fixed the chebyshev implementation and a live rendering bug

astar.go

@@ -4,9 +4,13 @@ import (
 	"container/heap"
 	"fmt"
 	"math"
+	"sync"
 	"time"
 )
 
+// parentNone marks cells with no predecessor; must not collide with 0–3 (cardinal directions).
+const parentNone byte = 0xff
+
 type Item struct {
 	index    int     // index of the cell in the grid (y * width + x)
 	priority float32 // f = g + h
@@ -48,6 +52,7 @@ type AStar struct {
 	gridTypes []byte
 	gScores   []float32
 	parents   []byte
+	parentsMu sync.RWMutex // live preview reads parents from the UI thread while CalculatePathLive writes
 	openSet   PriorityQueue
 	closedSet []bool
 	width     int
@@ -71,6 +76,11 @@ func (a *AStar) Init(width int, height int) {
 	for i := range a.gScores {
 		a.gScores[i] = math.MaxFloat32
 	}
+	a.parentsMu.Lock()
+	for i := range a.parents {
+		a.parents[i] = parentNone
+	}
+	a.parentsMu.Unlock()
 }
 
 func (a *AStar) ResetGrid(withTypes bool) {
@@ -79,20 +89,29 @@ func (a *AStar) ResetGrid(withTypes bool) {
 			a.gridTypes[i] = 0
 		}
 		a.gScores[i] = math.MaxFloat32
-		a.parents[i] = 0
 		a.closedSet[i] = false
 	}
+	a.parentsMu.Lock()
+	for i := range a.parents {
+		a.parents[i] = parentNone
+	}
+	a.parentsMu.Unlock()
 	a.openSet = a.openSet[:0]
 }
 
 func (a *AStar) RebuildGrid(width int, height int) {
 	a.gridTypes = make([]byte, width*height)
 	a.gScores = make([]float32, width*height)
+	a.parentsMu.Lock()
 	a.parents = make([]byte, width*height)
 	a.openSet = make(PriorityQueue, 0, 2000000)
 	a.closedSet = make([]bool, width*height)
 	a.width = width
 	a.height = height
+	for i := range a.parents {
+		a.parents[i] = parentNone
+	}
+	a.parentsMu.Unlock()
 }
 
 func (a *AStar) SetHeuristic(heuristic int32) {
@@ -107,7 +126,7 @@ func (a *AStar) SetHeuristic(heuristic int32) {
 		}
 	case 2:
 		a.heuristic = func(x int, y int, endX int, endY int) float32 {
-			return float32(math.Max(float64(x-endX), float64(y-endY))) // Chebyshev distance
+			return float32(math.Max(math.Abs(float64(x-endX)), math.Abs(float64(y-endY)))) // Chebyshev: max(|dx|, |dy|)
 		}
 	case 3:
 		a.heuristic = func(x int, y int, endX int, endY int) float32 {
@@ -147,6 +166,8 @@ func (a *AStar) GetGScores(x int, y int) float32 {
 }
 
 func (a *AStar) SetParent(x int, y int, parentx int, parenty int) {
+	a.parentsMu.Lock()
+	defer a.parentsMu.Unlock()
 	if parentx < x {
 		a.parents[y*a.width+x] = byte(0) // left of the node
 	} else if parentx > x {
@@ -159,24 +180,39 @@ func (a *AStar) SetParent(x int, y int, parentx int, parenty int) {
 }
 
 func (a *AStar) GetParent(x int, y int) byte {
+	a.parentsMu.RLock()
+	defer a.parentsMu.RUnlock()
 	return a.parents[y*a.width+x]
 }
 
-func (a *AStar) ParentIndexToXY(childx int, childy int, parent byte) (int, int) {
-	if parent == 0 {
-		return childx - 1, childy // parent left
-	} else if parent == 1 {
-		return childx, childy - 1 // parent above
-	} else if parent == 2 {
-		return childx + 1, childy // parent right
-	} else if parent == 3 {
-		return childx, childy + 1 // parent below
+func (a *AStar) ParentsSnapshot() []byte {
+	a.parentsMu.RLock()
+	defer a.parentsMu.RUnlock()
+	out := make([]byte, len(a.parents))
+	copy(out, a.parents)
+	return out
+}
+
+func (a *AStar) ParentIndexToXY(childx int, childy int, parent byte) (int, int) {
+	switch parent {
+	case 0:
+		return childx - 1, childy // parent left
+	case 1:
+		return childx, childy - 1 // parent above
+	case 2:
+		return childx + 1, childy // parent right
+	case 3:
+		return childx, childy + 1 // parent below
+	default:
+		return -1, -1
 	}
-	return childx, childy
 }
 
