I have been migrating my game project from Unity to MonoGame because of various issues I had with Unity. Mostly I use a Windows PC but sometimes I use a Macbook. So I need my project to build on both. MonoGame works fine on Windows, but the process of getting it to work on Mac has not been smooth.

Content Builder

This was the most serious, though not the first, problem. So I will start here.

Shaders

MonoGame comes with official instructions for setting up your development environment on Mac. These contain instructions to run a script in order for shader compilation to work. MonoGame uses a tool mojoshader to transate HLSL shaders into GLSL in the Desktop.GL backend, which is the default cross-platform desktop backend.

This tool only works on Windows. On Linux and Mac, shader compilation requires Wine. When the environment variable MGFXC_WINE_PATH is detected, the MonoGame effect compiler will re-invoke itself via a dotnet installed in the Wine prefix at that path.

The setup script creates this Wine prefix and adds a line to .profile and .zprofile to create that environment variable. The MonoGame project template creates a configuration file in the project directory which points to particular versions of the dotnet-mgcb* tools, so running dotnet mgcb-editor in your project directory will run the correct version of the editor and (provided you ran it from an environment with the MGFXC_WINE_PATH variable set) it will be able to compile effects.

The first problem is that Visual Studio does not (of course) have that environment variable set as a consequence of changing .profile. So starting the content editor from within Visual Studio results in a content editor that cannot build shaders. OK, fine, I will start it from the terminal.

Starting the content builder from the terminal, I was able to get it to find Wine. Hurrah! But effect compilation failed with no error message.

I think the Wine prefix configured by the script was suppressing error messages, but I could be wrong:

# disable wine crash dialog
cat > "$SCRIPT_DIR"/crashdialog.reg <<_EOF_
REGEDIT4
[HKEY_CURRENT_USER\\Software\\Wine\\WineDbg]
"ShowCrashDialog"=dword:00000000
_EOF_

Anyway, I read the source code of the effect compiler to figure out what it was trying to do, and wrote a script to do the same thing. It was something like

export WINEARCH=win64
export WINEDLLOVERRIDES=d3dcompiler_47=n
export WINEPREFIX=/Users/nathan/.winemonogame

assembly="/Users/nathan/.nuget/packages/dotnet-mgcb/3.8.1.303/tools/net6.0/any/mgfxc.dll"

wine64 dotnet "$assembly" "$@"

At this point I did a lot of googling, tried various Wine versions, and got a bunch of different error messages. But nothing actually worked. After some time, and after stumbling across the correct answer in a forum post, it turns out the problem was that the script linked in the official instructions at time of writing installed the 32-bit .NET SDK to the Wine prefix. Recent macs have no support for 32-bit applications. So it did not work. The fix, as mentioned in this forum thread, is to install the 64-bit .NET SDK instead. Indeed, this has already been done in the develop branch of MonoGame. But it has not reached master, and the docs link to the script from master. This meant I had originally dismissed this as the cause of the problem, since I had seen that it had been fixed. It was not until I carefully re-read the setup script I noticed it still had the problem.

What is the Wine prefix setup script doing?

If you boil it down to the essentials, it's not doing all that much.

export WINEARCH=win64
export WINEPREFIX=$HOME/.winemonogame
wine64 wineboot

7z x "/Users/nathan/Downloads/dotnet-sdk.zip" -o"$WINEPREFIX/drive_c/windows/system32/"
cp -f "/Users/nathan/Downloads/d3dcompiler_47.dll" "$WINEPREFIX/drive_c/windows/system32/d3dcompiler_47.dll"

The actual script downloads the .NET SDK. It also downloads Firefox in order to extract d3dcompiler_47.dll.

Textures

I got errors compiling a texture. Thankfully I was not using it, so I deleted it. I will probably end up needing to deal with this at some point

Fonts

SharpFont fails to load freetype. This is a binary compatibility issue.

lipo -info dotnet-mgcb/3.8.1.303/tools/net6.0/any/libfreetype6.dylib 
Non-fat file: dotnet-mgcb/3.8.1.303/tools/net6.0/any/libfreetype6.dylib is architecture: x86_64

lipo -info /usr/local/share/dotnet/dotnet
Non-fat file: /usr/local/share/dotnet/dotnet is architecture: arm64

This is an arm64 mac. The .NET SDK is arm64. The freetype bundled with MonoGame is x64.

I installed freetype using homebrew. Then I copied the .dylib to a temporary directory using the expected name.

#!/bin/bash

export DYLD_LIBRARY_PATH=/Users/nathan/Projects/NGLBuild/NGLMonoGame/libs

dotnet mgcb Content/Fonts/File.spritefont

This worked!

VS Plugin

Does not install successfully. Need to debug this some more. Thankfully everything seems to work without it more or less, so not as urgent.