Every animation needs a starting formation. The formation gives the number of dancers, their gender, where they start, and which direction they are facing. Here is the XML for a simple formation.
<formation name="Facing Couples">
<dancer gender="boy" x="-2" y="1" angle="0" />
<dancer gender="girl" x="-2" y="-1" angle="0" />
</formation>
Since the formations are always symmetrical, only the positions of 2 dancers are needed for a 4-dancer formation. The coordinate system is X pointing to the top of the screen and Y to the left, with (0,0) at the center of the dance floor. This is the same as a dancer's coordinates for a dancer at the center facing the top of the screen. A dancer facing the top of the screen has an angle of 0 degrees, facing Y is 90 degrees. For every dancer at (X,Y) with angle A the symmetrical dancer is at position (-X,-Y) facing A+180 degrees.
Just like there are pre-defined moves, there are pre-defined formations
with names such as the above "Facing Couples". This name can be used
as the value of the formation attribute of the tam element.
Recall the XML for the Forward animation from the previous page.
This uses the named formation Couples Facing Out.
<tam title="Forward" formation="Couples Facing Out" group=" ">
<path>
<move select="Forward"/>
</path>
<path>
<move select="Forward"/>
</path>
</tam>
The named formations are listed in the file formations.xml. If you need a formation not listed, it can be given as a formation element in the animation. Here is how the previous animation would look if there was no named formation for Couples Facing Out.
<tam title="Forward" group=" ">
<formation>
<dancer gender="girl" x="-2" y="1" angle="180" />
<dancer gender="boy" x="-2" y="-1" angle="180" />
</formation>
<path>
<move select="Forward"/>
</path>
<path>
<move select="Forward"/>
</path>
</tam>