Dear users!
I want to develop simple games for PC (Windows, Mac and Linux). I already have made some small games on Linux using SDL.
The last days I tried to setup a CMake Cross Platform SDL App - with success!
With the following guide (SDL2 with CMake) I created a CMake SDL Project which build on Windows, Mac and Linux.
On Windows I am working with Visual Studio (like in guide) and on Linux/Mac I am working with CLion.
My CMakeLists.txt file has the following content:
cmake_minimum_required(VERSION 3.13)
project(CMake_Demo_Mac)
set(CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/modules)
find_package(SDL2 REQUIRED)
include_directories (${SDL2_INCLUDE_DIRS})
set(CMAKE_CXX_STANDARD 11)
add_executable(CMake_Demo_Mac main.cpp)
target_link_libraries (CMake_Demo_Mac ${SDL2_LIBRARIES})
And is linked to the .cmake file from the linked guide, that searches for SDL on the system:
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#.rst:
# FindSDL2
# -------
#
# Locate SDL2 library
#
# This module defines
#
# ::
#
# SDL2_LIBRARY, the name of the library to link against
# SDL2_FOUND, if false, do not try to link to SDL
# SDL2_INCLUDE_DIR, where to find SDL.h
# SDL2_VERSION_STRING, human-readable string containing the version of SDL
#
#
#
# This module responds to the flag:
#
# ::
#
# SDL2_BUILDING_LIBRARY
# If this is defined, then no SDL2_main will be linked in because
# only applications need main().
# Otherwise, it is assumed you are building an application and this
# module will attempt to locate and set the proper link flags
# as part of the returned SDL2_LIBRARY variable.
#
#
#
# Don't forget to include SDLmain.h and SDLmain.m your project for the
# OS X framework based version. (Other versions link to -lSDLmain which
# this module will try to find on your behalf.) Also for OS X, this
# module will automatically add the -framework Cocoa on your behalf.
#
#
#
# Additional Note: If you see an empty SDL2_LIBRARY_TEMP in your
# configuration and no SDL2_LIBRARY, it means CMake did not find your SDL
# library (SDL.dll, libsdl.so, SDL.framework, etc). Set
# SDL2_LIBRARY_TEMP to point to your SDL library, and configure again.
# Similarly, if you see an empty SDLMAIN_LIBRARY, you should set this
# value as appropriate. These values are used to generate the final
# SDL2_LIBRARY variable, but when these values are unset, SDL2_LIBRARY
# does not get created.
#
#
#
# $SDL2DIR is an environment variable that would correspond to the
# ./configure --prefix=$SDL2DIR used in building SDL. l.e.galup 9-20-02
#
# Modified by Eric Wing. Added code to assist with automated building
# by using environmental variables and providing a more
# controlled/consistent search behavior. Added new modifications to
# recognize OS X frameworks and additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL
# guidelines. Added a search for SDLmain which is needed by some
# platforms. Added a search for threads which is needed by some
# platforms. Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of SDL2_LIBRARY to
# override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL/SDL.h to just SDL.h
# This needed to change because "proper" SDL convention is #include
# "SDL.h", not <SDL/SDL.h>. This is done for portability reasons
# because not all systems place things in SDL/ (see FreeBSD).
if(NOT SDL2_DIR)
set(SDL2_DIR "" CACHE PATH "SDL2 directory")
endif()
find_path(SDL2_INCLUDE_DIR SDL.h
HINTS
ENV SDL2DIR
${SDL2_DIR}
PATH_SUFFIXES SDL2
# path suffixes to search inside ENV{SDL2DIR}
include/SDL2 include
)
if(CMAKE_SIZEOF_VOID_P EQUAL 8)
set(VC_LIB_PATH_SUFFIX lib/x64)
else()
set(VC_LIB_PATH_SUFFIX lib/x86)
endif()
find_library(SDL2_LIBRARY_TEMP
NAMES SDL2
HINTS
ENV SDL2DIR
${SDL2_DIR}
PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
)
# Hide this cache variable from the user, it's an internal implementation
# detail. The documented library variable for the user is SDL2_LIBRARY
# which is derived from SDL2_LIBRARY_TEMP further below.
set_property(CACHE SDL2_LIBRARY_TEMP PROPERTY TYPE INTERNAL)
if(NOT SDL2_BUILDING_LIBRARY)
if(NOT SDL2_INCLUDE_DIR MATCHES ".framework")
# Non-OS X framework versions expect you to also dynamically link to
# SDLmain. This is mainly for Windows and OS X. Other (Unix) platforms
# seem to provide SDLmain for compatibility even though they don't
# necessarily need it.
find_library(SDL2MAIN_LIBRARY
NAMES SDL2main
HINTS
ENV SDL2DIR
${SDL2_DIR}
PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
PATHS
/sw
/opt/local
/opt/csw
/opt
)
endif()
endif()
