The algorithm can be implemented very easily. First we extend
the drawable interface so that any object that might be drawn is
capable of supplying a z value for sorting.
import Raster;
public abstract interface Drawable {
public abstract void Draw(Raster r);
public abstract float zCentroid();
}
Next, we add the required method to our triangle routine:
public final float zCentroid() {
return (1f/3f) * (vlist[v[0]].z + vlist[v[1]].z + vlist[v[2]].z);
}
