Changelog

2.1

New sketch features:

Lathe groups create circle and face entities.
New toolbar button for creating lathe groups.
Chord tolerance is separated into two: display chord tolerance (specified in percents, relative to model bounding box), and export chord tolerance (specified in millimeters as absolute value).
Bezier spline points can be added and removed after the spline is created.
When an unconstrained extrusion is switched between "union" and "difference", its normal is flipped.
Groups can be added in the middle of the stack. Note that this results in files incompatible with version 2.0.
Active group can be removed.
Removing an imported group does not cause all subsequent groups to also be removed.
When a new group with a solid is created, the color is taken from a previous group with a solid, if any.
Entities in a newly active group do not become visible.
When entities are selected, "Zoom to fit" zooms to fit only these entities and not the entire sketch.
Zero-length edges are reported with a "zero-length error", not "points not all coplanar".

New constraint features:

Height of the font used for drawing constraint labels can be changed.
New constraint, length difference, placed with J. (Patch by Peter Ruevski)
Horizontal/vertical constraints are automatically added if a line segment is close enough to being horizontal/vertical. This can be disabled by holding Ctrl.
Reference dimensions and angles can be placed with Shift+D and Shift+N.
Copying and pasting entities duplicates any constraints that only involve entities in the clipboard, as well as selected comments.
Diameter constraints can be shown as radius.
The "pi" identifier can be used in expressions.
Constraint labels can be snapped to grid.
Integer angles are displayed without trailing zeroes.
Angle constraints have proper reference lines and arrowheads.
Extension lines are drawn for point-line distance constraints.

New solver features:

Sketches with redundant and unsolvable constraints are distinguished.
New group setting, "allow redundant constraints". Note that it makes the solver less stable.

New rendering and styling features:

New line style parameter: stippling, based on ISO 128.
Outlines of solids can be drawn in a particular style (by default, thick lines) controlled by the "Show outline of solid model" button.
Occluded edges can be drawn in a particular style (by default, stippled with short dashes) controlled by the "Show hidden lines" button.
Solids can be made transparent.

New export/import features:

The old "import" command (for .slvs files) is renamed to "link".
If a linked .slvs file is not found, first the relative path recorded in the .slvs file is checked and then the absolute path; this is an inversion of the previously used order. If it is still not found, a dialog appears offering to locate it.
DXF and DWG files can be imported, with point-coincident, horizontal and vertical constraints automatically inferred from geometry, and distance and angle constraints created when a dimension placed against geometry exists.
Triangle mesh can be exported for viewing in the browser through WebGL.
Export dialogs remember the last file format used, and preselect it.
Exported DXF files have exact circles, arcs and splines instead of a piecewise linear approximation (unless hidden line removal was needed).
Exported DXF files preserve color and line thickness.
In exported DXF files, constraints are represented as DXF dimensions, instead of piecewise linear geometry.
When exporting 2d views, overlapping lines are removed.

Other new features:

Native Linux (GTK 2 and GTK 3) and Mac OS X ports.
Automatically save and then restore sketches if SolveSpace crashes. (Patch by Marc Britten)
Unicode is supported everywhere (filenames, group names, TTF text, comments), although RTL scripts and scripts making heavy use of ligatures are not rendered correctly.
The vector font is grid-fitted when rendered on screen to make it easier to read regardless of its size.

Initial public release.