Hi all, Recently I've been investigating Hi-DPI related issues in the LC Windows implementation. I thought about pestering the LC team (or paying them) to prioritize these fixes, but then I realized it was October and I came up with a different idea. In the spirit of Hacktoberfest I thought it would be nice to try and organize a community effort around some improvements that could be made to Hi-DPI support on Windows.
For those who aren't familiar with Hacktoberfest you can read more about it at the url below. [Side note: submitting PRs for LC documentation updates is a great way to earn a T-shirt. https://hacktoberfest.digitalocean.com -------------------------— Background —-—-—-—-—-—-—- LiveCode added support for Hi-DPI monitors almost 5 years ago. This is when they added properties such as usePixelScaling, screenPixelScale, screenPixelScales, etc. At the time, Windows had support for System DPI Awareness. After LC added support Windows changed the APIs to support different resolutions on each monitor. This is referred to as PerMonitor API Awareness. This was in Windows 8.1. The APIs were further improved in Windows 10. LiveCode needs to be updated to support these newer APIs. I'm aware of the following limitations and bugs around Hi-DPI support on Windows: 1. The `screenPixelScales` reports the pixelScale of the primary monitor for all attached monitors. For example, if you have a Windows 10 computer with two monitors attached and the primary monitor is set to displays at 100% (1.0 pixelScale) and a second monitor at 200% (2.0 pixelScale) then the `screenPixelScales` returns `1.0\n1.0` when it should return `1.0\n2.0`. https://quality.livecode.com/show_bug.cgi?id=19542 2. minWidth/minHeight/maxWidth/maxHeight are not handled properly on monitors with a pixelScale > 1.0. https://quality.livecode.com/show_bug.cgi?id=14314 --------------------—-—- Fixing these issues in the LC Community -------------------------— I think we can muster the LC Community troops and figure out how to fix these issues. I spent some time the other day doing some research in an attempt to figure out what needs to be done. I’ve been looking through the source code and reviewing the Windows API docs on the web in order to better understand the API changes required for switching from System DPI Awareness to PerMonitor API Awareness in LiveCode. I’ve looked at the [[ HiDPI ]] commits on GitHub and these two seem the most pertinent. They contain the changes to the source code when the pixel scale properties were added and the changes made specifically for Windows implementation. https://github.com/livecode/livecode/commit/1373bfdb7dc267d86e1a66953dce78d2046824d4 https://github.com/livecode/livecode/commit/27f65afb96de93873a435525fb684ff704abc575 This docs page on Microsoft's site is a nice introduction DPI Awareness: https://docs.microsoft.com/en-us/windows/desktop/hidpi/high-dpi-desktop-application-development-on-windows#per-monitor-and-per-monitor-v2-dpi-awareness Here are some notes I made in my research: - I think that responding to the WM_DPICHANGED message to update windows when DPI for a monitor changes should be pretty straightforward. I think the MCDispatch::reopen_stack_windows() function in dispatch.cpp would handle that as it is what is called when setting the pixelscale. - I’m not sure about the switch from GetDpiForMonitor() to GetDpiForWindow(). I would hope that if the LiveCode w32-manifest-template-dpiaware.xml manifest were updated to include the <dpiAwareness>PerMonitor</dpiAwareness> node that GetDpiForMonitor() would return the proper pixel_scale in w32dce.cpp > DescribeMonitorsCallback. If so then screenPixelScales may just start working. --------------------—-—- What is needed? -------------------------— In order to pull this off we would need some developers who are set up to compile LC 9 on Windows and who are familiar with working with the Windows APIs (C++). We also need people willing to test and review proposed code changes and make sure we aren't missing anything. I can provide a private Slack channel with audio/video/screen sharing capabilities for a small group. I have some unused guests on my company account that I can access for the duration of this project. I am not set up to compile LC on Windows at this time. Please respond to this thread if you are interested and have one or more of the skills necessary to try and pull this off. I'm sure we could poke the LC engineers for tips if we get stuck anywhere along the way. -- Trevor DeVore ScreenSteps www.screensteps.com _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
