major refactor

1 files changed, 92 insertions, 0 deletions

diff --git a/src/cavegen.c b/src/cavegen.c
new file mode 100644
index 0000000..1365e9d
--- /dev/null
+++ b/src/cavegen.c
@@ -0,0 +1,92 @@
+#include "cavegen.h"
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAX_STEPS   200
+#define NUM_WALKERS 100
+
+enum direction {
+    UP,
+    LEFT,
+    RIGHT,
+    DOWN,
+    NUM_DIRS,
+};
+
+void create_cave(struct map *map)
+{
+    map->width  = WIDTH;
+    map->height = HEIGHT;
+
+    // create a map consisting entirely of walls
+    map->map = malloc(sizeof(enum tile_type) * HEIGHT * WIDTH);
+    for (int i = 0; i < HEIGHT; ++i) {
+        for (int j = 0; j < WIDTH; ++j) {
+            map->map[i * WIDTH + j] = WALL;
+        }
+    }
+
+    // start in the middle of the screen
+    int start_x = WIDTH / 2;
+    int start_y = HEIGHT / 2;
+
+    // make the starting point GROUND
+    map->map[start_y * WIDTH + start_x] = GROUND;
+
+    // setup the open tiles
+    struct point *open_tiles = malloc(sizeof(struct point) * HEIGHT * WIDTH);
+
+    int num_open_tiles = 1;
+    open_tiles[0].x    = start_x;
+    open_tiles[0].y    = start_y;
+
+    for (int i = 0; i < NUM_WALKERS; ++i) {
+        // get a random open point
+        struct point curr_point = open_tiles[rand() % num_open_tiles];
+
+        int x_pos = curr_point.x;
+        int y_pos = curr_point.y;
+
+        // iterate until the walk exits the array or MAX_STEPS is reached
+        for (int j = 1; j < MAX_STEPS - 1 && x_pos < WIDTH - 1 && x_pos >= 1 &&
+                        y_pos < HEIGHT - 1 && y_pos >= 1;
+             ++j) {
+            // add new open point if the current point is still a wall
+            if (map->map[y_pos * WIDTH + x_pos] == WALL) {
+                open_tiles[num_open_tiles].x = x_pos;
+                open_tiles[num_open_tiles].y = y_pos;
+                ++num_open_tiles;
+            }
+
+            map->map[y_pos * WIDTH + x_pos] = GROUND; // assign ground
+
+            // move in a random direction
+            enum direction dir = rand() % NUM_DIRS;
+            switch (dir) {
+            case UP : --y_pos; break;
+            case LEFT : --x_pos; break;
+            case RIGHT : ++x_pos; break;
+            case DOWN : ++y_pos; break;
+            default : exit(EXIT_FAILURE); // should not occur
+            }
+        }
+    }
+
+    // assign the up stair and remove from open tiles
+    int in           = rand() % num_open_tiles;
+    map->entry_point = open_tiles[in];
+    open_tiles[in]   = open_tiles[num_open_tiles - 1];
+    --num_open_tiles;
+    map->map[map->entry_point.y * WIDTH + map->entry_point.x] = UP_STAIR;
+
+    // assign the down stair and remove from open tiles
+    in                = rand() % num_open_tiles;
+    struct point down = open_tiles[in];
+    open_tiles[in]    = open_tiles[num_open_tiles - 1];
+    --num_open_tiles;
+    map->map[down.y * WIDTH + down.x] = DOWN_STAIR;
+
+    free(open_tiles);
+}