It avoid trying to calculate arc angles (start, end or arc angle) that
frequently create issues due to reverse Y axis, plot mirrored and/or
angle normalization with different criteria.
Fixes#10914https://gitlab.com/kicad/code/kicad/issues/10914
They don't define a KiCad string class, so the header file name was
somewhat misleading. But the fact that they didn't match definitely
made coding more difficult.
They are used for chamfered round rect pads, and can be used for custom shaped pads.
No actual change currently, but the shape rotation of custom pads and chamfered rr pads
can be now used in gerber plots.
plotter.h contains now only a header common to all plotters.
The code does not actually change, but it allows modifying a specific plotter
without recompiling most of kicad files.
1) For a while now we've been using a calculated seg count from a given
maxError, and a correction factor to push the radius out so that all
the error is outside the arc/circle. However, the second calculation
(which pre-dates the first) is pretty much just the inverse of the first
(and yields nothing more than maxError back). This is particularly
sub-optimal given the cost of trig functions.
2) There are a lot of old optimizations to reduce segcounts in certain
situations, someting that our error-based calculation compensates for
anyway. (Smaller radii need fewer segments to meet the maxError
condition.) But perhaps more importantly we now surface maxError in the
UI and we don't really want to call it "Max deviation except when it's
not".
3) We were also clamping the segCount twice: once in the calculation
routine and once in most of it's callers. Furthermore, the caller
clamping was inconsistent (both in being done and in the clamping
value). We now clamp only in the calculation routine.
4) There's no reason to use the correction factors in the 3Dviewer;
it's just a visualization and whether the polygonization error is
inside or outside the shape isn't really material.
5) The arc-correction-disabling stuff (used for solder mask layer) was
somewhat fragile in that it depended on the caller to turn it back on
afterwards. It's now only exposed as a RAII object which automatically
cleans up when it goes out of scope.
6) There were also bugs in a couple of the polygonization routines where
we'd accumulate round-off error in adding up the segments and end up with
an overly long last segment (which of course would voilate the error
max). This was the cause of the linked bug and also some issues with vias
that we had fudged in the past with extra clearance.
Fixes https://gitlab.com/kicad/code/kicad/issues/5567
This is the first step to allowing non-segments in the line chain.
External routines cannot be allowed to change the line chain without
going through the internal routines. To accomplish this, we remove the
Vertex() and Point() access routines and only leave the const versions.
Transformations are given for both points as well as the chain itself.
Standard apertures are circle, rect, oblong and polygon (regular polygonal shapes with 3 to 12 vertices)
The support of the standard aperture type polygon was missing in Gerber plotter.
This places the arc approximation setting in the kicad_pcb file and uses
it for all parts of the board rendering where arcs are converted to
segments. This allows the user to customize their speed vs. accuracy
tradeoff. The default setting of maximum error of 0.005mm is acceptable
for small boards on moderate systems.
This corrects an issue with fill segments-per-circle and moves the error
to segmetns calculation down in a number of functions to expose the
single value for approximation