Improv

main.go

@@ -8,9 +8,9 @@ import (
 	"test-maze/mazer"
 )
 
-const SIZE_X = 48
-const SIZE_Y = 48
-const CELL_SCALE = 10
+const SIZE_X = 61
+const SIZE_Y = 61
+const CELL_SCALE = 1
 
 func main() {
 	matrix := mazer.GenerateMaze(SIZE_X, SIZE_Y)

mazer/maze.go

@@ -14,84 +14,78 @@ func GenerateMaze(width int, height int) [][]int {
 		matrix[y] = cells[rowStart : rowStart+width]
 	}
 
-	// Keep a full black border: path only exists inside [1..width-2] x [1..height-2].
 	if width < 3 || height < 3 {
 		return matrix
 	}
 
 	startX, startY := 1, 1
-	endX, endY := width-2, height-2
+	matrix[startY][startX] = 1
 
-	parent := make([]int, width*height)
-	for i := range parent {
-		parent[i] = -1
-	}
-	visited := make([]bool, width*height)
+	stackX := make([]int, 1, width*height/2)
+	stackY := make([]int, 1, width*height/2)
+	stackX[0], stackY[0] = startX, startY
 
-	dx := [4]int{0, -1, 1, 0}
-	dy := [4]int{1, 0, 0, -1}
+	for len(stackX) > 0 {
+		last := len(stackX) - 1
+		x, y := stackX[last], stackY[last]
+		dirs := shuffledDirections()
 
-	type node struct {
-		x    int
-		y    int
-		dirs [4]uint8
-		next int
-	}
+		carved := false
+		for _, d := range dirs {
+			dx, dy := 0, 0
+			switch d {
+			case 0:
+				dy = -2
+			case 1:
+				dx = 2
+			case 2:
+				dy = 2
+			default:
+				dx = -2
+			}
 
-	stack := make([]node, 1, (width-2)*(height-2))
-	stack[0] = node{x: startX, y: startY, dirs: shuffledDirections()}
-	startIdx := startY*width + startX
-	endIdx := endY*width + endX
-	visited[startIdx] = true
+			nx, ny := x+dx, y+dy
+			if nx <= 0 || nx >= width-1 || ny <= 0 || ny >= height-1 {
+				continue
+			}
+			if matrix[ny][nx] == 1 {
+				continue
+			}
 
-	found := false
-	for len(stack) > 0 {
-		last := len(stack) - 1
-		top := &stack[last]
-
-		if top.x == endX && top.y == endY {
-			found = true
+			matrix[y+dy/2][x+dx/2] = 1
+			matrix[ny][nx] = 1
+			stackX = append(stackX, nx)
+			stackY = append(stackY, ny)
+			carved = true
 			break
 		}
 
-		if top.next == 4 {
-			stack = stack[:last]
-			continue
-		}
-
-		d := top.dirs[top.next]
-		top.next++
-
-		nx := top.x + dx[d]
-		ny := top.y + dy[d]
-		if nx <= 0 || nx >= width-1 || ny <= 0 || ny >= height-1 {
-			continue
-		}
-
-		nIdx := ny*width + nx
-		if visited[nIdx] {
-			continue
-		}
-
-		visited[nIdx] = true
-		parent[nIdx] = top.y*width + top.x
-		stack = append(stack, node{x: nx, y: ny, dirs: shuffledDirections()})
-	}
-
-	if !found {
-		matrix[startY][startX] = 1
-		return matrix
-	}
-
-	for idx := endIdx; idx != -1; idx = parent[idx] {
-		x := idx % width
-		y := idx / width
-		matrix[y][x] = 1
-		if idx == startIdx {
-			break
+		if !carved {
+			stackX = stackX[:last]
+			stackY = stackY[:last]
 		}
 	}
 
+	// Entrance on top border at a random connected X.
+	topChoices := make([]int, 0, width/2)
+	for x := 1; x < width-1; x++ {
+		if matrix[1][x] == 1 {
+			topChoices = append(topChoices, x)
+		}
+	}
+	entranceX := topChoices[rand.IntN(len(topChoices))]
+	matrix[0][entranceX] = 1
+
+	// Exit on bottom border at a random connected X.
+	bottomChoices := make([]int, 0, width/2)
+	for x := 1; x < width-1; x++ {
+		if matrix[height-2][x] == 1 {
+			bottomChoices = append(bottomChoices, x)
+		}
+	}
+	exitX := bottomChoices[rand.IntN(len(bottomChoices))]
+	matrix[height-1][exitX] = 1
+
 	return matrix
 }