From 53141a56b4520489ab64ad0ba2c49fbd1a456901 Mon Sep 17 00:00:00 2001 From: Anonymous Maarten Date: Tue, 9 Aug 2022 22:05:03 +0200 Subject: [PATCH] Expand CMake documentation a bit (#5961) * cmake: remove duplicate check_required_components macro * Expand docs/README-cmake.md a bit * cmake: path needs `/` infix --- docs/README-cmake.md | 135 ++++++++++++++++++++++++++++++++++--------- sdl2-config.cmake.in | 12 +--- 2 files changed, 108 insertions(+), 39 deletions(-) diff --git a/docs/README-cmake.md b/docs/README-cmake.md index 03fd24421..b10751c1a 100644 --- a/docs/README-cmake.md +++ b/docs/README-cmake.md @@ -1,40 +1,102 @@ -CMake -================================================================================ +# CMake + (www.cmake.org) SDL's build system was traditionally based on autotools. Over time, this approach has suffered from several issues across the different supported platforms. -To solve these problems, a new build system based on CMake is under development. -It works in parallel to the legacy system, so users can experiment with it -without complication. -While still experimental, the build system should be usable on the following -platforms: +To solve these problems, a new build system based on CMake was introduced. +It is developed in parallel to the legacy autotools build system, so users +can experiment with it without complication. + +The CMake build system is supported on the following platforms: * FreeBSD * Linux -* VS.NET 2010 +* Microsoft Visual C * MinGW and Msys * macOS, iOS, and tvOS, with support for XCode +* Android +* Emscripten +* RiscOS +* Playstation Vita +## Building SDL -================================================================================ -Usage -================================================================================ +Assuming the source for SDL is located at `~/sdl` +```sh +cd ~ +mkdir build +cd build +cmake ~/sdl +cmake --build . +``` -Assuming the source for SDL is located at ~/sdl +This will build the static and dynamic versions of SDL in the `~/build` directory. +Installation can be done using: - cd ~ - mkdir build - cd build - cmake ../sdl +```sh +cmake --install . # '--install' requires CMake 3.15, or newer +``` -This will build the static and dynamic versions of SDL in the ~/build directory. +## Including SDL in your project +SDL can be included in your project in 2 major ways: +- using a system SDL library, provided by your (*nix) distribution or a package manager +- using a vendored SDL library: this is SDL copied or symlinked in a subfolder. -================================================================================ -Usage, iOS/tvOS -================================================================================ +The following CMake script supports both, depending on the value of `MYGAME_VENDORED`. + +```cmake +cmake_minimum_required(VERSION 3.0) +project(mygame) + +# Create an option to switch between a system sdl library and a vendored sdl library +option(MYGAME_VENDORED "Use vendored libraries" OFF) + +if(MYGAME_VENDORED) + add_subdirectory(vendored/sdl EXCLUDE_FROM_ALL) +else() + # 1. Look for a SDL2 package, 2. look for the SDL2 component and 3. fail if none can be found + find_package(SDL2 REQUIRED CONFIG REQUIRED COMPONENTS SDL2) + + # 1. Look for a SDL2 package, 2. Look for the SDL2maincomponent and 3. DO NOT fail when SDL2main is not available + find_package(SDL2 REQUIRED CONFIG COMPONENTS SDL2main) +endif() + +# Create your game executable target as usual +add_executable(mygame WIN32 mygame.c) + +# SDL2::SDL2main may or may not be available. It is e.g. required by Windows GUI applications +if(TARGET SDL2::SDL2main) + # It has an implicit dependency on SDL2 functions, so it MUST be added before SDL2::SDL2 (or SDL2::SDL2-static) + target_link_libraries(mygame PRIVATE SDL2::SDL2main) +endif() + +# Link to the actual SDL2 library. SDL2::SDL2 is the shared SDL library, SDL2::SDL2-static is the static SDL