Add cross-platform .NET build support and NuGet cache configuration

[Mosch0512]

Move .NET ClientLibrary and ConstantsReplacer builds out of the MSVC-only block so they work with any compiler (including MinGW cross-builds from WSL).

Key changes:

• Detect dotnet.exe first (for WSL interop), fallback to dotnet
• Convert Linux paths to Windows UNC paths (wslpath -w) when calling Windows dotnet.exe from WSL, since MSBuild treats '/' as a switch prefix
• Guard wslpath calls with CMAKE_HOST_SYSTEM_NAME to avoid errors on native Windows
• Add MU_NUGET_CACHE_DIR cache variable (defaults to /.nuget)
• Fix MinGW linker order: opengl32/dwmapi must follow imgui static lib
• Add _deps/ to .gitignore for locally-built dependencies

[gemini-code-assist]

Summary of Changes

Hello @Mosch0512, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly improves the build system's flexibility by enabling cross-platform compilation for .NET components, particularly for WSL environments. It addresses specific challenges related to path handling and compiler detection when integrating Windows-based .NET tools within a Linux build context, and provides better control over NuGet caching. Additionally, it includes a fix for MinGW linker order and updates the '.gitignore' for better dependency management.

Highlights

• Cross-platform .NET Build Support: The .NET ClientLibrary and ConstantsReplacer builds have been moved out of the MSVC-specific block, enabling them to work with any compiler, including MinGW cross-builds from WSL.
• WSL Interoperability for .NET: Enhanced detection for 'dotnet.exe' (prioritizing WSL interop) and implemented conversion of Linux paths to Windows UNC paths using 'wslpath -w' when calling Windows 'dotnet.exe' from WSL, to prevent MSBuild from misinterpreting '/' as a switch prefix. These 'wslpath' calls are guarded by 'CMAKE_HOST_SYSTEM_NAME' to avoid errors on native Windows.
• NuGet Cache Configuration: A new cache variable 'MU_NUGET_CACHE_DIR' has been introduced, defaulting to '/.nuget', allowing users to configure the NuGet package cache directory.
• MinGW Linker Order Fix: Corrected the MinGW linker order by ensuring 'opengl32' and 'dwmapi' follow the 'imgui' static library, addressing order-sensitive linking issues.
• Git Ignore Update: Added '_deps/' to the '.gitignore' file to exclude locally-built external dependencies from version control.

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Changelog

• .gitignore
  • Added '_deps/' to ignore locally-built external dependencies.
• src/CMakeLists.txt
  • Relocated .NET ClientLibrary and ConstantsReplacer build logic from the 'if (MSVC)' block to a platform-agnostic section.
  • Implemented 'find_program' to locate 'dotnet.exe' (for WSL interop) or 'dotnet'.
  • Introduced logic to convert Linux paths to Windows UNC paths ('wslpath -w') for variables like 'DOTNET_PROJ', 'DOTNET_TEMP_OUTPUT', 'DOTNET_NUGET_DIR', and 'DOTNET_TEMP_DIR' when 'dotnet.exe' is used from a Linux host.
  • Defined 'MU_NUGET_CACHE_DIR' as a cache variable for specifying the NuGet package cache location.
  • Updated 'dotnet publish' and 'dotnet build' commands to use the dynamically found 'DOTNET_EXECUTABLE' and the platform-appropriate native paths.
  • Added a warning message if the .NET SDK is not found, indicating that the Client Library will not be built.
  • Modified 'target_link_libraries' for the 'Main' target to explicitly link 'opengl32' and 'dwmapi' after 'imgui' when 'ENABLE_EDITOR' is true, specifically for MinGW's order-sensitive linker.

Activity

• No specific activity (comments, reviews, progress updates) has been recorded for this pull request yet.

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[gemini-code-assist]

Code Review

This pull request significantly improves the build process by adding cross-platform support for the .NET components, which is a great enhancement. The changes correctly handle path conversions for WSL environments and introduce a configurable NuGet cache directory. The fix for the MinGW linker order is also a valuable correction. I've included a couple of suggestions to refactor some duplicated logic in the CMake script, which will improve its maintainability. Overall, this is a well-executed and important update.

[Mosch0512]

/gemini review

[gemini-code-assist]

Code Review

This pull request significantly improves the build system by adding cross-platform support for .NET components, which is a great enhancement for developers on different systems, especially WSL. The changes are well-structured, and the addition of a detailed build guide is very helpful. I've identified a minor typo in the new documentation and a couple of opportunities in the CMake scripts to improve maintainability by reducing code duplication. Overall, this is a solid contribution.

[Mosch0512]

/gemini review

[gemini-code-assist]

Code Review

This pull request significantly improves the build system by adding cross-platform support for .NET components, particularly for developers using WSL and MinGW. The changes are well-structured, moving the .NET build logic out of the MSVC-specific block and introducing clever mechanisms like wslpath integration to handle path differences between Linux and Windows. The addition of a configurable NuGet cache directory is also a welcome improvement for build consistency. The new docs/build-guide.md is an excellent and thorough piece of documentation that will surely help developers navigate the various build scenarios.

My review includes a couple of suggestions: one to fix a path in the new build guide, and another to make the wslpath handling in the CMake script more robust against potential failures. Overall, this is a high-quality contribution that enhances the project's developer experience.

[Mosch0512]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces significant improvements to the build system by adding cross-platform .NET build support, particularly for MinGW cross-builds from WSL. The changes are well-thought-out, including the logic to detect the correct dotnet executable and handle path translations. The addition of the build-guide.md provides excellent documentation for the new, more complex build scenarios. I have one suggestion to further improve the maintainability of the new CMake logic. Overall, this is a high-quality contribution that greatly enhances the project's build flexibility.

