From fb59c890ca93e2aa468b3b80c157a2b5b5eb0493 Mon Sep 17 00:00:00 2001
From: Karma Riuk <riukkarma@gmail.com>
Date: Thu, 10 Aug 2023 19:13:24 +0200
Subject: [PATCH] Corrected some bugs for when it came to parsing and writing
 mazes

---
 io/writer/image.go    | 19 +++++++++++++++----
 io/writer/strings.go  |  3 +++
 maze/parser/parser.go | 12 ++++++++++--
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/io/writer/image.go b/io/writer/image.go
index 5731a83..e79f15f 100644
--- a/io/writer/image.go
+++ b/io/writer/image.go
@@ -56,17 +56,28 @@ func (w *ImageWriter) Write() error {
 	width, height = w.CellWidth, w.CellHeight
 	for i, from := range w.Maze.Solution[:len(w.Maze.Solution)-1] {
 		to := w.Maze.Solution[i+1]
+
 		if from.Coords.X == to.Coords.X {
+			// Fill verticallly
 			x0 = from.Coords.X * w.CellWidth
 
-			for y := from.Coords.Y; y < to.Coords.Y; y++ {
-				y0 = y * w.CellHeight
-				w.draw(x0, y0, width, height, colors[c])
-				c++
+			if from.Coords.Y < to.Coords.Y {
+				for y := from.Coords.Y; y < to.Coords.Y; y++ {
+					y0 = y * w.CellHeight
+					w.draw(x0, y0, width, height, colors[c])
+					c++
+				}
+			} else {
+				for y := from.Coords.Y; y > to.Coords.Y; y-- {
+					y0 = y * w.CellHeight
+					w.draw(x0, y0, width, height, colors[c])
+					c++
+				}
 			}
 			y0 = to.Coords.Y * w.CellHeight
 			w.draw(x0, y0, width, height, colors[c])
 		} else {
+			// Fill horizontally
 			y0 = from.Coords.Y * w.CellHeight
 
 			if from.Coords.X < to.Coords.X {
diff --git a/io/writer/strings.go b/io/writer/strings.go
index cab5510..6929072 100644
--- a/io/writer/strings.go
+++ b/io/writer/strings.go
@@ -58,6 +58,9 @@ func (w *StringsWriter) fillHorizontally(from maze.Coordinates, to maze.Coordina
 
 func (w *StringsWriter) fillVertically(from maze.Coordinates, to maze.Coordinates, char byte) {
 	x := from.X
+	if from.Y > to.Y {
+		from, to = to, from
+	}
 	for y := from.Y; y <= to.Y; y++ {
 		w.lines[y][x] = char
 	}
diff --git a/maze/parser/parser.go b/maze/parser/parser.go
index 7ea83a1..3422303 100644
--- a/maze/parser/parser.go
+++ b/maze/parser/parser.go
@@ -85,7 +85,7 @@ func lookupNeighbourAbove(raw_maze *reader.RawMaze, node *maze.Node, nodesByCoor
 			break
 		}
 
-		if y > 0 && raw_maze.IsWall(node.Coords.X, y) {
+		if y >= 0 && raw_maze.IsWall(node.Coords.X, y) {
 			y++
 			if y == node.Coords.Y {
 				break
@@ -107,6 +107,10 @@ func lookupNeighbourAbove(raw_maze *reader.RawMaze, node *maze.Node, nodesByCoor
 
 func lookupNeighbourLeft(raw_maze *reader.RawMaze, node *maze.Node, nodesByCoord *map[maze.Coordinates]*maze.Node) {
 	for x := node.Coords.X - 1; x > 0; x-- {
+		if raw_maze.IsWall(x, node.Coords.Y) && x == node.Coords.X-1 {
+			return
+		}
+
 		if raw_maze.IsWall(x, node.Coords.Y) && x < node.Coords.X-1 {
 			panic(fmt.Sprintf("Found no node before wall while looking to the left at neighbours of node %v (arrived at x=%v before hitting a wall)", node, x))
 		}
@@ -122,7 +126,11 @@ func lookupNeighbourLeft(raw_maze *reader.RawMaze, node *maze.Node, nodesByCoord
 
 func lookupNeighbourRight(raw_maze *reader.RawMaze, node *maze.Node, nodesByCoord *map[maze.Coordinates]*maze.Node) {
 	for x := node.Coords.X + 1; x < raw_maze.Width; x++ {
-		if raw_maze.IsWall(x, node.Coords.Y) {
+		if raw_maze.IsWall(x, node.Coords.Y) && x == node.Coords.X+1 {
+			return
+		}
+
+		if raw_maze.IsWall(x, node.Coords.Y) && x > node.Coords.X+1 {
 			panic(fmt.Sprintf("Found no node before wall while looking to the right at neighbours of node %v", node))
 		}