move prompt + help

src/chess.c

@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include "chess.h"
 #include "util.h"
 
@@ -22,7 +23,49 @@ void select_player(player_e *player, unsigned int round_count) {
     }
 }
 
-bool get_move(move_t *move);
+void show_help() {
+    puts(
+        "movement help:\n\
+        there is a prompt asking for where to move a piece every turn\n\
+        format: e.g. you want to move a knight from b1 to a3:\n\
+        you'd type -> b1 a3 <- (without the arrows)\n"
+    );
+}
+
+// returns false if the numbers of letters are out of bounds
+bool is_move_in_bounds(move_t move) {
+    if (
+        is_int_in_range(move.from.x, 0, 7) &&
+        is_int_in_range(move.from.y, 0, 7) &&
+        is_int_in_range(move.to.x, 0, 7) &&
+        is_int_in_range(move.to.y, 0, 7)
+    ) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+bool get_move(move_t *move) {
+    clear_stdin();
+    
+    char _x_from, _x_to;
+    int _y_from, _y_to;
+    scanf("%c%d %c%d", 
+        &_x_from,
+        &_y_from,
+        &_x_to,
+        &_y_to
+    );
+
+    move->from.x = _x_from-96-1; // char to int conversion
+    move->from.y = _y_from-1;
+
+    move->to.x = _x_to-96-1;
+    move->to.y = _y_to-1;
+
+    return is_move_in_bounds(*move);
+}
 
 bool perform_move(player_e player, move_t move);
 

src/chess.h

@@ -83,5 +83,7 @@ end_condition_e check_edge_cases(board_t board);
 // if there is one of the mates, end the game and show who has won
 void announce_results(player_e player);
 
+// shows a guide to help players understand the move prompt system
+void show_help();
 
 #endif // CHESS_H

src/main.c

@@ -28,6 +28,8 @@ int main() {
 
     init_board(&board);
 
+    show_help();
+
     while (running) {
         round_count++;
         

src/util.c

@@ -0,0 +1,14 @@
+#include "util.h"
+#include <stdio.h>
+
+void clear_stdin() {
+    while (getchar() != '\n');
+}
+
+bool is_int_in_range(int x, int start, int end) {
+    if (start <= x && x <= end) {
+        return true;
+    } else {
+        return false;
+    }
+}

src/util.h

@@ -1,9 +1,17 @@
 #ifndef UTIL_H
 #define UTIL_H
 
+#include <stdbool.h>
+
 // misc. defines and methods
 
 #define EXIT_SUCCESS 0
 #define EXIT_FAILURE 1
 
+// for input handling consistency
+void clear_stdin();
+
+// self-explanatory
+bool is_int_in_range(int x, int start, int end);
+
 #endif // UTIL_H