@hackage wumpus-core0.20.0

Pure Haskell PostScript and SVG generation.

Wumpus - (W)riter (M)onad (P)ost (S)cript.

Wumpus is a kernel library for generating 2D vector pictures, its salient feature is portability due to no FFI dependencies. It can generate PostScript (EPS) files and SVG files. The generated PostScript code is plain [1] and reasonably efficient as the use of stack operations, i.e gsave and grestore, is minimized.

Pictures in Wumpus are made from paths and text labels. Paths themselves are made from points. The usual affine transformations (rotations, scaling, translations) can be applied to geometric objects. Unlike PostScript there is no notion of a current point, Wumpus builds pictures in a coordinate-free style.

GENERAL DRAWBACKS...

For actually drawing pictures, diagrams, etc. Wumpus is very low level. There is a supplemantary package wumpus-basic available that helps create certain types of diagram, but even this lacks the higher-level stuff (polygons, arrows etc.) that would make creating general drawings easy.

Some of the design decisions made for wumpus-core are not sophisticated (e.g. how attributes like colour are handled, and how the bounding boxes of text labels are calculated), so Wumpus might be limited compared to other systems. However, the design permits a fairly simple implementation - which is a priority. Text encoding an exception - I'm not sure how reasonable the design is. The current implementation appears okay for Latin 1 but may be inadequate for other character sets, so I may have to revise it significantly.

WARNING...

The module Core.BoundingBox is likely to be reworked significantly in the future. It has too many functions that do not offer distinct functionality. Some functions were removed in revision 0.17.0 and some more are likely to follow.

The module Extra.PictureLanguage is deprecated. At some point it will be superceded by wumpus-basic but this will not be soon.

\[1\] Because the output is simple, straight-line PostScript code, it is possible to use GraphicsMagick or a similar tool to convert Wumpus's EPS files to many other formats (bitmaps).

Changelog:

  1. 19.0 to 0.20.0:

  • Removed the modules - Wumpus.Extra.SafeFonts, Wumpus.Extra.SVGColours, Wumpus.Extra.X11Colours - they are now in the package wumpus-basic.

  • Removed the example FontPic.hs to wumpus-basic.

  • Renamed two functions in Core.BoundingBox - trace changed to traceBoundary; retrace changed to retraceBoundary.

  • Fixed bug with picOver, previously the zorder was wrong and the function was actually working as picUnder.

  • Added capHeight to FontSize - get the size of an upper case letter without ascenders of descenders.

  • Guide updated regarding the new package wumpus-basic.