Use glad, glm system packages automatically if available

CMakeLists.txt

@@ -24,6 +24,8 @@ find_package(FontConfig QUIET)
 find_package(FreeImage  QUIET)
 find_package(Freetype   REQUIRED)
 find_package(Sphinx     QUIET)
+find_package(glad CONFIG QUIET)
+find_package(glm CONFIG QUIET)
 
 if(UNIX)
     dependency_check(FontConfig_FOUND
@@ -59,28 +61,44 @@ fg_deprecate(WITH_FREEIMAGE FG_WITH_FREEIMAGE)
 fg_deprecate(USE_STATIC_FREEIMAGE FG_USE_STATIC_FREEIMAGE)
 fg_deprecate(WITH_TOOLKIT FG_USE_WINDOW_TOOLKIT)
 
-message(STATUS "FreeImage Support turned ON")
-
 if(Boost_FOUND AND NOT TARGET Boost::boost)
     add_library(Boost::boost INTERFACE IMPORTED)
     set_property(TARGET Boost::boost
         PROPERTY INTERFACE_INCLUDE_DIRECTORIES ${Boost_INCLUDE_DIRS})
 endif(Boost_FOUND AND NOT TARGET Boost::boost)
 
-FetchContent_Declare(
-    ${glad_prefix}
-    GIT_REPOSITORY https://github.com/arrayfire/glad.git
-    GIT_TAG obj_lib
-)
-FetchContent_Populate(${glad_prefix})
-FetchContent_Declare(
-    ${glm_prefix}
-    GIT_REPOSITORY https://github.com/g-truc/glm.git
-    GIT_TAG 0.9.9.8
-)
-FetchContent_Populate(${glm_prefix})
+if(NOT TARGET glad::glad) # find_package(glad) failed
+    FetchContent_Declare(
+        ${glad_prefix}
+        GIT_REPOSITORY https://github.com/arrayfire/glad.git
+        GIT_TAG obj_lib
+        )
+    fg_check_and_populate(${glad_prefix})
+    add_subdirectory(${${glad_prefix}_SOURCE_DIR} ${${glad_prefix}_BINARY_DIR})
+
+    add_library(forge_glad STATIC $<TARGET_OBJECTS:glad_obj_lib>)
+    target_link_libraries(forge_glad PUBLIC ${CMAKE_DL_LIBS})
+    target_include_directories(forge_glad
+        PUBLIC
+        $<BUILD_INTERFACE:$<TARGET_PROPERTY:glad_obj_lib,INTERFACE_INCLUDE_DIRECTORIES>>
+        )
+else()
+    add_library(forge_glad ALIAS glad::glad)
+endif()
+
+if(NOT TARGET glm::glm AND NOT TARGET glm) # find_package(glm) failed
+    FetchContent_Declare(
+        ${glm_prefix}
+        GIT_REPOSITORY https://github.com/g-truc/glm.git
+        GIT_TAG 0.9.9.8
+        )
+    fg_check_and_populate(${glm_prefix})
+    add_library(glm INTERFACE IMPORTED)
+    set_target_properties(glm PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES "${${glm_prefix}_SOURCE_DIR}"
+        )
+endif()
 
-add_subdirectory(${${glad_prefix}_SOURCE_DIR} ${${glad_prefix}_BINARY_DIR})
 add_subdirectory(src/backend/common)
 add_subdirectory(src/backend/glsl_shaders)
 add_subdirectory(src/api/c)
@@ -175,6 +193,8 @@ mark_as_advanced(
     Z_VCPKG_PWSH_PATH
     Z_VCPKG_CL
     _VCPKG_INSTALLED_DIR
+    glm_DIR
+    glad_DIR
 )
 
 include(ForgeCPackConfig)

CMakeModules/ForgeConfigureDepsVars.cmake

@@ -43,3 +43,10 @@ if(FG_BUILD_OFFLINE)
   set_fetchcontent_src_dir(assets_prefix "glad")
   set_fetchcontent_src_dir(testdata_prefix "glm")
 endif()
+
+macro(fg_check_and_populate prefix)
+  FetchContent_GetProperties(${prefix})
+  if(NOT ${prefix}_POPULATED)
+    FetchContent_Populate(${prefix})
+  endif()
+endmacro()

CMakeModules/ForgeInternalUtils.cmake

@@ -91,10 +91,26 @@ function(fg_set_target_compilation_props target)
 
     target_include_directories(${target}
         SYSTEM PRIVATE
-        ${${glm_prefix}_SOURCE_DIR}
         $<TARGET_PROPERTY:Boost::boost,INTERFACE_INCLUDE_DIRECTORIES>
-        $<TARGET_PROPERTY:glad_obj_lib,INTERFACE_INCLUDE_DIRECTORIES>
+        $<TARGET_PROPERTY:forge_glad,INTERFACE_INCLUDE_DIRECTORIES>
         )
+    # As imported targets can't be aliased until CMake 3.11, below is a temporary
+    # work around until we move to a CMake version >= 3.11
+    if(TARGET glm::glm)
+        target_include_directories(${target}
+            SYSTEM PRIVATE
+            $<TARGET_PROPERTY:glm::glm,INTERFACE_INCLUDE_DIRECTORIES>
+            )
+    elseif(TARGET glm)
+        target_include_directories(${target}
+            SYSTEM PRIVATE
+            $<TARGET_PROPERTY:glm,INTERFACE_INCLUDE_DIRECTORIES>
+            )
+    else()
+        # Ideally it wouldn't reach here, just in case of corner case
+        # I couldn't think of or someother cmake bug
+        message(FATAL_ERROR "Please install glm dependency")
+    endif()
     target_include_directories(${target}
         PUBLIC
         $<INSTALL_INTERFACE:${FG_INSTALL_INC_DIR}>

src/backend/CMakeLists.txt

@@ -34,7 +34,6 @@ add_dependencies(${BkndTargetName} ${glsl_shader_targets})
 
 target_sources(${BkndTargetName}
     PRIVATE
-    $<TARGET_OBJECTS:glad_obj_lib>
     $<TARGET_OBJECTS:forge_wtk>
     $<TARGET_OBJECTS:forge_common_obj_lib>
     $<TARGET_OBJECTS:forge_c_api_obj_lib>
@@ -51,7 +50,7 @@ target_include_directories(${BkndTargetName}
 if(FG_WITH_FREEIMAGE)
     target_compile_definitions(${BkndTargetName} PRIVATE USE_FREEIMAGE)
     if(FG_USE_STATIC_FREEIMAGE)
-        target_link_libraries(${BkndTargetName} PRIVATE FreeImage::FreeImage_STATIC)
+        target_link_libraries(${BkndTargetName} PUBLIC FreeImage::FreeImage_STATIC)
     else()
         target_link_libraries(${BkndTargetName} PRIVATE FreeImage::FreeImage)
     endif()
@@ -61,6 +60,7 @@ endif()
 target_link_libraries(${BkndTargetName}
     PRIVATE
     Boost::boost
+    forge_glad
     ${FREETYPE_LIBRARIES}
     ${CMAKE_DL_LIBS}
     )

vcpkg/vcpkg.json

@@ -1,6 +1,6 @@
 {
   "name": "forge",
-  "version-string": "1.1.0",
+  "version": "1.1.0",
   "supports": "x64",
   "dependencies": [
     "boost-functional",
@@ -10,7 +10,9 @@
       "name": "fontconfig",
       "platform": "!windows"
     },
+    "glad",
     "glfw3",
+    "glm",
     "sdl2"
   ]
 }