+++ /dev/null
-/* src/server/field_of_view.c
- *
- * This file is part of PlomRogue. PlomRogue is licensed under the GPL version 3
- * or any later version. For details on its copyright, license, and warranties,
- * see the file NOTICE in the root directory of the PlomRogue source package.
- */
-
-#include "field_of_view.h"
-#include <math.h> /* pow() */
-#include <stddef.h> /* NULL */
-#include <stdint.h> /* uint8_t, uint16_t, uint32_t, int32_t, UINT8_MAX */
-#include <stdlib.h> /* free() */
-#include <string.h> /* memset() */
-#include "../common/rexit.h" /* exit_trouble() */
-#include "../common/try_malloc.h" /* try_malloc() */
-#include "../common/yx_uint8.h" /* yx_uint8 */
-#include "map.h" /* mv_yx_in_dir_legal(), init_empty_map() */
-#include "rrand.h" /* rrand() */
-#include "things.h" /* Thing, ThingInMemory, add_thing_to_memory_map() */
-#include "world.h" /* world */
-
-
-
-/* Number of degrees a circle is divided into. The greater it is, the greater
- * the angle precision. But make it one whole zero larger and bizarre FOV bugs
- * appear on large maps, probably due to value overflows (TODO: more research!).
- */
-#define CIRCLE 3600000
-
-
-
-/* Angle of a shadow. */
-struct shadow_angle
-{
- struct shadow_angle * next;
- uint32_t left_angle;
- uint32_t right_angle;
-};
-
-
-
-/* Recalculate angle < 0 or > CIRCLE to a value between these two limits. */
-static uint32_t correct_angle(int32_t angle);
-
-/* Try merging the angle between "left_angle" and "right_angle" to "shadow" if
- * it meets the shadow from the right or the left. Returns 1 on success, else 0.
- */
-static uint8_t try_merge(struct shadow_angle * shadow,
- uint32_t left_angle, uint32_t right_angle);
-
-/* Try merging the shadow angle between "left_angle" and "right_angle" into an
- * existing shadow angle in "shadows". On success, see if this leads to any
- * additional shadow angle overlaps and merge these accordingly. Return 1 on
- * success, else 0.
- */
-static uint8_t try_merging_angles(uint32_t left_angle, uint32_t right_angle,
- struct shadow_angle ** shadows);
-
-/* Test whether angle between "left_angle" and "right_angle", or at least
- * "middle_angle", is captured inside one of the shadow angles in "shadows". If
- * so, set hex in "fov_map" indexed by "pos_in_map" to 'H'. If the whole angle
- * and not just "middle_angle" is captured, return 1. Any other case: 0.
- */
-static uint8_t shade_hex(uint32_t left_angle, uint32_t right_angle,
- uint32_t middle_angle, struct shadow_angle ** shadows,
- uint16_t pos_in_map, char * fov_map);
-
-/* To "shadows", add shadow defined by "left_angle" and "right_angle", either as
- * new entry or as part of an existing shadow (swallowed whole or extending it).
- */
-static void set_shadow(uint32_t left_angle, uint32_t right_angle,
- struct shadow_angle ** shadows);
-
-/* Free shadow angles list "angles". */
-static void free_angles(struct shadow_angle * angles);
-
-/* Evaluate map position "test_pos" in distance "dist" to the view origin, and
- * on the circle of that distance to the origin on hex "hex_i" (as counted from
- * the circle's rightmost point), for setting shaded hexes in "fov_map" and
- * potentially adding a new shadow to linked shadow angle list "shadows".
- */
-static void eval_position(uint16_t dist, uint16_t hex_i, char * fov_map,
- struct yx_uint8 * test_pos,
- struct shadow_angle ** shadows);
-
-/* Update "t_eye"'s things-on-map memory by removing from its .t_mem all
- * memorized thing in FOV, and adding inanimate things in FOV to it.
