From afcc1fd6b076abe34bb35503a7caf32be566482b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Tom=C3=A1s?= <jtomas1815@gmail.com>
Date: Wed, 12 Sep 2018 15:13:40 -0300
Subject: initial commit

---
 maze.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100755 maze.c

(limited to 'maze.c')

diff --git a/maze.c b/maze.c
new file mode 100755
index 0000000..3156465
--- /dev/null
+++ b/maze.c
@@ -0,0 +1,146 @@
+#define SDL_DISABLE_IMMINTRIN_H
+#include <stdlib.h>
+#include <time.h>
+#include "SDL2/SDL.h"
+
+int mazeWidth = 50;
+int mazeHeight = 50;
+
+typedef struct cell {
+	int x, y;
+	char walls;
+	struct cell *parent;
+} Cell;
+
+int min(int a, int b) { return a < b ? a : b; }
+
+int max(int a, int b) { return a > b ? a : b; }
+
+int pos(int x, int y) {
+	x = min(mazeWidth - 1,  max(0, x));
+	y = min(mazeHeight - 1, max(0, y));
+	return x + y * mazeWidth;
+}
+
+void drawCell(SDL_Renderer *r, Cell n, int cell, int wall, char red, char green, char blue) {
+	SDL_SetRenderDrawColor(r, red, green, blue, 255);
+	SDL_Rect rect;
+	rect.x = n.x * cell + (n.x + 1) * wall;
+	rect.y = n.y * cell + (n.y + 1) * wall;
+	rect.w = cell;
+	rect.h = cell;
+	SDL_RenderFillRect(r, &rect);
+	int x = n.x * (wall + cell);
+	int y = n.y * (wall + cell);
+	if (~n.walls & 1) {
+		rect.x = x;
+		rect.y = wall + y;
+		rect.w = wall;
+		rect.h = cell;
+		SDL_RenderFillRect(r, &rect);
+	}
+	if (~n.walls & 4) {
+		rect.x = wall + x;
+		rect.y = y;
+		rect.w = cell;
+		rect.h = wall;
+		SDL_RenderFillRect(r, &rect);
+	}
+}
+
+void reset(Cell *maze) {
+	for (int i = 0; i < mazeWidth * mazeHeight; i++) {
+		maze[i].walls = 15;
+		maze[i].parent = 0;
+	}
+}
+
+int main(int argc, char**argv) {
+	srand(time(0));
+	if (argc >= 3) {
+		mazeWidth = atoi(argv[1]);
+		mazeHeight = atoi(argv[2]);
+	}
+	int cellSize = 16;
+	int wallSize = 4;
+	SDL_Init(SDL_INIT_VIDEO);
+	SDL_Window *w = 0;
+	SDL_Renderer *r = 0;
+	SDL_CreateWindowAndRenderer(0, 0, SDL_WINDOW_RESIZABLE, &w, &r);
+	SDL_RenderSetLogicalSize(r, mazeWidth  * (cellSize + wallSize) + wallSize,
+	                            mazeHeight * (cellSize + wallSize) + wallSize);
+	Cell maze[mazeWidth * mazeHeight];
+	for (int x = 0; x < mazeWidth; x++)
+		for (int y = 0; y < mazeHeight; y++) {
+			maze[pos(x, y)].x = x;
+			maze[pos(x, y)].y = y;
+		}
+	reset(maze);
+	Cell *curr = &maze[pos(rand() % mazeWidth, rand() % mazeHeight)];
+	curr->parent = curr;
+	SDL_Event e;
+	while (e.type != SDL_QUIT) {
+		while (SDL_PollEvent(&e)) {
+			if (e.key.type == SDL_KEYDOWN)
+				switch (e.key.keysym.sym) {
+				case SDLK_RETURN:
+					reset(maze);
+					curr = &maze[pos(rand() % mazeWidth, rand() % mazeHeight)];
+					break;
+				case SDLK_UP:
+					if (cellSize + 1 < 20) {
+						cellSize ++;
+						wallSize --;
+					}
+					SDL_RenderSetLogicalSize(r, mazeWidth  * (cellSize + wallSize) + wallSize,
+								    mazeHeight * (cellSize + wallSize) + wallSize);
+					break;
+				case SDLK_DOWN:
+					if (cellSize - 1 > 1) {
+						cellSize --;
+						wallSize ++;
+					}
+					SDL_RenderSetLogicalSize(r, mazeWidth  * (cellSize + wallSize) + wallSize,
+								    mazeHeight * (cellSize + wallSize) + wallSize);
+				}
+		}
+		SDL_SetRenderDrawColor(r, 80, 80, 80, 255);
+		SDL_RenderClear(r);
+		for (int i = 0; i < mazeWidth * mazeHeight; i++) {
+			if (maze[i].parent) drawCell(r, maze[i], cellSize, wallSize, 255, 255, 255);
+		}
+		drawCell(r, *curr, cellSize, wallSize, 0, 255, 0);
+		// not all neighbors have parent
+		if (!maze[pos(curr->x + 1, curr->y)].parent || !maze[pos(curr->x - 1, curr->y)].parent ||
+		    !maze[pos(curr->x, curr->y + 1)].parent || !maze[pos(curr->x, curr->y - 1)].parent) {
+			Cell *neighbor = curr;
+			char dir = 0;
+			char rdir = 0;
+			while (neighbor->parent) {
+				dir = 1 << rand() % 4;
+				int x = curr->x;
+				int y = curr->y;
+				switch (dir) {
+					case 1: x--; rdir = 2; break;
+					case 2: x++; rdir = 1; break;
+					case 4: y--; rdir = 8; break;
+					case 8: y++; rdir = 4; break;
+				}
+				if (!maze[pos(x, y)].parent) neighbor = &maze[pos(x, y)];
+			}
+			curr->walls &= ~dir;
+			neighbor->walls &= ~rdir;
+			neighbor->parent = curr;
+			curr = neighbor;
+		}
+		else if (curr->parent != curr) { // curr isn't the starting cell
+			curr = curr->parent;
+		}
+		SDL_RenderPresent(r);
+		SDL_Delay(10);
+	}
+	SDL_DestroyWindow(w);
+	SDL_DestroyRenderer(r);
+	SDL_Quit();
+	return 0;
+}
-- 
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