added en passant, version 1

3 files changed, 25 insertions, 4 deletions

diff --git a/chess.c b/chess.c
index b913536..92277dc 100644
--- a/chess.c
+++ b/chess.c
@@ -6,7 +6,13 @@
 #include "chesshelpers.h"
 #include "chess.h"
 
-int main() {
+int main(int argc, char **argv) {
+	if(argc == 2) {
+		if(strcmp(argv[1], "-v") == 0 || strcmp(argv[1], "--version") == 0) {
+			printf("Version 1.0.0\n");
+			exit(0);
+		}
+	}
 	//set up the board
 	int boardA[8][8] = { 
 		{ rook + 6, pawn + 6, 0, 0, 0, 0, pawn, rook }, 
@@ -198,7 +204,6 @@ vectorp_t get_moves_final(board_t board, vector_t position, piece_t piece) {
 	free(moves.vectors);
 	return finalMoves;
 }
-//TODO: add en passant
 vectorp_t get_pawn_moves(board_t board, vector_t position, int color) {
 	vector_t* moves = malloc(6 * sizeof(vector_t));
 	int moveCount = 0;
@@ -216,12 +221,12 @@ vectorp_t get_pawn_moves(board_t board, vector_t position, int color) {
 		}
 	}
 	vector_t captureL = init_vector(position.mx - 1, position.my + forwardDir);
-	if(in_board(captureL) && is_color(board, captureL, !color)) {
+	if(in_board(captureL) && (is_color(board, captureL, !color) || would_have_been_pawn(board, captureL, !color))) {
 		moves[moveCount] = captureL;
 		moveCount++;
 	}
 	vector_t captureR = init_vector(position.mx + 1, position.my + forwardDir);
-	if(in_board(captureR) && is_color(board, captureR, !color)) {
+	if(in_board(captureR) && (is_color(board, captureR, !color) || would_have_been_pawn(board, captureR, !color))) {
 		moves[moveCount] = captureR;
 		moveCount++;
 	}
diff --git a/chesshelpers.c b/chesshelpers.c
index 2e046c9..b64a0f4 100644
--- a/chesshelpers.c
+++ b/chesshelpers.c
@@ -17,6 +17,7 @@ board_t init_board(int** pieces) {
 //function applies side effects to board values like king move state
 board_t make_move(board_t board, vector_t origin, vector_t end) {
 	int piece = board.pieces[origin.mx][origin.my];
+	int captured = board.pieces[end.mx][end.my];
 	board.pieces[origin.mx][origin.my] = 0;
 	board.pieces[end.mx][end.my] = piece;
 	//white king moved
@@ -62,6 +63,11 @@ board_t make_move(board_t board, vector_t origin, vector_t end) {
 	//this is not an else if! lastPawnMove must be reset
 	if(piece == pawn || piece == pawn + 6) {
 		board.lastPawnMove = origin.mx;
+		//check if move was an en passant capture
+		if(captured == 0 && origin.mx != end.mx) {
+			//kill the enemy pawn
+			board.pieces[end.mx][origin.my] = 0;
+		}
 	}
 	else {
 		//en passant no longer possible
@@ -95,6 +101,15 @@ int is_color(board_t board, vector_t position, int color) {
 		return board.pieces[position.mx][position.my] >= 7;
 	}
 }
+//returns true if a pawn that moved two squares would have been here if it moved one square
+int would_have_been_pawn(board_t board, vector_t position, int color) {
+	if(board.lastPawnMove == position.mx) {
+		if((position.my == 6 && color == 0) || (position.my == 2 && color == 1)) {
+			return 1;
+		}
+	}
+	return 0;
+}
 //converts board coordinates into algebraic notation
 char* get_readable_coords(vector_t position) {
 	char* output = malloc(3 * sizeof(char));
diff --git a/chesshelpers.h b/chesshelpers.h
index b975740..b3a3d21 100644
--- a/chesshelpers.h
+++ b/chesshelpers.h
@@ -25,6 +25,7 @@ board_t clone_board(board_t board);
 int in_board(vector_t position);
 int is_empty(board_t board, vector_t position);
 int is_color(board_t board, vector_t position, int color);
+int would_have_been_pawn(board_t board, vector_t position, int color);
 char* get_readable_coords(vector_t position);
 char* get_move_name(board_t board, vector_t origin, vector_t end);
 #endif