xmake.lua

add_rules("mode.release", "mode.debug")
set_languages("cxx11")

option("language")
    set_showmenu(true)
    set_category("swig_options/target_binding_language")
    set_default("lua")
    set_values("lua")
option_end()

option("lua_flavor")
    set_showmenu(true)
    set_category("swig_options/lua_options/lua_flavor")
    set_default("luajit")
    set_values("luajit", "lua5.1", "lua5.2", "lua5.3", "lua5.4")
option_end()

option("backend")
    set_showmenu(true)
    set_category("imgui_options/target_backend")
    set_default("none")
    set_values("none", "glfw_opengl3")
option_end()

option("custom_user_config_enable")
    set_showmenu(true)
    set_category("imgui_options/custom_user_config/enable")
    set_description("See imconfig.h in imgui repo for details. If unsure, set this as `false`.")
    set_default(false)
option_end()

option("custom_user_config_includedir")
    set_showmenu(true)
    set_category("imgui_options/custom_user_config/includedir")
    set_default(".")
option_end()

option("custom_user_config_name")
    set_showmenu(true)
    set_category("imgui_options/custom_user_config/name")
    set_default("my_imgui_config.h")
option_end()

option("glfw_include")
    set_showmenu(true)
    set_category("imgui_options/glfw_options/glfw_include")
    set_default("glu")
    set_values("none", "glu", "glext", "vulkan", "es2", "es3")
option_end()

if is_config("language", "lua.*") then
    if is_config("lua_flavor", "luajit.*") then
        add_requires("luajit 2.1.0-beta3")
    elseif is_config("lua_flavor", "lua5%.1.*") then
        add_requires("lua 5.1")
    elseif is_config("lua_flavor", "lua5%.2.*") then
        add_requires("lua 5.2")
    elseif is_config("lua_flavor", "lua5%.3.*") then
        add_requires("lua 5.3")
    elseif is_config("lua_flavor", "lua5%.4.*") then
        add_requires("lua 5.4")
    end
end

if is_config("backend", "glfw.*") then
    local checks = {"glu", "glext", "vulkan", "es2", "es3"}
    local glfwIncludeStr = "none"
    for i = 1, #checks do if is_config("glfw_include", checks[i]) then glfwIncludeStr = checks[i] end end
    add_requires("glfw", {configs={glfw_include=glfwIncludeStr}})
end

local function getPlatformDefineSymbols()
    return (
        is_plat("windows") and {"-D_WIN32"}
        or is_plat("linux") and {"-D__linux__"}
        or is_plat("bsd") and {"-D__FreeBSD__"}  -- Untested
        or is_plat("macosx") and {"-D__APPLE__"}  -- Untested
        or is_plat("android") and {"-D__ANDROID__"}  -- Untested
        or is_plat("iphoneos") and {"-D__APPLE__", "-DTARGET_OS_IOS"}  -- Untested
        or is_plat("wasm") and {"-D__EMSCRIPTEN__"}  -- Untested
        or {}
    )
end

target("swigimgui")
    set_kind("phony")
    set_default(true)

    before_build(function(target)
        if not is_config("language", "lua.*") then
            cprint("${yellow underline}Bindings to the target language are not implemented! Doing nothing. Please point to a implemented target with `xmake f --language=xxx`. ${clear}")
        end
    end)

    if is_config("language", "lua.*") then
        add_deps("swigimgui_lua")
    end
target_end()

target("swigimgui_lua")
    set_kind("shared")
    set_default(false)

    add_rules("swig.cpp", {moduletype = "lua"})
    if is_config("lua_flavor", "luajit.*") then
        add_packages("luajit")
    elseif is_config("lua_flavor", "lua.*") then
        add_packages("lua")
    end

    local imguiDefs = {"-DIMGUI_DISABLE_OBSOLETE_FUNCTIONS"}
    local swigFlags = {"-no-old-metatable-bindings", "-Iimgui", "-Iimgui/backends"}
    table.join2(swigFlags, imguiDefs)
    table.join2(swigFlags, getPlatformDefineSymbols())

    before_build(function(target)
        swigFlags[#swigFlags+1] = "-DSWIGIMGUI_BACKEND_"..get_config("backend")
        if has_config("custom_user_config_enable") then
            local includedirFlag = "-I"..get_config("custom_user_config_includedir")
            local nameFlag = "-DIMGUI_USER_CONFIG=\""..get_config("custom_user_config_name").."\""
            target:add("cxflags", includedirFlag)
            target:add("cxflags", nameFlag)
            swigFlags[#swigFlags+1] = includedirFlag
            swigFlags[#swigFlags+1] = nameFlag
        end
    end)

    add_includedirs("imgui")
    add_files("imgui/*.cpp")
    add_files("imgui.i", {swigflags = swigFlags})

    add_includedirs("imgui/backends")
    if is_config("backend", ".*glfw.*") then
        add_files("imgui/backends/imgui_impl_glfw.cpp")
    end
    if is_config("backend", ".*opengl3.*") then
        add_files("imgui/backends/imgui_impl_opengl3.cpp")
    end

    if is_config("backend", "glfw.*") then
        add_packages("glfw")
        swigFlags[#swigFlags+1] = "-IbackendWrapper/backendWrapper_glfw"
        add_includedirs("backendWrapper/backendWrapper_glfw")
        add_files("backendWrapper/backendWrapper_glfw/backendWrapper_$(backend).cpp")
        add_files("backendWrapper/backendWrapper_glfw/backendWrapper_glfw.i", {swigflags = swigFlags})
    else
        -- Can add more backend supports here
    end

    add_cxflags(table.unpack(imguiDefs))

target_end()