gloss-algorithms- Data structures and algorithms for working with 2D graphics.

Safe HaskellNone



Represents an integral rectangular area of the 2D plane. Using Ints (instead of Floats) for the bounds means we can safely compare extents for equality.



data Extent Source #

A rectangular area of the 2D plane. We keep the type abstract to ensure that invalid extents cannot be constructed.


type Coord = (Int, Int) Source #

An integral coordinate.

makeExtent Source #


:: Int

y max (north)

-> Int

y min (south)

-> Int

x max (east)

-> Int

x min (west)

-> Extent 

Construct an extent. The north value must be > south, and east > west, else error.

takeExtent :: Extent -> (Int, Int, Int, Int) Source #

Take the NSEW components of an extent.

squareExtent :: Int -> Extent Source #

A square extent of a given size.

sizeOfExtent :: Extent -> (Int, Int) Source #

Get the width and height of an extent.

isUnitExtent :: Extent -> Bool Source #

Check if an extent is a square with a width and height of 1.

coordInExtent :: Extent -> Coord -> Bool Source #

Check whether a coordinate lies inside an extent.

pointInExtent :: Extent -> Point -> Bool Source #

Check whether a point lies inside an extent.

centerCoordOfExtent :: Extent -> (Int, Int) Source #

Get the coordinate that lies at the center of an extent.

cutQuadOfExtent :: Quad -> Extent -> Extent Source #

Cut one quadrant out of an extent.

quadOfCoord :: Extent -> Coord -> Maybe Quad Source #

Get the quadrant that this coordinate lies in, if any.

pathToCoord :: Extent -> Coord -> Maybe [Quad] Source #

Constuct a path to a particular coordinate in an extent.

intersectSegExtent :: Point -> Point -> Extent -> Maybe Point Source #

If a line segment (P1-P2) intersects the outer edge of an extent then return the intersection point, that is closest to P1, if any. If P1 is inside the extent then Nothing.

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touchesSegExtent :: Point -> Point -> Extent -> Bool Source #

Check whether a line segment's endpoints are inside an extent, or if it intersects with the boundary.