1 files changed, 40 insertions, 0 deletions
diff --git a/frontend/src/util/tetris.ts b/frontend/src/util/tetris.ts
new file mode 100644
index 0000000..3547108
--- /dev/null
+++ b/frontend/src/util/tetris.ts
@@ -0,0 +1,40 @@
+import type { Board } from "@/model/board";
+import type { Tetromino } from "@/model/tetrominoes";
+
+export function mergeTetrominoWithBoard(board: Board, tetromino: Tetromino): Board {
+  return board.map((row, rowIndex) => {
+    if (rowIndex >= tetromino.row && rowIndex < tetromino.row + tetromino.shapes[tetromino.rotation].length) {
+      return row.map((col, colIndex) => {
+        if (colIndex >= tetromino.col && colIndex < tetromino.col + tetromino.shapes[tetromino.rotation][0].length) {
+          return tetromino.shapes[tetromino.rotation][rowIndex - tetromino.row][colIndex - tetromino.col] || col;
+        }
+        return col;
+      });
+    }
+    return row;
+  });
+}
+
+export function tetrominoCollidesWithBoard(board: Board, tetromino: Tetromino): boolean {
+  return tetromino.shapes[tetromino.rotation].some((row, rowIndex) => {
+    return row.some((col, colIndex) => {
+      if (col) {
+        const boardRow = board[rowIndex + tetromino.row];
+        if (!boardRow) {
+          return true;
+        }
+        const boardCol = boardRow[colIndex + tetromino.col];
+        if (boardCol) {
+          return true;
+        }
+        if (colIndex + tetromino.col < 0 || colIndex + tetromino.col >= boardRow.length) {
+          return true;
+        }
+        if (rowIndex + tetromino.row < 0 || rowIndex + tetromino.row >= board.length) {
+          return true;
+        }
+      }
+      return false;
+    });
+  });
+}