From ba64e2bcf398cb4f58ab425e02fbbe1ce56892e9 Mon Sep 17 00:00:00 2001
From: "A.M. Rowsell" <amrowsell@frozenelectronics.ca>
Date: Sun, 3 Aug 2025 13:11:30 -0400
Subject: [PATCH] dev: Continue to write the chess logic, working through it
 bit by bit

---
 Board.cpp | 25 +++++++++++++++++++++++--
 Board.hpp |  7 ++++---
 Piece.cpp | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 Piece.hpp | 25 ++++++++++++++++++-------
 4 files changed, 96 insertions(+), 15 deletions(-)

diff --git a/Board.cpp b/Board.cpp
index ba4c3d2..7f4bdc4 100644
--- a/Board.cpp
+++ b/Board.cpp
@@ -13,8 +13,29 @@ Board::Board() {
     boardGrid.resize(8);
     for(int i = 0; i < 8; i++) {
         boardGrid[i].resize(8);
-        for(int j = 0; j < 8; j++) {
-            boardGrid[i][j] = std::make_unique<Piece>(PIECE_EMPTY);
+        switch(i) {
+            case 0:
+                // white back rank
+                break;
+            case 1:
+                // white pawn rank
+                break;
+            case 2:
+            case 3:
+            case 4:
+            case 5:
+                //empty squares
+                for(int j = 0; j <= 8; j++) {
+                    boardGrid[i][j] = std::make_unique<Piece>(PIECE_EMPTY);
+                }
+                break;
+            case 6:
+                // black pawn rank
+                break;
+            case 7:
+                // black back rank
+            default:
+                break;
         }
     }
 }
diff --git a/Board.hpp b/Board.hpp
index 179f554..6ce56fb 100644
--- a/Board.hpp
+++ b/Board.hpp
@@ -24,11 +24,12 @@ private:
 
 public:
   Board();
-  ~Board();
+  virtual ~Board();
   void setupInitialPosition();
-  Piece *getPieceAt(int x, int y) const;
+  Piece *getPieceAt(Square square) const;
   void movePiece(Square from, Square to);
-  bool isInBounds(int x, int y) const;
+  bool isInBounds(Square square) const;
+  bool isEmpty(Square square) const;
   uint64_t serialBoard = 0xFFFF00000000FFFF; // opening position
   void deserializeBoard(uint64_t incomingBoard);
 };
diff --git a/Piece.cpp b/Piece.cpp
index d6fc084..1dd616a 100644
--- a/Piece.cpp
+++ b/Piece.cpp
@@ -7,9 +7,57 @@
 
 #include "Piece.hpp"
 
-std::vector<std::pair<int, int>> King::getLegalMoves(int x, int y, const Board& board) const {
-    std::vector<std::pair<int, int>> moveList;
-    
+Piece::~Piece() {
+    return;
+}
+
+// because the Piece class is instantiated in another class using
+// unique_ptr, non-pure virtual functions apparently *must*
+// have definitions, or the linker freaks out
+// so this is just a stub that does nothing. it doesn't matter
+// because only the derived class versions should be called.
+
+std::vector<Move> Piece::getLegalMoves(const Square &from, const Board &board) const {
+    std::vector<Move> moveList;
+    return moveList;
+}
+
+std::vector<Move> King::getLegalMoves(const Square &from, const Board &board) const {
+    std::vector<Move> moveList;
+
+}
+
+std::vector<Move> Rook::getLegalMoves(const Square &from, const Board &board) const {
+    std::vector<Move> moveList;
+    const int directions[8][2] = {
+        {-1, 0}, // Up
+        {1, 0}, // Down
+        {0, -1}, // Left
+        {0, 1} // Right
+    };
+    for (auto& dir : directions) {
+        int r = from.rank + dir[0];
+        int f = from.file + dir[1];
+
+        while (r >= 0 && r < 8 && f >= 0 && f < 8) {
+            const auto& target = board[r][f];
+
+            if (!target) {
+                moves.push_back({from,
+                    {r, f}});
+            } else if (target->color != this->color) {
+                moves.push_back({from,
+                    {r, f}});
+                break;
+            } else {
+                break;
+            }
+
+            r += dir[0];
+            f += dir[1];
+        }
+    }
+
     // calculate legal moves somehow
     return moveList;
 }
diff --git a/Piece.hpp b/Piece.hpp
index 2501557..cbd602f 100644
--- a/Piece.hpp
+++ b/Piece.hpp
@@ -9,7 +9,7 @@
 #define PIECE_HPP
 #pragma once
 
-#include <stdint.h>
+#include <cstdint>
 #include <utility>
 #include <memory>
 #include <vector>
@@ -18,13 +18,19 @@ class Board;
 
 enum PieceType { PAWN, BISHOP, KNIGHT, ROOK, QUEEN, KING, EMPTY };
 enum PieceColour { PIECE_WHITE, PIECE_BLACK, PIECE_EMPTY };
-enum Rank { R1 = 1, R2 = 2, R3 = 3, R4 = 4, R5 = 5, R6 = 6, R7 = 7, R8 = 8 };
-enum File { A, B, C, D, E, F, G, H };
+enum Rank { R1 = 0, R2 = 1, R3 = 2, R4 = 3, R5 = 4, R6 = 5, R7 = 6, R8 = 7 };
+enum File { A = 0, B = 1, C = 2, D = 3, E = 4, F = 5, G = 6, H = 7 };
 struct Square {
   Rank rank;
   File file;
+    bool isValid() const {
+        return rank >= 0 && rank < 8 && file >= 0 && file < 8;
+    }
+};
+struct Move {
+    Square from;
+    Square to;
 };
-
 class Piece {
 protected:
   PieceColour colour;
@@ -32,15 +38,20 @@ protected:
 public:
   // methods
   Piece(PieceColour pColour) : colour(pColour) {}
-  virtual ~Piece() {}
-  virtual std::vector<std::pair<int, int>> getLegalMoves(int x, int y, const Board &board) const;
+  virtual ~Piece();
+  virtual std::vector<Move> getLegalMoves(const Square &from, const Board &board) const;
   PieceColour getColour() const { return colour; }
 };
 
 class King : public Piece {
 public:
   King(PieceColour colour) : Piece(colour) {}
-  std::vector<std::pair<int, int>> getLegalMoves(int x, int y, const Board &board) const override;
+  virtual std::vector<Move> getLegalMoves(const Square &from, const Board &board) const override;
+};
+
+class Rook : Public Piece {
+    Rook(PieceColour colour) : Piece(colour) {}
+    virtual std::vector<Move> getLegalMoves(const square &from, const Board &board) const override;
 };
 #endif // PIECE_HPP