Why doesn't CMAKE always copy resources when asked?

Question

I have a project with some asset (shader) files that are also frequently updated and need to be copied to a build destination folder every time my project is built.

Right now, the files are copied the first time, but then, when the project is rebuilt (from within Clion) the files are not continually copied. For instance, if I delete them from the directory they are copied to, they do not show up again.

Here is my Cmake file:

# Name for this project
set(PROJECT_NAME "3d_model")

# Choose the library for the final build
set(PROJECT_BUILD_DIR ${CMAKE_SOURCE_DIR}/bin/${PROJECT_NAME})
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BUILD_DIR}/$<CONFIG>)

# Set sources
set(PROJECTS_SOURCE_DIR ${CMAKE_SOURCE_DIR}/src/projects)
set(SOURCES
  src/main.cpp
  ${INCLUDE_DIR}/glad/src/glad.c)

add_executable(${PROJECT_NAME} ${SOURCES})
target_link_libraries(${PROJECT_NAME} ${CMAKE_DL_LIBS} glfw ${GLFW_LIBRARIES})

# Copy resources
file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/assets DESTINATION ${PROJECT_BUILD_DIR}/)

You can see in the last line my attempt to get the projects assets to copy every time the project is built.

Is there a way to ensure this happens?

@drescherjm is there a way to make it happen during building as well? — Startec, Dec 17 '18 at 00:41
`Is there a way to ensure this happens?` You need a custom target. See the help for add_custom_target() — drescherjm, Dec 17 '18 at 00:42
Related: https://stackoverflow.com/questions/10671916/how-to-copy-dll-files-into-the-same-folder-as-the-executable-using-cmake — drescherjm, Dec 17 '18 at 00:44

yjjjnls · Answer 1 · 2018-12-17T09:00:25.303

0

add_custom_command may be what you want

add_custom_command(TARGET ${ProjectName} PRE_BUILD
  COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/assets ${PROJECT_BUILD_DIR}/
 )

edited Dec 17 '18 at 09:00

answered Dec 17 '18 at 00:48

yjjjnls

62
5

This doesn't do anything different than my posted code. – Startec Dec 17 '18 at 00:59
You may want to add the `PRE_BUILD` option to that. – drescherjm Dec 17 '18 at 01:25
@Startec Try adding `PRE_BUILD` – yjjjnls Dec 17 '18 at 09:01

Why doesn't CMAKE always copy resources when asked?

1 Answers1