Fix move generation I think

ArduChess.ino

@@ -9,6 +9,58 @@
 #include "Movegen.h"
 #include "Types.h"
 
+unsigned int pseudo_perft(byte depth) {
+	// only checks pseudolegality
+	// but, it should work overall
+	if(depth == 0) return 1;
+	Serial.print(F("Start a PERFT "));
+	Serial.print(depth);
+	Serial.println('-');
+	print();
+	unsigned int move_count = 0;
+	Movegen gen;
+	Move m;
+	do {
+		m = gen.next_move();
+		//make(m);
+		move_count += pseudo_perft(depth-1);
+		//unmake();
+	} while (m.sq_from != 255);
+	return move_count - 1;	
+}
+
+void perft_test() {
+	for(byte i = 0; i < 2; i++) {
+		Serial.print(F("Perft "));
+		Serial.print(i);
+		Serial.print(F(": "));
+		Serial.println(pseudo_perft(i));
+	}
+}
+
+void debug_movegen() {
+	Movegen gen = Movegen();
+	Move m;
+	do {
+		DEBUG("start movegen");
+		m = gen.next_move();
+		Serial.print(F("FROM "));
+		Serial.print(m.sq_from, HEX);
+		Serial.print(F(" TO "));
+		Serial.print(m.sq_to, HEX);
+		Serial.print(F(" PROMOTE "));
+		Serial.println(m.pc_prom);
+		if(m.sq_from != 255) {
+			DEBUG("make");
+			make(m);
+			print();
+			DEBUG("unmake");
+			unmake();
+			DEBUG("unmake done");
+		}
+	} while (m.sq_from != 255);
+}
+
 void debug_castle() {
 	print();
 	make({0x06, 0x25, P_EMPTY}); print();

Board.h

@@ -34,7 +34,7 @@
 #define PTR_UNMOVE_LAST 0x7F
 
 byte field[128];
-byte PTR_UNMOVE = PTR_UNMOVE_START;
+byte PTR_UNMOVE;
 
 const byte field_default_value[] PROGMEM = BOARD_DEFAULT_VALUE;
 
@@ -42,6 +42,7 @@ void board_init() {
 	for(int i = 0; i < 128; i++) {
 		field[i] = pgm_read_byte_near(field_default_value + i);
 	}
+	PTR_UNMOVE = PTR_UNMOVE_START;
 	field[PTR_SIDE_AND_CASTLERIGHT] = 0b11110; // all castle rights allowed, white to move
 	field[PTR_W_KING] = 0x04; // e1
 	field[PTR_B_KING] = 0x74; // e8
@@ -267,7 +268,7 @@ void unmake() {
 		field[PTR_SIDE_AND_CASTLERIGHT] |= 0b01 << castleright_offset;
 	}
 
-	int sq_diff = (int)sq_to - (int)u.sq_from;
+	int sq_diff = (int)sq_to - (int)sq_from;
 	int sq_diff_abs = abs(sq_diff);
 	if((field[sq_from] & 0x7) == W_KING && sq_diff_abs == 2) {
 		// we castled

Config.h

@@ -5,3 +5,5 @@
 // PANIC_BLINK makes the Arduino blink an error code when it panics.
 // Costs a lot of flash though (around 700 bytes)
 //#define _ACF_PANIC_BLINK
+
+#define _ACF_DEBUG_PRINT

Movegen.h

@@ -25,7 +25,7 @@ class Movegen {
 };
 
 Move Movegen::next_move() {
-	while(square <= 0x7F) {
+	while(square <= 0x77) {
 		if(square & 0x88) square += 8;
 
 		byte piece_type = field[square] & 0x7;
@@ -37,14 +37,11 @@ Move Movegen::next_move() {
 			// there is an own piece to investigate
 			Move m;
 			if(piece_type == W_PAWN) {
-				Serial.println("GENERATE PAWN");
 				m = generate_pawn();
 			} else if(piece_type & 0b0100) {
-				Serial.println("GENERATE SLIDING");
 				// bishop, rook and queen are 01xx.
 				m = generate_sliding(piece_type);
 			} else {
-				Serial.println("GENERATE NONSLIDING");
 				m = generate_non_sliding(piece_type);
 			}
 			if(m.sq_to != 255) {
@@ -125,6 +122,8 @@ Move Movegen::generate_non_sliding(byte piece_type) {
 }
 
