norns-event-demo

demonstrate matron custom events from an external module

building (on norns)

git clone the repository some place outside of the dust/ tree such as /home/we. cd into the repository and run:

git submodule update --init

compiling the code requires add the matron src tree to the search path for header files and the submodule pulls in the norns code base as needed. alternatively you can skip submodule and create symlink to the location of an existing source tree, for example:

mkdir -pv dep/
ln -s ~/norns dep/norns

once the norns source tree is setup building the module can be done by running:

mkdir -pv build && cd build
cmake ..
make

the build directory should now contain norns-event-demo/ - a directory which is organized as a "mod" for matron.

• make install-zip will create norns-event-demo.zip suitable for distribution / installation via maiden
• make install-dust will copy the mod directly into /home/we/dust/code/

how it works

lua maintains separate package search paths, one for locating *.lua files and a second for locating compiled *.so files. matron by default does not configure the package.cpath variable which defines the search path for compiled modules. the mod/lib/mod.lua file (which becomes norns-event-demo/lib/mod.lua when built) takes care of:

• extending package.cpath such that the compiled module will be found at runtime
• loading the compiled model via require making it globally available

the lub_event_demo.cpp provides the implementation for (a) the functions used by matrons event loop to handle events generated by this module and (b) some functions which are directly callable from lua as event_demo.start() and event_demo.stop().

if a lua function called event_demo_handler exists it will be called each time the custom event is popped from the queue. with this mod installed under dust/code and enabled within the MENU try the following in the maiden REPL:

-- define the function which the extension expects to call
function event_demo_handler(v) print("lua handler got", v) end

-- start the custom event generation thread
event_demo.start()

-- stop the custom event generation thread
event_demo.stop()