wumpus-core-0.15.0: Pure Haskell PostScript and SVG generation.

PortabilityGHC with TypeFamilies and more
Stabilityunstable
Maintainerstephen.tetley@gmail.com

Wumpus.Core.Picture

Contents

Description

Construction of pictures, paths and text labels.

Synopsis

Construction

blankPicture :: Num u => BoundingBox u -> Picture uSource

Create a blank Picture sized to the supplied bounding box. This is useful for spacing rows or columns of pictures.

frame :: (Fractional u, Ord u) => Primitive u -> Picture uSource

Lift a Primitive to a Picture, located in the standard frame.

frameWithin :: (Fractional u, Ord u) => Primitive u -> BoundingBox u -> Picture uSource

Frame a picture within the supplied bounding box

A text label uses the supplied bounding box as is - no clipping is performed if the bounding box is smaller than the boundary size of the text. This may cause strange overlap for subsequent composite pictures, and incorrect bounding box annotations in the prologue of the generated EPS file.

Paths and ellipses are bound within the union of the supplied bounding box and the inherent bounding box or the path or ellipse. Thus the bounding box will never reframed to a smaller size than the natural bounding box.

frameMulti :: (Fractional u, Ord u) => [Primitive u] -> Picture uSource

Lift a list of primitives to a composite picture, all primitives will be located within the standard frame.

This function throws an error when supplied the empty list.

multi :: (Fractional u, Ord u) => [Picture u] -> Picture uSource

Place multiple pictures within the same affine frame.

This function throws an error when supplied the empty list.

path :: Point2 u -> [PathSegment u] -> Path uSource

Create a Path from a start point and a list of PathSegments.

lineTo :: Point2 u -> PathSegment uSource

Create a straight-line PathSegment.

curveTo :: Point2 u -> Point2 u -> Point2 u -> PathSegment uSource

Create a curved PathSegment.

vertexPath :: [Point2 u] -> Path uSource

Convert the list of vertices to a path of straight line segments.

curvedPath :: [Point2 u] -> Path uSource

Convert a list of vertices to a path of curve segments. The first point in the list makes the start point, each curve segment thereafter takes 3 points. Spare points at the end are discarded.

Constructing primitives

class Stroke t whereSource

Create a open, stroked path (ostroke) or a closed, stroked path (cstroke).

ostroke and cstroke are overloaded to make attributing the path more convenient.

Methods

ostroke :: (Num u, Ord u) => t -> Path u -> Primitive uSource

cstroke :: (Num u, Ord u) => t -> Path u -> Primitive uSource

zostroke :: (Num u, Ord u) => Path u -> Primitive uSource

Create an open stoke coloured black.

zcstroke :: (Num u, Ord u) => Path u -> Primitive uSource

Create a closed stroke coloured black.

class Fill t whereSource

Create a filled path (fill). Fills only have one property - colour. But there are various representations of colour.

fill () will fill with the default colour - black.

Methods

fill :: (Num u, Ord u) => t -> Path u -> Primitive uSource

Instances

zfill :: (Num u, Ord u) => Path u -> Primitive uSource

Create a filled path coloured black.

clip :: (Num u, Ord u) => Path u -> Picture u -> Picture uSource

Clip a picture with respect to the supplied path.

class TextLabel t whereSource

Create a text label. The string should not contain newline or tab characters. Use multilabel to create text with multiple lines.

textlabel is overloaded to make attributing the label more convenient.

Unless a FontAttr is specified, the label will use 12pt Courier.

Methods

textlabel :: t -> Point2 u -> String -> Primitive uSource

ztextlabel :: Point2 u -> String -> Primitive uSource

Create a label where the font is Courier, text size is 10 and colour is black.

multilabel :: (Fractional u, Ord u, TextLabel t) => t -> u -> VAlign -> Point2 u -> [String] -> Picture uSource

Create multiple lines of text.

The dimension argument is the linespacing, measured as the distance between the upper lines descender and the lower lines ascender.

An error is throw if the list of strings is empty

class Ellipse t whereSource

Create an ellipse, the ellipse will be filled unless the supplied attributes imply a stoked ellipse, e.g.:

 ellipse (LineWidth 4) zeroPt 40 40 

Note - within Wumpus, ellipses are considered an unfortunate but useful optimization. Drawing good cicles with Beziers needs at least eight curves, but drawing them with PostScript's arc command is a single operation. For drawings with many dots (e.g. scatter plots) it seems sensible to employ this optimaztion.

A deficiency of Wumpus's ellipse is that (non-uniformly) scaling a stroked ellipse also (non-uniformly) scales the pen it is drawn with. Where the ellipse is wider, the pen stroke will be wider too.

Methods

ellipse :: Fractional u => t -> u -> u -> Point2 u -> Primitive uSource

zellipse :: Num u => u -> u -> Point2 u -> Primitive uSource

Create a black, filled ellipse.

Operations

extendBoundary :: (Num u, Ord u) => u -> u -> Picture u -> Picture uSource

Extend the bounding box of a picture.

The bounding box is both horizontal directions by x and both vertical directions by y. x and y must be positive This function cannot be used to shrink a boundary.