FindWrapOpenGL.cmake

# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

# We can't create the same interface imported target multiple times, CMake will complain if we do
# that. This can happen if the find_package call is done in multiple different subdirectories.
if(TARGET WrapOpenGL::WrapOpenGL)
    set(WrapOpenGL_FOUND ON)
    return()
endif()

set(WrapOpenGL_FOUND OFF)

find_package(OpenGL ${WrapOpenGL_FIND_VERSION})

if (OpenGL_FOUND)
    set(WrapOpenGL_FOUND ON)

    add_library(WrapOpenGL::WrapOpenGL INTERFACE IMPORTED)
    if(APPLE)
        # On Darwin platforms FindOpenGL sets IMPORTED_LOCATION to the absolute path of the library
        # within the framework. This ends up as an absolute path link flag, which we don't want,
        # because that makes our .prl files un-relocatable.
        # Extract the framework path instead, and use that in INTERFACE_LINK_LIBRARIES,
        # which CMake ends up transforming into a reloctable -framework flag.
        # See https://gitlab.kitware.com/cmake/cmake/-/issues/20871 for details.
        get_target_property(__opengl_fw_lib_path OpenGL::GL IMPORTED_LOCATION)
        if(__opengl_fw_lib_path)
            get_filename_component(__opengl_fw_path "${__opengl_fw_lib_path}" DIRECTORY)
        endif()

        if(NOT __opengl_fw_path)
            # Just a safety measure in case if no OpenGL::GL target exists.
            set(__opengl_fw_path "-framework OpenGL")
        endif()

        find_library(WrapOpenGL_AGL NAMES AGL)
        if(WrapOpenGL_AGL)
            set(__opengl_agl_fw_path "${WrapOpenGL_AGL}")
        endif()
        if(NOT __opengl_agl_fw_path)
            set(__opengl_agl_fw_path "-framework AGL")
        endif()

        target_link_libraries(WrapOpenGL::WrapOpenGL INTERFACE ${__opengl_fw_path})
        target_link_libraries(WrapOpenGL::WrapOpenGL INTERFACE ${__opengl_agl_fw_path})
    else()
        target_link_libraries(WrapOpenGL::WrapOpenGL INTERFACE OpenGL::GL)
    endif()
endif()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(WrapOpenGL DEFAULT_MSG WrapOpenGL_FOUND)