libarary. +target_link_libraries(mygame PRIVATE SDL2::SDL2) +``` + +### A system SDL library + +For CMake to find SDL, it must be installed in [a default location CMake is looking for](https://cmake.org/cmake/help/latest/command/find_package.html#config-mode-search-procedure). + +The following components are available, to be used as an argument of `find_package`. + +| Component name | Description | +|----------------|--------------------------------------------------------------------------------------------| +| SDL2 | The SDL2 shared library, available through the `SDL2::SDL2` target [^SDL_TARGET_EXCEPTION] | +| SDL2-static | The SDL2 static library, available through the `SDL2::SDL2-static` target | +| SDL2main | The SDL2main static library, available through the `SDL2::SDL2main` target | +| SDL2test | The SDL2test static library, available through the `SDL2::SDL2test` target | + +### Using a vendored SDL + +This only requires a copy of SDL in a subdirectory. + +## CMake configuration options for platforms + +### iOS/tvOS CMake 3.14+ natively includes support for iOS and tvOS. SDL binaries may be built using Xcode or Make, possibly among other build-systems. @@ -53,32 +115,49 @@ To use, set the following CMake variables when running CMake's configuration sta - `CMAKE_OSX_ARCHITECTURES=` (example: "arm64;armv7s;x86_64") -### Examples (for iOS/tvOS): +#### Examples - for iOS-Simulator, using the latest, installed SDK: - `cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64` + ```bash + cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64 + ``` - for iOS-Device, using the latest, installed SDK, 64-bit only - `cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES=arm64` + ```bash + cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES=arm64 + ``` - for iOS-Device, using the latest, installed SDK, mixed 32/64 bit - `cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES="arm64;armv7s"` + ```cmake + cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES="arm64;armv7s" + ``` - for iOS-Device, using a specific SDK revision (iOS 12.4, in this example): - `cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos12.4 -DCMAKE_OSX_ARCHITECTURES=arm64` + ```cmake + cmake ~/sdl -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos12.4 -DCMAKE_OSX_ARCHITECTURES=arm64 + ``` - for iOS-Simulator, using the latest, installed SDK, and building SDL test apps (as .app bundles): - `cmake ~/sdl -DSDL_TESTS=1 -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64` + ```cmake + cmake ~/sdl -DSDL_TESTS=1 -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64 + ``` - for tvOS-Simulator, using the latest, installed SDK: - `cmake ~/sdl -DCMAKE_SYSTEM_NAME=tvOS -DCMAKE_OSX_SYSROOT=appletvsimulator -DCMAKE_OSX_ARCHITECTURES=x86_64` + ```cmake + cmake ~/sdl -DCMAKE_SYSTEM_NAME=tvOS -DCMAKE_OSX_SYSROOT=appletvsimulator -DCMAKE_OSX_ARCHITECTURES=x86_64 + ``` - for tvOS-Device, using the latest, installed SDK: - `cmake ~/sdl -DCMAKE_SYSTEM_NAME=tvOS -DCMAKE_OSX_SYSROOT=appletvos -DCMAKE_OSX_ARCHITECTURES=arm64` + ```cmake + cmake ~/sdl -DCMAKE_SYSTEM_NAME=tvOS -DCMAKE_OSX_SYSROOT=appletvos -DCMAKE_OSX_ARCHITECTURES=arm64` + ``` + + +[^SDL_TARGET_EXCEPTION]: `SDL2::SDL2` can be an ALIAS to a static `SDL2::SDL2-static` target for multiple reasons. diff --git a/sdl2-config.cmake.in b/sdl2-config.cmake.in index 59684b9c5..db864aab9 100644 --- a/sdl2-config.cmake.in +++ b/sdl2-config.cmake.in @@ -14,18 +14,8 @@ macro(set_and_check _var _file) endif() endmacro() -# Copied from `configure_package_config_file` -macro(check_required_components _NAME) - foreach(comp ${${_NAME}_FIND_COMPONENTS}) - if(NOT ${_NAME}_${comp}_FOUND) - if(${_NAME}_FIND_REQUIRED_${comp}) - set(${_NAME}_FOUND FALSE) - endif() - endif() - endforeach() -endmacro() - get_filename_component(prefix "${CMAKE_CURRENT_LIST_DIR}/@cmake_prefix_relpath@" ABSOLUTE) + set(exec_prefix "@exec_prefix@") set(bindir "@bindir@") set(libdir "@libdir@")