RatÃ³n
An open source Linux MIDI controller

RatÃ³n features include:

Mouse input
Tracks and outputs controllers in two dimensions
Assign separate channel, controller to each dimension
ALSA MIDI seq output
Editable map curves
Saves and loads project files
Saves and loads curves
Doesn't need focus to track mouse
Reverse and invert curves
Curve presets
Assign freeze point
Resizable
GPL license

RatÃ³n translates mouse movements into MIDI controller messages. Those movements are mapped through a user-defineable curve, which can change the characteristics of the mouse's location. Changing the curve can then expand, contract or step the controller messages to match the specific purpose.

RatÃ³n uses the ALSA sequencer MIDI interface, so audio apps such as JACK-rack, MuSE or Rosegarden can use it's controller stream.

Requirements

RatÃ³n is a GTK+ project, designed with Glade-2. It uses:

GTK+ libraries (anything >= 2.4)
The ALSA library

Development files (includes) for both are also required.

Automake >= 1.4 & autoconf >= 2.52 are also needed to build the code.

Building and Installing

Compile RatÃ³n like any GNU autoconf/automake project:

Untar the source file
Open a shell in the project dir
Enter (and wait for completion of each stage):

        ./autogen.sh
        make
        make install

'make install' must be executed as root, or it will fail. But the project can be compiled and used locally by any user.

Also, an optional step would be to strip the debugging info from the file, which can reduce the size 10:1. After 'make' but before 'make install', enter:

strip src/raton

Read the INSTALL file for more info (should be linked in the project dir.)

Known problems, etc.

Version 0.2

Unfortunately, I chose the GtkCurve widget as the basis of the curve edit function in RatÃ³n. However, GtkCurve has severe limitations--control points cannot be explicitly defined, and therefore cannot be restored. For this reason (and others), the widget is now tagged as depreciated (in the GTK+ API.)

When reediting a complex curve, much of the accuracy will be lost. However, the initial edit will be accurate, and can be saved as a project file or a curve file.

Also, a work-around is possible--Free curves are always accurate. A bug exists in RatÃ³n which has been left in as a 'feature'. When faced with an inaccurate curve in a reedit, click the 'Free' button and then 'Cancel'. Conceptually, 'Cancel' should abort the curve type change, but this 'bug' allows a type change without altering the curve. When edited again the curve will be a free-hand type, and will retain it's original shape. Of course, the 'spline' and 'linear' types are the most useful, so this is a compromise at best.

Eventually, the edit curve function will have to be rewritten, and replaced with a custom widget.