feat: add notations

3 files changed, 23 insertions, 2 deletions

diff --git a/src/board.c b/src/board.c
new file mode 100644
index 0000000..bc5855f
--- /dev/null
+++ b/src/board.c
@@ -0,0 +1,10 @@
+#include "board.h"
+
+BYTE notation_to_index(char file, int rank) {
+  return (rank - 1) * 8 + (file - 'a');
+}
+
+void index_to_notation(BYTE index, char notation[2]) {
+  notation[0] = (index & 0b0111) + 'a';
+  notation[1] = (index >> 3) + '1';
+}
diff --git a/src/board.h b/src/board.h
index 052e104..f7e89f2 100644
--- a/src/board.h
+++ b/src/board.h
@@ -27,3 +27,6 @@ static const char* pieces[] = {
   "♛", "♕",
   "♚", "♔",
 };
+
+void index_to_notation(BYTE index, char notation[2]);
+BYTE notation_to_index(char file, int rank);
diff --git a/src/main.c b/src/main.c
index a442231..75d3bb7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,9 +1,17 @@
 #include "unittest.h"
 #include "board.h"
 
+void test_notations() {
+  printf("%u\n", notation_to_index('e', 4));
+  unit_test(notation_to_index('e', 4) == 28, "Notation e4 is index 28");
+
+  char notation[2] = "x0";
+  index_to_notation(28, notation);
+  unit_test(notation[0] == 'e' && notation [1] == '4', "Index 28 is notation e4");
+}
+
 int main() {
-  unit_test(2 * 2 == 4, "2 * 2 == 4");
-  unit_test(2 * 2 == 5, "2 * 2 == 4");
+  test_notations();
 
   report();
   return 0;