From b89b4b64b2c1bfaeed1f71ffdab95bcfc759bb6a Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Mon, 4 Nov 2024 21:15:58 +0000
Subject: [PATCH] Seperate generate and solve procedures

---
 main.c | 99 ++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 54 insertions(+), 45 deletions(-)

diff --git a/main.c b/main.c
index 9d153c9..022f9b0 100644
--- a/main.c
+++ b/main.c
@@ -74,8 +74,7 @@ static void draw_visited(vec2_t p)
 	XFlush(dpy);
 }
 
-static bool
-random_walk(coord_pred_t should_visit, visit_fn_t visit_fn, vec2_t start)
+static void generate(vec2_t start)
 {
 	dir_t visit[] = { LEFT, RIGHT, UP, DOWN };
 	for (int i = 3; i > 0; --i) {
@@ -85,56 +84,66 @@ random_walk(coord_pred_t should_visit, visit_fn_t visit_fn, vec2_t start)
 		visit[i] = tmp;
 	}
 
-	vec2_t next, im;
 	for (int i = 0; i < 4; ++i) {
-		next.x = start.x + steps[visit[i]].x;
-		next.y = start.y + steps[visit[i]].y;
-		im.x = (start.x + next.x) / 2;
-		im.y = (start.y + next.y) / 2;
-
+		const vec2_t next = {
+			.x = start.x + steps[visit[i]].x,
+			.y = start.y + steps[visit[i]].y,
+		};
+		const vec2_t im = {
+			.x = (start.x + next.x) / 2,
+			.y = (start.y + next.y) / 2,
+		};
 		const bool x_in_bounds = next.x >= 0 && next.x < GRID_SIZE;
 		const bool y_in_bounds = next.y >= 0 && next.y < GRID_SIZE;
-		if (x_in_bounds && y_in_bounds && should_visit(next, im)) {
-			if (visit_fn(next, im)
-			    || random_walk(should_visit, visit_fn, next))
-				return true;
+
+		if (x_in_bounds && y_in_bounds) {
+			const bool is_wall = !maze[next.x][next.y].is_path;
+			if (is_wall) {
+				maze[next.x][next.y].is_path = true;
+				clear_path(next);
+				maze[im.x][im.y].is_path = true;
+				clear_path(im);
+
+				nanosleep(&gen_pause, NULL);
+				generate(next);
+			}
+		}
+	}
+}
+
+static bool solve(vec2_t start)
+{
+	for (int i = 0; i < 4; ++i) {
+		const vec2_t next = {
+			.x = start.x + steps[i].x,
+			.y = start.y + steps[i].y,
+		};
+		const vec2_t im = {
+			.x = (start.x + next.x) / 2,
+			.y = (start.y + next.y) / 2,
+		};
+		const bool x_in_bounds = next.x >= 0 && next.x < GRID_SIZE;
+		const bool y_in_bounds = next.y >= 0 && next.y < GRID_SIZE;
+
+		if (x_in_bounds && y_in_bounds) {
+			const bool accessible = maze[im.x][im.y].is_path;
+			const bool unvisited = !maze[next.x][next.y].visited;
+			if (accessible && unvisited) {
+				maze[next.x][next.y].visited = true;
+				draw_visited(next);
+				maze[im.x][im.y].visited = true;
+				draw_visited(im);
+
+				nanosleep(&solve_pause, NULL);
+				if ((GOAL == next.x && GOAL == next.y) || solve(next))
+					return true;
+			}
 		}
 	}
 
 	return false;
 }
 
-static bool is_wall(vec2_t c, vec2_t im)
-{
-	(void)im;
-	return !maze[c.x][c.y].is_path;
-}
-
-static bool generation_visit(vec2_t c, vec2_t im)
-{
-	maze[c.x][c.y].is_path = true;
-	maze[im.x][im.y].is_path = true;
-	clear_path(im);
-	clear_path(c);
-	nanosleep(&gen_pause, NULL);
-	return false;
-}
-
-static bool accessible_and_unvisited(vec2_t c, vec2_t im)
-{
-	return maze[im.x][im.y].is_path && !maze[c.x][c.y].visited;
-}
-
-static bool solve_visit(vec2_t c, vec2_t im)
-{
-	maze[c.x][c.y].visited = true;
-	maze[im.x][im.y].visited = true;
-	draw_visited(im);
-	draw_visited(c);
-	nanosleep(&solve_pause, NULL);
-	return GOAL == c.x && GOAL == c.y;
-}
-
 int main(void)
 {
 	// Seed random number generation from time
@@ -186,14 +195,14 @@ int main(void)
 		const vec2_t gen_start = { GOAL, GOAL };
 		maze[GOAL][GOAL].is_path = true;
 		clear_path(gen_start);
-		random_walk(is_wall, generation_visit, gen_start);
+		generate(gen_start);
 
 		// Solve
 		const vec2_t solve_start = { 0, 0 };
 		maze[0][0].visited = true;
 		XSetForeground(dpy, ctx, visited_col);
 		draw_visited(solve_start);
-		random_walk(accessible_and_unvisited, solve_visit, solve_start);
+		solve(solve_start);
 
 		// Draw exit path
 		const int x = PX(MARGIN + GRID_SIZE + 1), y = PX(MARGIN + GRID_SIZE);