--- /dev/null
+/* src/server/field_of_view.c */
+
+#define _POSIX_C_SOURCE 200809L /* strdup() */
+#include "field_of_view.h"
+#include <stdlib.h> /* free() */
+#include <stdint.h> /* uint8_t, uint16_t, uint32_t */
+#include <string.h> /* memset(), strchr(), strdup() */
+#include "../common/rexit.h" /* exit_trouble() */
+#include "../common/try_malloc.h" /* try_malloc() */
+#include "map_objects.h" /* MapObj, MapObjDef, get_player() */
+#include "yx_uint8.h" /* yx_uint8 */
+#include "world.h" /* global world */
+
+
+
+/* States that cells in the fov map may be in. */
+enum fov_cell_states {
+ VISIBLE = 0x01,
+ HIDDEN = 0x02,
+ SHADOW_LEFT = 0x04,
+ SHADOW_RIGHT = 0x08,
+ LIMIT = 0x10,
+ HIDE_LATER = 0x20
+};
+
+/* Values for mv_yx_in_dir_wrap()'s wrapping directory memory. */
+enum wraps
+{
+ WRAP_N = 0x01,
+ WRAP_S = 0x02,
+ WRAP_E = 0x04,
+ WRAP_W = 0x08
+};
+
+/* Transform "yx" to an index position in the world map. */
+static uint16_t yx_to_pos(struct yx_uint8 * yx);
+
+/* Move "yx" into hex direction "d". If this moves "yx" beyond the minimal (0)
+ * or maximal (UINT8_MAX) column or row, it wraps to the opposite side. Such
+ * wrapping is returned as a wraps enum value and stored, so that further calls
+ * to move "yx" back into the opposite direction may unwrap it again. Pass an
+ * "unwrap" of UNWRAP to re-set the internal wrap memory to 0.
+ */
+static uint8_t mv_yx_in_dir_wrap(char d, struct yx_uint8 * yx, uint8_t unwrap);
+
+/* Wrapper to "mv_yx_in_dir_wrap()", returns 1 if the wrapped function moved
+ * "yx" within the wrap borders and the map size, else 0.
+ */
+extern uint8_t mv_yx_in_dir_legal(char dir, struct yx_uint8 * yx);
+
+/* Return one by one hex dir characters of walking through a circle of "radius".
+ * The circle is initialized by passing a "new_circle" of 1 and the "radius"
+ * and only returns non-null hex direction characters if "new_circle" is 0.
+ */
+static char next_circle_dir(uint8_t new_circle, uint8_t radius_new);
+
+/* Draw circle of hexes flagged LIMIT "radius" away from "yx" to "fov_map". */
+extern void draw_border_circle(struct yx_uint8 yx, uint8_t radius,
+ uint8_t * fov_map);
+
+/* eye_to_cell_dir_ratio() helper. */
+static void geometry_to_char_ratio(uint8_t * n1, uint8_t * n2, uint8_t indent,
+ int16_t diff_y, int16_t diff_x,
+ uint8_t vertical, uint8_t variant);
+
+/* From the chars in "available_dirs" and the geometry described by the other
+ * parameters return a string of hex direction characters representing the
+ * approximation of a straight line. "variant" marks the direction as either in
+ * the northern, north-eastern or south-western hex neighborhood if 1, or the
+ * others if 0.
+ */
+static char * eye_to_cell_dir_ratio(char * available_dirs, uint8_t indent,
+ int16_t diff_y, int16_t diff_x,
+ uint8_t vertical, uint8_t variant,
+ uint8_t shift_right);
+
+/* Return string approximating in one or two hex direction chars the direction
+ * that a "diff_y" and "diff_x" lead to in the internal half-indented 2D
+ * encoding of hexagonal maps, with "indent" the movement's start indentation.
+ */
+static char * dir_from_delta(uint8_t indent, int16_t diff_y, int16_t diff_x);
+
+/* Return string of hex movement direction characters describing the best
+ * possible hex approximation to a straight line from "yx_eye" to "yx_cell". If
+ * "right" is set and the string is of length two, return it with the direction
+ * strings scarcer character appearing first.
+ */
+static char * eye_to_cell(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_cell,
+ uint8_t right);
+
+/* Return string of hex movement direction characters describing the best
+ * possible hex approximation to a straight line from "yx_eye" to "yx_cell". If
+ * "right" is set and the string is of length two, return it with the direction
+ * strings scarcer character appearing first.
