gassy2.cs

using System;
using System.Linq;
using System.Collections.Generic;

public static class GasConstants
{
    const float OneAtmosphere = 101.325; // kPa
    const float IdealGasEquation = 8.31; // kPa*L/(K*mol)
    const float TemperatureCosmicMicrowaveBackround = 2.7; // K
}

public sealed class GasType
{
    public string Name { get; private set; }
    public string ShortName { get; private set; }
    public float SpecificHeat { get; private set; }
    public int GasIndex { get; private set; }

    private static int nextIndex = 0;
    private static GasType[] byIndex = new GasType[Types];
    public static GasType ByIndex(int index)
    {
        return byIndex[index];
    }

    private GasType(string name, string shortName, float specificHeat)
    {
        Name = name;
        ShortName = shortName;
        SpecificHeat = specificHeat;
        GasIndex = nextIndex++;
        byIndex[GasIndex] = this;
    }

    public static readonly GasType Oxygen = new GasType("oxygen", "O2", 20);
    public static readonly GasType Nitrogen = new GasType("nitrogen", "N", 20);
    public static readonly GasType Plasma = new GasType("plasma", "Pl", 300);
    public static readonly GasType NitrousOxide = new GasType("nitrous oxide", "N2O", 40);
    public static readonly GasType CarbonDioxide = new GasType("carbon dioxide", "CO2", 30);
    public static readonly int Types = 5; // Make sure this is always accurate.
}

public class GasMixture
{
    private float[] moles = new float[GasType.Types];
    private float temperature = GasConstants.TemperatureCosmicMicrowaveBackround;

    // Moles
    public float this[GasType type] {
        get {
            return moles[type.GasIndex];
        }
        set
        {
            moles[type.GasIndex] = Math.Max(0, value);
        }
    }

    // Returns in K
    public float Temperature {
        get { return temperature; }
        set { temperature = Math.Max(value, GasConstants.TemperatureCosmicMicrowaveBackround); }
    }

    // Returns in kPa, volume in L
    public float Pressure(float volume)
    {
        return moles.Sum() * GasConstants.IdealGasEquation * temperature / volume;
    }

    public float HeatCapacity()
    {
        return moles.Select((moles, index) => moles < float.Epsilon ? 0 : moles * GasType.ByIndex(index).SpecificHeat).Sum();
    }

    //public void AddGas(GasMixture otherMixture) { ... }

    public void MoveGas(GasMixture otherMixture, float percentage) { ... }
}