## The advanced Palapeli Slicer Collection

The Palapeli Slicer Collection produces realistic jigsaw pieces with various basic patterns:

Rectangular grid

Contains the well-known rectangular pieces.

Cairo grid

With its pentagonal pieces and unequal edge angles, it's rather hard to puzzle because the pieces fit together in an unfamiliar manner.

Hexagonal grid

Produces hexagonal pieces, arranged like honeycomb cells.

Rotrex grid

Through a special composition of triangular, hexagonal and rectangular pieces, the pieces form a pattern resembling to many intersecting circles.

Irregular grid

This grid is available only if you have installed qvoronoi from the qhull package. qvoronoi is used to calculate irregular piece shapes from randomly placed points.

The Palapeli Slicer Collection has various parameters which control the appearance of the piece edges, especially the plugs on them. Default settings are provided for all of these parameters. An additional preset mode is available which reduces the amount of parameters to a bare minimum. The following parameters are available usually:

Piece count:

Here set the exact number in which the image will sliced into pieces. This option only appear if the mathematical logic of the slicer selected allows any number.

Approx. piece count:

Here set the desired number in which the image will sliced into pieces. This option only appears if the mathematical logic of the selected slicer can readjust this number.

Flipped edge percentage:

The probability for each plug to be flipped. A plug is considered flipped if it points in the opposite direction as it would in a fully regular grid. On the rectangular grid, this results in pieces with 3 or 4 plugs pointing inwards resp. outwards. Position the slider at the very left to obtain the normal fully regular grid. In the middle, plug orientation is random. At the right, the grid is fully regular again, but with an alternate rule. This does not mean reversal of all plugs: In the alternate regular grid, for instance, each piece has four inward-pointing or four outward-pointing plugs. This setting has no effect in the irregular grid.

Edge curviness:

Determines how curvy the edges are, i.e. how strongly the borders dent in or bulge out. Move the slider to the very left to obtain straight edge lines (except for the plugs).

Plug size:

Determines the size of the plug part of each edge. The default setting (middle position of the slider) is chosen to look like a real puzzle. The slider ranges from 50% to 150% this size, which already looks obscenely large. The program tries very hard to avoid collisions between plugs. Colliding edges are reshaped multiple times and shrinked in small steps. However there still remain cases where no solution can be found, especially for large plug sizes.

Diversity of curviness:

Determines how much the curviness (see above) varies between edges. Move the slider to the left to make the dents and bulges look all the same. Position the slider at the right, there may occur very curvy and very straight borders.

Diversity of plug position:

Determines how much the position of the plug on the edge varies. Position the slider at the very left, plugs are affixed to the middle of their edge.

Diversity of plugs:

Determines how individual the plugs look like. Position the slider at the very left, plugs look all the same. At the very right, each plug will be a unique piece of art crafted especially for you.

Diversity of piece size:

Only for irregular grid: Determines how the piece size varies. A very small setting means nearly no variation; crystallite-like structure arise. Higher settings produce very small and very large pieces.

Dump grid image:

Save an image of the grid (black edges on white background) at `~/goldberg-slicer-dump.png`. If a previous dump exists, it is overwritten.