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Diffstat (limited to 'misc/examples/astar.c')
| -rw-r--r-- | misc/examples/astar.c | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/misc/examples/astar.c b/misc/examples/astar.c deleted file mode 100644 index 7dd12d50..00000000 --- a/misc/examples/astar.c +++ /dev/null @@ -1,173 +0,0 @@ -// -// -- An A* pathfinder inspired by the excellent tutorial at Red Blob Games -- -// -// This is a reimplementation of the CTL example to STC: -// https://github.com/glouw/ctl/blob/master/examples/astar.c -// https://www.redblobgames.com/pathfinding/a-star/introduction.html -#include <stc/cstr.h> -#include <stdio.h> - -typedef struct -{ - int x; - int y; - int priorty; - int width; -} -point; - -point -point_init(int x, int y, int width) -{ - return (point) { x, y, 0, width }; -} - -int -point_cmp_priority(const point* a, const point* b) -{ - return c_default_cmp(&a->priorty, &b->priorty); -} - -int -point_equal(const point* a, const point* b) -{ - return a->x == b->x && a->y == b->y; -} - -point -point_from(const cstr* maze, const char* c, int width) -{ - int index = (int)cstr_find(maze, c); - return point_init(index % width, index / width, width); -} - -int -point_index(const point* p) -{ - return p->x + p->width * p->y; -} - -int -point_key_cmp(const point* a, const point* b) -{ - int i = point_index(a); - int j = point_index(b); - return (i == j) ? 0 : (i < j) ? -1 : 1; -} - -#define i_val point -#define i_cmp point_cmp_priority -#include <stc/cpque.h> - -#define i_val point -#define i_opt c_no_cmp -#include <stc/cdeq.h> - -#define i_key point -#define i_val int -#define i_cmp point_key_cmp -#define i_tag pcost -#include <stc/csmap.h> - -#define i_key point -#define i_val point -#define i_cmp point_key_cmp -#define i_tag pstep -#include <stc/csmap.h> - -cdeq_point -astar(cstr* maze, int width) -{ - cdeq_point ret_path = {0}; - - cpque_point front = {0}; - csmap_pstep from = {0}; - csmap_pcost costs = {0}; - c_defer( - cpque_point_drop(&front), - csmap_pstep_drop(&from), - csmap_pcost_drop(&costs) - ){ - point start = point_from(maze, "@", width); - point goal = point_from(maze, "!", width); - csmap_pcost_insert(&costs, start, 0); - cpque_point_push(&front, start); - while (!cpque_point_empty(&front)) - { - point current = *cpque_point_top(&front); - cpque_point_pop(&front); - if (point_equal(¤t, &goal)) - break; - point deltas[] = { - { -1, +1, 0, width }, { 0, +1, 0, width }, { 1, +1, 0, width }, - { -1, 0, 0, width }, /* ~ ~ ~ ~ ~ ~ ~ */ { 1, 0, 0, width }, - { -1, -1, 0, width }, { 0, -1, 0, width }, { 1, -1, 0, width }, - }; - for (size_t i = 0; i < c_arraylen(deltas); i++) - { - point delta = deltas[i]; - point next = point_init(current.x + delta.x, current.y + delta.y, width); - int new_cost = *csmap_pcost_at(&costs, current); - if (cstr_str(maze)[point_index(&next)] != '#') - { - const csmap_pcost_value *cost = csmap_pcost_get(&costs, next); - if (cost == NULL || new_cost < cost->second) - { - csmap_pcost_insert(&costs, next, new_cost); - next.priorty = new_cost + abs(goal.x - next.x) + abs(goal.y - next.y); - cpque_point_push(&front, next); - csmap_pstep_insert(&from, next, current); - } - } - } - } - point current = goal; - while (!point_equal(¤t, &start)) - { - cdeq_point_push_front(&ret_path, current); - current = *csmap_pstep_at(&from, current); - } - cdeq_point_push_front(&ret_path, start); - } - return ret_path; -} - -int -main(void) -{ - cstr maze = cstr_lit( - "#########################################################################\n" - "# # # # # # #\n" - "# # ######### # ##### ######### ##### ##### ##### # ! #\n" - "# # # # # # # # # #\n" - "######### # ######### ######### ##### # # # ######### #\n" - "# # # # # # # # # # #\n" - "# # ############# # # ######### ##### # ######### # #\n" - "# # # # # # # # # #\n" - "# ############# ##### ##### # ##### ######### # ##### #\n" - "# # # # # # # # # #\n" - "# ##### ##### # ##### # ######### # # # #############\n" - "# # # # # # # # # # # #\n" - "############# # # # ######### # ##### # ##### ##### #\n" - "# # # # # # # # # #\n" - "# ##### # ######### ##### # ##### ##### ############# #\n" - "# # # # # # # # # #\n" - "# # ######### # ##### ######### # # ############# # #\n" - "# # # # # # # # # # #\n" - "# ######### # # # ##### ######### ######### # #########\n" - "# # # # # # # # # #\n" - "# @ # ##### ##### ##### ######### ##### # ######### # #\n" - "# # # # # # #\n" - "#########################################################################\n" - ); - int width = (int)cstr_find(&maze, "\n") + 1; - cdeq_point ret_path = astar(&maze, width); - - c_foreach (it, cdeq_point, ret_path) - cstr_data(&maze)[point_index(it.ref)] = 'x'; - - printf("%s", cstr_str(&maze)); - - cdeq_point_drop(&ret_path); - cstr_drop(&maze); -} |