Release notes/0.47

Inkscape 0.47

(not released yet - AnnouncePlanning047)

Refactoring effort

The focus of the 0.47 release was to clean up legacy code and push forward the migration to clean object-oriented C++. The goal of this effort was to increase reliability and maintainability of Inkscape. In the long run, it will mean fewer bugs and more new features, because it will be easier to develop and find bugs in Inkscape.

Migration to lib2geom

Many parts of the code have been changed to use the 2Geom library for geometrical calculations instead of the old libnr and Livarot libraries.

Preferences

Instead of global functions directly manipulating an XML document, the preferences API is now exposed through the Inkscape::Preferences singleton. It abstracts away the way the preferences are stored in memory. In the future it may allow for different user settings storage backends (like GConf or the upcoming dconf on GNOME desktops or .plist files on OS X). Previously, Inkscape directly manipulated an internal XML document.

Tools

Node tool

• When hovering over a path in the Node tool, the path's outline will be displayed for a short time. This effect, its duration and the color of the outline is configurable.
• The Node tool can now edit clipping paths and masks of objects on canvas, without releasing them. If the selected object has a clipping path and mask, the corresponding buttons on the controls bar of the tool will be enabled; pressing these buttons will display the editable paths or handles of the clippath or mask. A clipping path is stroked green, a mask is stroked blue (the same colors as those used for them in Outline mode).
• Snapping has been improved (more details in Snapping below)
• When dragging a node handle with Ctrl pressed, it now snaps not only to the 15 degree increments starting from 0 and to the original handle direction, but also to the direction of the opposite handle (if it exists) or of the opposite line segment (if it is a straight line).
• The behavior of the buttons/shortcuts that make a node smooth or cusp has been improved:
  • If a node is already a cusp (diamond shaped), pressing Shift+C again on it will retract both its handles. As this works for any number of selected nodes, you can always retract all handles in all nodes by selecting all nodes and pressing Shift+C twice.
  • If a non-smooth node is next to a straight line segment, pressing Shift+S once makes it half-smooth: it now has one handle aligned with that line segment. Another press of Shift+S will expand the second handle as well turning it into a full smooth node. If a node is between two curve segments, Shift+S will expand both handles as before.
• Auto smooth nodes: a new "auto" node type was added, similar to the one Xara Xtreme has. An auto node is a smooth node which automatically adjusts (rotates and stretches) its handles when this node or its neighbors are moved. This adjustment (same as what you get when you convert node type to Smooth, but continuous) keeps the curve at this node as smooth as possible. It feels a bit like Spiro paths (see below); although not as smooth as a Spiro, auto nodes may often be preferable as they work without applying any Path Effect. Whenever you manually adjust the handles of an auto node or drag the adjacent curve, it loses its auto state and becomes simply smooth; for this reason, it is recommended to edit smooth nodes with the node handles hidden via a toggle button on the controls bar. Auto nodes are represented by little circles, as opposed to smooth/symmetric nodes (squares) and cusp nodes (diamonds). To convert selected node(s) to auto, press Shift+A or use the corresponding node type button on the controls bar.

Tweak tool

Several new modes are added to the Tweak tool for transforming, duplicating, and deleting selected objects using the same "soft brush" metaphor that the path editing and coloring modes use. Using these new modes, it is easy to "sculpt" scatterings of small objects, such as clone tilings, into complex and naturalistic textures.

• Push mode moves those selected objects that are under the brush in the direction in which you move the brush. This is similar to the Push path mode, except that the Move mode affects entire objects and not parts of the paths under the brush.

• Attract/Repel Objects mode moves those selected objects that are under the brush towards the cursor (default) or away from cursor (with Shift pressed). This is similar to the Attract/repel path mode, except that the Move in/out mode affects entire objects and not parts of the paths under cursor.

• Jitter mode moves those selected objects that are under the brush in random directions and by random amounts, but the overall amount of movement depends on Force, pen pressure (if you're using a tablet pen), on the closeness of the object to the center of brush, and on how long you apply the brush.

• Scale mode scales those selected objects that are under the brush down (by default) or up (with Shift pressed). The speed of scaling depends on Force, pen pressure (if you're using a tablet pen), on the closeness of the object to the center of brush, and on how long you apply the brush.

• Rotate mode rotates those selected objects that are under the brush clockwise (by default) or counterclockwise (with Shift pressed). The speed of rotation depends on Force, pen pressure (if you're using a tablet pen), on the closeness of the object to the center of brush, and on how long you apply the brush.

