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- Improvement Debug added to redundant solving in Iteration Mode, to show when just one iteration solved the system
- Fix wrong QR information on empty sketch
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The solver has been adapted to use Eigen's SparseQR QR decomposition algorithm. The original
Dense QR implementation is maintained and can be selected using the Advanced Control TaskBox (see below).
The use of SparseQR provides over an order of magnitude improvement in solving time in complex sketches due to
the Sparse nature of the Jacobian matrix of the system of equations.
The solver advanced control is a new TaskBox in the Sketcher that allows to select which algorithms are to be used for
the different solving operations and tweak its parameters. It is not intended to be a user control, but means to debug
solving problems and improve the algorithms and their configuration.
This commit also introduces multithread support for Eigen. Currently it is only limited to products and does not provide
a substantial speed improvement. It is expected to have more multithreaded operations in Eigen in the future.
As a bonus, the TaskBoxes in the Taskbar of the Sketcher remember the last state (collapsed or deployed).
Fixes a bug where an arc, ellipse, or arc-of-ellipse, being reversed in
XY plane, behaved badly in sketcher (see forum thread "Sketch: how to
handle reversed external arcs?"
http://forum.freecadweb.org/viewtopic.php?f=10&t=9130 ).
Also fixes a problem with rotated arcs (see forum thread "Rotating Arc
in Sketcher"
http://forum.freecadweb.org/viewtopic.php?f=22&t=9145#p74262 ).
This is done by adding an emulation flag to a few methods in
Part::GeomXXX, which makes the shape to pretend being non-reversed
(CCW). This causes endpoints of reversed arcs of circles lineked as
external geometry to swap, causing broken sketches sometimes.