+ */
+static char * eye_to_cell(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_cell,
+ uint8_t right);
+
+/* fill_shadow() helper, determining if map's top left cell starts a shadow. */
+static uint8_t is_top_left_shaded(uint16_t pos_a, uint16_t pos_b,
+ int16_t a_y_on_left);
+
+/* Flag as HIDDEN all cells in "fov_map" that are enclosed by 1) the map's
+ * borders or cells flagged LIMIT and 2) the shadow arms of cells flagged
+ * SHADOW_LEFT and SHADOW_RIGHT extending from "yx_cell", as seen as left and
+ * right as seen from "yx_eye". "pos_a" and "pos_b" store the terminal positions
+ * of these arms in "fov_map" ("pos_a" for the left, "pos_b" for the right one).
+ */
+static void fill_shadow(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_cell,
+ uint8_t * fov_map, uint16_t pos_a, uint16_t pos_b);
+
+/* Flag with "flag" cells of a path from "yx_start" to the end of the map or (if
+ * closer) the view border circle of the cells flagged as LIMIT, in a direction
+ * parallel to the one determined by walking a path from "yx_eye" to the cell
+ * reachable by moving one step into "dir" from "yx_start". If "shift_right" is
+ * set, choose among the possible paths the one whose starting cell is set most
+ * to the right, else do the opposite.
+ */
+static uint16_t shadow_arm(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_start,
+ uint8_t * fov_map, char dir, uint8_t flag,
+ uint8_t shift_right);
+
+/* From "yx_start", draw shadow of what is invisible as seen from "yx_eye" into
+ * "fov_map" by extending shadow arms from "yx_start" as shadow borders until
+ * the edges of the map or, if smaller, the maximum viewing distance, flag these
+ * shadow arms' cells as HIDE_LATER and the area enclosed by them as HIDDEN.
+ * "dir_left" and "dir_right" are hex directions to move to from "yx_start" for
+ * cells whose shortest straight path to "yx_eye" serve as the lines of sight
+ * enclosing the shadow left and right (left and right as seen from "yx_eye").
+ */
+static void shadow(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_start,
+ uint8_t * fov_map, char dir_left, char dir_right);
+
+/* In "fov_map", if cell of position "yx_cell" is not HIDDEN, set it as VISIBLE,
+ * and if an obstacle to view is positioned there in the game map, flag cells
+ *behind it, unseen from "yx_eye", as HIDDEN on the interior and HIDE_LATER on
+ * their borders.
+ *
+ * The shape and width of shadows is determined by 1) calculating an approximate
+ * direction of "yx_cell" as seen from "yx_eye" as one hex movement direction,
+ * or two directly neighboring each other (i.e. "east", "east and north-east"),
+ * 2) deriving the two hex movement directions clockwise immediately preceding
+ * the first (or only) direction and immediately succeeding the second (or only)
+ * one and 3) passing the two directions thus gained as shadow arm direction
+ * calibration values to shadow() (after this function's other arguments).
+ */
+static void set_view_of_cell_and_shadows(struct yx_uint8 * yx_cell,
+ struct yx_uint8 * yx_eye,
+ uint8_t * fov_map);
+
+/* Return overlay of world map wherein all cell positions visible from player's
+ * positions have flag VISIBLE set.
+ *
+ * This is achieved by spiraling out clock-wise from the player position,
+ * flagging cells as VISIBLE unless they're already marked as HIDDEN, and, on
+ * running into obstacles for view that are not HIDDEN, casting shadows from
+ * these, i.e. drawing cells as HIDDEN that would be hidden by said obstacle,
+ * before continuing the original spiraling path.
+ *
+ * Shadowcasting during spiraling is initially lazy, flagging only the shadows'
+ * interior cells as HIDDEN and their border cells as HIDE_LATER. Only at the
+ * end are all cells flagged HIDE_LATER flagged as HIDDEN. This is to handle
+ * cases where obstacles to view sit right at the border of pre-estabilshed
+ * shadows, therefore might be ignored if HIDDEN and not cast shadows on their
+ * own that may slightly extend beyond the pre-established shadows they border.