# SDL may require threads on your system.
# The Apple build may not need an explicit flag because one of the
# frameworks may already provide it.
# But for non-OSX systems, I will use the CMake Threads package.
if(NOT APPLE)
find_package(Threads)
endif()
# MinGW needs an additional link flag, -mwindows
# It's total link flags should look like -lmingw32 -lSDLmain -lSDL -mwindows
if(MINGW)
set(MINGW32_LIBRARY mingw32 "-mwindows" CACHE STRING "link flags for MinGW")
endif()
if(SDL2_LIBRARY_TEMP)
# For SDLmain
if(SDL2MAIN_LIBRARY AND NOT SDL2_BUILDING_LIBRARY)
list(FIND SDL2_LIBRARY_TEMP "${SDLMAIN_LIBRARY}" _SDL2_MAIN_INDEX)
if(_SDL2_MAIN_INDEX EQUAL -1)
set(SDL2_LIBRARY_TEMP "${SDLMAIN_LIBRARY}" ${SDL2_LIBRARY_TEMP})
endif()
unset(_SDL2_MAIN_INDEX)
endif()
# For OS X, SDL uses Cocoa as a backend so it must link to Cocoa.
# CMake doesn't display the -framework Cocoa string in the UI even
# though it actually is there if I modify a pre-used variable.
# I think it has something to do with the CACHE STRING.
# So I use a temporary variable until the end so I can set the
# "real" variable in one-shot.
if(APPLE)
set(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} "-framework Cocoa")
endif()
# For threads, as mentioned Apple doesn't need this.
# In fact, there seems to be a problem if I used the Threads package
# and try using this line, so I'm just skipping it entirely for OS X.
if(NOT APPLE)
set(SDL2_LIBRARY_TEMP ${SDL2_LIBRARY_TEMP} ${CMAKE_THREAD_LIBS_INIT})
endif()
# For MinGW library
if(MINGW)
set(SDL2_LIBRARY_TEMP ${MINGW32_LIBRARY} ${SDL2_LIBRARY_TEMP})
endif()
# Set the final string here so the GUI reflects the final state.
set(SDL2_LIBRARY ${SDL2_LIBRARY_TEMP} CACHE STRING "Where the SDL Library can be found")
endif()
if(SDL2_INCLUDE_DIR AND EXISTS "${SDL2_INCLUDE_DIR}/SDL2_version.h")
file(STRINGS "${SDL2_INCLUDE_DIR}/SDL2_version.h" SDL2_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SDL2_MAJOR_VERSION[ \t]+[0-9]+$")
file(STRINGS "${SDL2_INCLUDE_DIR}/SDL2_version.h" SDL2_VERSION_MINOR_LINE REGEX "^#define[ \t]+SDL2_MINOR_VERSION[ \t]+[0-9]+$")
file(STRINGS "${SDL2_INCLUDE_DIR}/SDL2_version.h" SDL2_VERSION_PATCH_LINE REGEX "^#define[ \t]+SDL2_PATCHLEVEL[ \t]+[0-9]+$")
string(REGEX REPLACE "^#define[ \t]+SDL2_MAJOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_MAJOR "${SDL2_VERSION_MAJOR_LINE}")
string(REGEX REPLACE "^#define[ \t]+SDL2_MINOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_MINOR "${SDL2_VERSION_MINOR_LINE}")
string(REGEX REPLACE "^#define[ \t]+SDL2_PATCHLEVEL[ \t]+([0-9]+)$" "\\1" SDL2_VERSION_PATCH "${SDL2_VERSION_PATCH_LINE}")
set(SDL2_VERSION_STRING ${SDL2_VERSION_MAJOR}.${SDL2_VERSION_MINOR}.${SDL2_VERSION_PATCH})
unset(SDL2_VERSION_MAJOR_LINE)
unset(SDL2_VERSION_MINOR_LINE)
unset(SDL2_VERSION_PATCH_LINE)
unset(SDL2_VERSION_MAJOR)
unset(SDL2_VERSION_MINOR)
unset(SDL2_VERSION_PATCH)
endif()
set(SDL2_LIBRARIES ${SDL2_LIBRARY} ${SDL2MAIN_LIBRARY})
set(SDL2_INCLUDE_DIRS ${SDL2_INCLUDE_DIR})
include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL
REQUIRED_VARS SDL2_LIBRARY SDL2_INCLUDE_DIR
VERSION_VAR SDL2_VERSION_STRING)
On Windows I created a Visual-Studio Project with the CMake-Gui. When I run it, it only needs the SDL2.dll file in the same path as the generated .exe-file. In Visual Studio, I linked all the .dll-dependencies needed to my .exe-file (properties / Configuration / C/C++ / Code Generation / Runtime library / Multithreaded). Then I copied my .exe file and the SDL2.dll file to another Windows Computer to see, if the SDL App would start and yes, it worked!