 func (a *AStar) ParentIndexToXYIndex(childx int, childy int, parent byte) int {
 	x, y := a.ParentIndexToXY(childx, childy, parent)
+	if x < 0 || y < 0 || x >= a.width || y >= a.height {
+		return -1
+	}
 	return y*a.width + x
 }
 
@@ -235,10 +271,18 @@ func (a *AStar) CalculatePath(startX int, startY int, endX int, endY int) [][]in
 			// We've found the goal!
 			fmt.Println("Found the goal!")
 			path := make([][]int, 0)
-			for currentIndex := current.index; currentIndex != startIndex; currentIndex = a.ParentIndexToXYIndex(currentIndex%a.width, currentIndex/a.width, a.parents[currentIndex]) {
-				x, y := a.ParentIndexToXY(currentIndex%a.width, currentIndex/a.width, a.parents[currentIndex])
-				path = append(path, []int{x, y})
+			a.parentsMu.RLock()
+			for currentIndex := current.index; currentIndex != startIndex; {
+				p := a.parents[currentIndex]
+				next := a.ParentIndexToXYIndex(currentIndex%a.width, currentIndex/a.width, p)
+				if next < 0 {
+					break
 				}
+				x, y := a.ParentIndexToXY(currentIndex%a.width, currentIndex/a.width, p)
+				path = append(path, []int{x, y})
+				currentIndex = next
+			}
+			a.parentsMu.RUnlock()
 			return path
 		}
 
@@ -264,3 +308,66 @@ func (a *AStar) CalculatePath(startX int, startY int, endX int, endY int) [][]in
 	}
 	return make([][]int, 0)
 }
+
+func (a *AStar) CalculatePathLive(startX int, startY int, endX int, endY int, updateChan chan int, speed *int) [][]int {
+	timer := time.Now()
+	defer func() {
+		a.timeTaken = time.Since(timer)
+	}()
+	startIndex := startY*a.width + startX
+	endIndex := endY*a.width + endX
+	a.gScores[startIndex] = 0
+	startF := a.heuristic(startX, startY, endX, endY)
+	heap.Push(&a.openSet, &Item{index: startIndex, priority: startF, gScore: 0})
+
+	for a.openSet.Len() > 0 {
+		current := heap.Pop(&a.openSet).(*Item)
+		if a.closedSet[current.index] {
+			continue
+		}
+		if current.index == endIndex {
+			// We've found the goal!
+			fmt.Println("Found the goal!")
+			path := make([][]int, 0)
+			a.parentsMu.RLock()
+			for currentIndex := current.index; currentIndex != startIndex; {
+				p := a.parents[currentIndex]
+				next := a.ParentIndexToXYIndex(currentIndex%a.width, currentIndex/a.width, p)
+				if next < 0 {
+					break
+				}
+				x, y := a.ParentIndexToXY(currentIndex%a.width, currentIndex/a.width, p)
+				path = append(path, []int{x, y})
+				currentIndex = next
+			}
+			a.parentsMu.RUnlock()
+			return path
+		}
+
+		a.closedSet[current.index] = true
+		updateChan <- current.index
+
+		for _, neighborIndex := range a.GetNeighbors(current.index%a.width, current.index/a.width) {
+			if a.closedSet[neighborIndex] {
+				continue
+			}
+			if a.gridTypes[neighborIndex] == 1 {
+				a.gScores[neighborIndex] = math.MaxFloat32
+				continue
+			}
+			terrainCost := a.GetTerrainCost(neighborIndex%a.width, neighborIndex/a.width)
+			tentativeGScore := a.gScores[current.index] + terrainCost
+			if tentativeGScore < a.gScores[neighborIndex] {
+				a.SetParent(neighborIndex%a.width, neighborIndex/a.width, current.index%a.width, current.index/a.width)
+				a.gScores[neighborIndex] = tentativeGScore
+				priority := tentativeGScore + a.heuristic(neighborIndex%a.width, neighborIndex/a.width, endX, endY)
+				heap.Push(&a.openSet, &Item{index: neighborIndex, priority: priority, gScore: tentativeGScore})
+			}
+		}
+
+		if *speed != 1000 {
+			time.Sleep(time.Duration(1000-*speed) * time.Millisecond)
+		}
+	}
+	return make([][]int, 0)
+}

