VulkanSDL is a package to simplify the build processes for Vulkan applications built on top of SDL. It is a variation of SDL App, a package builder that we designed for SDL Apps on top of OpenGL (and which is the core of CUGL, our simple game library). This is the reason for references to SDL App throughout this project.
While this package does add a few minor C functions to SDL, it mainly exists to minimize the work need to build a new project. While this may seem like a non-issue (CMake exists), creating SDL applications for mobile devices is nontrivial. Beyond compiling the software, there are issues with configuring the app permissions, setting the unique identifier, and assigning the asset directories. This is especially tricky when many of these settings are in things like plists or manifests not manageable by CMake.
This configuration process is particularly a problem for teams doing cross-platform development on Android and iOS together. We use SDL at Cornell to teach a course on cross-platform mobile game development. Before SDL App, we regularly had students submit assignments that kept the unique identifiers of our sample code, and therefore conflicted with each other during testing. Furthermore, students would develop using their platform-specific IDE (Android Studio or XCode), and this often led to the Android and iOS builds going out-of-sync.
To solve this problem, VulkanSDL is itself a Python script. This Python script enables the creation of an IDE project (Android Studio, Visual Studio, XCode, or CMake) for your application. The configured project is ready to build and deploy, minimizing the amount of time needed to port to a new platform. See the instructions for how to use this script. These instructions are stored as a README in the release folder.
VulkanSDL is regularly tested against Android, Linux, iOS, macOS, and Windows. It also provides a Flatpak project for packaging an x86 Linux build for the SteamDeck. While SDL itself supports a wider variety of platforms, these are the platforms we need for our course at Cornell, and are therefore the only ones we support at this time.
Note that while this version of SDL App is intended for Vulkan apps, it still fully supports OpenGL. That is so that students can experiment comparing to the two.
This repository does not contain any headers or binaries for supporting Vulkan.
This is not necessary for Android or CMake, as those tools will search for the
version of Vulkan installed on that platform. However, for Xcode and Visual
Studio, you will need to install extra files in the vulkan folder. See the
instructions for what to install.
In addition to the VulkanSDK, VulkanSDL is a software release composed of the following packages:
- SDL2, version 2.30.5
- SDL2-Image, version 2.8.2
- SDL2-TTF, version 2.20.1
These are integrated by source. On mobile devices, these have to be built from
source anyway, so we find it easiest to just to link these as submodules to
this project. They can be found in the components folder.
VulkanSDL is a source code release (with minimal dynamic libraries). Therefore,
it is packaged, not compiled. To create a release from this repository, run the
python program build.py in this folder as follows:
python build.py [<directory>]
You will need the module PyYAML to run this command. The
optional <directory> is the location to store the release. By default it is
stored in a folder called release. The version of the package can be set
with the optional flag, -v, --version.
Note that you should populate the vulkan folder with the necessary
headers and libraries before creating a release.
We have included ports of the first few steps of the
Vulkan Tutorial to show off VulkanSDL. They
come complete with their own config.yml files for configuration. After
creating a release, read the instructions for how to use the
release to build the demos.