wumpus-core: Pure Haskell PostScript and SVG generation.

Wumpus is a low-level library for generating static 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 Pictures. 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 it is experimental - functionality is added and dropped between releases.

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.

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

Changelog:

1. 33.0 to 0.34.0:

• Clipping paths fixed. Previously they did not work for SVG or PostScript.

• picOver fixed. Drawing order was changed in version 0.33.0, but picOver was not updated accordingly (so it actually started drawing pictures under). It now works correctly.

• The lexer for escape characters embedded in label strings has been rewritten. It now supports octal and hexadecimal codes.

1. 32.0 to 0.33.0:

• Major change - reworked support for text encoding. Encoding maps are now linked with fonts - it was spotted that the Symbol font does not use the Latin1 names. The TextEncoder data type has been changed and there is a new FontEncoder data type. There are also new modules for the Symbol Font encoder table and for the Default Encoder which accommodates both Latin1 and the Symbol font. This has also mandated changes to the FontFace data type.

• Major change - the printing order has been changed. The first element in a frame of Prims is draw first. This means it appears first in the output file (this makes sense) - it also means it is at the back in the Z-Order. This latter point might not be so intuitive, but changing the printing order at least makes Wumpus-Core match SVG and PostScript.

• Changed the visiblity of the new colours (yellow, cyan, magenta) to be hidden at the top level. They can be exposed by importing Wumpus.Core.Colour.

• Wumpus.Core.FontSize - added spacerWidth function.

Modules

[Index]

Downloads

• wumpus-core-0.34.0.tar.gz [browse] (Cabal source package)
• Package description (revised from the package)

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Package maintainers

• StephenTetley

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