[client] windows: add native clang-cl build

Build the Windows client against the MSVC ABI while retaining clang
language support. Use vcpkg for ANGLE and libsamplerate, and build
MsQuic with its bundled static OpenSSL.

doc/build_client_windows.rst

@@ -0,0 +1,44 @@
+.. _build_client_windows:
+
+Build the Windows client
+########################
+
+The Windows client uses ``clang-cl`` and the MSVC ABI. ANGLE continues to
+provide EGL and OpenGL ES, while MsQuic and its bundled OpenSSL are linked
+statically.
+
+Requirements
+------------
+
+Install the following tools:
+
+- Visual Studio 2022 Build Tools with the Desktop development with C++
+  workload, Clang tools for Windows, and a Windows SDK
+- CMake 3.21 or newer
+- Ninja
+- Git
+- Perl
+- NASM
+- vcpkg
+
+Set ``VCPKG_ROOT`` to the vcpkg checkout. The client manifest installs native
+MSVC-ABI builds of ANGLE and libsamplerate automatically.
+
+Building
+--------
+
+Open an x64 Native Tools command prompt or Developer PowerShell, then run:
+
+.. code:: powershell
+
+   git submodule update --init --recursive
+   cd client
+   cmake --preset windows-clangcl
+   cmake --build --preset windows-clangcl-release
+
+The executable is written beneath ``client/build/windows-clangcl``. The
+vcpkg toolchain copies the required ANGLE and libsamplerate runtime DLLs
+beside it.
+
+The native build deliberately does not consume MinGW ``.a`` or ``.dll.a``
+libraries. All statically linked code must use the MSVC ABI.

doc/index.rst

@@ -13,6 +13,7 @@ memory for frames, and a native Linux client for display and input.
    quickstart
 
    build
+   build_client_windows
    install
 
    usage

doc/words.txt

@@ -1,3 +1,5 @@
+ABI
+ANGLE
 Anime4K
 backend
 backends
@@ -9,6 +11,7 @@ cadence
 cgroups
 checkboxes
 clang
+clang-cl
 cmake
 codec
 compositor
@@ -53,6 +56,7 @@ lexically
 libdecor
 libpipewire
 libpulse
+libsamplerate
 libvirt
 linux
 LookingGlass
@@ -65,9 +69,12 @@ mingw
 mipmapping
 modprobe
 mpv
+MsQuic
+MSVC
 msys
 multisampling
 namespace
+NASM
 Navi
 NvFBC
 Nvidia
@@ -123,6 +130,7 @@ upscaled
 upscaler
 upscales
 upscaling
+vcpkg
 viewport
 virt
 VirtIO