fltk/CMakeLists.txt

#
# Main CMakeLists.txt to build the FLTK project using CMake (www.cmake.org)
# Originally written by Michael Surette
#
# Copyright 1998-2023 by Bill Spitzak and others.
#
# This library is free software. Distribution and use rights are outlined in
# the file "COPYING" which should have been included with this file.  If this
# file is missing or damaged, see the license at:
#
#     https://www.fltk.org/COPYING.php
#
# Please see the following page on how to report bugs and issues:
#
#     https://www.fltk.org/bugs.php
#

#######################################################################
# Set CMake minimum version first: must be before `project()`
#######################################################################

# Minimum CMake version required by FLTK 1.4

# Note 1: Linking against OBJECT libraries (fluid, test) requires
#         at least CMake 3.12.0
# Note 2: Used in fluid since 05/2023,
#         used for Windows (MSVC) shared lib builds much earlier

cmake_minimum_required (VERSION 3.12.0 FATAL_ERROR) # 05/2023

#######################################################################

# Use "legacy mode" of FindOpenGL (avoid CMake developer warning).
# Note: we're using FindOpenGL with `OPENGL_LIBRARIES` and not (yet)
# the `OpenGL::GL` target. This may be changed in the future.
# See https://cmake.org/cmake/help/latest/policy/CMP0072.html
# Update Feb 28, 2021: To avoid a warning about "OLD" policies we set
# OpenGL_GL_PREFERENCE directly to "LEGACY" (other option: "GLVND").

# if (POLICY CMP0072)
#   cmake_policy (SET CMP0072 OLD)
# endif ()

set (OpenGL_GL_PREFERENCE LEGACY)

#######################################################################
# define the FLTK project and version
#######################################################################

project (FLTK VERSION 1.4.0)

#######################################################################
# include macro and function definitions for general usage
#######################################################################

include (CMake/fl_debug_var.cmake)
include (CMake/fl_debug_pkg.cmake)
include (CMake/fl_add_library.cmake)
include (CMake/compatibility.cmake)

if (0)
  fl_debug_var (FLTK_VERSION_MAJOR)
  fl_debug_var (FLTK_VERSION_MINOR)
  fl_debug_var (FLTK_VERSION_PATCH)
  fl_debug_var (FLTK_VERSION)
  fl_debug_var (CMAKE_VERSION)
endif ()

#######################################################################
# basic setup
#######################################################################
include (CMake/setup.cmake)

#######################################################################
# check for headers, libraries and functions
#######################################################################
include (CMake/resources.cmake)

#######################################################################
# options
#######################################################################
include (CMake/options.cmake)

#######################################################################
# print (debug) several build variables and options
#######################################################################

set (debug_build 0) # set to 1 to show debug info

if (debug_build)
  message ("")
  message (STATUS "${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt: set 'debug_build' to 0 to disable the following info:")
  fl_debug_var (WIN32)
  fl_debug_var (MINGW)
  fl_debug_var (CYGWIN)
  fl_debug_var (MSVC)
  fl_debug_var (UNIX)
  fl_debug_var (APPLE)
  fl_debug_var (CMAKE_BUILD_TYPE)
  fl_debug_var (CMAKE_SIZEOF_VOID_P)
  fl_debug_var (OPTION_OPTIM)
  fl_debug_var (CMAKE_C_FLAGS)
  fl_debug_var (CMAKE_CXX_FLAGS)
  fl_debug_var (CMAKE_EXE_LINKER_FLAGS)
  message (STATUS "${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt: end of debug_build info.")
endif (debug_build)

unset (debug_build)

#######################################################################
# Build a dummy ("empty") Cairo library for backwards compatibility.
# This should be removed some time after 1.4.0 was released, maybe
# in FLTK 1.4.1, 1.4.2, 1.5.0, or whatever the next minor release is.
#######################################################################

if (FLTK_HAVE_CAIRO)
  add_subdirectory (cairo)
endif ()

#######################################################################
# build the standard FLTK libraries
#######################################################################

add_subdirectory(src)

#######################################################################
# build fluid
#######################################################################

if (FLTK_BUILD_FLUID)
  add_subdirectory (fluid)
endif (FLTK_BUILD_FLUID)

#######################################################################
# build fltk-options
#######################################################################

if (FLTK_BUILD_FLTK_OPTIONS)
  add_subdirectory (fltk-options)
endif (FLTK_BUILD_FLTK_OPTIONS)

#######################################################################
# variables shared by export and install
# export.cmake creates configuration files for direct use in a built but uninstalled FLTK
# install.cmake creates these files for an installed FLTK
# these two would only differ in paths, so common variables are set here
#######################################################################

include (CMake/variables.cmake)

#######################################################################
# final config and export
#######################################################################

include (CMake/export.cmake)

configure_file (
  ${CMAKE_CURRENT_SOURCE_DIR}/fl_config.cmake.in
  ${CMAKE_CURRENT_BINARY_DIR}/FL/fl_config.h
  @ONLY
)

#######################################################################
# options to build test/demo and example programs
#######################################################################

if (FLTK_BUILD_TEST)
  add_subdirectory (test)
endif (FLTK_BUILD_TEST)

if (FLTK_BUILD_EXAMPLES)
  add_subdirectory (examples)
endif (FLTK_BUILD_EXAMPLES)

#######################################################################
# installation
#######################################################################

include (CMake/install.cmake)

