Safe Haskell	None

Game.LambdaHack.Common.Vector

Description

Basic operations on 2D vectors represented in an efficient, but not unique, way.

Synopsis

Documentation

data Vector Source

2D vectors in cartesian representation. Coordinates grow to the right and down, so that the (1, 1) vector points to the bottom-right corner of the screen.

Constructors

Vector
Fields vx :: !X vy :: !Y

Instances

Enum Vector
Eq Vector
Ord Vector
Read Vector
Show Vector
Binary Vector

isUnit :: Vector -> Bool Source

Tells if a vector has length 1 in the chessboard metric.

isDiagonal :: Vector -> Bool Source

Checks whether a unit vector is a diagonal direction, as opposed to cardinal. If the vector is not unit, it checks that the vector is not horizontal nor vertical.

neg :: Vector -> Vector Source

Reverse an arbirary vector.

chessDistVector :: Vector -> Int Source

The lenght of a vector in the chessboard metric, where diagonal moves cost 1.

euclidDistSqVector :: Vector -> Vector -> Int Source

Squared euclidean distance between two vectors.

moves :: [Vector]Source

Vectors of all unit moves in the chessboard metric, clockwise, starting north-west.

compassText :: Vector -> Text Source

vicinity Source

Arguments

:: X
-> Y	limit the search to this area
-> Point	position to find neighbours of
-> [Point]

All (8 at most) closest neighbours of a point within an area.

vicinityCardinal Source

Arguments

:: X
-> Y	limit the search to this area
-> Point	position to find neighbours of
-> [Point]

All (4 at most) cardinal direction neighbours of a point within an area.

shift :: Point -> Vector -> Point Source

Translate a point by a vector.

shiftBounded :: X -> Y -> Point -> Vector -> Point Source

Translate a point by a vector, but only if the result fits in an area.

trajectoryToPath :: Point -> [Vector] -> [Point]Source

A list of points that a list of vectors leads to.

displacement :: Point -> Point -> Vector Source

A vector from a point to another. We have

 shift pos1 (displacement pos1 pos2) == pos2

pathToTrajectory :: [Point] -> [Vector]Source

A list of vectors between a list of points.

type RadianAngle = Double Source

rotate :: RadianAngle -> Vector -> Vector Source

Rotate a vector by the given angle (expressed in radians) counterclockwise and return a unit vector approximately in the resulting direction.

towards :: Point -> Point -> Vector Source

Given two distinct positions, determine the direction (a unit vector) in which one should move from the first in order to get closer to the second. Ignores obstacles. Of several equally good directions (in the chessboard metric) it picks one of those that visually (in the euclidean metric) maximally align with the vector between the two points.

data BfsDistance Source

Instances

Bounded BfsDistance
Enum BfsDistance
Eq BfsDistance
Ord BfsDistance
Show BfsDistance
Bits BfsDistance

data MoveLegal Source

Constructors

MoveBlocked
MoveToOpen
MoveToUnknown

Instances

Eq MoveLegal

apartBfs :: BfsDistance Source

fillBfs Source

Arguments

:: (Point -> Point -> MoveLegal)	is move from a known tile legal
-> (Point -> Point -> Bool)	is a move from unknown legal
-> Point	starting position
-> Array BfsDistance	initial array, with `apartBfs`
-> Array BfsDistance	array with calculated distances

findPathBfs :: (Point -> Point -> MoveLegal) -> (Point -> Point -> Bool) -> Point -> Point -> Int -> Array BfsDistance -> Maybe [Point]Source

Find a path, without the source position, with the smallest length. The eps coefficient determines which direction (or the closest directions available) that path should prefer, where 0 means north-west and 1 means north.

accessBfs :: Array BfsDistance -> Point -> Maybe Int Source

posAimsPos :: Array BfsDistance -> Point -> Point -> Bool Source