Library cleanup & fixes (#57)

No need to look for `fmtlib` as we use the bundled one from `spdlog`
Use header only `spdlog` in release builds for speed and also to avoid CRT DLL boundary related issue affecting Windows

Author: jamylak

CMakeLists.txt

@@ -52,16 +52,7 @@ if(CMAKE_BUILD_TYPE STREQUAL "Release")
         find_package(glfw3 REQUIRED)
     endif()
 
-    # Try to find static spdlog (needs fmt too)
-    find_library(SPDLOG_STATIC_LIB NAMES libspdlog.a spdlog PATHS /opt/homebrew/opt/spdlog/lib /usr/local/lib NO_DEFAULT_PATH)
-    find_library(FMT_STATIC_LIB NAMES libfmt.a fmt PATHS /opt/homebrew/opt/fmt/lib /usr/local/lib NO_DEFAULT_PATH)
-    if(SPDLOG_STATIC_LIB AND FMT_STATIC_LIB)
-        message(STATUS "Found static spdlog: ${SPDLOG_STATIC_LIB}")
-        message(STATUS "Found static fmt: ${FMT_STATIC_LIB}")
-        set(spdlog_FOUND TRUE)
-    else()
-        find_package(spdlog REQUIRED)
-    endif()
+    find_package(spdlog REQUIRED)
 else()
     find_package(glfw3 REQUIRED)
     find_package(spdlog REQUIRED)
@@ -148,13 +139,14 @@ endif()
 
 target_link_libraries(${PROJECT_NAME} PRIVATE volk)
 
-if(CMAKE_BUILD_TYPE STREQUAL "Release" AND SPDLOG_STATIC_LIB AND FMT_STATIC_LIB)
-    target_link_libraries(${PROJECT_NAME} PRIVATE ${SPDLOG_STATIC_LIB} ${FMT_STATIC_LIB})
-    target_include_directories(${PROJECT_NAME} PRIVATE /opt/homebrew/opt/spdlog/include)
+if(CMAKE_BUILD_TYPE STREQUAL "Release")
+    set(SPDLOG_TARGET spdlog::spdlog_header_only)
 else()
-    target_link_libraries(${PROJECT_NAME} PRIVATE spdlog::spdlog)
+    set(SPDLOG_TARGET spdlog::spdlog)
 endif()
 
+target_link_libraries(${PROJECT_NAME} PRIVATE ${SPDLOG_TARGET})
+
 target_link_libraries(${PROJECT_NAME} PRIVATE glslang::glslang glslang::glslang-default-resource-limits glslang::SPIRV)
 
 # Include Vulkan headers for types (volk needs them)