Hash :
dbfd47e7
Author :
Date :
2023-08-07T19:03:18
(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 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:
Assuming the source for SDL is located at ~/sdl
cd ~
mkdir build
cd build
cmake ~/sdl
cmake --build .
This will build the static and dynamic versions of SDL in the ~/build
directory.
Installation can be done using:
cmake --install . # '--install' requires CMake 3.15, or newer
SDL can be included in your project in 2 major ways:
The following CMake script supports both, depending on the value of MYGAME_VENDORED
.
cmake_minimum_required(VERSION 3.5)
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)
For CMake to find SDL, it must be installed in a default location CMake is looking for.
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 |
This only requires a copy of SDL in a subdirectory.
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:
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”) for iOS-Simulator, using the latest, installed SDK:
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
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"
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
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
for tvOS-Simulator, using the latest, installed SDK:
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`
[^SDL_TARGET_EXCEPTION]: SDL2::SDL2
can be an ALIAS to a static SDL2::SDL2-static
target for multiple reasons.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163
# 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 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
* Microsoft Visual C
* MinGW and Msys
* macOS, iOS, and tvOS, with support for XCode
* Android
* Emscripten
* RiscOS
* Playstation Vita
## Building SDL
Assuming the source for SDL is located at `~/sdl`
```sh
cd ~
mkdir build
cd build
cmake ~/sdl
cmake --build .
```
This will build the static and dynamic versions of SDL in the `~/build` directory.
Installation can be done using:
```sh
cmake --install . # '--install' requires CMake 3.15, or newer
```
## 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 3.5)
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.
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_config.h for iOS (using SDL_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`
```
[^SDL_TARGET_EXCEPTION]: `SDL2::SDL2` can be an ALIAS to a static `SDL2::SDL2-static` target for multiple reasons.