Architecture:Map Object Format

Example Map Object Model

The following XML structure describes a simple Map Object that has been serialized.

 <?xml version="1.0"?>
 
   <list id="entity">
     <string id="state">default</string>
     <list id="model">
       <list id="default">
         <list id="shape">
           <u_int16 id="num">1</u_int16>
           <list id="cube">
             <string id="p3d">[0, 0, 0]</string>
             <string id="p3d">[40, 0, 0]</string>
             <string id="p3d">[40, 40, 0]</string>
             <string id="p3d">[0, 40, 0]</string>
             <string id="p3d">[0, 0, 5]</string>
             <string id="p3d">[40, 0, 5]</string>
             <string id="p3d">[40, 40, 5]</string>
             <string id="p3d">[0, 40, 5]</string>
           </list>
         </list>
       </list>
       <string id="sprite">data/gfx/map/ground/outside/grass/grass-ground.xml</string>
     </list>
   </list>
 

It is a flat ground tile of size 40x40 and height of 5 (tiles with no height are not allowed, as that would break collision detection).

Parameters of a Map Object

A Map Object has two components: the model part contains the 'physical' properties of the object (its extend in world space), while the sprite part contains its graphical representation (i.e. its looks). Model and sprite are grouped into an entity, the smallest piece used by the engine to compose the visual representation of the game world. Simple map objects are made of a single entity, but more complex objects can consist of multiple entities.

The model part of an entity is composed of one or more states that correspond to separate animations in the associated sprite. Each state is represented by a shape, which in turn is composed of one or more cubes. These are defined by the position of their 8 corner points (in pixels), relative to the bottom left corner of the corresponding animation.

All cubes of all entities together, placed inside a bounding box, define the length (extension along the x axis), width (extension along the y axis) and height (extension along the z axis) of the map object.