Re: Qemu Display Coacoa Patch Serie Qemu 9.0 RC1

[Akihiko Odaki <akihiko.odaki@daynix.com>]

On 2024/03/29 6:44, BALATON Zoltan wrote:
> On Thu, 28 Mar 2024, Rene Engel wrote:
>> I wanted to discuss this topic with you again, there was already a 
>> patch series that worked well under Qemu with
>> Pegasos2/AmigaOneXe/Same460 and AmigaOs4.1. The option zoom-to-fit=on 
>> should be used to adjust all resolutions provided by the guest
>> system to the aspect ratio if there are no Virtio GPU drivers 
>> available that allow this.
>>
>> In my opinion exactly this option zoom-to-fit=on makes this possible. 
>> If you don't want to use this option you still have the possibility
>> to deactivate it. In Qemu 9.0 RC1 not all resolutions are stretched 
>> like in previous patches e.g. 640x480/800x600/1024x720 etc. but this
>> is exactly what we need for the Pegasos2/AmigaOneXe/Same460 machine 
>> with AmigaOs4.1.
> 
> There seems to be a bit of confusion about how this zoom-to-fit option 
> is implemented by different -display backends and I'm not sure what is 
> the intended behaviour or how other -display backends handle it. Maybe a 
> single option is not even enough to describe all possible preferences so 
> another one i.e. keep-aspect=true|false may also be needed to cover all 
> possible settings (don't zoom, zoom with aspect ratio kept, zoom to fit 
> window even if that stretches the picture out of aspect ratio). For 9.0 
> ptobsbly we should go for consistency with other backends now as adding 
> new options is not possible during freeze and then resolve this afterwards.

It is indeed something that requires a new flag like zoom-interpolation.

> 
>> There are also problems within the resolutions with the mouse pointer 
>> where the screen output flickers it currently affects all patch 
>> series. I would be happy if we could find a solution for all this.
> 
> The flicker may be due to the resize algorithm used by macOS not giving 
> the same result always. To resolve it maybe yet another option may be 
> needed to not zoom to full available window but try to keep the zoom 
> factor some integer value to avoid fractional scaling but I'm not sure 
> that's the best way to solve it.

Flickering sounds more like a bug. I appreciate if you can share some 
recording.

Regards,
Akihiko Odaki

> 
> Regards,
> BALATON Zoltan
> 
>> I'll leave you 2 videos so you can decide for yourself what would make 
>> the most sense. It shows once for me the working zoom behavior
>> which works very well and the behavior with Qemu 9.0Rc1 including new 
>> Cocoa patches.
>>
>> Qemu zoom-to fit=on for all Screenmodes 
>> working: https://www.youtube.com/watch?v=dnJ3W8egAFY
>>
>> Qemu 9.0. RC1 zoom-to fit=on not working for all 
>> Screenmodes: https://www.youtube.com/watch?v=Ddq68ViudrA
>>
>>
>>
>>