[Mosch0512]

/gemini review

[gemini-code-assist]

Code Review

This pull request significantly enhances the project's build system by introducing robust cross-platform support for .NET ClientLibrary and ConstantsReplacer builds, moving them out of the MSVC-only block. Key improvements include intelligent detection of dotnet.exe (with WSL interop considerations), proper path translation for Windows UNC paths when building from WSL, and configurable NuGet cache location to mitigate issues with special characters in user profiles. The addition of docs/build-guide.md is an excellent contribution, providing comprehensive instructions and insights into the various build scenarios and their tradeoffs. The fix for MinGW linker order sensitivity for ImGui dependencies also improves cross-platform compatibility. Overall, these changes greatly improve the flexibility and maintainability of the build process.

[Mosch0512]

/gemini summary

[gemini-code-assist]

Summary of Changes

This pull request significantly enhances the project's build system by introducing robust cross-platform support for .NET components, particularly improving compatibility and performance within Windows Subsystem for Linux (WSL) environments. It streamlines the build process by intelligently handling path translations and NuGet caching, ensuring a more consistent and reliable development experience across different operating systems and IDEs. The changes also include crucial linker fixes for MinGW and comprehensive documentation to guide developers through various build configurations.

Highlights

• Cross-Platform .NET Build Support: The build logic for the .NET ClientLibrary and ConstantsReplacer has been refactored to be platform-agnostic, moving it out of the MSVC-specific block. This enables successful builds with various compilers, including MinGW cross-builds from WSL.
• WSL Interoperability for .NET: The build system now intelligently detects dotnet.exe (prioritizing the Windows binary for WSL interop) and converts Linux paths to Windows UNC paths using wslpath -w when invoking Windows dotnet.exe from WSL. This prevents MSBuild from misinterpreting Linux path separators as command-line switches. These wslpath calls are conditionally executed based on CMAKE_HOST_SYSTEM_NAME to avoid errors on native Windows.
• Configurable NuGet Cache: A new CMake cache variable, MU_NUGET_CACHE_DIR, has been introduced, allowing users to specify the NuGet package cache directory. It defaults to <project>/.nuget, addressing potential issues with special characters in user profile paths and improving build reliability.
• MinGW Linker Order Fix: The MinGW linker order has been corrected for the Main target. opengl32 and dwmapi are now explicitly linked after the imgui static library when ENABLE_EDITOR is active, resolving order-sensitive linking issues specific to MinGW.
• Comprehensive Build Guide Documentation: A new docs/build-guide.md file has been added, providing detailed explanations of the build system's behavior across supported environments (WSL, CLion, Visual Studio), setup instructions, performance considerations, and directory layouts for various scenarios.
• Updated Build Requirements and Git Ignore: The minimum CMake requirement has been updated to 3.25 in README.md. Additionally, _deps/ has been added to .gitignore to exclude locally-built external dependencies from version control.

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Changelog

• .gitignore
  • Added _deps/ to exclude locally-built external dependencies from version control.
• README.md
  • Updated the minimum CMake requirement from 3.16 to 3.25.
  • Revised the working directory instruction for CLion to point to the build output directory, clarifying that game assets are copied there automatically.
• docs/build-guide.md
  • Added a new comprehensive guide detailing build system mechanics, supported scenarios (WSL, CLion, Windows native), setup instructions, performance notes, and directory layouts for each environment.
• src/CMakeLists.txt
  • Moved .NET ClientLibrary and ConstantsReplacer build logic out of the if (MSVC) block to enable cross-platform compilation.
  • Implemented find_program to prioritize dotnet.exe (for Windows/WSL interop) and fallback to dotnet (for Linux).
  • Added a warning message if a Linux dotnet is found but the target is Windows, as cross-OS Native AOT is not supported.
  • Introduced a mu_native_path CMake function to convert Linux paths to Windows UNC paths (wslpath -w) when dotnet.exe is used from a Linux host, ensuring correct path interpretation by MSBuild.
  • Defined MU_NUGET_CACHE_DIR as a cache variable, defaulting to ${CMAKE_SOURCE_DIR}/.nuget, to configure the NuGet package cache location.
  • Updated dotnet publish and dotnet build commands to use the dynamically found DOTNET_EXECUTABLE and the newly translated native paths for project files, output directories, and environment variables.
  • Added a warning if the .NET SDK is not found, indicating that the Client Library will not be built.
  • Modified target_link_libraries for the Main target to conditionally link opengl32 and dwmapi after imgui for MinGW builds, addressing linker order sensitivity.

Activity

• A bot provided an initial summary of the pull request, highlighting key changes such as cross-platform .NET build support, WSL interoperability, NuGet cache configuration, MinGW linker order fix, and .gitignore updates.
• The author issued multiple /gemini review commands, requesting automated code reviews.
• The author issued a /gemini summary command, requesting an updated summary.
• A bot suggested simplifying path conversion logic for the client library by initializing native path variables before conditional wslpath calls.
• A bot suggested a similar simplification for the ConstantsReplacer path conversion logic.
• A bot identified a typo in README.md, suggesting Visual Studio 2022 instead of 2026.
• A bot recommended encapsulating the wslpath conversion logic into a CMake macro to reduce code duplication, particularly for the ConstantsReplacer target.
• A bot suggested making the opengl32 and dwmapi linking conditional for MinGW only, to avoid redundant linking for other toolchains.
• A bot pointed out an incorrect imgui submodule path in a git config command example within docs/build-guide.md.
• A bot advised adding a success check for the wslpath command within the mu_native_path macro (or function) to improve robustness and provide clearer error messages.
• A bot recommended converting the mu_native_path macro to a CMake function for better variable scope management, given the project's CMake version requirement.
• A bot queried the meaning of "Claude Code" mentioned in the new build guide documentation, suggesting clarification for external users.