Graphics.Rendering.Diagrams.Paths

Type definitions and convenience functions for Graphics.Rendering.Diagrams, an embedded domain-specific language (EDSL) for creating simple diagrams.

Documentation

emptyPath :: Path

The empty path, i.e. a path with no edges.

pathFromVertices :: [Point] -> Path

Create an open path from a list of vertices. For example, pathFromVertices [(1,3), (4,4), (6,5)] describes the path with two segments which starts at (1,3), has a corner at (4,4), and ends at (6,5). Note, however, that the vertices themselves are not significant, only the distances between them. That is, pathFromVertices [(0,1), (3,2), (5,3)] describes exactly the same path.

pathFromVectors :: [Vec] -> Path

Create an open path from a list of edge displacement vectors. For example, pathFromVectors [(1,1), (3,4)] describes the path with two segments which first moves one unit in the positive x and y directions, and then moves three units in the positive x direction and four in the positive y direction.

pathToVertices :: Point -> Path -> [Point]

Convert a path into a list of vertices, starting with the given vertex.

pathToVectors :: Path -> [Vec]

Convert a path to a list of vectors corresponding to the edges of the path.

pathConcat :: Path -> Path -> Path

Concatenate two open paths into a single open path consisting of the first followed by the second.

closed :: Path -> Path

Create a closed path (by connecting the first and last points in the path).

isClosed :: Path -> Bool

Determine whether a Path is closed or open.

rotPath :: Double -> Path -> Path

Rotate a path by a fraction of a circle. rotPath d rotates paths by an angle of d*2*pi radians. Note that creating a Diagram from a Path (using straight or curved or some other such function) and then applying rotate to it is different than first applying rotPath to the Path before making it into a Diagram. In the latter case, the bounding box will be correct, whereas in the former case, the bounding box will still correspond to the unrotated version of the path.

pathSizeAndOffset :: Path -> (Vec, Point)

Compute the size of a bounding box for the given Path, and the | offset of the starting vertex from the center.

renderPath :: PathStyle -> Path -> Render ()

Render a path using a particular style in the Cairo rendering monad.