Introduction, Installation and Examples of Common Lisp-SDL2 (cl-sdl2)

Introduction to Lisp/Common Lisp

The programming language LISP, which stands for list processing, was created to make manipulating data strings simple. It is a widely used artificial intelligence (AI) programming language that was created by John McCarthy in 1959. It is one of the most ancient programming languages that is still widely used.

Common Lisp (CL) is a dialect of the Lisp programming language, published in ANSI standard document ANSI INCITS 226-1994 (S20018) (formerly X3.226-1994 (R1999)). The Common Lisp HyperSpec, a hyperlinked HTML version, has been derived from the ANSI Common Lisp standard. Learn more, here.

cl-sdl2

cl-sdl2 is a Common Lisp wrapper for the SDL 2.0 C Library, with many contributors, currently maintained by Michael Fiano [email protected].

It is licensed under the MIT license.

Check out, Incredible Utility Kit for Common Lisp-SDL2 (cl-sdl2).

Installation

sdl2 is in Quicklisp, see below for instructions.

SDL 2.0 C Library Install

See https://wiki.libsdl.org/Installation

On Linux, you can probably find SDL2 in your distribution’s package set. For other platforms, or for building manually, download the source.

Package

• Debian based: Ubuntu, Mint etc

sudo apt-get install libsdl2-2.0

• Arch

sudo pacman -S sdl2

Compilation

If you need to compile from source for your Linux platform:

1. Download source code
2. Compile
3. Install

For example:

cd /tmp
wget https://www.libsdl.org/release/SDL2-2.0.4.tar.gz
tar -xzvf SDL2-2.?.?.tar.gz
cd SDL2-2.?.?
./configure
make
sudo make install

This will install the SDL-2.0.x C Library into your /usr/local location.

It’s generally a good idea to install at a minimum the version of SDL2 that was wrapped; however, sub revisions should not introduce binary incompatibility and should be fine. If you install a different version, certain features may not be available or may not work correctly.

Quicklisp Install

sdl2 is best installed via QuickLisp, though for cutting-edge changes, you may want to install from github as below.

If you don’t have Quicklisp, then follow the directions to install it. We assume you placed the Quicklisp repository in the default place as indicated by the directions and have added it to your lisp init file.

github install

cd $HOME/quicklisp/local-projects
git clone https://github.com/rpav/cl-autowrap.git
git clone https://github.com/lispgames/cl-sdl2.git

Then, use quicklisp to install the libraries required by cl-sdl2:

Start your lisp. Then, just:

(ql:quickload "sdl2")

Swank/Slynk features

sdl2 enables certain restarts for friendly interaction with SLIME or Sly if you have either properly installed. “Proper installation” in this case means swank.asd or slynk.asd is linked such that ASDF can find and load it.

Note this is easily achieved even if you have installed them from github or some other non-Quicklisp repository:

• Symlink the directory to $HOME/quicklisp/local-projects/
• Symlink the .asd to $HOME/.local/common-lisp/sources/

Similarly you could just clone into ~/quicklisp/local-projects as well; this should work on Windows as well. There are numerous other options for configuring and managing ASDs, as well.

Running the sdl2 examples

Start your lisp:

(ql:quickload :sdl2/examples)
(sdl2-examples:basic-test)

This example will open a window with an opengl primitive in it. Any mouse movements or keystrokes are recorded in the terminal (or emacs SLIME output buffer *inferior-lisp*). Hitting the ESCAPE key will terminate the example.

OSX

Newer versions of OSX have had some difficulties as calls which require nextEventMatchingMask must be called from the main thread of your program.

This is especially relevant to SBCL, although issues have also been noticed in CCL.

Currently, initialisation must take place on your main thread:

(ql:quickload :sdl2/examples)

;; We should be able to run examples as normal on CCL
#-sbcl (sdl2-examples:basic-test)

;; SBCL requires that we initialise in the main thread
#+sbcl (sdl2:make-this-thread-main #'sdl2-examples:basic-test)

Thank you for using sdl2!

GitHub

Source Code: cl-sdl2.