goeasystar

README

goeasystar

A port of EasyStar.js to the Go programming language.

##Installation

go get github.com/prettymuchbryce/goeasystar

##Documentation GoDoc

API

Main Methods

easystar := goeasystar.NewPathfinder()

easystar.SetGrid(grid [][]int)

easystar.SetAcceptableTiles(t []int)`

easystar.FindPath(startX, startY, endX, endY) ([]*goeasystar.Point, error)

Additional Features

• Avoiding additional points (outside of acceptable tiles)

• Diagonals

• Corner cutting

• Setting costs per-tile

• Setting additional point costs (outside of tile costs)

Usage

First create an instance of the Pathfinder.

easystar := NewPathfinder()

Create a grid, or tilemap. You may have made this with a level editor, or procedurally. Let's keep it simple for this example.

var grid [][]int
grid = append(grid, []int{1, 0, 0, 0, 0})
grid = append(grid, []int{0, 1, 0, 0, 0})
grid = append(grid, []int{0, 0, 1, 0, 0})
grid = append(grid, []int{0, 0, 0, 1, 0})
grid = append(grid, []int{0, 0, 0, 0, 1})

Set our grid.

easystar.SetGrid(grid)

Set tiles which are "walkable".

easystar.SetAcceptableTiles([]int{1})

Find a path.

path, err := easystar.FindPath(0, 0, 4, 4)
fmt.Println(err == nil) // false

Oops. We didn't have diagonals enabled so there is no valid path. Lets try again.

easystar.EnableDiagonals()
path, err := easystar.FindPath(0, 0, 4, 4)
fmt.Println(err) // nil
len(path) // 4

License

goeasystar is licensed under the MIT license.

goeasystar uses facebookgo's pqueue which falls under the Apache 2 License.

I would be happy to eventually remove it in favor of an MIT-licensed priority queue implementation.

Support

If you have any questions, comments, or suggestions please open an issue.

Documentation

Index

• type Pathfinder
  • func NewPathfinder() *Pathfinder
  • func (p *Pathfinder) AvoidAdditionalPoint(x int, y int)
  • func (p *Pathfinder) DisableCornerCutting()
  • func (p *Pathfinder) DisableDiagonals()
  • func (p *Pathfinder) EnableCornerCutting()
  • func (p *Pathfinder) EnableDiagonals()
  • func (p *Pathfinder) FindPath(startX int, startY int, endX int, endY int) ([]*Point, error)
  • func (p *Pathfinder) RemoveAdditionalPointCost(x int, y int)
  • func (p *Pathfinder) RemoveAllAdditionalPointCosts()
  • func (p *Pathfinder) SetAcceptableTiles(t []int)
  • func (p *Pathfinder) SetAdditionalPointCost(x int, y int, cost float64)
  • func (p *Pathfinder) SetGrid(grid [][]int)
  • func (p *Pathfinder) StopAvoidingAdditionalPoint(x int, y int)
  • func (p *Pathfinder) StopAvoidingAllAdditionalPoints()
• type Point

Types

type Pathfinder

type Pathfinder struct {
	// contains filtered or unexported fields
}

Pathfinder represents a single instance of a pathfinding configuration

func NewPathfinder

func NewPathfinder() *Pathfinder

NewPathfinder returns a new instance of a pathfinder

func (*Pathfinder) AvoidAdditionalPoint

func (p *Pathfinder) AvoidAdditionalPoint(x int, y int)

AvoidAdditionalPoint avoids a particular point on the grid regardless of whether or not it is an acceptable tile

func (*Pathfinder) DisableCornerCutting

func (p *Pathfinder) DisableCornerCutting()

DisableCornerCutting disables corner cutting in diagonal movement

func (*Pathfinder) DisableDiagonals

func (p *Pathfinder) DisableDiagonals()

DisableDiagonals disables diagonals on the Pathfinder

func (*Pathfinder) EnableCornerCutting

func (p *Pathfinder) EnableCornerCutting()

EnableCornerCutting enables corner cutting in diagonal movement

func (*Pathfinder) EnableDiagonals

func (p *Pathfinder) EnableDiagonals()

EnableDiagonals enables diagonals on the Pathfinder

func (*Pathfinder) FindPath

func (p *Pathfinder) FindPath(startX int, startY int, endX int, endY int) ([]*Point, error)

FindPath finds a path Returns a slice of points which consists the starting point up to the end point inclusively

func (*Pathfinder) RemoveAdditionalPointCost

func (p *Pathfinder) RemoveAdditionalPointCost(x int, y int)

RemoveAdditionalPointCost removes the additional cost for a particular point

func (*Pathfinder) RemoveAllAdditionalPointCosts

func (p *Pathfinder) RemoveAllAdditionalPointCosts()

RemoveAllAdditionalPointCosts removes all additional point costs

func (*Pathfinder) SetAcceptableTiles

func (p *Pathfinder) SetAcceptableTiles(t []int)

SetAcceptableTiles sets a list of tiles which are deemed acceptable to pass through

func (*Pathfinder) SetAdditionalPointCost

func (p *Pathfinder) SetAdditionalPointCost(x int, y int, cost float64)

SetAdditionalPointCost sets the an additional cost for a particular point Overrides the cost from SetTileCost

func (*Pathfinder) SetGrid

func (p *Pathfinder) SetGrid(grid [][]int)

SetGrid sets the grid of the Pathfinder

func (*Pathfinder) StopAvoidingAdditionalPoint

func (p *Pathfinder) StopAvoidingAdditionalPoint(x int, y int)

StopAvoidingAdditionalPoint stops avoiding a particular point on the grid

func (*Pathfinder) StopAvoidingAllAdditionalPoints

func (p *Pathfinder) StopAvoidingAllAdditionalPoints()

StopAvoidingAllAdditionalPoints stops avoiding all additional points on the grid

type Point

type Point struct {
	X int
	Y int
}

Point represents a point in the completed path