iOS Build (First Attempt: Failure)

I attempted to build the project for iOS because I wanted to play the game on an iPad and to see how portable the project really was.

Building for iOS (iPad)

I initially attempted to update the Xcode project that I was using to build the macOS executable to target iOS, but the build phase failed because the SDL2 frameworks I was linking against were compiled for a different architecture.

I created a new project and followed the guide at wiki.libsdl.org/SDL2/README/ios. I’m using SDL2 2.30.11.

After creating the new project, I:

1. Deleted the redundant template files
2. Added the SDL2 Xcode project: Xcode/SDL/SDL.xcodeproj
3. Removed the “Main storyboard file base name” setting
4. Added the path to the SDL “Public Headers” folder in the “Header Search Paths” configuration
5. Added the SDL2.framework and changed the option to “Embed & Sign” the framework
6. Copied SDL_uikit_main.c into the project

Property ‘preferredFrameRateRange’ Not Found

When I tried to build the project, I got a build error in src/video/uikit/SDL_uikitviewcontroller.m:

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Property 'preferredFrameRateRange' not found on object of type 'CADisplayLink *'

Initially, it was a bit difficult to find the source of the error. After searching for a bit, I found it in the build logs under the “Report Navigator” tab in the left side panel:

I fixed the error by using a deprecated property: preferredFramesPerSecond. The change to use preferredFrameRateRange had been introduced recently, about three days prior, but the error was unexpected because the code should have been ignored if I was targeting an API version that didn’t support the property.

Undefined Symbol: _SDL_main

I encountered another build error:

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Undefined symbol: _SDL_main

This was relatively easy to fix, but it took me longer than expected to figure out.

The new main definition in SDL_uikit_main.c calls SDL_UIKitRunApp with SDL_main as an argument:

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int main(int argc, char *argv[]) {
  return SDL_UIKitRunApp(argc, argv, SDL_main);
}

That symbol was missing from my project because I needed to define a new SDL_main function.