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This commit adds support for building imgui using cmake. Signed-off-by: Elvis Dowson <elvis.dowson@gmail.com>
…ibrary target. This commit adds FILE_SET features to target_sources and install(TARGETS) in order to associate a set of headers and their containing include directory with a target. Installing the target installs the headers in the same layout, and provides the include directory to consumers. Signed-off-by: Elvis Dowson <elvis.dowson@gmail.com>
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would be nice if there was a way to force disable the use of this CMakeLists.txt (like a simple flag you set) so you can still manually define the library with custom backends (like rlImGui) while still using fetchcontent. With custom backends you might end up with the following: FetchContent_MakeAvailable(raylib imgui rlimgui)
add_library(imgui
${imgui_SOURCE_DIR}/imgui.cpp
${imgui_SOURCE_DIR}/imgui_demo.cpp
${imgui_SOURCE_DIR}/imgui_draw.cpp
${imgui_SOURCE_DIR}/imgui_tables.cpp
${imgui_SOURCE_DIR}/imgui_widgets.cpp
${rlimgui_SOURCE_DIR}/rlImGui.cpp
)
target_include_directories(imgui PUBLIC ${imgui_SOURCE_DIR} ${rlimgui_SOURCE_DIR})
target_link_libraries(imgui raylib)This would break with the inclusion of the CMakeLists.txt file. And since FetchContent_Populate is deprecated now the workaround would be sketchy. The workaround you would need: FetchContent_Declare(
imgui
#GIT_REPOSITORY https://github.com/ocornut/imgui.git
GIT_REPOSITORY https://github.com/edowson/imgui.git
GIT_TAG docking
#Set SRC SUBDIR to something that does not exist,
#so cmake does not run automatically
SOURCE_SUBDIR "adskmladfskljadfsklad"
) |
The # conditionally fetch and build external libraries
option(BUILD_IMGUI "Enable building imgui" ON)
# fetch content
include(FetchContent)
if (BUILD_IMGUI)
# declare external library: imgui
# -------------------------------
FetchContent_Declare(
imgui
GIT_REPOSITORY "https://github.com/ocornut/imgui.git"
GIT_TAG "docking"
GIT_SHALLOW ON
FIND_PACKAGE_ARGS NAMES imgui
)
# set the build option to override
set(IMGUI_BACKEND_GLFW ON CACHE INTERNAL "Turn on GLFW backend support for imgui" FORCE)
set(IMGUI_BACKEND_OPENGL3 ON CACHE INTERNAL "Turn on GLFW backend support for imgui" FORCE)
set(IMGUI_BACKEND_VULKAN ON CACHE INTERNAL "Turn on VULKAN backend support for imgui" FORCE)
FetchContent_MakeAvailable(imgui)
endif()The master project could have sub-directories, which have their own CMakeLists.txt file, to build examples that use the imgui library. These sub-directories can be activitated by a CMakeLists.txt file as well, based on the above option. # add subdirectories
if (BUILD_IMGUI)
add_subdirectory(imgui-glfw-opengl3)
add_subdirectory(imgui-glfw-vulkan)
endif()
if (BUILD_IMPLOT AND BUILD_IMGUI)
add_subdirectory(implot-demo)
endif()
if (BUILD_IMPLOT3D AND BUILD_IMGUI)
add_subdirectory(implot3d-demo)
endif()This is the example I have for the cmake_minimum_required(VERSION 3.18)
project(imgui-glfw-opengl3
LANGUAGES CXX C
VERSION 1.0.0.0)
# find the libraries which will be needed by imgui-glfw-opengl3
find_package(glfw3 REQUIRED)
set(OpenGL_GL_PREFERENCE "GLVND") # Following `cmake --help-policy CMP0072`
find_package(OpenGL REQUIRED)
find_package(imgui CONFIG REQUIRED)
if(${imgui_FOUND})
message(STATUS "Found imgui library.")
message(STATUS "imgui_SOURCE_DIR: ${imgui_SOURCE_DIR}")
else()
message(FATAL_ERROR "Could not locate imgui library. Please install the required development files.")
endif()
# Print status messages to show what variables were set by find_package(imgui)
# Reference: https://cmake.org/cmake/help/latest/manual/cmake-properties.7.html#properties-on-targets
if(TARGET imgui)
# get the VERSION property
get_target_property(IMGUI_PACKAGE_VERSION imgui VERSION)
message(STATUS "imgui library version: ${IMGUI_PACKAGE_VERSION}")
# get the INTERFACE_INCLUDE_DIRECTORIES property
get_target_property(IMGUI_PACKAGE_INCLUDE_DIRS imgui INTERFACE_INCLUDE_DIRECTORIES)
message(STATUS "imgui interface include directories: ${IMGUI_PACKAGE_INCLUDE_DIRS}")
else()
message(STATUS "imgui target not found, please check top-level CMakeLists.txt and ensure it correctly fetches the imgui library.")
endif()
set(EXE_TARGET_NAME ${PROJECT_NAME}.exe)
set(${EXE_TARGET_NAME}_HEADER_FILES
)
set(${EXE_TARGET_NAME}_SOURCE_FILES
src/main.cpp
)
set(${EXE_TARGET_NAME}_LINK_LIBRARIES
PUBLIC
imgui::imgui
glfw
OpenGL::GL
m
)
add_executable(
${EXE_TARGET_NAME}
${${EXE_TARGET_NAME}_SOURCE_FILES}
${${EXE_TARGET_NAME}_HEADER_FILES})
target_link_libraries(
${EXE_TARGET_NAME}
${${EXE_TARGET_NAME}_LINK_LIBRARIES})
# install target
install(TARGETS ${EXE_TARGET_NAME}
DESTINATION bin)
message(STATUS "Created target ${EXE_TARGET_NAME} for ${PROJECT_NAME}.")As you can see, you master project can choose to include specific libraries, the inclusion of specific sub-directories that use specific examples can be controlled bu the build option, and I only have to call find_package(imgui CONFIG REQUIRED) and specify At the moment, several projects that depend on imgui keep defining cmake fetchcontent code fragments to manage pulling the source code dependency each time. The including of an imgui/CMakeLists.txt to build the library and the use of a build option in an external master project, will help control inclusion and usage of imgui as I have outlined above. You can add a build option for rlimgui into your own CMakeLists.txt file to control which backend to use. |
3 participants
This pull request adds a top-level CMakeLists.txt file to allow an application to fetchcontent and link imgui with supported backends.
Here is an example
CMakeLists.txtfor building the imgui-gmfw-opengl3 example.