/* src/server/ai.c */
#include "ai.h"
-#include <stdint.h> /* uint8_t, uint32_t, UINT8_MAX */
-#include <string.h> /* strlen(), memset() */
-#include "../common/yx_uint16.h" /* struct yx_uint16 */
+#include <stddef.h> /* NULL */
+#include <stdint.h> /* uint8_t, uint16_t, uint32_t, UINT16_MAX */
+#include <stdlib.h> /* free() */
+#include "../common/try_malloc.h" /* try_malloc() */
#include "map_object_actions.h" /* get_moa_id_by_name() */
#include "map_objects.h" /* struct MapObj */
#include "world.h" /* global world */
-/* Write into "neighbor_scores" scores for immediate neighbors to cell at
- * "pos_yx" (YX coordinates) and "pos_i" (arry_index) in "score_map". Directions
- * determining neighborhood are defined by the letters of "dir"; their order
- * also determines in what order scores are written into "neighbor_score".
- * "len_dirs" is to store the result of a previous strlen(dir) (so it does not
- * have to be called repeatedly and costly in dijkstra_map(); same reason for
- * "pos_i"'s redundancy.). "max_score" is written into "neighbor_scores" for
- * illegal directions (that from "pos_yx" would lead beyond the map's border).
+#define N_DIRS 6
+
+
+
+/* Write into "neighbors" scores of the N_DIRS immediate neighbors of the
+ * "score_map" cell at "pos_i" (array index), as found in the directions
+ * north-east, east, south-east etc. (clockwise order). Use "max_score" for
+ * illegal neighborhoods (i.e. if direction would lead beyond the map's border).
*/
-static void get_neighbor_scores(char * dirs, uint8_t len_dirs,
- uint8_t * score_map, struct yx_uint16 pos_yx,
- uint32_t pos_i, uint8_t max_score,
- uint8_t * neighbor_scores)
+static void get_neighbor_scores(uint16_t * score_map, uint16_t pos_i,
+ uint16_t max_score, uint16_t * neighbors);
+
+/* Iterate over scored cells in "score_map" of world.map's geometry. Compare
+ * each cell's score against the score of its immediate neighbors in N_DIRS
+ * directions. If it's neighbors are low enough that the result would be lower
+ * than the current value, re-set it to 1 point higher than its lowest-scored
+ * neighbor- Repeat this whole process until all cells have settled on their
+ * final score. Ignore cells whose position in "score_map" fits cells of
+ * unreachable terrain in world.map.cells. Expect "max_score" to be the maximum
+ * score for cells, marking them as unreachable.
+ */
+static void dijkstra_map(uint16_t * score_map, uint16_t max_score);
+
+/* Return numpad char of direction ("8", "6", "2", "4" etc.) of enemy with the
+ * shortest path to "mo_origin". If no enemy is around, return 0.
+ */
+static char get_dir_to_nearest_enemy(struct MapObj * mo_origin);
+
+
+
+static void get_neighbor_scores(uint16_t * score_map, uint16_t pos_i,
+ uint16_t max_score, uint16_t * neighbors)
{
- memset(neighbor_scores, max_score, len_dirs);
- uint8_t i_dirs;
- for (i_dirs = 0; i_dirs < len_dirs; i_dirs++)
+ uint32_t map_size = world.map.size.y * world.map.size.x;
+ uint8_t i_dir;
+ for (i_dir = 0; i_dir < N_DIRS; neighbors[i_dir] = max_score, i_dir++);
+ uint8_t open_north = pos_i >= world.map.size.x;
+ uint8_t open_east = pos_i + 1 % world.map.size.x;
+ uint8_t open_south = pos_i + world.map.size.x < map_size;
+ uint8_t open_west = pos_i % world.map.size.x;
+ uint8_t is_indented = (pos_i / world.map.size.x) % 2;
+ uint8_t open_diag_west = is_indented || open_west;
+ uint8_t open_diag_east = !is_indented || open_east;
+ if (open_north && open_diag_east)
{
- if ('N' == dirs[i_dirs] && pos_yx.y > 0)
- {
- neighbor_scores[i_dirs] = score_map[pos_i - world.map.size.x];
- }
- else if ('E' == dirs[i_dirs] && pos_yx.x < world.map.size.x - 1)
- {
- neighbor_scores[i_dirs] = score_map[pos_i + 1];
- }
- else if ('S' == dirs[i_dirs] && pos_yx.y < world.map.size.y - 1)
- {
- neighbor_scores[i_dirs] = score_map[pos_i + world.map.size.x];
- }
- else if ('W' == dirs[i_dirs] && pos_yx.x > 0)
- {
- neighbor_scores[i_dirs] = score_map[pos_i - 1];
- }
+ neighbors[0] = score_map[pos_i - world.map.size.x + is_indented];
+ }
+ if (open_east)
+ {
+ neighbors[1] = score_map[pos_i + 1];
+ }
+ if (open_south && open_diag_east)
+ {
+ neighbors[2] = score_map[pos_i + world.map.size.x + is_indented];
+ }
+ if (open_south && open_diag_west)
+ {
+ neighbors[3] = score_map[pos_i + world.map.size.x - !is_indented];
+ }
+ if (open_west)
+ {
+ neighbors[4] = score_map[pos_i - 1];
+ }
+ if (open_north && open_diag_west)
+ {
+ neighbors[5] = score_map[pos_i - world.map.size.x - !is_indented];
}
}
-/* Iterate over scored cells in "score_map" of world.map's 2D geometry. Compare
- * each cell's score against the scores of its immediate neighbors in "dirs"
- * directions; if at least one of these is lower, re-set the current cell's
- * score to one higher than its lowest neighbor score. Repeat this whole process
- * until all cells have settled on their final score. Ignore cells whose
- * position in "score_map" fits a non-island cell in world.map.cells. Expect
- * "max_score" to be the maximum score for cells, marking them as unreachable.