Now I need the same for Linux/Mac, I already tried running the SDL App on my sisters MacBook but it says it can’t find the sdl-framework. How can I set it up that the sdl-framework needed libraries are linked to my executable-file in Mac/Linux? What do I have do add to my CMakeLists.txt-File to build id properly with all the dependencies so it works on a non-SDL Linux/Mac system? I also read about, that I need to include a .a
or .dylib
file as they are the equivalent to the .dll-files on windows but I was not able to find these files (something like SDL2.a or SDL2.dylib (?)). I also studied A LOT threads but a lot of them were old or didn’t build the project with cmake, so they didn’t help me either…
Could someone help? I would much appreciate any help how I can run my Mac/Linux CMake-SDL App on Mac/Linux w/o SDL or any other needed lib installed. I tried so much but wasn’t successful.
Thank you guys!
the source code of my SDL App (testing):
#include "SDL.h"
int main(int argc, char *argv[])
{
SDL_Init(SDL_INIT_VIDEO);
SDL_Window *window = SDL_CreateWindow(
"SDL2Test",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
640,
480,
0
);
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_SOFTWARE);
SDL_SetRenderDrawColor(renderer, 255, 255, 0, SDL_ALPHA_OPAQUE);
SDL_RenderClear(renderer);
SDL_RenderPresent(renderer);
SDL_Delay(10000);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}
EDIT:
The documentation of SDL mentions on Mac “You can ship an SDL.framework, or just build the .dylib file and ship it with an appropriate install_name to ship beside your program’s binary.” How does this work? How can I make that with my SDL App?
And how does this work on Linux?
Source
BUT it also says on the wiki under static linking " SDL 2.0, unlike 1.2, uses the zlib license, which means you can build a static library linked directly to your program, or just compile SDL’s C code directly as part of your project. You are completely allowed to do that. However, we encourage you to not do this for various technical and moral reasons". How can I make my SDL2 App then runnable on other platforms, without static linking on Mac/Linux?
EDIT2
The only thing I met that somehow is like my problem was the follwing post from 2005: SDL under MacOSX. But that didn’t help me either…
EDIT3
Ony my Mac, i found the mentioned files libSDL2-2.0.0.dylib
, libSDL2_test.a
, libSDL2.a
and libSDL2main.a
under /usr/local/Cellar/sdl2/2.0.9_1/lib
. I copied the files the build folder where the binary-executable is stored. Then I tried to run it on my sisters Mac but still, I get the same error dylib: Library not loaded: @rpath/SDL2.framework/Versions/A/SDL2
.
FINAL EDIT
After a lot more searching, i found a recently post on this forum: Creating an Easily Distributable Executable File. As the discusssion progresses, it says that it is indeed not easy to setup everything for Mac or Linux. Altough there are some working ideas, I think it is not worth it for me to make the game for non-installed SDL for Mac/Linux as it would require me to get more into that topic. I think the easiest way for me is to just build for Windows. Potentially a solution on Mac could be using an install-setup to move the sdl2.framwork files to the /Libray/Frameworks folder, but I don’t know if this is even possible.
As long as there is not a complete “easy” tutorial for people like me I guess it is not worth the effort since I don’t wanna waste to much time on this. However, I learned some new things.