Purpose of builds

• Verify that ANGLE is a viable alternative to native OpenGL for Windows users
• Collect GPU and driver information (esp. for those who get crashes with Intel drivers)
• Collect general user feedback on performance (mainly from those who had to disable OpenGL canvas for reasons)

Data to collect

• Probably the Qt logging output, but it would be too troublesome to require testers to have DebugView installed, so perhaps we should use qInstallMessageHandler to capture the wanted messages and capture them to somewhere easily accessible by the user
  • Logging category`qt.qpa.gl` (mainly for the messages during startup)
  • Output from KisOpenGL::* (or maybe they are already available in "system information")
  • Other logs in case it crashed.
• System information from Krita
• Hardware specs as reported by testers themselves
• Whether they can enable OpenGL canvas and whether they get crashes on stable / normal 4.0 pre-alpha
• The testers' brief impressions (exp. on the performance)

Specific changes to be made

• Add a message box on startup to warn users about this build being only for testing ANGLE renderer
  • Something like "This build uses the ANGLE renderer in place with the OpenGL renderer for testing purpose. For details, please see <some news post URL>". Does anyone have any suggestions for the specific wording?
  • Have buttons for choosing "Desktop OpenGL" or "ANGLE".
• Rename "OpenGL" checkbox in config UI to be "OpenGL / ANGLE renderer" instead and have it disabled (force checked), and add a message stating "this is a test build, cannot disable" blah blah
• Disable writing to the "OpenGL enabled" option and the OpenGL crash check code (to avoid affecting the normal versions)
• Use qInstallMessageHandler to capture qt.qpa.gl logging during startup and show in "System information" dialog in Krita
• Use qInstallMessageHandler to capture all logs to krita-debug.log in the parent directory of krita.exe
• Set DrMingw backtrace dump file to krita-crash.log in the parent directory of krita.exe

Note: will need to update the URL on the message box