From 87a15e960e31365698df7e06cd3e6b851e17c1a5 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Sun, 5 Mar 2023 10:13:01 +0100
Subject: I made a mess, but it works. Still need to implement new optimal
 solver. After that, a big redesign is due.

---
 src/movesets.c | 194 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 194 insertions(+)
 create mode 100644 src/movesets.c

(limited to 'src/movesets.c')

diff --git a/src/movesets.c b/src/movesets.c
new file mode 100644
index 0000000..d8f5bc1
--- /dev/null
+++ b/src/movesets.c
@@ -0,0 +1,194 @@
+#define MOVESETS_C
+
+#include "movesets.h"
+
+static bool allowed_HTM(Move m);
+static bool allowed_URF(Move m);
+static bool allowed_eofb(Move m);
+static bool allowed_drud(Move m);
+static bool allowed_htr(Move m);
+static bool can_append_HTM(Move l2, Move l1, Move m);
+static bool can_append_HTM_cached(Alg *alg, Move m, bool inverse);
+static bool cancel_niss_HTM_cached(Alg *alg);
+static void init_can_append_HTM();
+
+Moveset
+moveset_HTM = {
+	.name        = "HTM",
+	.allowed     = allowed_HTM,
+	.can_append  = can_append_HTM_cached,
+	.cancel_niss = cancel_niss_HTM_cached,
+};
+
+Moveset
+moveset_URF = {
+	.name        = "URF",
+	.allowed     = allowed_URF,
+	.can_append  = can_append_HTM_cached,
+	.cancel_niss = cancel_niss_HTM_cached,
+};
+
+Moveset
+moveset_eofb = {
+	.name        = "eofb",
+	.allowed     = allowed_eofb,
+	.can_append  = can_append_HTM_cached,
+	.cancel_niss = cancel_niss_HTM_cached,
+};
+
+Moveset
+moveset_drud = {
+	.name        = "drud",
+	.allowed     = allowed_drud,
+	.can_append  = can_append_HTM_cached,
+	.cancel_niss = cancel_niss_HTM_cached,
+};
+
+Moveset
+moveset_htr = {
+	.name        = "htr",
+	.allowed     = allowed_htr,
+	.can_append  = can_append_HTM_cached,
+	.cancel_niss = cancel_niss_HTM_cached,
+};
+
+Moveset *
+all_movesets[] = {
+	&moveset_HTM,
+	&moveset_URF,
+	&moveset_eofb,
+	&moveset_drud,
+	&moveset_htr,
+	NULL
+};
+
+static uint64_t can_append_HTM_mask[NMOVES][NMOVES];
+
+static bool
+allowed_HTM(Move m)
+{
+	return m >= U && m <= B3;
+}
+
+static bool
+allowed_URF(Move m)
+{
+	Move b = base_move(m);
+
+	return b == U || b == R || b == F;
+}
+
+static bool
+allowed_eofb(Move m)
+{
+	Move b = base_move(m);
+
+	return b == U || b == D || b == R || b == L ||
+	       ((b == F || b == B) && m == b+1);
+}
+
+static bool
+allowed_drud(Move m)
+{
+	Move b = base_move(m);
+
+	return b == U || b == D ||
+	       ((b == R || b == L || b == F || b == B) && m == b + 1);
+}
+
+static bool
+allowed_htr(Move m)
+{
+	Move b = base_move(m);
+
+	return moveset_HTM.allowed(m) && m == b + 1;
+}
+
+static bool
+can_append_HTM(Move l2, Move l1, Move m)
+{
+	bool cancel, cancel_last, cancel_swap;
+
+	cancel_last = l1 != NULLMOVE && base_move(l1) == base_move(m);
+	cancel_swap = l2 != NULLMOVE && base_move(l2) == base_move(m);
+	cancel = cancel_last || (commute(l1, l2) && cancel_swap);
+
+	return !cancel;
+}
+
+static bool
+can_append_HTM_cached(Alg *alg, Move m, bool inverse)
+{
+	Move *moves, l1, l2;
+	uint64_t mbit;
+	int n;
+
+	if (inverse) {
+		moves = alg->move_inverse;
+		n = alg->len_inverse;
+	} else {
+		moves = alg->move_normal;
+		n = alg->len_normal;
+	}
+
+	l1 = n > 0 ? moves[n-1] : NULLMOVE;
+	l2 = n > 1 ? moves[n-2] : NULLMOVE;
+
+	mbit = ((uint64_t)1) << m;
+
+	return can_append_HTM_mask[l2][l1] & mbit;
+}
+
+static bool
+cancel_niss_HTM_cached(Alg *alg)
+{
+	Move i1, i2;
+	int n;
+	bool can_first, can_swap;
+
+	n = alg->len_inverse;
+	i1 = n > 0 ? alg->move_inverse[n-1] : NULLMOVE;
+	i2 = n > 1 ? alg->move_inverse[n-2] : NULLMOVE;
+
+	can_first = can_append_HTM_cached(alg, inverse_move(i1), false);
+	can_swap  = can_append_HTM_cached(alg, inverse_move(i2), false);
+
+	return can_first && (!commute(i1, i2) || can_swap);
+}
+
+static void
+init_can_append_HTM()
+{
+	Move l2, l1, m;
+
+	for (l1 = 0; l1 < NMOVES; l1++)
+		for (l2 = 0; l2 < NMOVES; l2++)
+			for (m = 0; m < NMOVES; m++)
+				if (can_append_HTM(l2, l1, m))
+					can_append_HTM_mask[l2][l1]
+					    |= (((uint64_t)1) << m);
+}
+
+void
+init_moveset(Moveset *ms)
+{
+	int j;
+	Move m;
+
+	for (j = 0, m = U; m < NMOVES; m++)
+		if (ms->allowed(m))
+			ms->sorted_moves[j++] = m;
+	ms->sorted_moves[j] = NULLMOVE;
+
+/* TODO: should be here? maybe just init all movesets together anyway... */
+	init_can_append_HTM();
+}
+
+void
+init_movesets()
+{
+	int i;
+
+	for (i = 0; all_movesets[i] != NULL; i++)
+		init_moveset(all_movesets[i]);
+}
-- 
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