Architecture:Map Module
There is no map module in v0.4 at present. What is described below refers to the v0.3 map engine, but chances are that a new implementation will work in similar ways. For more details regarding the implementation refer to the Mapengine and Mapview tasks.
Maps and Views
One prominent component of the engine is the renderer. It produces the graphical representation of a scene, and that about 40 times per second. (A new scene – or internal engine state – is computed about 75 times per second, btw.)
More important than those numbers or the fact that drawing and update operations are disjunct is the implementation. As the heading suggests, a model-view-controller (MVC) architecture is used.
The part of the map being displayed is determined by so-called mapviews. A mapview can be of any size and can direct output to any surface. Multiple mapviews can be active at the same time, although at present they can’t show different maps, just different areas of the same map.
The question that remains is how a mapview knows what part of a map to display. For that purpose, each mapview may have a schedule script assigned (the controller), which is executed before rendering takes place. The script in turn can use the methods provided by the mapview class for all kinds of effects. Usually, it will want to center the view on a certain character, but it is not limited to this.
Map Events
The engine itself implements only the rendering of the map. Everything else, like transitions between map areas (characters entering buildings for example), interaction with items or characters on the map (picking up, initiating dialogue) and interaction with the map itself (traps, falling down) are handled by Python scripts. To trigger these scripts, so called map events are implemented and registered with the Event system.
The following events were implemented in the v0.3 engine and will probably appear in v0.4 as well:
- An enter event is triggered when a character enters a location (tile)
- A leave event is triggered when a character leaves a location (tile)
- An action event is triggered when the player interacts with characters or objects on the map