main.go

@@ -265,7 +265,7 @@ func drawInfiniteGridLines(camera rl.Camera2D, canvasW float32, canvasH float32,
 
 func main() {
 	rl.SetConfigFlags(rl.FlagWindowResizable)
-	rl.InitWindow(int32(800), int32(600), "A* Visualizer")
+	rl.InitWindow(int32(1200), int32(800), "A* Visualizer")
 	defer rl.CloseWindow()
 
 	scale := rl.GetWindowScaleDPI().X + 0.25
@@ -304,6 +304,11 @@ func main() {
 	activeHeuristic := int32(0)
 	heuristicDropdownOpen := false
 
+	mazeOptions := []string{"Recursive Divison", "Iterative DFS", "Cellular Automata"}
+	mazeOptionsText := strings.Join(mazeOptions, ";")
+	activeMaze := int32(0)
+	mazeDropdownOpen := false
+
 	cellSize := float32(25)
 
 	lastMousePos := rl.NewVector2(-1, -1)
@@ -315,11 +320,19 @@ func main() {
 	defer rl.UnloadTexture(mapTexture)
 	defer rl.UnloadImage(mapImage)
 
+	updateChan := make(chan int, 100000)
+
 	autoCompute := false
+	speed := 1000
+	speedInputValue := "100"
+	editModeSpeed := false
 
 	astar := AStar{}
 	astar.Init(width, height)
 
+	// Above the channel loop
+	lastEvaluatedNode := -1 // Track the "tip of the spear"
+
 	for !rl.WindowShouldClose() {
 		screenWidth := float32(rl.GetScreenWidth())
 		screenHeight := float32(rl.GetScreenHeight())
@@ -459,6 +472,30 @@ func main() {
 			}
 			lastMousePos = rl.NewVector2(-1, -1)
 		}
+		updatesProcessed := 0
+	DrainLoop: // Use a label so we can break out of the infinite 'for' loop
+		for {
+			select {
+			case nodeIndex := <-updateChan:
+				x := nodeIndex % width
+				y := nodeIndex / width
+				if x != int(startPos.X) || y != int(startPos.Y) {
+					// Bake the blue pixel into the image
+					rl.ImageDrawPixel(mapImage, int32(x), int32(y), rl.NewColor(0, 0, 255, 255))
+					tex.markRegion(x, y, x, y, width, height)
+				}
+
+				lastEvaluatedNode = nodeIndex // Save the absolute latest node
+				updatesProcessed++
+
+				if updatesProcessed > 50000 {
+					break DrainLoop
+				}
+			default:
+				// Channel is empty
+				break DrainLoop
+			}
+		}
 
 		// --- DRAWING ---
 		rl.BeginDrawing()
@@ -475,6 +512,42 @@ func main() {
 			cellSize,            // Scale factor
 			rl.White,            // Tint (White means no tint)
 		)
+
+		// 2. Trace parent chain and draw a yellow polyline (cell centers) each frame.
+		if lastEvaluatedNode != -1 {
+			startIndex := int(startPos.Y)*width + int(startPos.X)
+			parents := astar.ParentsSnapshot()
+			pathThickness := float32(16.0)
+			if pathThickness < 1 {
+				pathThickness = 1
+			}
+			pathColor := rl.NewColor(255, 255, 0, 255)
+
+			var centers []rl.Vector2
+			for idx := lastEvaluatedNode; idx >= 0 && idx < width*height && idx != startIndex; {
+				cx := (float32(idx%width) + 0.5) * cellSize
+				cy := (float32(idx/width) + 0.5) * cellSize
+				centers = append(centers, rl.NewVector2(cx, cy))
+
+				if idx == startIndex {
+					break
+				}
+				p := parents[idx]
+				if p == parentNone {
+					break
+				}
+				next := astar.ParentIndexToXYIndex(idx%width, idx/width, p)
+				if next < 0 || next == idx {
+					break
+				}
+				idx = next
+			}
+
+			for i := 0; i < len(centers)-1; i++ {
+				rl.DrawLineEx(centers[i], centers[i+1], pathThickness, pathColor)
+			}
+		}
+
 		drawInfiniteGridLines(camera, canvasWidth, screenHeight, cellSize, width, height)
 		rl.EndMode2D()
 		rl.EndScissorMode()
@@ -488,6 +561,7 @@ func main() {
 			editModeWidth = !editModeWidth
 			if editModeWidth {
 				editModeHeight = false
+				editModeSpeed = false
 			}
 		}
 		rg.Label(rl.NewRectangle(sidebarX+(95*scale), (10*scale), (10*scale), (20*scale)), "x")
@@ -497,6 +571,7 @@ func main() {
 			editModeHeight = !editModeHeight
 			if editModeHeight {
 				editModeWidth = false
+				editModeSpeed = false
 			}
 		}
 
