SDL/docs/README-cmake.md

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# CMake
(www.cmake.org)
The CMake build system is supported on the following platforms:
* FreeBSD
* Linux
* Microsoft Visual C
* MinGW and Msys
* macOS, iOS, and tvOS, with support for XCode
* Android
* Emscripten
* RiscOS
* Playstation 2
* Playstation Vita
* Nintendo 3DS
* QNX 7.x/8.x
## Building SDL
Assuming the source for SDL is located at `~/sdl`.
```sh
cmake -S ~/sdl -B ~/build
cmake --build ~/build
```
This will build SDL in the `~/build` directory.
Installation can be done using:
```sh
cmake --install ~/build --prefix /usr/local # '--install' requires CMake 3.15, or newer
```
This will install SDL to /usr/local.
## 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.
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 SDL3 package, 2. look for the SDL3 component and 3. fail if none can be found
find_package(SDL3 REQUIRED CONFIG REQUIRED COMPONENTS SDL3)
endif()
# Create your game executable target as usual
add_executable(mygame WIN32 mygame.c)
# Link to the actual SDL3 library. SDL3::SDL3 is the shared SDL library, SDL3::SDL3-static is the static SDL libarary.
target_link_libraries(mygame PRIVATE SDL3::SDL3)
```
### 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 |
|----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| SDL3-shared | The SDL3 shared library, available through the `SDL3::SDL3-shared` target |
| SDL3-static | The SDL3 static library, available through the `SDL3::SDL3-static` target |
| SDL3_test | The SDL3_test static library, available through the `SDL3::SDL3_test` target |
| SDL3 | The SDL3 library, available through the `SDL3::SDL3` target. This is an alias of `SDL3::SDL3-shared` or `SDL3::SDL3-static`. This component is always available. |
| Headers | The SDL3 headers, available through the `SDL3::Headers` target. This component is always available. |
### Using a vendored SDL
This only requires a copy of SDL in a subdirectory.
## CMake configuration options
### Build optimized library
By default, CMake provides 4 build types: `Debug`, `Release`, `RelWithDebInfo` and `MinSizeRel`.
The main difference(s) between these are the optimization options and the generation of debug info.
To configure SDL as an optimized `Release` library, configure SDL with:
```sh
cmake ~/SDL -DCMAKE_BUILD_TYPE=Release
```
To build it, run:
```sh
cmake --build . --config Release
```
### Pass custom compile options to the compiler
- Use [`CMAKE_<LANG>_FLAGS`](https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_FLAGS.html) to pass extra
flags to the compiler.
- Use [`CMAKE_EXE_LINKER_FLAGS`](https://cmake.org/cmake/help/latest/variable/CMAKE_EXE_LINKER_FLAGS.html) to pass extra option to the linker for executables.
- Use [`CMAKE_SHARED_LINKER_FLAGS`](https://cmake.org/cmake/help/latest/variable/CMAKE_SHARED_LINKER_FLAGS.html) to pass extra options to the linker for shared libraries.
#### Examples
- build a SDL library optimized for (more) modern x64 microprocessor architectures.
With gcc or clang:
```sh
cmake ~/sdl -DCMAKE_C_FLAGS="-march=x86-64-v3" -DCMAKE_CXX_FLAGS="-march=x86-64-v3"
```
With Visual C:
```sh
cmake .. -DCMAKE_C_FLAGS="/ARCH:AVX2" -DCMAKE_CXX_FLAGS="/ARCH:AVX2"
```
### 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.
When using a recent version of CMake (3.14+), it should be possible to:
- build SDL for iOS, both static and dynamic
- build SDL test apps (as iOS/tvOS .app bundles)
- generate a working SDL_build_config.h for iOS (using SDL_build_config.h.cmake as a basis)
To use, set the following CMake variables when running CMake's configuration stage:
- `CMAKE_SYSTEM_NAME=<OS>` (either `iOS` or `tvOS`)
- `CMAKE_OSX_SYSROOT=<SDK>` (examples: `iphoneos`, `iphonesimulator`, `iphoneos12.4`, `/full/path/to/iPhoneOS.sdk`,
`appletvos`, `appletvsimulator`, `appletvos12.4`, `/full/path/to/AppleTVOS.sdk`, etc.)
- `CMAKE_OSX_ARCHITECTURES=<semicolon-separated list of CPU architectures>` (example: "arm64;armv7s;x86_64")
#### Examples
- for iOS-Simulator, using the latest, installed SDK:
```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
```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
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
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
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
cmake ~/sdl -DCMAKE_SYSTEM_NAME=tvOS -DCMAKE_OSX_SYSROOT=appletvsimulator -DCMAKE_OSX_ARCHITECTURES=x86_64
```
- for tvOS-Device, using the latest, installed SDK:
```cmake
cmake ~/sdl -DCMAKE_SYSTEM_NAME=tvOS -DCMAKE_OSX_SYSROOT=appletvos -DCMAKE_OSX_ARCHITECTURES=arm64`
```
- for QNX/aarch64, using the latest, installed SDK:
```cmake
cmake ~/sdl -DCMAKE_TOOLCHAIN_FILE=~/sdl/build-scripts/cmake-toolchain-qnx-aarch64le.cmake -DSDL_X11=0
```