Server: On map generation, put lots of 'X' cells for trees on island.

[plomrogue] / src / server / map.c

diff --git a/src/server/map.c b/src/server/map.c
index 0edd955c4265419f7f09d19d14e10c1066384a62..36c446580205e67041237c3e950c8441d62b6ac4 100644 (file)
--- a/src/server/map.c
+++ b/src/server/map.c
@@ -1,7 +1,8 @@
 /* src/server/map.c */
 
 #include "map.h"
-#include <stdint.h> /* uint8_t, uint16_t, uint32_t */
+#include <stdint.h> /* uint8_t, uint16_t, uint32_t, UINT16_MAX */
+#include "../common/rexit.h" /* exit_err() */
 #include "../common/try_malloc.h" /* try_malloc() */
 #include "../common/yx_uint8.h" /* struct yx_uint8 */
 #include "rrand.h" /* rrand() */
@@ -9,11 +10,70 @@
 
 
 
-extern void init_map()
+/* Call this too often with "init" of 0 and the game exits with an error message
+ * about reaching an iteration limit. An "init" of 1 sets the iteration counter
+ * to 0. Iteration limit is currently 256 * UINT16_MAX.
+ */
+static uint8_t iter_limit(uint8_t init);
+
+/* Return 1 if cell on "pos" is neighbor to a cell of "type", else return 0. */
+static uint8_t is_neighbor(struct yx_uint8 pos, char type);
+
+/* Fill map with '~' cells. */
+static void make_sea();
+
+/* Put island of '.' cells inside map sea. */
+static void make_sea();
+
+/* Put tree cells of 'X' on island. */
+static void make_trees();
+
+
+
+static uint8_t iter_limit(uint8_t init)
+{
+    static uint32_t i = 0;
+    char * err = "Map generation reached iteration limit. Change map size?";
+    if (init)
+    {
+        i = 0;
+        return 0;
+    }
+    i++;
+    exit_err(256 * UINT16_MAX == i, err);
+    return 1;
+}
+
+
+
+static uint8_t is_neighbor(struct yx_uint8 pos, char type)
+{
+    uint8_t ind = pos.y % 2;
+    uint8_t diag_west = pos.x + ind > 0;
+    uint8_t diag_east = pos.x + ind <= world.map.size.x - 1;
+    uint16_t pos_i = (pos.y * world.map.size.x) + pos.x;
+    if (   (   pos.y > 0                    && diag_east
+            && type == world.map.cells[pos_i - world.map.size.x + ind])
+        || (   pos.x < world.map.size.x - 1
+            && type == world.map.cells[pos_i + 1])
+        || (   pos.y < world.map.size.y - 1 && diag_east
+            && type == world.map.cells[pos_i + world.map.size.x + ind])
+        || (   pos.y > 0                    && diag_west
+            && type == world.map.cells[pos_i - world.map.size.x - !ind])
+        || (   pos.x > 0
+            && type == world.map.cells[pos_i - 1])
+        || (   pos.y < world.map.size.y - 1 && diag_west
+            && type == world.map.cells[pos_i + world.map.size.x - !ind]))
+    {
+        return 1;
+    }
+    return 0;
+}
+
+
+
+static void make_sea()
 {
-    char * f_name = "init_map()";
-    uint32_t size = world.map.size.x * world.map.size.y;
-    world.map.cells = try_malloc(size, f_name);
     uint16_t y, x;
     for (y = 0; y < world.map.size.y; y++)
     {
@@ -21,37 +81,72 @@ extern void init_map()
              x < world.map.size.x;
              world.map.cells[(y * world.map.size.x) + x] = '~', x++);
     }
+}
+
+
+
+static void make_island()
+{
+    char type = '.';
     uint8_t add_half_width = !(world.map.size.y % 2) * (world.map.size.x / 2);
-    world.map.cells[(size / 2) + add_half_width] = '.';
-    uint16_t curpos;
-    while (1)
+    uint32_t size = world.map.size.x * world.map.size.y;
+    world.map.cells[(size / 2) + add_half_width] = type;
+    struct yx_uint8 pos;
+    iter_limit(1);
+    while (iter_limit(0))
     {
-        y = rrand() % world.map.size.y;
-        x = rrand() % world.map.size.x;
-        curpos = (y * world.map.size.x) + x;
-        if ('~' == world.map.cells[curpos]
-            && (   (   curpos >= world.map.size.x
-                    && '.' == world.map.cells[curpos - world.map.size.x])
-                || (   curpos < world.map.size.x * (world.map.size.y-1)
-                    && '.' == world.map.cells[curpos + world.map.size.x])
-                || (   curpos > 0 && curpos % world.map.size.x != 0
-                    && '.' == world.map.cells[curpos-1])
-                || (   curpos < (world.map.size.x * world.map.size.y)
-                    && (curpos+1) % world.map.size.x != 0
-                    && '.' == world.map.cells[curpos+1])))
+        pos.y = rrand() % world.map.size.y;
+        pos.x = rrand() % world.map.size.x;
+        uint16_t pos_i = (pos.y * world.map.size.x) + pos.x;
+        if ('~' == world.map.cells[pos_i] && is_neighbor(pos, type))
         {
-            if (   y == 0 || y == world.map.size.y - 1
-                || x == 0 || x == world.map.size.x - 1)
+            if (   pos.y == 0 || pos.y == world.map.size.y - 1
+                || pos.x == 0 || pos.x == world.map.size.x - 1)
             {
                 break;
             }
-            world.map.cells[y * world.map.size.x + x] = '.';
+            world.map.cells[pos_i] = type;
         }
     }
 }
 
 
 
+static void make_trees()
+{
+    char type = 'X';
+    struct yx_uint8 pos;
+    uint16_t n_trees = (world.map.size.x * world.map.size.y) / 16;
+    uint16_t i_trees = 0;
+    iter_limit(1);
+    while (i_trees <= n_trees && iter_limit(0))
+    {
+        uint8_t single_allowed = rrand() % 32;
+        pos.y = rrand() % world.map.size.y;
+        pos.x = rrand() % world.map.size.x;
+        uint16_t pos_i = (pos.y * world.map.size.x) + pos.x;
+        if ('.' == world.map.cells[pos_i]
+            && (!single_allowed || is_neighbor(pos, type)))
+        {
+            world.map.cells[pos_i] = type;
+            i_trees++;
+        }
+    }
+}
+
+
+
+extern void init_map()
+{
+    char * f_name = "init_map()";
+    world.map.cells = try_malloc(world.map.size.x * world.map.size.y, f_name);
+    make_sea();
+    make_island();
+    make_trees();
+}
+
+
+
 extern uint8_t is_passable(struct yx_uint8 pos)
 {
     uint8_t passable = 0;