Examples: Upgrade SDL2 -> SDL3

[hermet]

SDL3 was released early this year.
https://wiki.libsdl.org/SDL3/FrontPage

1. What are benefits for ThorVG example?
2. Does it very portable across platforms today?

[vtorri]

benefits:

• the api is simpler and more consistent
• the integration in IDE like codeblocks and visual studio is a lot simpler : with sdl2, you have to pass several import libraries and a macro, while just 1 import library with sdl3. I guess it's the same for other IDEs

portability:

• debian trixie, ubuntu 25.4
• msys2
• archlinux
• fedora 41 to 43
• freebsd, openbsd
• openindiana

[hermet]

benefits:

• the api is simpler and more consistent
• the integration in IDE like codeblocks and visual studio is a lot simpler : with sdl2, you have to pass several import libraries and a macro, while just 1 import library with sdl3. I guess it's the same for other IDEs

@vtorri So how simpler apis and integration helps for our examples. We don't use SDL for library development. :)

[vtorri]

simpler: from my experience yesterday, for example, less arguments in SDL_CreateWindow, but others api too (renderer and keyboard events)
ide integration : if people on Windows with VS want to run the examples, the configuration of the project is simple : 2 directories to set and 1 import lib. With SDL2, you need to pass 2 import lib and a macro which is in sdl2.pc (unlikely that they know this)

maybe you can set the label for thorvg 1.0

[hermet]

Require EGL Integration -> #14

[hermet]

ThorVG's example projects currently rely on SDL2 for window management and rendering context setup. With the release of SDL3, it is recommended to upgrade to the latest version to benefit from:

• Improved API consistency and maintainability
• Better support for modern platforms and graphics backends
• Ongoing upstream support and bug fixes

This upgrade will help future-proof the examples and align ThorVG with modern development practices.

Goals

• Replace SDL2 dependencies with SDL3 in all example projects
• Update build scripts accordingly
• Modify example code to match SDL3 API changes
• Test across all supported platforms (Linux, Windows, macOS) to ensure no regressions
• Remove deprecated SDL2-specific workarounds or compatibility layers

Considerations

• SDL3 introduces breaking changes from SDL2; careful migration is required
• CI environments may need updates to install SDL3 development libraries
• Backward compatibility with SDL2 is not required once the transition is complete

[vtorri]

see PR #16

I tested Lottie.exe and Svg.exe on Windows with software backend

[vtorri]

ubuntu-latest is 24.04, but libsdl3-dev needs ubuntu 25.10. CI is failing, but works locally as said above