Lua-OOCairo provides Lua with full access to the Cairo vector graphics API. It can be used for drawing onto bitmap images and saving the resulting files in PNG format, or for generating files in vector formats like SVG and PDF. It can also be used for drawing in a Gtk+ GUI application.

Full reference documentation for all the functions and methods supported by this module are provided in the 'doc' directory in the source code in POD and Unix manpage format, and on the website as web pages:

https://www.geoffrichards.co.uk/lua/oocairo/doc/

There are example programs in the 'examples' directory of the source code, which demonstrate many of the features available. Feel free to copy bits of code from them to get started. All example programs should be run from within the extracted source code directory, but not from in the 'examples' directory itself, and they will save their output files into the current directory. You may need to use the LUA_CPATH environment variable if you want to the examples to run after you've compiled, but not installed, the module:

LUA_CPATH='.libs/liblua-?.so;;' lua examples/arc.lua
# saves 'arc.png'

If you just want to see what output is produced from the different examples but aren't in a position to run them yet, the output files are shown here:

https://www.geoffrichards.co.uk/lua/oocairo/example/

This module can now (as of version 1.2) be used to draw in a window in a graphical user interface created with the Lua-Gnome/Gtk package. See the programs examples/gtk-drawing.lua and examples/gtk-image.lua for code which uses most of the new features. This new stuff has so far only been tested with lua-gtk-0.9.

Surfaces can be exported as tensors using the function rgb2tensor with the following prototype:

rgb2tensor(surface, [useAlpha])

This returns either a 3xNxM or 4xNxM ByteTensor with values in the range [0, 255].

The inverse operation can be achieved with the function tensor2rgb24.

The supplied 'Makefile' or 'Makefile.osx' should work on Linux and MacOS X without changes (just run 'make'), although on some Linux distributions you might need to change the 'pkg-config' commands if the names used are different. On other platforms you might need to provide the compiler options for finding the Lua and Cairo libraries yourself, rather than relying on pkg-config.

On a Debian system you should be able to install the precompiled Debian packages, or build your own if they don't work by running 'dpkg-buildpackage -tc -uc -us -rfakeroot' from in the unpacked tarball.

Let me know if you can provide compilation instructions for other platforms.

There is a 'make install' target which will install the compiled library and manpages, by default under '/usr/local'. You can install manually just by copying the compiled library file to the appropriate place. That should be enough to use the module.

The module comes with a test suite in the 'test' directory, which at least on Linux systems can be run with 'make test'. If there are any problems with the test programs being able to load your compiled 'oocairo' module, try adjusting the first few lines of 'test-setup.lua'.

The tests are run with a slightly modified Lunit 0.4, which is included. They should all pass. Some tests won't run if they can't load an extra module they need, but they shouldn't produce failures even then.