- */
-static void add_things_to_map_memory(struct Thing * t_eye);
-
-
-
-static uint32_t correct_angle(int32_t angle)
-{
- while (angle < 0)
- {
- angle = angle + CIRCLE;
- }
- while (angle > CIRCLE)
- {
- angle = angle - CIRCLE;
- }
- return angle;
-}
-
-
-
-static uint8_t try_merge(struct shadow_angle * shadow,
- uint32_t left_angle, uint32_t right_angle)
-{
- if ( shadow->right_angle <= left_angle + 1
- && shadow->right_angle >= right_angle)
- {
- shadow->right_angle = right_angle;
- }
- else if ( shadow->left_angle + 1 >= right_angle
- && shadow->left_angle <= left_angle)
- {
- shadow->left_angle = left_angle;
- }
- else
- {
- return 0;
- }
- return 1;
-}
-
-
-
-static uint8_t try_merging_angles(uint32_t left_angle, uint32_t right_angle,
- struct shadow_angle ** shadows)
-{
- uint8_t angle_merge = 0;
- struct shadow_angle * shadow;
- for (shadow = *shadows; shadow; shadow = shadow->next)
- {
- if (try_merge(shadow, left_angle, right_angle))
- {
- angle_merge = 1;
- }
- }
- if (angle_merge)
- {
- struct shadow_angle * shadow1;
- for (shadow1 = *shadows; shadow1; shadow1 = shadow1->next)
- {
- struct shadow_angle * last_shadow = NULL;
- struct shadow_angle * shadow2;
- for (shadow2 = *shadows; shadow2; shadow2 = shadow2->next)
- {
- if ( shadow1 != shadow2
- && try_merge(shadow1, shadow2->left_angle,
- shadow2->right_angle))
- {
- struct shadow_angle * to_free = shadow2;
- if (last_shadow)
- {
- last_shadow->next = shadow2->next;
- shadow2 = last_shadow;
- }
- else
- {
- *shadows = shadow2->next;
- shadow2 = *shadows;
- }
- free(to_free);
- }
- last_shadow = shadow2;
- }
- }
- }
- return angle_merge;
-}
-
-
-
-static uint8_t shade_hex(uint32_t left_angle, uint32_t right_angle,
- uint32_t middle_angle, struct shadow_angle ** shadows,
- uint16_t pos_in_map, char * fov_map)
-{
- struct shadow_angle * shadow_i;
- if (fov_map[pos_in_map] == 'v')
- {
- for (shadow_i = *shadows; shadow_i; shadow_i = shadow_i->next)
- {
- if ( left_angle <= shadow_i->left_angle
- && right_angle >= shadow_i->right_angle)
- {
- fov_map[pos_in_map] = 'H';
- return 1;
- }
- if ( middle_angle < shadow_i->left_angle
- && middle_angle > shadow_i->right_angle)
- {
- fov_map[pos_in_map] = 'H';
- }
- }
- }
- return 0;
-}
-
-
-
-static void set_shadow(uint32_t left_angle, uint32_t right_angle,
- struct shadow_angle ** shadows)
-{
- struct shadow_angle * shadow_i;
- if (!try_merging_angles(left_angle, right_angle, shadows))
- {
- struct shadow_angle * shadow;
- shadow = try_malloc(sizeof(struct shadow_angle), __func__);
- shadow->left_angle = left_angle;
- shadow->right_angle = right_angle;
- shadow->next = NULL;
- if (*shadows)
- {
- for (shadow_i = *shadows; shadow_i; shadow_i = shadow_i->next)
- {
- if (!shadow_i->next)
- {
- shadow_i->next = shadow;
- return;
- }
- }
- }
- *shadows = shadow;
- }
-}
-
-
-
-static void free_angles(struct shadow_angle * angles)
-{
- if (angles->next)
- {
- free_angles(angles->next);
- }
- free(angles);
-}
-
-
-
-static void eval_position(uint16_t dist, uint16_t hex_i, char * fov_map,
- struct yx_uint8 * test_pos,
- struct shadow_angle ** shadows)
-{
- int32_t left_angle_uncorrected = ((CIRCLE / 12) / dist)
- - (hex_i * (CIRCLE / 6) / dist);
- int32_t right_angle_uncorrected = left_angle_uncorrected
- - (CIRCLE / (6 * dist));
- uint32_t left_angle = correct_angle(left_angle_uncorrected);
