Pd is a graphical real-time computer-music system that follows the tradition of IRCAMs ISPW-max.
Although plenty of functions are built into Pd, it is sometimes a pain or simply impossible to create a patch with a certain functionality out of the given primitives and combinations of these.
Therefore, Pd can be extended with self made primitives (“objects”) that are written in complex programming-languages, like C/C++.
This document aims to explain how to write such primitives in C, the popular language that was used to realize Pd.
You can download this HOWTO as pdf (English).