Base types for Drawing Objects, Graphics / Images (a Graphic that also returns an answer), etc.
** WARNING ** - some names are expected to change particularly the naming of the append and concat functions.
- data HPrim u
- hprimToList :: HPrim u -> [PrimElement u]
- singleH :: PrimElement u -> HPrim u
- type Point2F u = Point2 u -> Point2 u
- type DPoint2F = Point2F Double
- data DrawingF a
- type LocDrawingF u a = Point2 u -> DrawingF a
- type DLocDrawingF a = LocDrawingF Double a
- runDF :: DrawingContext -> DrawingF a -> a
- pureDF :: a -> DrawingF a
- askDF :: DrawingF DrawingContext
- asksDF :: (DrawingContext -> a) -> DrawingF a
- localDF :: (DrawingContext -> DrawingContext) -> DrawingF a -> DrawingF a
- type Graphic u = DrawingF (HPrim u)
- type DGraphic = Graphic Double
- runGraphic :: DrawingContext -> Graphic u -> HPrim u
- xlinkGraphic :: XLink -> Graphic u -> Graphic u
- type LocGraphic u = Point2 u -> Graphic u
- type DLocGraphic = LocGraphic Double
- localLG :: (DrawingContext -> DrawingContext) -> LocGraphic u -> LocGraphic u
- lgappend :: LocGraphic u -> LocGraphic u -> LocGraphic u
- type Image u a = DrawingF (a, HPrim u)
- type DImage a = Image Double a
- type LocImage u a = Point2 u -> Image u a
- type DLocImage a = LocImage Double a
- runImage :: DrawingContext -> Image u a -> (a, HPrim u)
- intoImage :: DrawingF a -> Graphic u -> Image u a
- intoLocImage :: LocDrawingF u a -> LocGraphic u -> LocImage u a
- xlinkImage :: XLink -> Image u a -> Image u a
- type ConnDrawingF u a = Point2 u -> Point2 u -> DrawingF a
- type DConnDrawingF a = ConnDrawingF Double a
- type ConnGraphic u = Point2 u -> Point2 u -> Graphic u
- type DConnGraphic = ConnGraphic Double
- type ConnImage u a = Point2 u -> Point2 u -> Image u a
- type DConnImage a = ConnImage Double a
- intoConnImage :: ConnDrawingF u a -> ConnGraphic u -> ConnImage u a
Graphics objects, even simple ones (line, arrow, dot) might need more than one primitive (path or text label) for their construction. Hence, the primary representation that all the others are built upon must support concatenation of primitives.
Wumpus-Core has a type Picture - made from one or more Primitives - but Pictures include support for affine frames. For drawing many simple graphics (dots, connector lines...) that do not need individual affine transformations this is a penalty. A list of Primitives is therefore more suitable representation, and a Hughes list which supports efficient concatenation is wise.
Drawings in Wumpus-Basic have an implicit graphics state
DrawingContext, the most primitive building block is
a function from the DrawingContext to some polymorphic answer.
This functional type is represented concretely as
DrawingF :: DrawingContext -> a
Run a Drawing Function with the supplied Drawing Context.
Wrap a value into a DrawingF.
Note the value is pure it does depend on the DrawingContext (it is context free).
Commonly graphics take a start point as well as a drawing context.
Here they are called a LocGraphic - graphic with a (starting) location.
Composition operator for LocGraphic - both LocGraphics are drawn at the same origin and the results concatenated.
Images return a value as well as drawing. A node is a typical example - nodes are drawing but the also support taking anchor points.
ConnGraphic is a connector drawn between two points contructing a Graphic.
ConImage is a connector drawn between two points constructing an Image.