Multiple Screen scaling confusion

[sunep]

I have discovered a problem when I use my Laptop with high res display (UHD - scaling=200%) where I connect low res projectors (XGA or similar Scaling =100%). when moving renderers to the low res screen, they keep the 200% scaling, meaning 4 times the number of pixels on the screen.

1 start vvvv on screen 1 with scaling = 200%
2 make a renderer, either DX9 or DX11, note the resolution.
3 drag the renderer to the other screen, Scaling = 100%
4 Maximize the window on that screen
5 note the resolution, it is twice the size of the screen, meaning you are rendering 4 times the number of pixels present on the screen/projector.

[tonfilm]

did you set a specific resolution in the Inspektor? or is it not in fullscreen?

[sunep]

Well in this case I couldn’t actually go full screen, the window simply disappeared when I tried. With dx11 I gave up regular full screen a long time ago, after I was pointed to vsync and flip sequential.

But it’s the same problem when the renderer is windowed.

[tonfilm]

looks like the DPI setting is only updated once on startup… i’ll add it to our tracker.

[sunep]

But is there just one dpi setting or one per display?

[sunep]

I mean the screens don’t change after vvvv is started.

[tonfilm]

don’t know how that is checked from the top of my head. needs some investigation…

[joreg]

sounds like a duplicate of this: https://discourse.vvvv.org/t/dpi-aware-scaling-minor-bug-for-multiple-devices-with-different-scalings/13473

vvvv does not deal with dpi per monitor. iirc this is a new feature introduced by windows only after we introduced dpi-handling into vvvv. so it needs some coding…

[sunep]

weirdly enough, it seems like DX11 is working as expected.

how about leaving the scaling as an output on the renderer, then you can decide whether or not to use it. and then just have the UI respond to it.

btw. the UI also behaves weird when you drag it between screens with different scaling