@@ -532,24 +607,18 @@ func main() {
 			}
 		}
 
-		// Tool Selector (text must be "opt1;opt2;..." — raygui splits on ';' and needs 2+ items)
-		rg.Label(rl.NewRectangle(sidebarX+(10*scale), (75*scale), (180*scale), (30*scale)), "Tool:")
-		if rg.DropdownBox(rl.NewRectangle(sidebarX+(10*scale), (100*scale), (180*scale), (30*scale)), toolOptionsText, &activeTool, toolDropdownOpen) {
-			toolDropdownOpen = !toolDropdownOpen
+		// While a dropdown list is open it overlaps controls below; those widgets are handled
+		// earlier in the frame and would otherwise steal the release-click. GuiLock skips input
+		// for other controls; DropdownBox still handles input when its editMode is true.
+		if toolDropdownOpen || heuristicDropdownOpen || mazeDropdownOpen {
+			rg.Lock()
 		}
 
-		// Heuristic Selector
-		if !toolDropdownOpen {
-			rg.Label(rl.NewRectangle(sidebarX+(10*scale), (135*scale), (180*scale), (30*scale)), "Heuristic:")
-			if rg.DropdownBox(rl.NewRectangle(sidebarX+(10*scale), (160*scale), (180*scale), (30*scale)), heuristicOptionsText, &activeHeuristic, heuristicDropdownOpen) {
-				heuristicDropdownOpen = !heuristicDropdownOpen
-			}
-		}
-
-		// Reset Visualization Button
-		if !toolDropdownOpen && !heuristicDropdownOpen {
-			if rg.Button(rl.NewRectangle(sidebarX+(10*scale), (200*scale), (180*scale), (30*scale)), "Reset Visualization") {
+		// Generate Maze Button
+		if rg.Button(rl.NewRectangle(sidebarX+(10*scale), (260*scale), (180*scale), (30*scale)), "Generate Maze") {
+			astar.GenerateMaze(activeMaze)
 			astar.ResetGrid(false) // keep grid types, otherwise it will delete the board before simulating
+			lastEvaluatedNode = -1
 			gridTypes := astar.GetGridTypes()
 			for i, gridType := range gridTypes {
 				// reset the map image
@@ -566,6 +635,97 @@ func main() {
 			}
 			tex.markFull()
 		}
+
+		// Reset Visualization Button
+		if rg.Button(rl.NewRectangle(sidebarX+(10*scale), (screenHeight-(120*scale)), (180*scale), (30*scale)), "Reset Visualization") {
+			astar.ResetGrid(false) // keep grid types, otherwise it will delete the board before simulating
+			lastEvaluatedNode = -1
+			gridTypes := astar.GetGridTypes()
+			for i, gridType := range gridTypes {
+				// reset the map image
+				switch gridType {
+				case 0:
+					rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(240, 240, 240, 255))
+				case 1:
+					rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(0, 0, 0, 255))
+				case 2:
+					rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(0, 255, 0, 255))
+				case 3:
+					rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(255, 0, 0, 255))
+				}
+			}
+			tex.markFull()
+		}
+
+		// Speed Slider
+		speedText := ""
+		if speed == 1000 {
+			speedText = "Uncapped"
+		} else {
+			speedText = strconv.Itoa(speed/10) + "%"
+		}
+		speedLabel := "Speed: " + speedText
+		rg.Label(rl.NewRectangle(sidebarX+(10*scale), (screenHeight-(185*scale)), (180*scale), (30*scale)), speedLabel)
+		newSpeed := int(rg.SliderBar(rl.NewRectangle(sidebarX+(10*scale), (screenHeight-(160*scale)), (140*scale), (30*scale)), "", "", float32(speed), 0, 1000))
+		if editModeSpeed {
+			if newSpeed != speed {
+				speed = newSpeed
+				speedInputValue = strconv.Itoa(speed)
+				editModeSpeed = false
+			}
+		} else {
+			speed = newSpeed
+			speedInputValue = strconv.Itoa(speed)
+		}
+		if rg.TextBox(rl.NewRectangle(sidebarX+(160*scale), (screenHeight-(160*scale)), (30*scale), (30*scale)), &speedInputValue, 20, editModeSpeed) {
+			editModeSpeed = !editModeSpeed
+			if editModeSpeed {
+				speedInputValue = strconv.Itoa(speed)
+				editModeWidth = false
+				editModeHeight = false
+			} else {
+				v, err := strconv.Atoi(strings.TrimSpace(speedInputValue))
+				if err != nil {
+					speedInputValue = strconv.Itoa(speed)
+				} else {
+					if v < 0 {
+						v = 0
+					} else if v > 1000 {
+						v = 1000
+					}
+					speed = v
+					speedInputValue = strconv.Itoa(speed)
+				}
+			}
+		}
+
+		// Calculate Path (Live) Button
+		if rg.Button(rl.NewRectangle(sidebarX+(10*scale), (screenHeight-(80*scale)), (180*scale), (30*scale)), "Calculate Path (Live)") {
+			if int(startPos.X) < 0 || int(startPos.X) >= width || int(startPos.Y) < 0 || int(startPos.Y) >= height || int(endPos.X) < 0 || int(endPos.X) >= width || int(endPos.Y) < 0 || int(endPos.Y) >= height {
+				posError = true
+			} else {
+				astar.ResetGrid(false) // keep grid types, otherwise it will delete the board before simulating
+				astar.SetHeuristic(activeHeuristic)
+				lastEvaluatedNode = -1
+				gridTypes := astar.GetGridTypes()
+				for i, gridType := range gridTypes {
+					// reset the map image
+					switch gridType {
+					case 0:
+						rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(240, 240, 240, 255))
+					case 1:
+						rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(0, 0, 0, 255))
+					case 2:
+						rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(0, 255, 0, 255))
+					case 3:
+						rl.ImageDrawPixel(mapImage, int32(i%width), int32(i/width), rl.NewColor(255, 0, 0, 255))
+					}
+				}
+				tex.markFull()
+				go func() {
+					astar.CalculatePathLive(int(startPos.X), int(startPos.Y), int(endPos.X), int(endPos.Y), updateChan, &speed)
+				}()
+			}
 		}
 
 		// AutoCompute
@@ -578,6 +738,7 @@ func main() {
 			} else {
 				astar.ResetGrid(false) // keep grid types, otherwise it will delete the board before simulating
 				astar.SetHeuristic(activeHeuristic)
+				lastEvaluatedNode = -1
 				gridTypes := astar.GetGridTypes()
 				for i, gridType := range gridTypes {
 					// reset the map image
@@ -615,6 +776,33 @@ func main() {
 		// Status Label
 		rg.Label(rl.NewRectangle((10*scale), (screenHeight-(30*scale)), (canvasWidth-(20*scale)), (30*scale)), "Evaluated "+strconv.Itoa(astar.GetEvaluatedCells())+" cells in "+astar.GetTimeTaken().String())
 
