#
# Irrlicht 3D engine
#
cmake_minimum_required(VERSION 3.8)
project(Irrlicht)

set_property(GLOBAL PROPERTY USE_FOLDERS ON)
    
# Irrlicht directories
# -------------------------------------------------------------------------------------------------
set(IRR_ROOT_DIR "")
set(IRR_SRC_DIR "source/Irrlicht")
set(IRR_INC_DIR "include")

# Options
# -------------------------------------------------------------------------------------------------
set(DXSDK "")
if(DEFINED ENV{DXSDK_DIR})
    set(DXSDK "ENV{DXSDK_DIR}")
endif()

set(IRR_FAST_MATH 0 CACHE BOOL "Whether to enable fast maths (at the expense of precision)")
set(IRR_SHARED_LIB 1 CACHE BOOL "Whether to generate shared libraries instead of static libraries")
set(IRR_DIRECTX_SDK ${DXSDK} CACHE PATH "Path to the DirectX SDK (for DirectX 9, this folder should contain /Include, /Lib)")
set(IRR_BUILD_TOOLS 0 CACHE BOOL "Whether to generate the tools")

# Some helper functions
# -------------------------------------------------------------------------------------------------
function(glob_c_cpp_sources result folder)
    file(GLOB res
        "${folder}/*.c"
        "${folder}/*.cpp"
        "${folder}/*.h"
        "${folder}/*.hpp"
        "${folder}/*.rc")
    set(${result} ${res} PARENT_SCOPE)
endfunction()

# Source files
# -------------------------------------------------------------------------------------------------
glob_c_cpp_sources(IRR_SRC_FILES                    ${IRR_SRC_DIR})
glob_c_cpp_sources(IRR_SRC_FILES_INTERFACE          ${IRR_INC_DIR})
glob_c_cpp_sources(IRR_SRC_FILES_AESGLADMAN         ${IRR_SRC_DIR}/aesGladman)
glob_c_cpp_sources(IRR_SRC_FILES_LZMA               ${IRR_SRC_DIR}/lzma)

glob_c_cpp_sources(IRR_TOOL_FILES_FILE_TO_HEADER    ${IRR_ROOT_DIR}/tools/FileToHeader/)
glob_c_cpp_sources(IRR_TOOL_FILES_GUI_EDITOR        ${IRR_ROOT_DIR}/tools/GUIEditor/)
glob_c_cpp_sources(IRR_TOOL_FILES_FONT_TOOL         ${IRR_ROOT_DIR}/tools/IrrFontTool/newFontTool/)
glob_c_cpp_sources(IRR_TOOL_FILES_MESH_CONVERTER    ${IRR_ROOT_DIR}/tools/MeshConverter/)
    
# Group files
# -------------------------------------------------------------------------------------------------
source_group(Irrlicht\\engine           FILES ${IRR_SRC_FILES})
source_group(Irrlicht\\interface        FILES ${IRR_SRC_FILES_INTERFACE})
source_group(Irrlicht\\libs\\aesGladman FILES ${IRR_SRC_FILES_AESGLADMAN})
source_group(Irrlicht\\libs\\lzma       FILES ${IRR_SRC_FILES_LZMA})

# Library files
# -------------------------------------------------------------------------------------------------
find_package(ZLIB REQUIRED)
find_package(PNG REQUIRED)
find_package(JPEG REQUIRED)
find_package(BZip2 REQUIRED)
#find_package(LIBLZMA REQUIRED) # LIBLZMA does not export _LzmaDecode

# Irrlicht target
# -------------------------------------------------------------------------------------------------
set(IRR_ALL_SRC_FILES
    ${IRR_SRC_FILES}
    ${IRR_SRC_FILES_INTERFACE}
    ${IRR_SRC_FILES_AESGLADMAN}
    ${IRR_SRC_FILES_LZMA}
    )

if(${IRR_SHARED_LIB})
    add_library(Irrlicht SHARED ${IRR_ALL_SRC_FILES})
else()
    add_library(Irrlicht STATIC ${IRR_ALL_SRC_FILES})
endif()

target_link_libraries(Irrlicht PRIVATE 
    ${PNG_LIBRARY} 
    ${JPEG_LIBRARY} 
    ${ZLIB_LIBRARY}
    ${BZIP2_LIBRARY}
    )

if(IRR_BUILD_TOOLS)
    add_executable(FileToHeader         ${IRR_TOOL_FILES_FILE_TO_HEADER})

    add_executable(GUIEditor            ${IRR_TOOL_FILES_GUI_EDITOR})
    target_link_libraries(GUIEditor     Irrlicht)

    add_executable(FontTool             ${IRR_TOOL_FILES_FONT_TOOL})
    target_link_libraries(FontTool      Irrlicht)

    add_executable(MeshConverter        ${IRR_TOOL_FILES_MESH_CONVERTER})
    target_link_libraries(MeshConverter Irrlicht)
endif()