 Move Movegen::generate_pawn() {
+	// TODO: implement capture promotion
+	
 	byte color = black_moving();
 	byte offset;
 	byte target;
@@ -166,19 +165,21 @@ Move Movegen::generate_pawn() {
 			offset = color ? -0x11 : 0xF;
 			target_square = square + offset;
 			target = field[target_square];
-			if(target && (target & 0x8) != (field[square] & 0x8)) {
-				// normal capture allowded
-				return Move{square, target_square, P_EMPTY};
-			} else if(field[PTR_ENPASSANT]) {
-				// note that EP being legal only happens
-				// when the target field is empty. so this saves some effort.
-				byte ep_col = field[PTR_ENPASSANT] & 0x7;
-				if(
-					ep_col == (target_square & 0x7) &&
-					(square & 0x70) == (color ? 0x30 : 0x40)
-				) {
-					// EP-capture possible
+			if(!(target_square & 0x88)) {
+				if(target && (target & 0x8) != (field[square] & 0x8)) {
+					// normal capture allowded
 					return Move{square, target_square, P_EMPTY};
+				} else if(field[PTR_ENPASSANT]) {
+					// note that EP being legal only happens
+					// when the target field is empty. so this saves some effort.
+					byte ep_col = field[PTR_ENPASSANT] & 0x7;
+					if(
+						ep_col == (target_square & 0x7) &&
+						(square & 0x70) == (color ? 0x30 : 0x40)
+					) {
+						// EP-capture possible
+						return Move{square, target_square, P_EMPTY};
+					}
 				}
 			}
 			// fall through
@@ -188,19 +189,21 @@ Move Movegen::generate_pawn() {
 			offset = color ? -0xF : 0x11;
 			target_square = square + offset;
 			target = field[target_square];
-			if(target && (target & 0x8) != (field[square] & 0x8)) {
-				// normal capture allowded
-				return Move{square, target_square, P_EMPTY};
-			} else if(field[PTR_ENPASSANT]) {
-				// note that EP being legal only happens
-				// when the target field is empty. so this saves some effort.
-				byte ep_col = field[PTR_ENPASSANT] & 0x7;
-				if(
-					ep_col == (target_square & 0x7) &&
-					(square & 0x70) == (color ? 0x30 : 0x40)
-				) {
-					// EP-capture possible
+			if(!(target_square & 0x88)) {
+				if(target && (target & 0x8) != (field[square] & 0x8)) {
+					// normal capture allowded
 					return Move{square, target_square, P_EMPTY};
+				} else if(field[PTR_ENPASSANT]) {
+					// note that EP being legal only happens
+					// when the target field is empty. so this saves some effort.
+					byte ep_col = field[PTR_ENPASSANT] & 0x7;
+					if(
+						ep_col == (target_square & 0x7) &&
+						(square & 0x70) == (color ? 0x30 : 0x40)
+					) {
+						// EP-capture possible
+						return Move{square, target_square, P_EMPTY};
+					}
 				}
 			}
 			// fall through

Types.h

@@ -1,6 +1,14 @@
 #ifndef __TYPES_H_INC
 #define __TYPES_H_INC
 
+#include "Config.h""
+
+#ifdef _ACF_DEBUG_PRINT
+#define DEBUG(x) Serial.println(F(x)); Serial.flush()
+#else
+#define DEBUG(x)
+#endif
+
 enum Piece: byte {
 	P_EMPTY = 0b0000,
 	P_ANY = 0b1000,