Add cmake library support.

CMakeLists.txt

@@ -0,0 +1,168 @@
+cmake_minimum_required(VERSION 3.18)
+
+project(imgui
+        LANGUAGES CXX C
+        VERSION 1.92.7)
+
+set(CMAKE_CXX_STANDARD  20)
+
+set(LIBRARY_TARGET_NAME ${PROJECT_NAME})
+
+# define source and install directories
+set(${LIBRARY_TARGET_NAME}_SOURCE_DIR   "${CMAKE_CURRENT_SOURCE_DIR}")
+set(${LIBRARY_TARGET_NAME}_BACKENDS_DIR "${CMAKE_CURRENT_SOURCE_DIR}/backends")
+
+set(${LIBRARY_TARGET_NAME}_HEADER_FILES
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui.h
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui_internal.h
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imconfig.h
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imstb_rectpack.h
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imstb_truetype.h
+   )
+
+set(${LIBRARY_TARGET_NAME}_SOURCE_FILES
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui.cpp
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui_demo.cpp
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui_draw.cpp
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui_tables.cpp
+      ${${LIBRARY_TARGET_NAME}_SOURCE_DIR}/imgui_widgets.cpp
+   )
+
+# set options for backends
+option(IMGUI_BACKEND_GLFW    "Use GLFW backend"    ON)
+option(IMGUI_BACKEND_GLUT    "Use GLUT backend"    OFF)
+option(IMGUI_BACKEND_OPENGL3 "Use OpenGL3 backend" OFF)
+option(IMGUI_BACKEND_VULKAN  "Use Vulkan  backend" ON)
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_GLFW_HEADER_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_glfw.h
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_GLFW_SOURCE_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_glfw.cpp
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_GLUT_HEADER_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_glut.h
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_GLUT_SOURCE_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_glut.cpp
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_OPENGL3_HEADER_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_opengl3.h
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_OPENGL3_SOURCE_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_opengl3.cpp
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_VULKAN_HEADER_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_vulkan.h
+   )
+
+set(${LIBRARY_TARGET_NAME}_BACKEND_VULKAN_SOURCE_FILES
+      ${${LIBRARY_TARGET_NAME}_BACKENDS_DIR}/imgui_impl_vulkan.cpp
+   )
+
+# conditionally inlcude backends
+if(IMGUI_BACKEND_GLFW)
+    find_package(glfw3 CONFIG REQUIRED)
+
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_HEADER_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_GLFW_HEADER_FILES})
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_SOURCE_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_GLFW_SOURCE_FILES})
+    list(APPEND ${LIBRARY_TARGET_NAME}_LINK_LIBRARIES glfw)
+endif()
+
+if(IMGUI_BACKEND_GLUT)
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_HEADER_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_GLUT_HEADER_FILES})
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_SOURCE_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_GLUT_SOURCE_FILES})
+endif()
+
+if(IMGUI_BACKEND_OPENGL3)
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_HEADER_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_OPENGL3_HEADER_FILES})
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_SOURCE_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_OPENGL3_SOURCE_FILES})
+endif()
+
+if(IMGUI_BACKEND_VULKAN)
+    find_package(Vulkan REQUIRED)
+
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_HEADER_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_VULKAN_HEADER_FILES})
+    list(APPEND ${LIBRARY_TARGET_NAME}_BACKEND_SOURCE_FILES ${${LIBRARY_TARGET_NAME}_BACKEND_VULKAN_SOURCE_FILES})
+    list(APPEND ${LIBRARY_TARGET_NAME}_LINK_LIBRARIES Vulkan::Vulkan)
+endif()
+
+add_library(
+  ${LIBRARY_TARGET_NAME}
+  ${${LIBRARY_TARGET_NAME}_SOURCE_FILES}
+  ${${LIBRARY_TARGET_NAME}_BACKEND_SOURCE_FILES})
+
+add_library(
+  ${PROJECT_NAME}::${LIBRARY_TARGET_NAME}
+  ALIAS ${LIBRARY_TARGET_NAME})
+
+set_target_properties(${LIBRARY_TARGET_NAME}
+  PROPERTIES
+    VERSION "${${PROJECT_NAME}_VERSION}"
+    PUBLIC_HEADER "${${LIBRARY_TARGET_NAME}_HEADER_FILES}")
+
+# check if the CONDA_PREFIX environment variable is defined
+if(DEFINED ENV{CONDA_PREFIX})
+    message(STATUS "Conda environment detected. Prefix: $ENV{CONDA_PREFIX}")
+    set(CONDA_FOUND 1)
+else()
+    message(STATUS "No active Conda environment detected.")
+    set(CONDA_FOUND 0)
+endif()
+
+# use target_sources with PUBLIC FILE_SET HEADERS to manage headers.
+# the BASE_DIRS argument is crucial for preserving the directory structure relative to that base.
+# a BASE_DIR cannot be a sub-directory of an existing BASE_DIR.
+target_sources(${LIBRARY_TARGET_NAME} PUBLIC FILE_SET HEADERS
+  BASE_DIRS
+    "${${LIBRARY_TARGET_NAME}_SOURCE_DIR}"
+  FILES
+    "${${LIBRARY_TARGET_NAME}_HEADER_FILES}"
+    "${${LIBRARY_TARGET_NAME}_BACKEND_HEADER_FILES}")
+
+# specify include directories for both compilation and installation process.
+target_include_directories(${LIBRARY_TARGET_NAME}
+  PUBLIC
+    # This path is included if the condition "CONDA_FOUND" is true (1)
+    # The $<...: ...> syntax is a generator expression
+    $<IF:${CONDA_FOUND},$<BUILD_INTERFACE:$ENV{CONDA_PREFIX}/include>,>
+    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>"
+    "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/backends>"
+    "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+
+# specify target link libraries.
+target_link_libraries(${LIBRARY_TARGET_NAME}
+  PRIVATE
+    ${${LIBRARY_TARGET_NAME}_LINK_LIBRARIES})
+
+# specify default install location
+IF(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+    SET(CMAKE_INSTALL_PREFIX "${CMAKE_BINARY_DIR}/install" CACHE PATH "Specify install location." FORCE)
+ENDIF(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+
+# defines CMAKE_INSTALL_LIBDIR, CMAKE_INSTALL_BINDIR and many other useful macros.
+# see https://cmake.org/cmake/help/latest/module/GNUInstallDirs.html
+include(GNUInstallDirs)
+
+# specify installation targets, typology and destination folders.
+install(TARGETS ${LIBRARY_TARGET_NAME}
+        EXPORT  ${LIBRARY_TARGET_NAME}   # associates this target with an export name
+        LIBRARY          DESTINATION "${CMAKE_INSTALL_LIBDIR}"                            COMPONENT shlib
+        ARCHIVE          DESTINATION "${CMAKE_INSTALL_LIBDIR}"                            COMPONENT lib
+        RUNTIME          DESTINATION "${CMAKE_INSTALL_BINDIR}"                            COMPONENT bin
+        PUBLIC_HEADER    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/${LIBRARY_TARGET_NAME}" COMPONENT dev
+        FILE_SET HEADERS DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/${LIBRARY_TARGET_NAME}" COMPONENT dev)
+
+# specify export configuration to make the library discoverable by other cmake project using find_package()
+install(EXPORT ${LIBRARY_TARGET_NAME}
+   DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
+   NAMESPACE   ${PROJECT_NAME}::
+)
+
+message(STATUS "Created target ${LIBRARY_TARGET_NAME} for ${PROJECT_NAME}.")