chalkboard-0.2: Combinators for building and processing 2D images.

MaintainerAndy Gill <>



This module contains some basic shape generators, expressed as Board Bool.



circle :: Board BoolSource

unit circle, radius 0.5, over origin.

vbar :: Board BoolSource

unit vertical bar, 1 wide over origin.

hbar :: Board BoolSource

unit horizontal bar, 1 high over origin.

square :: Board BoolSource

unit square, 1x1 over origin.

checker :: Board BoolSource

cheacker board, with squares 1x1.

straightline :: (Point, Point) -> R -> Board BoolSource

Given two Points, and a thickness, draw a line between the points. line :: Line -> Double -> Board Bool

functionline :: (R -> Point) -> R -> Int -> Board BoolSource

A line generated by sampling a function from R to Points, with a specific width. There needs to be at least 2 sample points.

arrowhead :: Point -> Radian -> R -> Board BoolSource

arrowhead is a triangle, pointing straight up, height 1, width 1, with the (0,0) at the center of the base.