It would be nice to have a option to show the content piped to rofi row by row.
As far as I can see the current behavior is limited to fill a grid with lets say 3 lines x 3 columns in the following order:

[ 1 | 4 | 7 ]  
[ 2 | 5 | 8 ]  
[ 3 | 6 | 9 ]  

I would like to show the content passed to rofi in this order:

[ 1 | 2 | 3 ]
[ 4 | 5 | 6 ]
[ 7 | 8 | 9 ]

Use case

My current use case: I would like to have a rofi calendar where I can select a specific day and not just a week. Most rofi calendars I found look like this:

| Mo Tu We Th Fr Sa Su |
|                1   2 |
|  3  4  5  6  7  8  9 |
| 10 11 12 13 14 15 16 |
| 17 18 19 20 21 22 23 |
| 24 25 26 27 28 29    |

To select a day I need a grid with 7 columns and 6 lines in this example. By using cal and sed I get the single dates from left to right (Mo Tu We ... 1 2 3 ... 28 29). By piping the result to rofi I get a calender which looks like this:

| Mo |    |  3 | 10 | 17 | 24 |
| Tu |    |  4 | 11 | 18 | 25 |
| We |    |  5 | 12 | 19 | 26 |
| Th |    |  6 | 13 | 20 | 27 |
| Fr |    |  7 | 14 | 21 | 28 |
| Sa |  1 |  8 | 15 | 22 | 29 |
| So |  2 |  9 | 16 | 23 |    |

I would like to specify a parameter like --from-left-to-right to fill the rofi grid in the desired order.

Additional info:

rofi -v
Version: 1.5.4