User Interface Service Software Developerís Guide - Hitech Projects

January 2008
Public
Scene description
The scene has been improved compared to previous version. Now a scene is a set of objects,
each one described by a set of states represented by sprites and masks. Each state is
associated to an identifier which allows changing the current state of an object dynamically. In
addition, the polygons now serve as masks to identify selectable areas in an object.
The scene is encoded in the MMIL format by a participant whose objType is Scene. The
objects of the scene are represented as sub-participants which should have at least :
• a mmil:mmilId feature which is a unique id identifying the object in the amigo
framework (the id attribute of the participants identifies them only in the component),
• a vis:position feature which represent its coordinates in the scene,
• at least one sprite.
A sprite is defined a as objects' sub-participants, they are defined by :
• a mmil:objType feature which has always "Sprite" for value
• a mmil:mmilId feature identifying uniquely the sprite
• an optional vis:image feature giving the url of the image
• an optional mask encoded by a vis:maskPoints feature
• aspect features (fill, visible, color)
A sprite should have a vis:image or a vis:maskPoints to be represented. The following table
explains the look of an object according to the presence or absence of these features.
Look of an object vis:image present vis:image absent
vis:maskPoints present
vis:maskPoints absent
the object is an image with
selectable areas given by the
mask
the object is an image fully
selectable (a rectangular
mask is created)
the object is a polygon with
no background image
an exception is thrown while
building the scene
List of visual features:
The visual namespace encodes all the visual aspects of the scene. In the following list :
• a point is formatted as and a list of points are points separated from
each other by spaces (x, y integers).
• a color is either a symbolic value in { black, blue, cyan, darkGray, gray, green,
lightGray, magenta, orange, pink, red, white, yellow } or a numeric rgb triplet
, where , ,
and are integers ranging from 0 to 255.
vis:image = optional URL of a background image
vis:position = a position in the scene (point)
vis:zIndex = the z-index representing the depth of the object, the lowest z-index corresponds
to the most distant object (integer)
Amigo IST-2004-004182 77/114