Make samples use Metal instead of OpenGL on macOS?

[jwwalker]

How can I build the samples to use Metal on macOS? I am not very familiar with CMake and Ninja. A commit on March 2 [1189c9e] seriously broke my Metal rendering, and if I could reproduce the problem in a sample, that would be easier than trying to make one of my Xcode projects self-contained enough to put in a bug report.

[romainguy]

There's nothing special to do. The main thing is to request a Metal backend when you create the Engine in your app. Some of our samples like gltf_viewer let you pick the backend with a command line flag (-a metal when running the sample).

[romainguy]

Also @pixelflinger who wrote that big refactor

[jwwalker]

Thanks. For the record, rendertarget is another sample that accepts -a metal.

[jwwalker]

For posterity I will also note that one can change the backend for all the samples that don't take command line parameters by editing filament/libs/filamentapp/include/filamentapp/Config.h, where it sets the default value of Config.backend.

[romainguy]

You can do a lot of things by changing the source code ^^

[jwwalker]

My point was that one doesn't need to change the source code of each sample individually.