A pre-production phase of a digital animation is mainly characterized by the documentation of films production details. This step is essential for understanding the films idea and also which specific technique will be used. This article proposes a new approach to the main pre-production documents: storyboards. A new visual language for semi-automated computer generation of animatics, named SLAP (Storyboard Language for Animation Programming), is presented, along with a proof of concept using a web-based tool designed for interpret its symbols.