+		// FPS counter
+		rg.Label(rl.NewRectangle((10*scale), (0*scale), (canvasWidth-(20*scale)), (30*scale)), "FPS: "+strconv.Itoa(int(rl.GetFPS())))
+
+		rg.Unlock()
+
+		// Tool Selector (text must be "opt1;opt2;..." — raygui splits on ';' and needs 2+ items)
+		rg.Label(rl.NewRectangle(sidebarX+(10*scale), (75*scale), (180*scale), (30*scale)), "Tool:")
+		if rg.DropdownBox(rl.NewRectangle(sidebarX+(10*scale), (100*scale), (180*scale), (30*scale)), toolOptionsText, &activeTool, toolDropdownOpen) {
+			toolDropdownOpen = !toolDropdownOpen
+		}
+
+		// Heuristic Selector
+		if !toolDropdownOpen {
+			rg.Label(rl.NewRectangle(sidebarX+(10*scale), (135*scale), (180*scale), (30*scale)), "Heuristic:")
+			if rg.DropdownBox(rl.NewRectangle(sidebarX+(10*scale), (160*scale), (180*scale), (30*scale)), heuristicOptionsText, &activeHeuristic, heuristicDropdownOpen) {
+				heuristicDropdownOpen = !heuristicDropdownOpen
+			}
+		}
+
+		// Maze Selector
+		if !toolDropdownOpen && !heuristicDropdownOpen {
+			rg.Label(rl.NewRectangle(sidebarX+(10*scale), (195*scale), (180*scale), (30*scale)), "Maze:")
+			if rg.DropdownBox(rl.NewRectangle(sidebarX+(10*scale), (220*scale), (180*scale), (30*scale)), mazeOptionsText, &activeMaze, mazeDropdownOpen) {
+				mazeDropdownOpen = !mazeDropdownOpen
+			}
+		}
+
 		rl.EndDrawing()
 	}
 }