#######################################################################
# Generate Library Export Headers          *** EXPERIMENTAL *** WIP ***
#######################################################################

# Enable (1) or disable (0) generation of experimental headers (WIP)
set (GENERATE_EXPORT_HEADERS 0)

if (OPTION_BUILD_SHARED_LIBS AND GENERATE_EXPORT_HEADERS)

  include (GenerateExportHeader)

  generate_export_header (fltk_SHARED
    BASE_NAME fl
    EXPORT_FILE_NAME FL/fltk_export.h
    STATIC_DEFINE FL_STATIC_LIB
  )

  if (NOT MSVC)

    # Visual Studio builds only one shared lib (DLL)

    generate_export_header (fltk_images_SHARED
      BASE_NAME fl_images
      EXPORT_FILE_NAME FL/fltk_images_export.h
      STATIC_DEFINE FL_STATIC_LIB
    )

    generate_export_header (fltk_forms_SHARED
      BASE_NAME fl_forms
      EXPORT_FILE_NAME FL/fltk_forms_export.h
      STATIC_DEFINE FL_STATIC_LIB
    )

    generate_export_header (fltk_gl_SHARED
      BASE_NAME fl_gl
      EXPORT_FILE_NAME FL/fltk_gl_export.h
      STATIC_DEFINE FL_STATIC_LIB
    )

  endif (NOT MSVC)

endif (OPTION_BUILD_SHARED_LIBS AND GENERATE_EXPORT_HEADERS)

#######################################################################
# Output Configuration Summary
#######################################################################

include (FeatureSummary)

message ("")
set (_descr "${PROJECT_NAME} ${FLTK_VERSION} generated by CMake ${CMAKE_VERSION}")
feature_summary (WHAT ALL DESCRIPTION "Configuration Summary for ${_descr} --\n")

message (STATUS "Static libraries will be built in ${CMAKE_CURRENT_BINARY_DIR}/lib")

if (OPTION_BUILD_SHARED_LIBS)
  message (STATUS "Shared libraries will be built in ${CMAKE_CURRENT_BINARY_DIR}/lib")
else ()
  message (STATUS "Shared libraries will not be built (set OPTION_BUILD_SHARED_LIBS=ON to build)")
endif ()

if (FLTK_BUILD_FLUID)
  message (STATUS "FLUID            will be built in ${CMAKE_CURRENT_BINARY_DIR}/bin/fluid")
else ()
  message (STATUS "FLUID            will not be built (set FLTK_BUILD_FLUID=ON to build)")
endif ()

if (FLTK_BUILD_FLTK_OPTIONS)
  message (STATUS "fltk-options     will be built in ${CMAKE_CURRENT_BINARY_DIR}/bin/fltk-options")
else ()
  message (STATUS "fltk-options     will not be built (set FLTK_BUILD_FLTK_OPTIONS=ON to build)")
endif ()

if (FLTK_BUILD_TEST)
  message (STATUS "Test programs    will be built in ${CMAKE_CURRENT_BINARY_DIR}/bin/test")
endif ()

if (FLTK_BUILD_EXAMPLES)
  message (STATUS "Example programs will be built in ${CMAKE_CURRENT_BINARY_DIR}/bin/examples")
else ()
  message (STATUS "Example programs will not be built (set FLTK_BUILD_EXAMPLES=ON to build)")
endif ()

if (FLTK_USE_BUILTIN_JPEG)
  message (STATUS "Image Libraries         : JPEG = Builtin")
else ()
  message (STATUS "Image Libraries         : JPEG = System")
endif ()

if (FLTK_USE_BUILTIN_PNG)
  message (STATUS "                        : PNG  = Builtin")
else ()
  message (STATUS "                        : PNG  = System")
endif ()

if (FLTK_USE_BUILTIN_ZLIB)
  message (STATUS "                        : ZLIB = Builtin")
else ()
  message (STATUS "                        : ZLIB = System")
endif ()

if (UNIX AND NOT (APPLE AND NOT OPTION_APPLE_X11))

  if (OPTION_USE_WAYLAND)
    message (STATUS "Use Wayland             : Yes (if available at run-time)")
  else ()
    message (STATUS "Use Wayland             : No (therefore, X11 is used)")
  endif ()

  if (FLTK_USE_CAIRO)
    message (STATUS "All drawing uses Cairo  : Yes")
  else ()
    message (STATUS "All drawing uses Cairo  : No")
  endif ()

  if (USE_PANGO)
    message (STATUS "Use Pango               : Yes")
  else (USE_PANGO)
    message (STATUS "Use Pango               : No")
    if (USE_XFT)
      message (STATUS "Use Xft                 : Yes")
    else ()
      message (STATUS "Use Xft                 : No")
    endif (USE_XFT)
  endif (USE_PANGO)

endif (UNIX AND NOT (APPLE AND NOT OPTION_APPLE_X11))

if (FLTK_HAVE_CAIROEXT)
  message (STATUS "Fl_Cairo_Window support : Yes (extended)")
elseif (FLTK_HAVE_CAIRO)
  message (STATUS "Fl_Cairo_Window support : Yes (standard)")
else ()
  message (STATUS "Fl_Cairo_Window support : No")
endif ()

if (FLTK_USE_STD)
  message (STATUS "Use std::               : Yes")
else ()
  message (STATUS "Use std::               : No")
endif ()

message ("")
message (STATUS "End of Configuration Summary --\n")