• Duplicate/delete mode randomly duplicates those selected objects that are under the brush (by default) or deletes them (with Shift pressed). The chance of an object to be duplicated and deleted depends on Force, pen pressure (if you're using a tablet pen), on the closeness of the object to the center of brush, and on how long you apply the brush. Like with the regular Duplicate command, duplicating with Tweak tool places the copies right over the originals, and you may need to use the Jitter mode to ruffle them apart. The duplicates created by the tool are automatically added to selection if the originals objects were in selection (e.g. if you're tweaking a group of objects, they are duplicated within that group and are not by themselves selected).

• Blur mode blurs the selected objects under the brush more (by default) or less (with Shift pressed). The amount of blur added or removed depends on Force, pen pressure (if you're using a tablet pen), on the closeness of the object to the center of brush, and on how long you apply the brush.

Also, the existing path editing modes of the tool have been rearranged: now Shrink and Grow are one mode (shrinks by default, grows with Shift), and Attract and Repel are one mode (attracts by default, repels with Shift). Here is a complete list of modes and shortcuts of the Tweak tool:

Shift+m, Shift+0	        move mode
Shift+i, Shift+1	attract/repel objects mode
Shift+z, Shift+2	jitter mode
Shift+<, Shift+>, Shift+3	scale mode
Shift+[, Shift+], Shift+4	rotate mode
Shift+d, Shift+5	duplicate/delete mode
Shift+p, Shift+6	push path mode
Shift+s, Shift+7	shrink/grow path mode
Shift+a, Shift+8	attract/repel path mode
Shift+r, Shift+9	roughen mode
Shift+c	        paint mode
Shift+j	        color jitter mode
Shift+b	        blur mode

In Paint mode, painting with Shift inverts the color you're applying (e.g. when painting with yellow, Shift will switch the applied color to blue).

Calligraphy tool

• The tool's settings can now be saved and restored as presets.

• When drawing with Alt pressed, Inkscape subtracts the path you have created from the selected path. With Shift, it unions with the selected path. This allows you to quickly patch or fix problems in a stroke you have drawn without leaving the tool.

• The behavior of the tool when tracking a guide (drawing with Ctrl) has been improved:

• • The initial "jerk" when you start drawing is suppressed.

• • The undesired flipping of the stroke to the other side of the guide path, when drawing along closed paths, is fixed.

• • If you lose connection with your guide path, the tool tries to continue moving in the same direction as if by inertia, so as to minimize the tearoff jerk.

Paint Bucket tool

• Paint Bucket is now more tightly integrated with potrace. As a result, memory and CPU usage on each fill operation have been reduced significantly.

Eraser Tool

A new eraser tool has been added. Its shortcut is Shift+E. It has two main modes:

• Delete Objects mode where any shape touched by the tool is deleted completely. This operation is in line with "vector" editing.
• Cut mode where erasing acts similar to erasing in a standard bitmap editor. It acts on all objects in the current layer.

Pen and Pencil

Apart from the regular Bezier mode, the pen tool now provides several new modes:

• Spiro mode: This mode automatically applies the new Spiro Splines LPE (see the section on new effects) to any newly drawn path. As mentioned below, it is not yet possible to preview Spiros before the path is finished.

• Polyline mode: This mode makes it easy to draw many straight line segments in quick succession by disallowing curves (even when you drag with the mouse).

• Paraxial polyline mode: In this mode, you can create straight line segments that are parallel to one of the coordinate axes. Normally, each line segment is drawn perpendicular to the previous one. The direction of the line segment being drawn can be toggled with Shift. When clicking on the start anchor, the path is closed with an L-shaped segment (the direction of which can also be flipped with Shift).

Furthermore, it is now possible to automatically apply predefined vector brushes to path strokes in pen and pencil tools. This is a first step towards this blueprint.

In Pencil tool, the controls bar now provides the Smoothing parameter, changeable in the range from 1 to 100, which controls how much smoothing is applied to the freehand line. Small Smoothing values produce rough lines with many nodes; large values give smooth lines with few nodes. Previously, this control was only available in Inkscape Preferences.

Pencil sketch mode

[johan] Press alt and sketch away, release alt to finalize result.

Text tool

When editing multiline or flowed text, the PgUp and PgDn keys now work to move the cursor by one screen (i.e. by as many lines as fit into the screen at current zoom).

Path effects

Notable bug fixes and effect changes

We try to refrain from changing the behavior of LPE's, because it will change appearance in old files when opened in new version of Inkscape (but not in any other SVG viewer or editor). However, when an effect is really broken, we have to fix it:

• The Pattern Along Path effect:
  • The pattern used to be stretched across discontinuities. This has been fixed; now it treats a discontinuous path as a group of continuous paths and applies the effect separately to each.
  • Successive copies of the pattern can now be fused into continuous paths (using the new "fuse nearby ends" feature) so that "filling" the result works as expected.

New effects

• Sketch: Simulates hand-drawn lines. A set of parameters lets you tune the effect. They are all summarized in this picture.

