Animation start with the a element
A click on one of the magenta symbols gives
a by animation for a circle as expected intuitively by the type
of the symbol. fill is set to freeze, therefore the
animations stop at their end points.
Because by animations without from are additive, the start
of an animation depends on the history.
The first click on a symbol resolves the begin time for the
corresponding animation. If the symbol is clicked again,
all animations after the first click have to be repeated with
corresponding begin times.
(see SMIL animation recommendation for hyperlinking rules).
For example: If after one motion the opposite
direction is chosen, the motion starts at the final position
of the previous animation. If the same direction is chosen,
the animation has to start with the initial value for the
first click. This can
be the initial value of the same animation or the
final position of an previous animation in the opposite
direction, depending on the history. Anyway the history
since the last click on the same symbol has to be repeated.
If the animation is started, while itself is already running,
it has to start at the intial value. If it is started, while an
animation in the opposite direction is running, it is
additive, the visual effect is, that it stops until the other
animation is finished.
Animation for different attributes superpose always and
have no influence on each other.
Initial values for horizontal and vertical motions are given
as small circle and lines as a help.