wumpus-core: Pure Haskell PostScript and SVG generation.
Wumpus - (W)riter (M)onad (P)ost (S)cript.
Wumpus is a 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.
Wumpus-core includes some extra helper modules that are not really part of the "core", but are otherwise currently homeless. They provide lists of named colours and safe fonts, plus some prototype code (Extra.PictureLanguage) for arranging pictures.
WARNING...
The modules Core.BoundingBox
and Extra.PictureLanguage
are
likely to be reworked significantly in the future.
Core.BoundingBox
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.
Extra.PictureLanguage
needs some more thought. The current
set of classes is rather cumbersome, and some of the operations
would benefit new names.
NOTE...
Revision 0.17.0 added affine transformations for primitives (paths, text labels, ellipses), one consequence of this is the bounding box may be tighter for a primitive under affine transformation then lifted to a picture, than a primitive lifted to picture then transformed, i.e.:
boundary (liftToPicture (transform PRIM)) /= boundary (transform (liftToPicture PRIM))
Where liftToPicture is usually frame
from
Wumpus.Core.Picture
.
This is because the bounding box of a transformed picture is calculated by applying the transformation to the corner points of its (previous) bounding box rather than finding the bounding box union of all the composite primitives.
GENERAL DRAWBACKS...
For actually drawing pictures, diagrams, etc. Wumpus is very
low level. I'm working on a complementary package
wumpus-extra
with higher-level stuff (polygons, arrows etc.)
but it is too unstable for Hackage. Preview releases can be
found at http://code.google.com/p/copperbox/ though.
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.
\[1\] 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:
18,0 to 0.19.0:
Added
Transform
type class to apply a matrix transformation directly.Changed the ordering of picture drawing in PostScript and SVG output so the list gets drawn from tail to head with right folds. This makes the list order of pictures match their zorder.
Renamed the function
withinBB
(Core.BoundingBox) towithin
.On many type signatures with e.g. Points, I've changed the parameter name on the type constructor from
a
tou
. This is to indicate thatu
is some unit - almost always a Double. e.gPoint2 a
becomesPoint2 u
and all the class obligations change lexically as wellFloating a =>
toFloating u =>
. Superficially this means a lot of type signatures have diffs but haven't really changed.Added function
bezierCircle
to generate the Bezier curve points for arcs describing a circle.Added new demo - MultiPic. The PostScript it generates is efficient - no extraneous use of
concat
.Added wumpus_default_font constant.
17.0 to 0.18.0:
Added instances of the affine operation classes (Scale, Rotate ...) for Primitives (path, text label, ellipse).
Added some picture composition functions to Core.Picture. These are useful for testing where the type class complications of Extra.PictureLanguage are an overhead.
Added iRGB to Core.Colour - create RGB colours with integer components [0..255] - and iHSB, iGrey.
Added some test modules for the affine transformations. These illustrate a quirk in Wumpus where, under affine transformation, Pictures may generate a larger bounding box than composite primitives.
Minor change - ztextlabel changed to use 24pt type rather than 12pt.
Corrected the cabal file to include the correct files for the manual. The Haskell source file
WorldFrame.hs
was missing with the generated fileWorldFrame.eps
incorrectly included instead.
Downloads
- wumpus-core-0.19.0.tar.gz [browse] (Cabal source package)
- Package description (revised from the package)
Note: This package has metadata revisions in the cabal description newer than included in the tarball. To unpack the package including the revisions, use 'cabal get'.
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For package maintainers and hackage trustees
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Versions [RSS] | 0.12.0, 0.13.0, 0.13.1, 0.14.0, 0.15.0, 0.16.0, 0.17.0, 0.18.0, 0.19.0, 0.20.0, 0.21.0, 0.22.0, 0.23.0, 0.30.0, 0.31.0, 0.32.0, 0.33.0, 0.34.0, 0.35.0, 0.36.0, 0.37.0, 0.40.0, 0.41.0, 0.42.0, 0.42.1, 0.43.0, 0.50.0, 0.51.0, 0.52.0, 0.52.1 |
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Change log | CHANGES |
Dependencies | algebra (<0.1), base (<5), containers, monadLib, time (>=1.1.3 && <1.2), vector-space, wl-pprint, xml [details] |
License | BSD-3-Clause |
Copyright | Stephen Tetley <stephen.tetley@gmail.com> |
Author | |
Maintainer | Stephen Tetley <stephen.tetley@gmail.com> |
Revised | Revision 1 made by HerbertValerioRiedel at 2015-11-07T12:22:09Z |
Category | Graphics |
Home page | http://code.google.com/p/copperbox/ |
Uploaded | by StephenTetley at 2010-05-24T12:06:25Z |
Distributions | |
Reverse Dependencies | 5 direct, 0 indirect [details] |
Downloads | 25294 total (46 in the last 30 days) |
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Status | Docs uploaded by user Build status unknown [no reports yet] |