using System; using static System.Buffers.Binary.BinaryPrimitives; namespace PKHeX.Core { /// /// Unpacks data from legality binary inputs. /// public static class LearnsetReader { private static readonly Learnset EMPTY = new(Array.Empty(), Array.Empty()); /// /// Loads a learnset using the 8-bit-per-move storage structure used by Generation 1 & 2 games. /// /// Raw ROM data containing the contiguous moves /// Highest species ID for the input game. public static Learnset[] GetArray(byte[] input, int maxSpecies) { var data = new Learnset[maxSpecies + 1]; int offset = 0; for (int s = 0; s < data.Length; s++) data[s] = ReadLearnset8(input, ref offset); return data; } /// /// Loads a learnset by reading 16-bit move,level pairs. /// /// Entry data public static Learnset[] GetArray(byte[][] entries) { Learnset[] data = new Learnset[entries.Length]; for (int i = 0; i < data.Length; i++) data[i] = ReadLearnset16(entries[i]); return data; } /// /// Reads a Level up move pool definition from a contiguous chunk of GB era ROM data. /// /// Moves and Levels are 8-bit private static Learnset ReadLearnset8(ReadOnlySpan data, ref int offset) { int end = offset; // scan for count if (data[end] == 0) { ++offset; return EMPTY; } do { end += 2; } while (data[end] != 0); var Count = (end - offset) / 2; var Moves = new int[Count]; var Levels = new int[Count]; for (int i = 0; i < Moves.Length; i++) { Levels[i] = data[offset++]; Moves[i] = data[offset++]; } ++offset; return new Learnset(Moves, Levels); } /// /// Reads a Level up move pool definition from a single move pool definition. /// /// Count of moves, followed by Moves and Levels which are 16-bit private static Learnset ReadLearnset16(ReadOnlySpan data) { if (data.Length == 0) return EMPTY; var Count = (data.Length / 4) - 1; var Moves = new int[Count]; var Levels = new int[Count]; for (int i = 0; i < Count; i++) { var move = data.Slice(i * 4, 4); Moves[i] = ReadInt16LittleEndian(move); Levels[i] = ReadInt16LittleEndian(move[2..]); } return new Learnset(Moves, Levels); } } }