Fixes#997. The enter, update and exit selections are now initialized as fixed-
length arrays rather than dynamically populated with nulls. If duplicate keys
are used for either data or selected elements, only the first datum or element
is considered and subsequent data or elements are ignored.
3D rotations are not commutative, so we must perform an inverse rotation
to move something from origin [0, 0] to [λ, φ]. Normally we are moving
origin [λ, φ] to [0, 0].
The south pole rotation could result in line segments that go through
the poles. These are characterised by a 180° longitudinal difference.
These cases were not handled properly by the approximation algorithm,
but it now handles both north and south pole cases.
Rather than doing something like picking the last seen point, return
an undefined centroid if it is ambiguous.
Users can decide what to do, e.g. when picking an origin for a rotating
globe, using the last coordinate in a MultiPoint or LineString seems
reasonable in an ambiguous situation.
This allows us to generate the clip outline for whole-earth projections
with arbitrary rotations.
Internally, this is interpreted as a polygon with null coordinates.
This reverts commit 7712dcd59e.
Unfortunately, this caused empty polygons to be interpreted as "the
whole sphere", which is undesirable. Also, it is more useful to have a
definite graticule outline, at least for a graticule that doesn't cover
the whole sphere.
This fixes various problems that were occurring due to winding numbers
being tricky on a finite sphere.
This also includes some cleanup and fixes for degenerate points.
1. We no longer perform an equality check on GeoJSON polygon endpoints,
since we know that the first and last points should be equal.
2. However, there are special cases where a polygon just touches the
clip edge, generating two coincident intersection points. Here we avoid
generating a coincident point, and continue as normal.
3. Another special case is where we have coincident intersection points
e.g. due to a self-intersecting polygon. Here we continue calculating
the winding number as if this is a closed polygon (so we know whether to
insert a polygon around the whole clip edge).
It's not always meaningful to define the centroid of a collection because
collections are heterogenous: they can contain points, lines, polygons, or all
these types together. The previous code ignored objects that had dimensionality
lower than the collection's maximum dimensionality; for example, ignoring lines
and points if the collection contains polygons. While this may be what you want,
this feels magical and it's simpler to just define the centroid as undefined.
I'd prefer to force the user to state what they want explicitly, say by creating
a MultiPolygon that merges together a collection's polygons.
For example, "%-d" formats the day with no padding, "%_d" formats the day with
space-padding equivalent to "%e", and "%0d" formats the day with zero-padding
equivalent to "%d".
Rather than computing the ending value when the transition starts, the ending
value is computed when the transition is scheduled. This gives more predictable
behavior and makes it easier to debug evaluation errors since they occur
immediately (during user code) rather than inside a d3_timer callback.
The behavior of attrTween and styleTween are unchanged, since the interpolator
can only be constructed once the starting value is known. This commit also
removes d3.tween; I may add this back in a future commit, but I think there is
probably a better way to specify an interpolator for transitions.
The start event is now fired before any tweens are evaluated, such that you can
do any necessary preprocessing work beforehand. The end event no longer causes
the transition id to be inherited, since we can do that more elegantly now using
transition.transition.
This commit moves easing and event listeners down to the node's transition
object, allowing these fields to be modified via post-selection. This removes
the last vestige of private state for transitions.
This required a few changes to tests that depended on the order of callbacks for
tweens and events. Because timers are called back in reverse order, tweens are
now initialized in reverse order, and listeners are now invoked in order.
It is now possible to reselect elements with scheduled transitions and redefine
associated tweens; this enables "post-selection" to customize the behavior of
reusable components undergoing transitions, such as an axis. This commit also
makes it much easier to sequence transitions.
Previously, a transition's tweens were stored privately by the transition and
could only be accessed through the transition. This made it impossible to modify
transitions created by components: the transition is not accessible externally,
and cannot be reselected from the document. Consider the following snippet:
g.select(".x.axis")
.call(xAxis)
.selectAll("text")
.attr("dy", null);
If `g` is a selection, then this code alters the appearance of the axis as
expected. However, if `g` is a transition, then transition.selectAll creates a
new concurrent transition, and now multiple tweens compete to set the "dy"
attribute. Oy!
Under the new design, an element's scheduled tweens are stored semi-privately on
the node (in the existing node.__transition__). Transition parameters can thus
be reselected and modified by transitions that share the same id. If you now
reselect a transitioning element, you modify the transition rather creating a
competing transition; this should be less surprising and allow greater control.
As a side-effect of this change, it is no longer possible to schedule concurrent
transitions on the same element, even with the same id: only one transition may
be active on a given element at any time. (Note that you can still schedule
multiple future transitions on the same element, and concurrent transitions on
different elements.) For example, you could previously schedule overlapping
transitions with different easing functions, delays or durations, provided you
were careful to avoid conflict. This seems like a relatively obscure use-case
compared to modifying a transition, so I believe this is a reasonable change.
This commit also changes transition.transition, such that the returned
transition starts at the end of the originating transition, rather than
overlapping. This makes it much easier to schedule sequenced transitions without
the complexity of transition.each("end") and d3.select(this).
Also, transitions are now simply arrays of nodes, consistent with selections!
And d3.xhr now detects if the data has a type attribute; if so, this is used to
set the Content-Type header if one has not already been specified. In
conjunction with d3.urlencode, it is now easy to post encoded parameters.
This is backwards-compatible, yet adds numerous features to d3.xhr. You can now:
* Use standard node-style callbacks (fixes#473).
* Abort in-flight requests.
* Listen for progress events.
* Listen for load, error and abort events separately.
* Make POST requests (or any other method), including data.
* Set arbitrary request headers.
* Have multiple listeners on requests.
Note: the previous commit broke some tests relating to locale date
parsing, due to expecting "%m/%d/%y". On my system, the "en_US" locale
uses "%m/%d/%Y" by default. I've updated the tests to use %Y.
The process.env.TZ trick no longer seems to work. The fix automatically
adds an offset to the minutes being set, relative to the current
timezone. It assumes that the dates being tested in the scope are not in
DST, since the offset is relative to the timezone offset at the epoch.
Mike Bostock
Jason Davies
Nathan Vander Wilt