Add ios support

[Markos-Th09]

Add support for iOS. and the ASTC texture format.

[IsaacMarovitz]

As far as I can tell the ASTC changes have nothing to do with iOS support and should be moved to another PR.

[Markos-Th09]

@DarioSamo @IsaacMarovitz other than that is there anything else to discuss?

[IsaacMarovitz]

Do you have a way to run the example projects on iOS?

[Markos-Th09]

Do you have a way to run the example projects on iOS?

Yes, although I did not include it here. I have been also developing a port of Unleashed Recompiled for iOS (hopefully coming soon) and so far these changes have been enough.

[IsaacMarovitz]

There seems to be some problems with signing that prevent file_to_c and spirv_cross_msl from working.

[Markos-Th09]

There seems to be some problems with signing that prevent file_to_c and spirv_cross_msl from working.

I didn't use the Xcode generator for building for iOS if you used that. With the make or ninja generators I did not encounter any issues.

Getting it on device is a bit more convoluted this way so I will investigate what is happening with the Xcode generator.

Edit: I made it work with the Xcode generator you can try again.

[IsaacMarovitz]

Can you share the command you used?

cmake -B cmake-ios -G Xcode -DCMAKE_TOOLCHAIN_FILE=./contrib/ios-cmake/ios.toolchain.cmake -DPLATFORM=OS64 -DPLUME_BUILD_EXAMPLES=ON

This worked on my machine as far as cmake is concerned, but it tried to compile using macOS system SDL2 which doesn't contain the binaries or headers for iOS.

[Markos-Th09]

Can you share the command you used?

cmake -B cmake-ios -G Xcode -DCMAKE_TOOLCHAIN_FILE=./contrib/ios-cmake/ios.toolchain.cmake -DPLATFORM=OS64 -DPLUME_BUILD_EXAMPLES=ON

This worked on my machine as far as cmake is concerned, but it tried to compile using macOS system SDL2 which doesn't contain the binaries or headers for iOS.

Sure. I actually used vcpkg to get a build of SDL2 for iOS, so my configure command was:
cmake -B build/ios -DPLUME_BUILD_EXAMPLES=ON -G Xcode -DCMAKE_TOOLCHAIN_FILE=vcpkg/scripts/buildsystems/vcpkg.cmake -DVCPKG_CHAINLOAD_TOOLCHAIN_FILE=contrib/ios-cmake/ios.toolchain.cmake -DPLATFORM=OS64

Either clone vcpkg in the same directory and bootstrap it or if you already have it set up just proceed with installing SDL2. The target triple for ios is arm64-ios, so you can use vcpkg install sdl2:arm64-ios or use a proper vcpkg.json.

Should I add vcpkg to this PR?

[Markos-Th09]

@IsaacMarovitz were you able to build it this way?

[Markos-Th09]

@IsaacMarovitz I just wanted to following up on this. Were you able to get the iOS examples building using the vcpkg and the commands shared above?