To customize your build, you may change several variables that are consumed by make.
These variables, along with some explanations can be found in Makefile.conf.
You can edit that file, or create a file
local.conf in the root of the repository, which will also be parsed by make.
local.conf looks like this:
PREFIX=$(HOME)/code/libad/build ENGINE_LIB=-L$(HOME)/code/engine/build/lib ENGINE_INC=-I$(HOME)/code/engine/build/include
make all make install