b0f9d2f713
One of the major issues with the old tracking code is a data race between the cursor thread updating g_cursor.guest and the app_handleMouseBasic function. Specifically, the latter may have sent mouse input via spice that has not been processed by the guest and updated g_cursor.guest, but the guest may overwrite g_cursor.guest to a previous state before the input is processed. This causes some movements to be doubled. Eventually, the cursor positions will synchronize, but this nevertheless causes a lot of jitter. In this commit, we introduce a new field g_cursor.projected, which is unambiguously the position of the cursor after taking into account all the input already sent via spice. This is synced up to the guest cursor upon entering the window and when the host restarts. Afterwards, all mouse movements will be based on this position. This eliminates all cursor jitter as far as I could tell. Also, the cursor is now synced to the host position when exiting capture mode. A downside of this commit is that if the 1:1 movement patch is not correctly applied, the cursor position would be wildly off instead of simply jittering, but that is an unsupported configuration and should not matter. Also unsupported is when an application in guest moves the cursor programmatically and bypassing spice. When using those applications, capture mode must be on. Before this commit, we try to move the guest cursor back to where it should be, but it's inherently fragile and may lead to scenarios such as wild movements in first-person shooters.
Looking Glass
An extremely low latency KVMFR (KVM FrameRelay) implementation for guests with VGA PCI Passthrough.
- Project Website: https://looking-glass.io
- Getting Started: https://looking-glass.io/wiki/Installation
Donations
I (Geoffrey McRae) am the primary developer behind this project and I have invested thousands of hours of development time into it.
If you like this project and find it useful and would like to help out you can support me directly using the following platforms.
Documentation
** IMPORTANT ** This project contains submodules that must be checked out if building from the git repository! If you are not a developer and just want to compile Looking Glass please download the source archive from the website instead:
https://looking-glass.io/downloads
Please also be sure to see the following files for more information
Note: The README.md files are slowly being deprecated from this project in
favor of the wiki at https://looking-glass.io/wiki, and as such the
information in these files may be dated.
Latest Version
If you would like to use the latest bleeding edge version of Looking Glass please be aware there will be no support at this time.
Latest bleeding edge builds of the Windows host application can be obtained from:
https://looking-glass.io/downloads
Help and support
Web
https://forum.level1techs.com/c/software/lookingglass/142
Discord
- Looking Glass: https://discord.gg/52SMupxkvt
- VFIO: https://discord.gg/4ahCn4c
IRC
Join us in the #LookingGlass channel on the FreeNode network