- uint32_t right_angle = correct_angle(right_angle_uncorrected);
- uint32_t right_angle_1st = right_angle > left_angle ? 0 : right_angle;
- uint32_t middle_angle = 0;
- if (right_angle_1st)
- {
- middle_angle = right_angle + ((left_angle - right_angle) / 2);
- }
- uint16_t pos_in_map = test_pos->y * world.map.length + test_pos->x;
- uint8_t all_shaded = shade_hex(left_angle, right_angle_1st, middle_angle,
- shadows, pos_in_map, fov_map);
- if (!all_shaded && 'X' == world.map.cells[pos_in_map])
- {
- set_shadow(left_angle, right_angle_1st, shadows);
- if (right_angle_1st != right_angle)
- {
- left_angle = CIRCLE;
- set_shadow(left_angle, right_angle, shadows);
- }
- }
-}
-
-
-
-static void add_things_to_map_memory(struct Thing * t_eye)
-{
- struct ThingInMemory * tm = t_eye->t_mem;
- struct ThingInMemory * tm_prev = NULL;
- struct ThingInMemory * tm_next = NULL;
- for (; tm; tm = tm_next)
- {
- tm_next = tm->next;
- if ('v' == t_eye->fov_map[tm->pos.y * world.map.length + tm->pos.x])
- {
- if (tm_prev)
- {
- tm_prev->next = tm->next;
- }
- else
- {
- t_eye->t_mem = tm->next;
- }
- free(tm);
- continue;
- }
- tm_prev = tm;
- }
- struct Thing * t = world.things;
- for (; t; t = t->next)
- {
- if ( !t->lifepoints
- && 'v' == t_eye->fov_map[t->pos.y * world.map.length + t->pos.x])
- {
- add_thing_to_memory_map(t_eye, t->type, t->pos.y, t->pos.x);
- }
- }
-}
-
-
-
-extern void update_map_memory(struct Thing * t_eye, uint8_t age_map)
-{
- if (!t_eye->mem_map)
- {
- init_empty_map(&(t_eye->mem_map));
- }
- if (!t_eye->mem_depth_map)
- {
- init_empty_map(&(t_eye->mem_depth_map));
- }
- uint32_t i;
- for (i = 0; i < (uint32_t) (world.map.length * world.map.length); i++)
- {
- if ('v' == t_eye->fov_map[i])
- {
- t_eye->mem_depth_map[i] = '0';
- if (' ' == t_eye->mem_map[i])
- {
- t_eye->mem_map[i] = world.map.cells[i];
- }
- continue;
- }
- if (age_map &&
- '0' <= t_eye->mem_depth_map[i] && '9' > t_eye->mem_depth_map[i]
- && !(rrand() % (uint16_t) pow(2, t_eye->mem_depth_map[i] - 48)))
- {
- t_eye->mem_depth_map[i]++;
- }
- }
- add_things_to_map_memory(t_eye);
-}
-
-
-
-extern void build_fov_map(struct Thing * t)
-{
- uint32_t map_size = world.map.length * world.map.length;
- t->fov_map = t->fov_map ? t->fov_map : try_malloc(map_size, __func__);
- memset(t->fov_map, 'v', map_size);
- struct shadow_angle * shadows = NULL;
- struct yx_uint8 test_pos = t->pos;
- char * circledirs_string = "xswedc";
- uint16_t circle_i;
- uint8_t circle_is_on_map;
- for (circle_i = 1, circle_is_on_map = 1; circle_is_on_map; circle_i++)
- {
- circle_is_on_map = 0;
- if (1 < circle_i) /* All circles but the 1st are */
- { /* moved into starting from a */
- mv_yx_in_dir_legal('c', &test_pos);/* previous circle's last hex, */
- } /* i.e. from the upper left. */
- char dir_char = 'd'; /* Circle's 1st hex is entered by rightward move.*/
- uint8_t dir_char_pos_in_circledirs_string = UINT8_MAX;
- uint16_t dist_i, hex_i;
- for (hex_i=0, dist_i=circle_i; hex_i < 6 * circle_i; dist_i++, hex_i++)
- {
- if (circle_i < dist_i)
- {
- dist_i = 1;
- dir_char=circledirs_string[++dir_char_pos_in_circledirs_string];
- }
- if (mv_yx_in_dir_legal(dir_char, &test_pos))
- {
- eval_position(circle_i, hex_i, t->fov_map, &test_pos, &shadows);
- circle_is_on_map = 1;
- }
- }
- }
- mv_yx_in_dir_legal(0, NULL);
- free_angles(shadows);
-}
projects / plomrogue / blobdiff