local col = std.mod(index, panelsPerRow);
      panel + { gridPos+: { x: panel.gridPos.w * col } };

    local panelsBeforeRowsWithX = std.mapWithIndex(CalculateXforPanel, panelsBeforeRows);

    local rowPanelsWithX =
      std.map(
        function(row)
          row + { panels: std.mapWithIndex(CalculateXforPanel, row.panels) },
        rowPanels
      );