GEGL GObject introspection Examples

Examples to start playing with GEGL in Python and JavaScript.

Install

We need GEGL and its dependencies compiled with GObject introspection enabled. We'll also install MyPaint with GEGL support to play with its brushes. We'll build everything in user-space, so no need to be root or mess the system.

mkdir gegl-project
cd gegl-project

# clone dependencies

git clone git://git.gnome.org/babl
git clone git://git.gnome.org/gegl
git clone git://git.gnome.org/gegl-gtk
git clone git://gitorious.org/mypaint/mypaint.git

# clone these examples too

git clone https://github.com/manuq/gegl-examples.git

# these variables are to build in user-space and to enable GEGL in
# MyPaint.

mkdir workplace
export prefix=`realpath .`/workplace
export XDG_DATA_DIRS=$prefix/share/:/usr/share/:$XDG_DATA_DIRS
export GI_TYPELIB_PATH=$prefix/lib/girepository-1.0
export PKG_CONFIG_PATH=$prefix/lib/pkgconfig
export LD_LIBRARY_PATH=$prefix/lib
export MYPAINT_ENABLE_GEGL=1

# compile each dependency

cd babl
./autogen.sh --prefix=$prefix
make
make install
cd ..

cd gegl
./autogen.sh --enable-introspection --prefix=$prefix
make
make install
cd ..

cd gegl-gtk
./autogen.sh --enable-introspection --prefix=$prefix --without-vala
make
make install
cd ..

cd mypaint
scons enable_gegl=true enable_introspection=true prefix=$prefix install
cd ..

Play

For learning purposes, you can see the examples as incremental steps that grow in complexity. You can move from step to step with git:

git checkout -f step-0

An explanation of each step is drawn in graph.ora.