Find libepoxy without pkg-config (MSVC + vcpkg); Windows build notes

CMakeLists.txt

@@ -23,9 +23,24 @@ include(FetchContent)
 # --- Dependencies -----------------------------------------------------------
 # System packages are preferred; anything missing is fetched.
 find_package(OpenGL REQUIRED)
-find_package(PkgConfig REQUIRED)
+# libepoxy: pkg-config where available (Linux, MSYS2), else a plain header/library search
+# (MSVC + vcpkg ships no pkg-config by default).
 if(NOT TARGET PkgConfig::EPOXY)
-  pkg_check_modules(EPOXY REQUIRED IMPORTED_TARGET epoxy)
+  find_package(PkgConfig QUIET)
+  if(PkgConfig_FOUND)
+    pkg_check_modules(EPOXY QUIET IMPORTED_TARGET epoxy)
+  endif()
+  if(NOT TARGET PkgConfig::EPOXY)
+    find_path(EPOXY_INCLUDE_DIR epoxy/gl.h)
+    find_library(EPOXY_LIBRARY NAMES epoxy libepoxy epoxy-0)
+    if(NOT EPOXY_INCLUDE_DIR OR NOT EPOXY_LIBRARY)
+      message(FATAL_ERROR "libepoxy not found (install it, e.g. pacman -S libepoxy, "
+                          "pacman -S mingw-w64-ucrt-x86_64-libepoxy or vcpkg install libepoxy)")
+    endif()
+    add_library(PkgConfig::EPOXY UNKNOWN IMPORTED)
+    set_target_properties(PkgConfig::EPOXY PROPERTIES IMPORTED_LOCATION "${EPOXY_LIBRARY}"
+                          INTERFACE_INCLUDE_DIRECTORIES "${EPOXY_INCLUDE_DIR}")
+  endif()
 endif()
 
 if(NOT TARGET glfw)

README.md

@@ -56,6 +56,12 @@ ninja -C build
 ./build/hd2d_demo
 ```
 
+Windows: in the MSYS2 **UCRT64** shell,
+`pacman -S --needed mingw-w64-ucrt-x86_64-{gcc,cmake,ninja,pkgconf,glfw,glm,libepoxy}` and the
+same `cmake` / `ninja` commands. With Visual Studio, `vcpkg install glfw3 glm libepoxy` and pass
+`-DCMAKE_TOOLCHAIN_FILE=<vcpkg>/scripts/buildsystems/vcpkg.cmake`. libepoxy is found through
+pkg-config when present, else by a plain header/library search.
+
 The asset path is baked in at configure time (`HD2D_ASSET_DIR`), so the demo can
 be run from any working directory.