Add up2_main function to support configurable page layouts (2x2, 3x3,…

… 1x2, 2x1) without impacting default behavior.

pdfly/up2.py

@@ -27,3 +27,45 @@ def main(pdf: Path, output: Path) -> None:
     with open(output, "wb") as fp:
         writer.write(fp)
     print("done.")
+
+def up2_main(pdf: Path, output: Path, layout: str = None) -> None:
+    reader = PdfReader(str(pdf))
+    writer = PdfWriter()
+
+    if layout:
+        # Define layout configurations (columns, rows) for each grid type
+        layout_options = {
+            "2x2": (2, 2),
+            "3x3": (3, 3),
+            "1x2": (1, 2),
+            "2x1": (2, 1)
+        }
+
+        if layout not in layout_options:
+            raise ValueError(f"Unsupported layout: {layout}")
+
+        columns, rows = layout_options[layout]
+        # Adjusted to use 'mediabox' instead of 'media_box'
+        page_width = reader.pages[0].mediabox.width / columns
+        page_height = reader.pages[0].mediabox.height / rows
+
+        # Arrange pages in specified grid
+        for i in range(0, len(reader.pages), columns * rows):
+            new_page = writer.add_blank_page(width=reader.pages[0].mediabox.width,
+                                             height=reader.pages[0].mediabox.height)
+
+            for col in range(columns):
+                for row in range(rows):
+                    index = i + row * columns + col
+                    if index < len(reader.pages):
+                        page = reader.pages[index]
+                        x_position = col * page_width
+                        y_position = reader.pages[0].mediabox.height - (row + 1) * page_height
+                        new_page.merge_translated_page(page, x_position, y_position)
+    else:
+        # Default behavior: add pages without grid layout
+        for page in reader.pages:
+            writer.add_page(page)
+
+    with open(output, "wb") as f_out:
+        writer.write(f_out)