Display flipping possibility?

[EarthwormJim]

Hi all,

I wonder if anyone has managed to horizontally flip the display output of the raspberry pi. I own an old arcade cabinet with the crt mounted vertically and a mirror above. The crt has been physically modded to create the mirror effect. I have been considering to replace the crt wit a flat display, but these can not be tweaked to display mirrorwise. Windows won't let me do this either (only rotating and display duplication), so maybe someone knows how to manage this on the Raspberry. Any help would be highly appreciated.

[W. H. Heydt]

Hi all,

I wonder if anyone has managed to horizontally flip the display output of the raspberry pi. I own an old arcade cabinet with the crt mounted vertically and a mirror above. The crt has been physically modded to create the mirror effect. I have been considering to replace the crt wit a flat display, but these can not be tweaked to display mirrorwise. Windows won't let me do this either (only rotating and display duplication), so maybe someone knows how to manage this on the Raspberry. Any help would be highly appreciated.

In /boot/config.txt,
display_rotate=N

If find N=3 works for monitors that can be rotated to portrait format. What works will depend on which way the orientation has been shifted. If it comes out upside down when using a value of 3, then try a value of 1. (A value of 2 should invert the image.)

[davidcoton]

Hi all,
In /boot/config.txt,
dispaly_rotate=N

If find N=3 works for monitors that can be rotated to portrait format. What works will depend on which way the orientation has been shifted. If it comes out upside down when using a value of 3, then try a value of 1. (A value of 2 should invert the image.)

Apart from the typo, I don't think that will work. Rotation is not equivalent to reflection.

Sorry I don't know of a better answer.

[AndyD]

Hi all,

I wonder if anyone has managed to horizontally flip the display output of the raspberry pi. I own an old arcade cabinet with the crt mounted vertically and a mirror above. The crt has been physically modded to create the mirror effect. I have been considering to replace the crt wit a flat display, but these can not be tweaked to display mirrorwise. Windows won't let me do this either (only rotating and display duplication), so maybe someone knows how to manage this on the Raspberry. Any help would be highly appreciated.

Yes, it is in the documentation for config.txt the section on display_rotate:-

display_rotate

Can be used to rotate or flip the screen orientation; the default value is 0.
display_rotate result
0 no rotation
1 rotate 90 degrees clockwise
2 rotate 180 degrees clockwise
3 rotate 270 degrees clockwise
0x10000 horizontal flip
0x20000 vertical flip

Note that the 90 and 270 degree rotation options require additional memory on the GPU, so these won't work with the 16MB GPU split.

You can horizontally flip the display by adding

Code: Select all

display_rotate=0x10000

to config.txt

[W. H. Heydt]

Hi all,
In /boot/config.txt,
dispaly_rotate=N

If find N=3 works for monitors that can be rotated to portrait format. What works will depend on which way the orientation has been shifted. If it comes out upside down when using a value of 3, then try a value of 1. (A value of 2 should invert the image.)

Apart from the typo, I don't think that will work. Rotation is not equivalent to reflection.

Sorry I don't know of a better answer.

Thanks for catching my typo (I've fixed it). I was going off the OPs statement about the orientation of the display he wanted to use. Of course, a more complete answer has now been given, but unless one is going to view the display in a mirror, it seems unlikely that he actually wants to "flip" the image.

[davidcoton]

@W H Heydt

Hi all,

I wonder if anyone has managed to horizontally flip the display output of the raspberry pi. I own an old arcade cabinet with the crt mounted vertically and a mirror above. ...

(Emphasis mine) ... and I too have missed bits like that in replying to other posts!

[W. H. Heydt]

@W H Heydt

Hi all,

I wonder if anyone has managed to horizontally flip the display output of the raspberry pi. I own an old arcade cabinet with the crt mounted vertically and a mirror above. ...

(Emphasis mine) ... and I too have missed bits like that in replying to other posts!

Fair enough...I sit corrected.

Now the question comes...what setting would one use to *both* flip the image *and* rotate it?

[AndyD]

... unless one is going to view the display in a mirror, it seems unlikely that he actually wants to "flip" the image.

The OP is viewing the display in a mirror (as the post says in detail) ...

... I own an old arcade cabinet with the crt mounted vertically and a mirror above. The crt has been physically modded to create the mirror effect. I have been considering to replace the crt wit a flat display, but these can not be tweaked to display mirrorwise. Windows won't let me do this either (only rotating and display duplication), so maybe someone knows how to manage this on the Raspberry. ...

[AndyD]

... Now the question comes...what setting would one use to *both* flip the image *and* rotate it?

The display_rotate setting is a bitmask. So you can *both* flip and rotate the display e.g.

Code: Select all

display_rotate=0x10001

Will both rotate the display 90 degrees and do a horizontal flip.

[W. H. Heydt]

... Now the question comes...what setting would one use to *both* flip the image *and* rotate it?

The display_rotate setting is a bitmask. So you can *both* flip and rotate the display e.g.

Code: Select all

display_rotate=0x10001

Will both rotate the display 90 degrees and do a horizontal flip.

Good to know. I wondered if that was the case.