1 files changed, 85 insertions, 0 deletions
diff --git a/board.h b/board.h
new file mode 100644
index 0000000..a144ed7
--- /dev/null
+++ b/board.h
@@ -0,0 +1,85 @@
+#pragma once
+
+#include <iostream>
+#include <vector>
+#include <bitset>
+#include <functional>
+#include <cstdint>
+#include "params.h"
+
+using namespace std;
+
+
+class Bag {
+public:
+	static Bag uninitialised();
+	static Bag makeFull();
+
+	int numLeft(uint8_t clr) const;
+	int totalLeft() const;
+	uint8_t drawRandom();
+	uint8_t peekRandom() const;  // picks random colour but doesn't draw
+	void drawColour(uint8_t clr);
+	void replace(uint8_t clr);
+
+private:
+	// Number of stones left of the given colours. Index with clr-1.
+	int num[NC];
+
+	// Sum of num[0 .. NC-1].
+	int sum;
+
+	Bag() = default;
+};
+
+struct Bounds {
+	int left = BSZ, right = -1, top = BSZ, bottom = -1;
+};
+
+class Board {
+public:
+	// Up to the user to keep this in sync with the board. (It is initialised
+	// in makeEmpty().)
+	Bag bag = Bag::uninitialised();
+
+	static Board makeEmpty();
+
+	inline const uint8_t& operator[](int idx) const { return bd[idx]; }
+
+	void put(int idx, uint8_t clr);
+	void undo(int idx);
+
+	uint8_t putCW(int idx, uint8_t clr);
+
+	// The callback may modify the board, but must leave it as it was after returning.
+	void forEachMove(const function<void(int idx)> &f);
+
+	void write(ostream &os) const;
+
+	Bounds computeBounds() const;
+
+private:
+	// 0 = empty, 1...NC = coloured stones
+	uint8_t bd[BSZ * BSZ];
+
+	// Candidates for edge cells; all cells that can take a stone must be
+	// elements of this list, but there may be more.
+	vector<int> edgeCands;
+
+	// Whether a particular cell is in edgeCands.
+	bitset<BSZ * BSZ> inEdgeCands;
+
+	Board() = default;
+
+	int countStones(uint8_t clr, int idx, int delta) const;
+	void newEdgeCand(int idx);
+	bool checkEdge(int idx) const;
+};
+
+struct Stone {
+	uint8_t clr;
+	inline Stone(uint8_t clr) : clr(clr) {}
+};
+
+ostream& operator<<(ostream &os, Stone stone);
+ostream& operator<<(ostream &os, const Board &bd);