use this as the text format for newly created layer labels
Instead of defaulting to a random font, this gives us a mechanism
to supply a better default label font to users via the default
style database. And users can always modify this "default" text
format if they'd like to change the default font!
For now this is the underlying code logic changes only -- we
don't yet include a 'Default' text format in the default style database
to take advantage of this functionality.
layers by a preset amount
This allows for the line rendering to trim off the first x mm
and last y mm from the actual line string when drawing the line.
It can be used eg when creating complex symbols where a line layer
should not overlap marker symbol layers placed at the start
and end of the line.
The start/end trim distance supports a range of units, including
percentage of the overall line length, and can be data defined
for extra control.
Should return true for feature renderers which require embedded
feature symbology. The corresponding feature request flag will
be set on the iterator used for the renderer will rendering vector
layers.
Returns true if the symbol layer rendering can cause visible
artifacts across a single feature when the feature is rendered
as a series of adjacent map tiles each containing a portion
of the feature's geometry.
This depends on the symbol layer derived class itself - eg
a simple solid color fill won't show any artifacts, but a shapeburst
fill WILL.
This renderer merges (or unions/dissolves) the line or polygon features
from a layer prior to rendering them. It's useful for rendering
a polygon layer with overlapping features as one single "coverage" feature,
or a line layer consisting of many smaller component line features
using a regularly spaced marker line or similar.
Internally, this just moves the guts of the existing inverted polygons
renderer to a new base class, as that renderer already had an option
to merge features prior to rendering. Basically it just exposes a new
renderer to users which is the inverted polygon renderer without
the inversion step!
