Initial commit

PkmnLib.Static/GrowthRate.cs

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+using PkmnLib.Static.Utils;
+
+namespace PkmnLib.Static;
+
+/// <summary>
+/// A growth rate defines how much experience is required per level.
+/// </summary>
+public interface IGrowthRate
+{
+    /// <summary>
+    /// The name of the growth rate.
+    /// </summary>
+    public StringKey Name { get; }
+
+    ///<summary>
+    /// Calculate the level something with this growth rate would have at a certain experience.
+    /// </summary>
+    /// <param name="experience">The experience to calculate the level for.</param>
+    /// <returns>The level at the given experience.</returns>
+    LevelInt CalculateLevel(uint experience);
+
+    ///<summary>
+    /// Calculate the experience something with this growth rate would have at a certain level.
+    /// </summary>
+    /// <param name="level">The level to calculate the experience for.</param>
+    /// <returns>The starting experience at the given level.</returns>
+    uint CalculateExperience(LevelInt level);
+}
+
+/// <summary>
+/// An implementation of the growth rate that uses a lookup table for experience.
+/// </summary>
+public class LookupGrowthRate : IGrowthRate
+{
+    /// <inheritdoc />
+    public StringKey Name { get; }
+
+    private readonly uint[] _experienceTable;
+
+    /// <inheritdoc cref="LookupGrowthRate" />
+    public LookupGrowthRate(StringKey name, IEnumerable<uint> experienceTable)
+    {
+        Name = name;
+        _experienceTable = experienceTable.ToArray();
+        if (_experienceTable.Length < 1)
+        {
+            throw new ArgumentException("Experience table must have at least one entry.");
+        }
+
+        if (_experienceTable[0] != 0)
+        {
+            throw new ArgumentException("Experience table must start at 0.");
+        }
+
+        if (_experienceTable.Length > LevelInt.MaxValue)
+        {
+            throw new ArgumentException($"Experience table may have at most {LevelInt.MaxValue} entries.");
+        }
+    }
+
+    /// <inheritdoc />
+    public LevelInt CalculateLevel(uint experience)
+    {
+        for (LevelInt level = 0; level < _experienceTable.Length; level++)
+        {
+            if (_experienceTable[level] > experience)
+            {
+                return level;
+            }
+        }
+
+        return (LevelInt)(_experienceTable.Length);
+    }
+
+    /// <inheritdoc />
+    public uint CalculateExperience(LevelInt level)
+    {
+        if (level < 1) level = 1;
+        return level >= _experienceTable.Length ? _experienceTable[^1] : _experienceTable[level - 1];
+    }
+}