• Hatches Fills the given shape with rough, configurable and randomized hatches, simulating a quick hand drawing.

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• von Koch: This effect creates fractal pictures. A collection of transformations (rotations, rescalings, etc...) is recursively applied to the input path. The transforms are derived from a "reference" path (a line segment) and a "generating" path (basically a collection of segments): the thransforms are the one needed to move the reference onto each segment of the generating path (components in the generating path having more than one segment might be used to define shearing/mirroring transforms). A famous example is the von Koch's snowflake.

Warning: the complexity of the output path grows exponentially fast with the number of generations. As a guardrail, an (editable) complexity bound is provided, above which the effect is disabled.

• Knot: Creates a knot from a flat self intersecting curve. At each crossing, one string is interrupted to make it look like going under the other. The "sign" of each crossing can be set independantly.

Warning: Should not be applied to groups yet, unless you don't want to edit the crossing signs.

• Perspective paths: Draw an arbitrary path as if viewed in perspective. This is work in progress. Known limitations (among others): It can only use the first perspective that exists in the document defs, and the perspective cannot be adapted interactively yet (the effect must be removed and reapplied after modifying the perspective). [max]

• Spiro splines are a novel way of defining curvilinear paths developed by Raph Levien. It takes some getting used to, but for certain tasks (such as lettershape design) Spiros have a clear advantage over Bezier curves. Recently, Spiro support was added to the FontForge font editor; now it is available in Inkscape too, which means you can use all the convenient Inkscape path tools (moving and transforming groups of nodes, node sculpting, etc.) on Spiro paths.

A Spiro path is defined by a sequence of points, but unlike a regular path with Bezier curves, all Spiro points lie on the path and there are no off-path handles. The curvature of the path is defined entirely by the positions of the points and their types. The path behaves very similar to a springy rod which is forced to pass through the given points and which uses the minimum possible curvature to satisfy the requirement. As such, it feels quite natural and the resulting path is very smooth - not just superficially smooth (i.e. having no cusps), but smooth at a deeper level, which you can achieve with Beziers only after a lot of laborious tweaking.

To create a Spiro path, select any path and assign the "Spiro spline" path effect to it. There are no parameters. Each node of your path becomes a point of a Spiro path, depending on the type of node:

• Smooth nodes (those with two collinear Bezier handles; use Shift+S to make a node smooth) become smooth curve points of the Spiro path. Note that the length or direction of the Bezier handles of the source path is ignored; the only thing that matters is their collinearity.

• Cusp nodes of the source path become corner points of the Spiro path, like free hinges on the springy rod. Between two corner points, the path is always a straight line. To make a node cusp, retract its Bezier handles by Ctrl+click, or press Shift+C and move one of the handles so they are no longer collinear.

• Half-smooth nodes - those with one Bezier handle collinear with a straight line segment on the other hand - become "left" or "right" points on the Spiro path which behave exactly the same: they sit between a straight line and a curve and enforce that these two segments join smoothly without a cusp. To create such a node, make sure one of the segments is a line (select its ends and press Shift+L), then Ctrl+drag the remaining handle to make it snap to the direction of the straight line segment on the other side, or press Shift+S to lock it to that direction.

Note that what matters is the actual collinearity of a node's handles, regardless of the node type that the node has in the Node tool; for example, if a node designated as cusp (diamond-shaped) has collinear handles, it will become a smooth curve point of the Spiro path.

Some configurations of points do not converge and produce wild loops and spirals instead of a smooth curve. According to Raph, "The spline solver in this release is _not_ numerically robust. When you start drawing random points, you'll quickly run into divergence. However, "sensible" plates based on real fonts usually converge." Avoid too sharp changes in direction between points to prevent divergence. Hopefully, the robustness of the algorithm will be improved in future releases.

For now, to edit Spiro paths viewing the result in real time, you have to use the Node tool; it is recommended to turn off the red highlight of the source path. The Pen tool does not yet allow you to preview a Spiro as you draw, although you can paste the Spiro effect on the path and see the result as soon as the path is finalized.

You can always use the Node tool to continue a Spiro path by duplicating and dragging away its end nodes. Also, when you have a Spiro path selected, you can add a new subpath to it with Pen or Pencil if you start drawing with Shift.

• Construct Grid [johan] Draws a grid using the first three nodes of a path. The center node defines the origin. The other two nodes define the direction and length of the two adjacent sides of the first cell. If a path has more than three nodes, the other nodes are ignored. One can select the number of cells in the two orthogonal directions.

• Envelope Deformation allows you to deform an object (or a group of object) by deforming its sides. Modifications are done by deforming the four path parameters: Top, Bottom, Left and Right.

• Ruler: [max]

• Interpolate Subpaths: [Johan]