maze.c

/* Maze generator in C.
 * Joe Wingbermuehle
 * 19990805
 */

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/* Display the maze. */
void ShowMaze(const bool maze[], int width, int height) {
   int x, y;
   for(y = 0; y < height; y++) {
      for(x = 0; x < width; x++) {
         switch(maze[y * width + x]) {
         case 1:  printf("[]");  break;
         default: printf("  ");  break;
         }
      }
      printf("\n");
   }
}
/* Display the maze. */
void dump_maze(const bool maze[], int width, int height, int px, int py) {
   int x, y;
   for(y = 0; y < height; y++) {
      for(x = 0; x < width; x++) {
         if (x == px && y == py) {
            printf("<>");
         } else if (maze[y * width + x]) {
            printf("[]");
         } else {
            printf("  ");
         }
      }
      printf("\n");
   }
}

/*  Carve the maze starting at x, y. */
void CarveMaze(bool maze[], int width, int height, int x, int y) {

   int x1, y1;
   int x2, y2;
   int dx, dy;
   int dir, count;

   dir = rand() % 4;
   count = 0;
   while(count < 4) {
      dx = 0; dy = 0;
      switch(dir) {
      case 0:  dx = 1;  break;
      case 1:  dy = 1;  break;
      case 2:  dx = -1; break;
      default: dy = -1; break;
      }
      x1 = x + dx;
      y1 = y + dy;
      x2 = x1 + dx;
      y2 = y1 + dy;
      if(   x2 > 0 && x2 < width && y2 > 0 && y2 < height
         && maze[y1 * width + x1] == 1 && maze[y2 * width + x2] == 1) {
         maze[y1 * width + x1] = false;
         maze[y2 * width + x2] = false;
         x = x2; y = y2;
         dir = rand() % 4;
         count = 0;
      } else {
         dir = (dir + 1) % 4;
         count += 1;
      }
   }

}

/* Generate maze in matrix maze with size width, height. */
void GenerateMaze(bool maze[], int width, int height) {

   int x, y;

   /* Initialize the maze. */
   for(x = 0; x < width * height; x++) {
      maze[x] = true;
   }
   maze[1 * width + 1] = false;

   /* Seed the random number generator. */
   srand(time(0));

   /* Carve the maze. */
   for(y = 1; y < height; y += 2) {
      for(x = 1; x < width; x += 2) {
         CarveMaze(maze, width, height, x, y);
      }
   }
}