LambdaHack- A roguelike game engine in early and active development

Safe HaskellNone



Basic operations on 2D points represented as linear offsets.



type Point = IntSource

The type of locations on the 2D level map, heavily optimized.

We represent the (level map on the) screen as a linear framebuffer, where Point is an Int offset counted from the first cell. We do bounds check for the X size whenever we convert between representations and each subsequent array access performs another check, effectively for Y size. After dungeon is generated (using PointXY, not Point), and converted to the Point representation, points are used mainly as keys and not constructed often, so the performance will improve due to smaller save files, the use of IntMap and cheaper array indexing, including cheaper bounds checks. We don't define Point as a newtype to avoid the trouble with using EnumMap in place of IntMap, etc.

toPoint :: X -> PointXY -> PointSource

Conversion from cartesian coordinates to Point.

showPoint :: X -> Point -> TextSource

Print a point as a tuple of cartesian coordinates.

origin :: PointSource

The top-left corner location of the level.

chessDist :: X -> Point -> Point -> IntSource

The distance between two points in the chessboard metric.

adjacent :: X -> Point -> Point -> BoolSource

Checks whether two points are adjacent on the map (horizontally, vertically or diagonally).

vicinity :: X -> Y -> Point -> [Point]Source

Returns the 8, or less, surrounding locations of a given location.

vicinityCardinal :: X -> Y -> Point -> [Point]Source

Returns the 4, or less, surrounding locations in cardinal directions from a given location.

inside :: X -> Point -> Area -> BoolSource

Checks that a point belongs to an area.

displacementXYZ :: X -> Point -> Point -> VectorXYSource

Calculate the displacement vector from a location to another.

bla :: X -> Y -> Int -> Point -> Point -> Maybe [Point]Source

Bresenham's line algorithm generalized to arbitrary starting eps (eps value of 0 gives the standard BLA). Skips the source point and goes through the second point to the edge of the level. GIves Nothing if the points are equal.