From a9fba179437ebb86b673ad87ba1cc0f677b8e17b Mon Sep 17 00:00:00 2001
From: kts of kettek <kts@kettek.net>
Date: Sat, 3 Feb 2024 00:03:45 -0800
Subject: [PATCH] Add pathfinding garbagio
---
cmd/prog/main.go | 28 +++++++++++
sauce/astar.go | 127 ++++++++++++++++++++++++++---------------------
2 files changed, 99 insertions(+), 56 deletions(-)
diff --git a/cmd/prog/main.go b/cmd/prog/main.go
index d58cd6d..33b050c 100644
--- a/cmd/prog/main.go
+++ b/cmd/prog/main.go
@@ -27,6 +27,8 @@ type Game struct {
cellX, cellY int
fromX, fromY int
toX, toY int
+ path []sauce.Node
+ pathSuccess bool
whichFromTo bool
}
@@ -35,6 +37,10 @@ func NewGame() *Game {
g.world = sauce.NewWorld(3, 3)
g.world.HueristicLine(10, 0, 10, 10, 1)
g.world.HueristicLine(10, 13, 10, 30, 1)
+ g.fromX = -1
+ g.fromY = -1
+ g.toX = -1
+ g.toY = -1
return g
}
@@ -62,10 +68,13 @@ func (g *Game) Update() error {
g.cellX = cursorX / CellSize
g.cellY = cursorY / CellSize
if cell := g.world.At(g.cellX, g.cellY); cell != nil {
+ var reroll bool
if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonLeft) {
cell.Hueristic++
+ reroll = true
} else if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonRight) {
cell.Hueristic--
+ reroll = true
} else if inpututil.IsMouseButtonJustPressed(ebiten.MouseButtonMiddle) {
if !g.whichFromTo {
g.fromX, g.fromY = g.cellX, g.cellY
@@ -73,6 +82,13 @@ func (g *Game) Update() error {
g.toX, g.toY = g.cellX, g.cellY
}
g.whichFromTo = !g.whichFromTo
+ reroll = true
+ }
+ if reroll {
+ if g.fromX != -1 && g.fromY != -1 && g.toX != -1 && g.toY != -1 {
+ g.path, g.pathSuccess = sauce.FindPath(g.world, g.fromX, g.fromY, g.toX, g.toY)
+ }
+
}
}
return nil
@@ -117,6 +133,18 @@ func (g *Game) Draw(screen *ebiten.Image) {
}
}
}
+ // Draw path dots overtop.
+ for _, node := range g.path {
+ x := node.X*CellSize + CellSize/2
+ y := node.Y*CellSize + CellSize/2
+
+ c := color.RGBA{0, 255, 0, 255}
+ if !g.pathSuccess {
+ c = color.RGBA{255, 0, 0, 255}
+ }
+
+ vector.DrawFilledCircle(screen, float32(x), float32(y), 5, c, false)
+ }
ebitenutil.DebugPrint(screen, fmt.Sprintf("TPS: %0.2f\nFPS: %0.2f", ebiten.ActualTPS(), ebiten.ActualFPS()))
}
diff --git a/sauce/astar.go b/sauce/astar.go
index a197fa9..2654fc8 100644
--- a/sauce/astar.go
+++ b/sauce/astar.go
@@ -1,85 +1,100 @@
package sauce
-type Node struct {
- parent *Node
- x, y int
- f, g, h int
+import (
+ "math"
+)
+
+type Coord struct {
+ X, Y int16
}
-func FindPath(w *World, fromX, fromY int, toX, toY int) []Node {
- openList := make([]*Node, 0)
- closedList := make([]*Node, 0)
+type Node struct {
+ Coord
+ parent *Node
+ g int
+ f int
+ d int
+}
- startNode := &Node{x: fromX, y: fromY}
- endNode := &Node{x: toX, y: toY}
+type Nodes map[Coord]*Node
- openList = append(openList, startNode)
+func FindPath(w *World, fromX, fromY int, toX, toY int) ([]Node, bool) {
+ var open []*Node
+ visited := make(Nodes)
- for len(openList) > 0 {
- var cnode *Node
- var cindex int
- for i, node := range openList {
- if cnode == nil || node.f < cnode.f {
- cnode = node
- cindex = i
+ open = append(open, &Node{Coord: Coord{int16(fromX), int16(fromY)}})
+
+ for len(open) > 0 {
+ var current *Node
+ var currentI int
+ // Set current to lowest f in open
+ for i, n := range open {
+ if current == nil || n.f < current.f {
+ current = n
+ currentI = i
}
}
- openList = append(openList[:cindex], openList[cindex+1:]...)
- closedList = append(closedList, cnode)
- if cnode.x == endNode.x && cnode.y == endNode.y {
- path := make([]Node, 0)
- for cnode != nil {
- path = append(path, *cnode)
- cnode = cnode.parent
+ // Return reconstructed path if current is the destination.
+ if current.X == int16(toX) && current.Y == int16(toY) {
+ var path []Node
+ for current.parent != nil {
+ path = append(path, *current)
+ current = current.parent
}
- return path
+ return path, true
}
+ // Remove current from the open set.
+ open = append(open[:currentI], open[currentI+1:]...)
- var neighbors []Node
+ // Get neighbors.
+ var neighbors []*Node
for x := -1; x <= 1; x++ {
for y := -1; y <= 1; y++ {
if x == 0 && y == 0 {
continue
}
- if x != 0 && y != 0 {
+ coord := Coord{current.X + int16(x), current.Y + int16(y)}
+ if cell := w.At(int(coord.X), int(coord.Y)); cell == nil || cell.Hueristic == 255 {
continue
}
- if cell := w.At(cnode.x+x, cnode.y+y); cell != nil {
- neighbors = append(neighbors, Node{x: cnode.x + x, y: cnode.y + y, parent: cnode})
- }
+ neighbors = append(neighbors, &Node{Coord: coord, parent: current, g: math.MaxUint16, f: math.MaxUint16})
}
}
+ // Iterate over neighbors.
for _, neighbor := range neighbors {
- exists := false
- for _, node := range closedList {
- if node.x == neighbor.x && node.y == neighbor.y {
- exists = true
- break
+ tentativeG := current.g + 1
+ distance := int(math.Abs(float64(neighbor.X)-float64(toX)) + math.Abs(float64(neighbor.Y)-float64(toY)))
+ tentativeF := tentativeG + distance
+
+ var node *Node
+ if node = visited[neighbor.Coord]; node == nil || tentativeF < node.f {
+ if node == nil {
+ node = neighbor
}
+ node.g = tentativeG
+ node.f = tentativeF
+ node.d = distance
+ visited[node.Coord] = node
+ open = append(open, node)
}
- if exists {
- continue
- }
-
- exists = false
- for _, node := range openList {
- if node.x == neighbor.x && node.y == neighbor.y {
- exists = true
- break
- }
- }
- if exists {
- continue
- }
-
- neighbor.g = cnode.g + 1 // this value potentially should be a float and modified if a diagonal.
- neighbor.h = (toX - neighbor.x) + (toY - neighbor.y) // Maybe should be calculated differently.
- neighbor.f = neighbor.g + neighbor.h
-
- openList = append(openList, &neighbor)
}
}
- return nil
+
+ var current *Node
+ // Set current to lowest f in open
+ for _, n := range visited {
+ if current == nil || n.d < current.d {
+ current = n
+ }
+ }
+
+ // Return reconstructed path if current is the destination.
+ var path []Node
+ for current != nil && current.parent != nil {
+ path = append(path, *current)
+ current = current.parent
+ }
+ return path, false
}