# #
# # Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
# #
# # Redistribution and use in source and binary forms, with or without
# # modification, are permitted provided that the following conditions
# # are met:
# #  * Redistributions of source code must retain the above copyright
# #    notice, this list of conditions and the following disclaimer.
# #  * Redistributions in binary form must reproduce the above copyright
# #    notice, this list of conditions and the following disclaimer in the
# #    documentation and/or other materials provided with the distribution.
# #  * Neither the name of NVIDIA CORPORATION nor the names of its
# #    contributors may be used to endorse or promote products derived
# #    from this software without specific prior written permission.
# #
# # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
# # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# # PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# # PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
# # OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# #

# # Locate the OptiX distribution.  Search relative to the SDK first, then look in the system.

if(TARGET OptiX::OptiX)
    return()
endif()

find_package(CUDAToolkit REQUIRED)

set(OptiX_INSTALL_DIR "OptiX_INSTALL_DIR-NOTFOUND" CACHE PATH "Path to the installed location of the OptiX SDK.")

if(NOT OptiX_FIND_VERSION)
    set(OptiX_FIND_VERSION "*")
endif()

# If they haven't specified a specific OptiX SDK install directory, search likely default locations for SDKs.
if(NOT OptiX_INSTALL_DIR)
    if(CMAKE_HOST_WIN32)
        # This is the default OptiX SDK install location on Windows.
        file(GLOB OPTIX_SDK_DIR "$ENV{ProgramData}/NVIDIA Corporation/OptiX SDK ${OptiX_FIND_VERSION}*")
    else()
        # On linux, there is no default install location for the SDK, but it does have a default subdir name.
        foreach(dir "/opt" "/usr/local" "$ENV{HOME}" "$ENV{HOME}/Downloads")
            file(GLOB OPTIX_SDK_DIR "${dir}/NVIDIA-OptiX-SDK-${OptiX_FIND_VERSION}*")
            if(OPTIX_SDK_DIR)
                break()
            endif()
        endforeach()
    endif()

    # If we found multiple SDKs, try to pick the one with the highest version number
    list(LENGTH OPTIX_SDK_DIR len)
    if(${len} GREATER 0)
        list(SORT OPTIX_SDK_DIR)
        list(REVERSE OPTIX_SDK_DIR)
        list(GET OPTIX_SDK_DIR 0 OPTIX_SDK_DIR)
    endif()
endif()

find_path(OptiX_ROOT_DIR NAMES include/optix.h PATHS ${OptiX_INSTALL_DIR} ${OPTIX_SDK_DIR} REQUIRED)
file(READ "${OptiX_ROOT_DIR}/include/optix.h" header)
string(REGEX REPLACE "^.*OPTIX_VERSION ([0-9]+)([0-9][0-9])([0-9][0-9])[^0-9].*$" "\\1.\\2.\\3" OPTIX_VERSION ${header})

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(OptiX
    FOUND_VAR OptiX_FOUND
    VERSION_VAR OPTIX_VERSION
    REQUIRED_VARS
        OptiX_ROOT_DIR
    REASON_FAILURE_MESSAGE
        "OptiX installation not found. Please use CMAKE_PREFIX_PATH or OptiX_INSTALL_DIR to locate 'include/optix.h'."
)

set(OptiX_INCLUDE_DIR ${OptiX_ROOT_DIR}/include)

add_library(OptiX::OptiX INTERFACE IMPORTED)
target_include_directories(OptiX::OptiX INTERFACE ${OptiX_INCLUDE_DIR} ${CUDAToolkit_INCLUDE_DIRS})
target_link_libraries(OptiX::OptiX INTERFACE ${CMAKE_DL_LIBS})