4 #include <stddef.h> /* NULL */
5 #include <stdint.h> /* uint8_t, uint16_t, uint32_t, int16_t, UINT16_MAX */
6 #include <stdlib.h> /* free() */
7 #include "../common/try_malloc.h" /* try_malloc() */
8 #include "hardcoded_strings.h" /* s */
9 #include "thing_actions.h" /* get_thing_action_id_by_name() */
10 #include "things.h" /* Thing, ThingType */
11 #include "world.h" /* world */
19 /* Write into "neighbors" scores of the N_DIRS immediate neighbors of the
20 * "score_map" cell at "pos_i" (array index), as found in the directions
21 * north-east, east, south-east etc. (clockwise order). Use "max_score" for
22 * illegal neighborhoods (i.e. if direction would lead beyond the map's border).
24 static void get_neighbor_scores(uint16_t * score_map, uint16_t pos_i,
25 uint16_t max_score, uint16_t * neighbors);
27 /* Iterate over scored cells in "score_map" of world.map's geometry. Compare
28 * each cell's score against the score of its immediate neighbors in N_DIRS
29 * directions. If any neighbor's score is at least two points lower than the
30 * current cell's score, re-set it to 1 point higher than its lowest-scored
31 * neighbor. Repeat this whole process until all cells have settled on their
32 * final score. Ignore cells whose score is greater than "max_score". Expect
33 * "max_score" to be the maximum score for cells, marking them as unreachable.
35 static void dijkstra_map(uint16_t * score_map, uint16_t max_score);
37 /* Return numpad char of direction ("8", "6", "2", "4" etc.) of enemy with the
38 * shortest path visible to "t_origin". If no enemy is around, return 0.
40 static char get_dir_to_nearest_enemy(struct Thing * thing_origin);
42 /* Return 1 if any animate thing not "t_origin" is in its FOV, else 0. */
43 static uint8_t seeing_enemies(struct Thing * t_origin);
45 /* Return slot ID of strongest consumable in "t_owner"'s inventory, else -1. */
46 static int16_t get_inventory_slot_to_consume(struct Thing * t_owner);
50 static void get_neighbor_scores(uint16_t * score_map, uint16_t pos_i,
51 uint16_t max_score, uint16_t * neighbors)
53 uint32_t map_size = world.map.length * world.map.length;
55 for (i_dir = 0; i_dir < N_DIRS; neighbors[i_dir] = max_score, i_dir++);
56 uint8_t open_north = pos_i >= world.map.length;
57 uint8_t open_east = pos_i + 1 % world.map.length;
58 uint8_t open_south = pos_i + world.map.length < map_size;
59 uint8_t open_west = pos_i % world.map.length;
60 uint8_t is_indented = (pos_i / world.map.length) % 2;
61 uint8_t open_diag_west = is_indented || open_west;
62 uint8_t open_diag_east = !is_indented || open_east;
63 if (open_north && open_diag_east)
65 neighbors[0] = score_map[pos_i - world.map.length + is_indented];
69 neighbors[1] = score_map[pos_i + 1];
71 if (open_south && open_diag_east)
73 neighbors[2] = score_map[pos_i + world.map.length + is_indented];
75 if (open_south && open_diag_west)
77 neighbors[3] = score_map[pos_i + world.map.length - !is_indented];
81 neighbors[4] = score_map[pos_i - 1];
83 if (open_north && open_diag_west)
85 neighbors[5] = score_map[pos_i - world.map.length - !is_indented];
91 static void dijkstra_map(uint16_t * score_map, uint16_t max_score)
93 uint32_t map_size = world.map.length * world.map.length;
95 uint16_t i_scans, neighbors[N_DIRS], min_neighbor;
96 uint8_t scores_still_changing = 1;
98 for (i_scans = 0; scores_still_changing; i_scans++)
100 scores_still_changing = 0;
101 for (pos = 0; pos < map_size; pos++)
103 if (score_map[pos] <= max_score)
105 get_neighbor_scores(score_map, pos, max_score, neighbors);
106 min_neighbor = max_score;
107 for (i_dirs = 0; i_dirs < N_DIRS; i_dirs++)
109 if (min_neighbor > neighbors[i_dirs])
111 min_neighbor = neighbors[i_dirs];
114 if (score_map[pos] > min_neighbor + 1)
116 score_map[pos] = min_neighbor + 1;
117 scores_still_changing = 1;
126 static char get_dir_to_nearest_enemy(struct Thing * t_origin)
128 /* Calculate for each cell distance to visibly nearest enemy, with movement
129 * possible in the directions or "dir". (Actor's own cells start with 0
130 * distance towards themselves. Cells of actors of own type are invisible.)
132 uint32_t map_size = world.map.length * world.map.length;
133 uint16_t max_score = UINT16_MAX - 1;
134 uint16_t * score_map = try_malloc(map_size * sizeof(uint16_t), __func__);
136 for (i = 0; i < map_size; i++)
138 score_map[i] = UINT16_MAX;
139 if ('.' == t_origin->mem_map[i])
141 score_map[i] = max_score;
144 struct Thing * t = world.things;
145 for (; t != NULL; t = t->next)
147 if ( !t->lifepoints || t == t_origin
148 || 'H' == t_origin->fov_map[t->pos.y * world.map.length + t->pos.x])
152 if (t->lifepoints && t->type == t_origin->type)
154 score_map[t->pos.y * world.map.length + t->pos.x] = UINT16_MAX;
157 score_map[t->pos.y * world.map.length + t->pos.x] = 0;
159 dijkstra_map(score_map, max_score);
161 /* Return direction of "t_origin"'s lowest-scored neighbor cell. */
162 uint16_t neighbors[N_DIRS];
163 uint16_t pos_i = (t_origin->pos.y * world.map.length) + t_origin->pos.x;
164 get_neighbor_scores(score_map, pos_i, max_score, neighbors);
166 char dir_to_nearest_enemy = 0;
167 uint16_t min_neighbor = max_score;
168 char * dirs = "edcxsw"; /* get_neighbor_scores()'s clockwise dir order.*/
169 for (i = 0; i < N_DIRS; i++)
171 if (min_neighbor > neighbors[i])
173 min_neighbor = neighbors[i];
174 dir_to_nearest_enemy = dirs[i];
177 return dir_to_nearest_enemy;
182 static uint8_t seeing_enemies(struct Thing * t_origin)
184 struct Thing * t = world.things;
185 for (; t != NULL; t = t->next)
189 && 'v' == t_origin->fov_map[t->pos.y * world.map.length + t->pos.x])
199 static int16_t get_inventory_slot_to_consume(struct Thing * t_owner)
201 uint8_t compare_consumability = 0;
202 int16_t selection = -1;
203 struct Thing * t = t_owner->owns;;
205 for (i = 0; t != NULL; t = t->next, i++)
207 struct ThingType * tt = get_thing_type(t->type);
208 if (tt->consumable > compare_consumability)
210 compare_consumability = tt->consumable;
219 extern void ai(struct Thing * t)
221 t->command = get_thing_action_id_by_name(s[S_CMD_WAIT]);
222 if (seeing_enemies(t))
224 char sel = t->fov_map ? get_dir_to_nearest_enemy(t) : 0;
227 t->command = get_thing_action_id_by_name(s[S_CMD_MOVE]);
233 int16_t sel = get_inventory_slot_to_consume(t);
236 t->command = get_thing_action_id_by_name(s[S_CMD_USE]);
237 t->arg = (uint8_t) sel;