maze.go

@@ -0,0 +1,211 @@
+package main
+
+import (
+	"math/rand"
+	"time"
+)
+
+func (a *AStar) GenerateMaze(mazeType int32) {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	switch mazeType {
+	case 0:
+		a.GenerateRecursiveDivisionMaze(r)
+	case 1:
+		a.GenerateIterativeDFSMaze(r)
+	case 2:
+		a.GenerateCellularAutomataMaze(r)
+	}
+}
+
+func (a *AStar) GenerateRecursiveDivisionMaze(r *rand.Rand) {
+	// 1. Start with an entirely empty grid
+	for i := range a.gridTypes {
+		a.gridTypes[i] = 0
+	}
+
+	// 2. Draw outer boundary walls
+	for x := 0; x < a.width; x++ {
+		a.gridTypes[x] = 1
+		a.gridTypes[(a.height-1)*a.width+x] = 1
+	}
+	for y := 0; y < a.height; y++ {
+		a.gridTypes[y*a.width] = 1
+		a.gridTypes[y*a.width+(a.width-1)] = 1
+	}
+
+	// 3. Declare the recursive closure
+	var divide func(x, y, w, h int)
+	divide = func(x, y, w, h int) {
+		// Base case: room is too small to divide safely
+		if w <= 3 || h <= 3 {
+			return
+		}
+
+		// Choose orientation based on proportions to keep rooms somewhat square
+		horizontal := h > w
+		if w == h {
+			horizontal = r.Intn(2) == 0
+		}
+
+		if horizontal {
+			// Horizontal Wall: Must be on an EVEN local Y coordinate
+			wallY := (r.Intn((h-2)/2) * 2) + 2
+			// Gap (door): Must be on an ODD local X coordinate
+			gapX := (r.Intn((w-1)/2) * 2) + 1
+
+			for px := 0; px < w; px++ {
+				if px != gapX {
+					a.gridTypes[(y+wallY)*a.width+(x+px)] = 1
+				}
+			}
+			// Recurse top and bottom
+			divide(x, y, w, wallY)
+			divide(x, y+wallY, w, h-wallY)
+
+		} else {
+			// Vertical Wall: Must be on an EVEN local X coordinate
+			wallX := (r.Intn((w-2)/2) * 2) + 2
+			// Gap (door): Must be on an ODD local Y coordinate
+			gapY := (r.Intn((h-1)/2) * 2) + 1
+
+			for py := 0; py < h; py++ {
+				if py != gapY {
+					a.gridTypes[(y+py)*a.width+(x+wallX)] = 1
+				}
+			}
+			// Recurse left and right
+			divide(x, y, wallX, h)
+			divide(x+wallX, y, w-wallX, h)
+		}
+	}
+
+	// Start the recursion on the inside of the boundary walls
+	divide(1, 1, a.width-2, a.height-2)
+}
+
+func (a *AStar) GenerateIterativeDFSMaze(r *rand.Rand) {
+	// 1. Fill the entire grid with walls (type 1)
+	for i := range a.gridTypes {
+		a.gridTypes[i] = 1
+	}
+
+	// 2. The Stack (We use a Go slice instead of recursion to prevent Stack Overflow)
+	stack := make([]int, 0)
+
+	// 3. Pick a random starting cell (MUST be odd coordinates for the step-by-two math)
+	startX := (r.Intn(a.width/2) * 2) + 1
+	startY := (r.Intn(a.height/2) * 2) + 1
+
+	// Bounds check just in case
+	if startX >= a.width {
+		startX = a.width - 2
+	}
+	if startY >= a.height {
+		startY = a.height - 2
+	}
+
+	startIdx := startY*a.width + startX
+	a.gridTypes[startIdx] = 0 // Carve the first floor
+	stack = append(stack, startIdx)
+
+	// Directions for stepping by TWO (Up, Down, Left, Right)