# Target properties (for compilation & export)
# -------------------------------------------------------------------------------------------------
target_include_directories(Irrlicht
    PRIVATE ${IRR_SRC_DIR}
    PRIVATE ${IRR_SRC_DIR}/aesGladman
    PRIVATE ${BZIP2_INCLUDE_DIR}
    PRIVATE ${JPEG_INCLUDE_DIR}
    PRIVATE ${LIBPNG_INCLUDE_DIR}
    PRIVATE ${IRR_SRC_DIR}/lzma
    PRIVATE ${ZLIB_INCLUDE_DIR}
    )

# I dont realy understand why this is necesary or what it is doing,
# but it is necesarry to build and export a package. 
# See: https://cmake.org/cmake/help/v3.8/command/target_include_directories.html
target_include_directories(Irrlicht PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    $<INSTALL_INTERFACE:include/irrlicht>  # <prefix>/include/irrlicht
)

if(NOT ${IRR_DIRECTX_SDK} STREQUAL "")
    target_include_directories(Irrlicht PRIVATE ${IRR_DIRECTX_SDK}/Include)
    if(${CMAKE_SIZEOF_VOID_P} EQUAL 4)
        set(DX_LIBS ${IRR_DIRECTX_SDK}/Lib/x86)
    else()
        set(DX_LIBS ${IRR_DIRECTX_SDK}/Lib/x64)
    endif()
    target_link_libraries(Irrlicht
        PRIVATE ${DX_LIBS}/d3dx9.lib
        PRIVATE ${DX_LIBS}/dinput8.lib
        PRIVATE ${DX_LIBS}/dxguid.lib)
else()
    target_compile_definitions(Irrlicht PRIVATE NO_IRR_COMPILE_WITH_DIRECT3D_9_)
endif()

if(NOT ${IRR_SHARED_LIB})
    target_compile_definitions(Irrlicht PUBLIC _IRR_STATIC_LIB_)
endif()

# Disable Irrlicht building already provided dependencies
target_compile_definitions(Irrlicht
    PRIVATE NO_IRR_USE_NON_SYSTEM_ZLIB_
    PRIVATE NO_IRR_USE_NON_SYSTEM_LIB_PNG_
    PRIVATE NO_IRR_USE_NON_SYSTEM_BZLIB_
    PRIVATE NO_IRR_USE_NON_SYSTEM_JPEG_LIB_
    )

# Per platform config
# -------------------------------------------------------------------------------------------------

# Export symbols
target_compile_definitions(Irrlicht PRIVATE IRRLICHT_EXPORTS)

if(WIN32)
    # Import the symbols of bzip2
    target_compile_definitions(Irrlicht PRIVATE BZ_IMPORT)

    # Disable the ton of warnings from standard library
    target_compile_definitions(Irrlicht PRIVATE _CRT_SECURE_NO_WARNINGS)

    # Multi processor compilation
    target_compile_options(Irrlicht PRIVATE /MP)

    # Fast math options
    if(${IRR_FAST_MATH})
        target_compile_options(Irrlicht PRIVATE /fp:fast)
        message("Fast Math Enabled")
        # SSE2 is automatically activated on x64
        if(${CMAKE_SIZEOF_VOID_P} EQUAL 4)
            target_compile_options(Irrlicht PRIVATE /arch:SSE2)
        endif()
    endif()

elseif(UNIX)
    # Standard mode
    target_compile_options(Irrlicht
        PRIVATE -Wall
        PRIVATE -pipe
        PRIVATE -fno-exceptions
        PRIVATE -fno-strict-aliasing)
    
    # Disable RTTI on C++ files only (no sense for C files)
    set_source_files_properties(${IRR_SRC_FILES} ${IRR_SRC_FILES_AESGLADMAN}
        PROPERTIES COMPILE_FLAGS -fno-rtti)

    # Debug macro
    target_compile_options(Irrlicht PRIVATE $<$<CONFIG:Debug>:-D_DEBUG>)

    # X11 and OpenGL
    target_link_libraries(Irrlicht
        PRIVATE X11
        PRIVATE GL
        PRIVATE Xxf86vm)
endif()

# Installation
# -------------------------------------------------------------------------------------------------
install(
    TARGETS Irrlicht
    EXPORT Irrlicht
    RUNTIME DESTINATION bin
    LIBRARY DESTINATION lib
    ARCHIVE DESTINATION lib
)

install(FILES ${IRR_SRC_FILES_INTERFACE} DESTINATION "include/irrlicht" CONFIGURATIONS Release)

if(IRR_BUILD_TOOLS)
    install(
        TARGETS FileToHeader GUIEditor FontTool MeshConverter 
        RUNTIME DESTINATION tools/irrlicht/
        CONFIGURATIONS Release
    )
endif()

install(EXPORT Irrlicht FILE irrlicht-targets.cmake DESTINATION share/irrlicht)