Wumpus.Core.GraphicProps

Data types for stroke and label styles corresponding to the styles provided by PostScript / SVG (StrokeAttr, etc.).

Data types for annotating Primitives with their drawing style (PathProps, etc.). Wumpus represents pictures as trees and decorates all elements (paths, text-labels) with their drawing style. This is boardly similar to how SVG handles attributes. For PostScript output, Wumpus renders attribute changes as graphics state updates.

Stroke attributes

data StrokeAttr

Stroke attributes for drawing paths.

Constructors

StrokeAttr

Fields

line_width :: Double

miter_limit :: Double

line_cap :: LineCap

line_join :: LineJoin

dash_pattern :: DashPattern

Instances

Eq StrokeAttr

Show StrokeAttr

data LineCap

Line cap - default in output is butt.

  Cap Butt:

  .-------.
  |=======|
  '-------'

  Cap Round:

  .-------.
 ( ======= )
  '-------'

  Cap Square:

  .---------.
  | ======= |
  '---------'

Constructors

CapButt

CapRound

CapSquare

Instances

Enum LineCap

Eq LineCap

Show LineCap

data LineJoin

Line join - default in output is miter.

  Join Miter:

      /\
     /..\ 
    /./\.\
   /./  \.\
  /./    \.\

 Join Round:

  \.\  
   \.\ 
    ,.)
   /./
  /./

 Join Bevel:

      __
     /..\ 
    /./\.\
   /./  \.\
  /./    \.\

Constructors

JoinMiter

JoinRound

JoinBevel

Instances

Enum LineJoin

Eq LineJoin

Show LineJoin

data DashPattern

Dash pattern - either a solid line or a list of on-off pairs together with an offset into the dashes.

 Solid

 Dash offset [(on,off )..]

Constructors

Solid

Dash Int [(Int, Int)]

Instances

Eq DashPattern

Show DashPattern

Font attributes

data FontAttr

Font face and size. Equivalent fonts have different names in PostScript and SVG. A PostScript font name includes the font style (e.g. Times-BoldItalic) whereas an SVG font has a name (the font-family attribute) and a style.

For PostScript, the following fonts are expected to exist:

 Times-Roman  Times-Italic  Times-Bold  Times-BoldOtalic
 Helvetica  Helvetica-Oblique  Helvetica-Bold  Helvetica-Bold-Oblique
 Courier  Courier-Oblique  Courier-Bold  Courier-Bold-Oblique
 Symbol

See the PostScript Language Reference Manual.

Constructors

FontAttr

Fields

font_size :: Int

font_face :: FontFace

Instances

Eq FontAttr

Ord FontAttr

Show FontAttr

data FontFace

FontFace : postscript_name * svg_font_family * svg_font_style * encoding_vector

For the writing fonts in the Core 14 set the definitions are:

 "Times-Roman"       "Times New Roman" SVG_REGULAR     standard_encoding
 "Times-Italic"      "Times New Roman" SVG_ITALIC      standard_encoding
 "Times-Bold"        "Times New Roman" SVG_BOLD        standard_encoding
 "Times-BoldItalic"  "Times New Roman" SVG_BOLD_ITALIC standard_encoding
 
 "Helvetica"              "Helvetica" SVG_REGULAR      standard_encoding
 "Helvetica-Oblique"      "Helvetica" SVG_OBLIQUE      standard_encoding
 "Helvetica-Bold"         "Helvetica" SVG_BOLD         standard_encoding
 "Helvetica-Bold-Oblique" "Helvetica" SVG_BOLD_OBLIQUE standard_encoding

 "Courier"              "Courier New"    SVG_REGULAR      standard_encoding
 "Courier-Oblique"      "Courier New"    SVG_OBLIQUE      standard_encoding
 "Courier-Bold"         "Courier New"    SVG_BOLD         standard_encoding
 "Courier-Bold-Oblique" "Courier New"    SVG_BOLD_OBLIQUE standard_encoding

Constructors

FontFace

Fields

ps_font_name :: String

svg_font_family :: String

svg_font_style :: SVGFontStyle

font_enc_vector :: EncodingVector

Instances

Eq FontFace

Ord FontFace

Show FontFace

data SVGFontStyle

SVG font styles - potentially a style may generate both font-weight and font-style attributes in the SVG output.

Constructors

SVG_REGULAR

SVG_BOLD

SVG_ITALIC

SVG_BOLD_ITALIC

SVG_OBLIQUE

SVG_BOLD_OBLIQUE

Instances

Eq SVGFontStyle

Ord SVGFontStyle

Show SVGFontStyle

Drawing styles for Primitives

data PathProps

Note when drawn filled and drawn stroked the same polygon will have (slightly) different size:

• A filled shape fills within the boundary of the shape
• A stroked shape draws a pen line around the boundary of the shape. The actual size depends on the thickness of the line (stroke width).

 CFill - closed path filled with the colour.

 CStroke - closed path, stroked with the colour.

 OStroke - open path, stroked with the colour.

 CFillStroke - closed path, filled with the first colour, 
 stroked with the stroke attributes and second colour.

Constructors

CFill RGBi

CStroke StrokeAttr RGBi

OStroke StrokeAttr RGBi

CFillStroke RGBi StrokeAttr RGBi

Instances

Eq PathProps

Show PathProps

Format PathProps

data LabelProps

Font rendering properties for a PrimLabel.

Constructors

LabelProps

Fields

label_colour :: RGBi

label_font :: FontAttr

Instances

Eq LabelProps

Ord LabelProps

Show LabelProps

Format LabelProps

data EllipseProps

Ellipses and circles are always closed.

 EFill - filled ellipse.

 EStroke - stroked ellipse.

 EFillStroke - ellipse filled with the first colour and stroked 
 with the stroke attributes and second colour.

Constructors

EFill RGBi

EStroke StrokeAttr RGBi

EFillStroke RGBi StrokeAttr RGBi

Instances

Eq EllipseProps

Show EllipseProps

Format EllipseProps

Defaults

default_stroke_attr :: StrokeAttr

Default stroke attributes.

 line_width      = 1
 miter_limit     = 1
 line_cap        = CapButt
 line_join       = JoinMiter
 dash_pattern    = Solid

defaultFont :: Int -> FontAttr

defaultFont : font_size -> FontAttr

Constructor for the default font, which is Courier (aliased to Courier New for SVG) at the supplied size.

Note - the font uses the Standard encoding - this is common to fonts but uses different indices to the more common Latin1.

For instance 232 is Lslash not egrave.

Both GhostScript and the standard AFM Core 14 metrics supplied by Adobe use Standard Encoding but include further characters (e.g. egrave) in the non-indexed higher-region.

wumpus_default_font :: FontAttr

Constant for the default font (Courier) at 14 point.