetPhysics.FixturesMass);
        }

        /// <summary>
        /// Tries to compare both entities damage to the damage they will enter crit at.
        /// After that, it runs the % towards crit through a converter that smooths out and makes
        /// the the ratios less severe.
        /// Returns the roller's adjusted damage value divided by the target's. Higher is better for the roller.
        /// <summary>
        public float DamageContest(EntityUid roller, EntityUid target, DamageableComponent? rollerDamage = null, DamageableComponent? targetDamage = null)
        {
            if (!Resolve(roller, ref rollerDamage) || !Resolve(target, ref targetDamage))
                return 1f;

            if (rollerDamage == null || targetDamage == null)
                return 1f;

            // First, we'll see what health they go into crit at.
            float rollerThreshold = 100f;
            float targetThreshold = 100f;

            if (TryComp<MobStateComponent>(roller, out var rollerState) && rollerState != null &&
                _mobStateSystem.TryGetEarliestIncapacitatedState(rollerState, 10000, out _, out var rollerCritThreshold))
                rollerThreshold = (float) rollerCritThreshold;

            if (TryComp<MobStateComponent>(target, out var targetState) && targetState != null &&
                _mobStateSystem.TryGetEarliestIncapacitatedState(targetState, 10000, out _, out var targetCritThreshold))
                targetThreshold = (float) targetCritThreshold;

            // Next, we'll see how their damage compares
            float rollerDamageScore = (float) rollerDamage.TotalDamage / rollerThreshold;
            float targetDamageScore = (float) targetDamage.TotalDamage / targetThreshold;

            return DamageThresholdConverter(rollerDamageScore) / DamageThresholdConverter(targetDamageScore);
        }

        /// <summary>
        /// Finds the % of each entity's stamina damage towards its stam crit threshold.
        /// It then runs the % towards the converter to smooth/soften it.
        /// Returns the roller's decimal % divided by the target's. Higher value is better for the roller.
        /// <summary>
        public float StaminaContest(EntityUid roller, EntityUid target, StaminaComponent? rollerStamina = null, StaminaComponent? targetStamina = null)
        {
            if (!Resolve(roller, ref rollerStamina) || !Resolve(target, ref targetStamina))
                return 1f;

            if (rollerStamina == null || targetStamina == null)
                return 1f;

            var rollerDamageScore= rollerStamina.StaminaDamage / rollerStamina.CritThreshold;
            var targetDamageScore = targetStamina.StaminaDamage / targetStamina.CritThreshold;

            return DamageThresholdConverter(rollerDamageScore) / DamageThresholdConverter(targetDamageScore);
        }

        /// <summary>
        /// This will compare the roller and target's damage, mass, and stamina. See the functions for what each one does.
        /// You can change the 'weighting' to make the tests weigh more or less than the other tests.
        /// Returns a weighted average of all 3 tests.
        /// <summary>
        public float OverallStrengthContest(EntityUid roller, EntityUid target, float damageWeight = 1f, float massWeight = 1f, float stamWeight = 1f)
        {
            var weightTotal = damageWeight + massWeight + stamWeight;
            var damageMultiplier = damageWeight / weightTotal;
            var massMultiplier = massWeight / weightTotal;
            var stamMultiplier = stamWeight / weightTotal;

            return ((DamageContest(roller, target) * damageMultiplier) + (MassContest(roller, target) * massMultiplier)
                    + (StaminaContest(roller, target) * stamMultiplier));
        }

        /// <summary>
        /// This softens out the huge advantages that damage contests would lead to otherwise.
        /// Once you are crit or near crit, we just let the massive advantages roll with what could be a 20x.
        /// </summary>
        public float DamageThresholdConverter(float score)
        {
            return score switch
            {
                <= 0 => 1f,
                <= 0.25f => 0.9f,
                <= 0.5f => 0.75f,
                <= 0.75f => 0.6f,
                <= 0.95f => 0.45f,
                _ => 0.05f
            };
        }
    }
}