+	dirs := [][]int{{0, -2}, {0, 2}, {-2, 0}, {2, 0}}
+
+	// 4. The DFS Loop
+	for len(stack) > 0 {
+		// Pop the top of the stack
+		currentIdx := stack[len(stack)-1]
+		cx := currentIdx % a.width
+		cy := currentIdx / a.width
+
+		// Find all valid, unvisited neighbors (distance 2)
+		validNeighbors := make([][]int, 0)
+		for _, dir := range dirs {
+			nx, ny := cx+dir[0], cy+dir[1]
+			// Check bounds
+			if nx > 0 && nx < a.width-1 && ny > 0 && ny < a.height-1 {
+				// If it's still a wall, we haven't visited it yet
+				if a.gridTypes[ny*a.width+nx] == 1 {
+					validNeighbors = append(validNeighbors, []int{nx, ny, dir[0], dir[1]})
+				}
+			}
+		}
+
+		if len(validNeighbors) > 0 {
+			// Pick a random valid neighbor
+			next := validNeighbors[r.Intn(len(validNeighbors))]
+			nx, ny, dx, dy := next[0], next[1], next[2], next[3]
+
+			// Carve the neighbor (distance 2)
+			a.gridTypes[ny*a.width+nx] = 0
+
+			// Carve the wall BETWEEN current and neighbor (distance 1)
+			wallX, wallY := cx+(dx/2), cy+(dy/2)
+			a.gridTypes[wallY*a.width+wallX] = 0
+
+			// Push the neighbor to the stack
+			stack = append(stack, ny*a.width+nx)
+		} else {
+			// Backtrack! No valid neighbors, so pop it permanently
+			stack = stack[:len(stack)-1]
+		}
+	}
+}
+
+func (a *AStar) GenerateCellularAutomataMaze(r *rand.Rand) {
+	// 1. Initial State: Fill with random noise (approx 45% walls)
+	for i := range a.gridTypes {
+		// Leave the edges as walls to contain the caves
+		x := i % a.width
+		y := i / a.width
+		if x == 0 || x == a.width-1 || y == 0 || y == a.height-1 {
+			a.gridTypes[i] = 1
+		} else if r.Float32() < 0.45 {
+			a.gridTypes[i] = 1
+		} else {
+			a.gridTypes[i] = 0
+		}
+	}
+
+	// 2. The Smoothing Passes (5 iterations is usually the sweet spot)
+	buffer := make([]byte, a.width*a.height)
+
+	for step := 0; step < 5; step++ {
+		for y := 0; y < a.height; y++ {
+			for x := 0; x < a.width; x++ {
+				wallCount := 0
+
+				// Count the 8 surrounding neighbors
+				for dy := -1; dy <= 1; dy++ {
+					for dx := -1; dx <= 1; dx++ {
+						if dx == 0 && dy == 0 {
+							continue
+						}
+						nx, ny := x+dx, y+dy
+
+						// Edges of the map count as walls
+						if nx < 0 || nx >= a.width || ny < 0 || ny >= a.height {
+							wallCount++
+						} else if a.gridTypes[ny*a.width+nx] == 1 {
+							wallCount++
+						}
+					}
+				}
+
+				// The Automata Rules:
+				// If surrounded by walls, become a wall.
+				// If surrounded by empty space, become empty.
+				idx := y*a.width + x
+				if wallCount > 4 {
+					buffer[idx] = 1
+				} else if wallCount < 4 {
+					buffer[idx] = 0
+				} else {
+					buffer[idx] = a.gridTypes[idx] // Stays the same
+				}
+			}
+		}
+		// Copy the buffer back to the main grid for the next pass
+		copy(a.gridTypes, buffer)
+	}
+}