General

• Checkout the packages/xpce directory of the Prolog tree to the branch sdl
• Install the dependencies, notably SDL3 and Cairo
• Configure using cmake -DSDL=ON ...

Using the default setup, thus should work for first installation:

git clone https://github.com/SWI-Prolog/swipl-devel.git
cd swipl-devel
git submodule update --init
cd packages/xpce
git checkout sdl
cd ../..
mkdir build.sdl
cd build.sdl
../scripts/configure
ninja

To update

cd /path/to/swipl-devel
git pull
git submodule update
git packages/xpce
git checkout sdl
git pull
cd ../../build.sdl
ninja

Platform notes

Linux

Fedora 42 is the main development environment.

Dependencies for linux distros with SDL3

• Fedora (42)
  • dnf install SDL3-devel SDL3_image-devel cairo-devel pango-devel

Porting to linux distros without SDL3

According to ChatGPT, sdl3-headers may allow us to compile against SDL2.

find_package(SDL3 REQUIRED COMPONENTS Headers)
target_link_libraries(my_app PUBLIC SDL3::Headers)

• Try this route
• Find list of distros that support this.

MacOS

Compilation works on MacOS. There are several problems

• Resizing the epilog terminal terminal sometimes causes memory errors. This is a bit weird as the Fedora version passes with ASAN enabled.
• The terminal content writes over the scrollbar
• The fonts look rather rough.
• Color glyphs such as emoji are not yet supported. Cairo does not seem to support these using Quartz as backend.

Dependencies

• Macports
  • port install SDL3 SDL3_image cairo pango

Windows

MinGW64 provides packages for SDL3, Cairo and Pango, both static and dynamic. Note that XPCE no longer supports 32 bit platforms due to the switch to doubles as primary representation for numbers.

• Build XPCE for Windows
  • Replace POSIX Pty by Windows pseudo consoles
  • Replace poll()-based I/O stream handling