- */
-static void dijkstra_map(char * dirs, uint8_t * score_map, uint8_t max_score)
+static void dijkstra_map(uint16_t * score_map, uint16_t max_score)
{
- uint8_t len_dirs = strlen(dirs);
- uint8_t neighbor_scores[len_dirs];
- struct yx_uint16 pos_yx;
- uint32_t pos_i;
- uint8_t i_scans, i_dirs, local_score, min_neighbor_score;
+ uint32_t map_size = world.map.size.y * world.map.size.x;
+ uint16_t pos, i_scans, neighbors[N_DIRS], min_neighbor;
uint8_t scores_still_changing = 1;
+ uint8_t i_dirs;
for (i_scans = 0; scores_still_changing; i_scans++)
{
scores_still_changing = 0;
- for (pos_yx.y = 0, pos_i = 0; pos_yx.y < world.map.size.y; pos_yx.y++)
+ for (pos = 0; pos < map_size; pos++)
{
- for (pos_yx.x = 0; pos_yx.x < world.map.size.x; pos_yx.x++, pos_i++)
+ if ('.' == world.map.cells[pos])
{
- if ('.' == world.map.cells[pos_i])
+ get_neighbor_scores(score_map, pos, max_score, neighbors);
+ min_neighbor = max_score;
+ for (i_dirs = 0; i_dirs < N_DIRS; i_dirs++)
{
- local_score = score_map[pos_i];
- get_neighbor_scores(dirs, len_dirs, score_map, pos_yx,
- pos_i, max_score, neighbor_scores);
- min_neighbor_score = max_score;
- for (i_dirs = 0; i_dirs < len_dirs; i_dirs++)
+ if (min_neighbor > neighbors[i_dirs])
{
- if (min_neighbor_score > neighbor_scores[i_dirs])
- {
- min_neighbor_score = neighbor_scores[i_dirs];
- }
- }
- if (local_score > min_neighbor_score + 1)
- {
- score_map[pos_i] = min_neighbor_score + 1;
- scores_still_changing = 1;
+ min_neighbor = neighbors[i_dirs];
}
}
+ if (score_map[pos] > min_neighbor + 1)
+ {
+ score_map[pos] = min_neighbor + 1;
+ scores_still_changing = 1;
+ }
}
}
}
-/* Return char of direction ("N", "E", "S" or "W") of enemy with the shortest
- * path to "mo_target". If no enemy is around, return 0.
- */
-static char get_dir_to_nearest_enemy(struct MapObj * mo_target)
+static char get_dir_to_nearest_enemy(struct MapObj * mo_origin)
{
+ char * f_name = "get_dir_to_nearest_enemy()";
+
/* Calculate for each cell the distance to the nearest map actor that is
- * not "mo_target", with movement only possible in the directions of "dir".
- * (Actor's own cells start with a distance of 0 towards themselves.)
+ * not "mo_origin", with movement only possible in the directions of "dir".
+ * (Actors' own cells start with a distance of 0 towards themselves.)
*/
- uint8_t max_score = UINT8_MAX; /* Score for cells treated as unreachable. */
- char * dirs = "NESW";
- uint8_t score_map[world.map.size.y * world.map.size.x];
- memset(score_map, max_score, world.map.size.y * world.map.size.x);
+ uint32_t map_size = world.map.size.y * world.map.size.x;
+ uint16_t max_score = UINT16_MAX;
+ uint16_t * score_map = try_malloc(map_size * sizeof(uint16_t), f_name);
+ uint32_t i;
+ for (i = 0; i < map_size; i++)
+ {
+ score_map[i] = max_score;
+ }
struct MapObj * mo = world.map_objs;
for (; mo != NULL; mo = mo->next)
{
- if (!mo->lifepoints || mo == mo_target)
+ if (!mo->lifepoints || mo == mo_origin)
{
continue;
}
score_map[(mo->pos.y * world.map.size.x) + mo->pos.x] = 0;
}
- dijkstra_map(dirs, score_map, max_score);
-
- /* Return direction of "mo_target"'s lowest-scored neighbor cell. */
- uint8_t len_dirs = strlen(dirs);
- uint32_t pos_i = (mo_target->pos.y * world.map.size.x) + mo_target->pos.x;
- uint8_t neighbor_scores[len_dirs];
- get_neighbor_scores(dirs, len_dirs, score_map, mo_target->pos, pos_i,
- max_score, neighbor_scores);
+ dijkstra_map(score_map, max_score);
+
+ /* Return direction of "mo_origin"'s lowest-scored neighbor cell. */
+ uint16_t neighbors[N_DIRS];
+ uint16_t pos_i = (mo_origin->pos.y * world.map.size.x) + mo_origin->pos.x;
+ get_neighbor_scores(score_map, pos_i, max_score, neighbors);
+ free(score_map);
char dir_to_nearest_enemy = 0;
- uint8_t min_neighbor_score = max_score;
- uint8_t i_dirs;
- for (i_dirs = 0; i_dirs < len_dirs; i_dirs++)
+ uint16_t min_neighbor = max_score;
+ char * dirs = "edcxsw"; /* get_neighbor_scores()'s clockwise dir order.*/
+ for (i = 0; i < N_DIRS; i++)
{
- if (min_neighbor_score > neighbor_scores[i_dirs])
+ if (min_neighbor > neighbors[i])
{
- min_neighbor_score = neighbor_scores[i_dirs];
- dir_to_nearest_enemy = dirs[i_dirs];
+ min_neighbor = neighbors[i];
+ dir_to_nearest_enemy = dirs[i];
}
}
return dir_to_nearest_enemy;
projects / plomrogue / blobdiff