+ */
+static uint8_t * build_fov_map();
+
+
+
+static uint16_t yx_to_pos(struct yx_uint8 * yx)
+{
+ return (yx->y * world.map.size.x) + yx->x;
+}
+
+
+
+static uint8_t mv_yx_in_dir_wrap(char d, struct yx_uint8 * yx, uint8_t unwrap)
+{
+ static uint8_t wrap = 0;
+ if (unwrap)
+ {
+ wrap = 0;
+ return 0;
+ }
+ struct yx_uint8 original;
+ original.y = yx->y;
+ original.x = yx->x;
+ if (d == 'e')
+ {
+ yx->x = yx->x + (yx->y % 2);
+ yx->y--;
+ }
+ else if (d == 'd')
+ {
+ yx->x++;
+ }
+ else if (d == 'c')
+ {
+ yx->x = yx->x + (yx->y % 2);
+ yx->y++;
+ }
+ else if (d == 'x')
+ {
+ yx->x = yx->x - !(yx->y % 2);
+ yx->y++;
+ }
+ else if (d == 's')
+ {
+ yx->x--;
+ }
+ else if (d == 'w')
+ {
+ yx->x = yx->x - !(yx->y % 2);
+ yx->y--;
+ }
+ else
+ {
+ exit_trouble(1, "mv_yx_in_dir_wrap()", "illegal direction");
+ }
+ if (strchr("edc", d) && yx->x < original.x)
+ {
+ wrap = wrap & WRAP_W ? wrap ^ WRAP_W : wrap | WRAP_E;
+ }
+ else if (strchr("xsw", d) && yx->x > original.x)
+ {
+ wrap = wrap & WRAP_E ? wrap ^ WRAP_E : wrap | WRAP_W;
+ }
+ if (strchr("we", d) && yx->y > original.y)
+ {
+ wrap = wrap & WRAP_S ? wrap ^ WRAP_S : wrap | WRAP_N;
+ }
+ else if (strchr("xc", d) && yx->y < original.y)
+ {
+ wrap = wrap & WRAP_N ? wrap ^ WRAP_N : wrap | WRAP_S;
+ }
+ return wrap;
+}
+
+
+
+extern uint8_t mv_yx_in_dir_legal(char dir, struct yx_uint8 * yx)
+{
+ uint8_t wraptest = mv_yx_in_dir_wrap(dir, yx, 0);
+ if (!wraptest && yx->x < world.map.size.x && yx->y < world.map.size.y)
+ {
+ return 1;
+ }
+ return 0;
+}
+
+
+
+static char next_circle_dir(uint8_t new_circle, uint8_t radius_new)
+{
+ static uint8_t i_dirs = 0;
+ static uint8_t i_dist = 0;
+ static uint8_t radius = 0;
+ char * dirs = "dcxswe";
+ if (new_circle)
+ {
+ i_dirs = 0;
+ i_dist = 0;
+ radius = radius_new;
+ return '\0';
+ }
+ char ret_dir = dirs[i_dirs];
+ i_dist++;
+ if (i_dist == radius)
+ {
+ i_dist = 0;
+ i_dirs++;
+ }
+ return ret_dir;
+}
+
+
+
+extern void draw_border_circle(struct yx_uint8 yx, uint8_t radius,
+ uint8_t * fov_map)
+{
+ uint8_t dist;
+ for (dist = 1; dist <= radius; dist++)
+ {
+ mv_yx_in_dir_wrap('w', &yx, 0);
+ }
+ next_circle_dir(1, radius);
+ char dir;
+ while ('\0' != (dir = next_circle_dir(0, 0)))
+ {
+ if (mv_yx_in_dir_legal(dir, &yx))
+ {
+ uint16_t pos = yx_to_pos(&yx);
+ fov_map[pos] = LIMIT;
+ }
+ }
+ mv_yx_in_dir_wrap(0, NULL, 1);
+}
+
+
+
+static void geometry_to_char_ratio(uint8_t * n1, uint8_t * n2, uint8_t indent,
+ int16_t diff_y, int16_t diff_x,
+ uint8_t vertical, uint8_t variant)
+{
+ if (vertical)
+ {
+ *n1 = (diff_y / 2) - diff_x + ( indent * (diff_y % 2));
+ *n2 = (diff_y / 2) + diff_x + (!indent * (diff_y % 2));
+ }
+ else if (!vertical)
+ {
+ *n1 = diff_y;
+ *n2 = diff_x - (diff_y / 2) - (indent * (diff_y % 2));
+ }
+ if (!variant)
+ {
+ uint8_t tmp = *n1;
+ *n1 = *n2;
+ *n2 = tmp;
+ }
+}
+
+
+
+static char * eye_to_cell_dir_ratio(char * available_dirs, uint8_t indent,
+ int16_t diff_y, int16_t diff_x,
+ uint8_t vertical, uint8_t variant,
+ uint8_t shift_right)
+{
+ char * f_name = "eye_to_cell_dir_ratio()";
+ uint8_t n1, n2;
+ geometry_to_char_ratio(&n1, &n2, indent, diff_y, diff_x, vertical, variant);
+ uint8_t size_chars = n1 + n2;
+ char * dirs = try_malloc(size_chars + 1, f_name);
+ uint8_t n_strong_char = n1 / n2;
+ uint8_t more_char1 = 0 < n_strong_char;
+ n_strong_char = !more_char1 ? (n2 / n1) : n_strong_char;
+ uint16_t i, i_alter;
+ uint8_t i_of_char = shift_right;
+ for (i = 0, i_alter = 0; i < size_chars; i++)
+ {
+ char dirchar = available_dirs[i_of_char];
+ if (more_char1 != i_of_char)
+ {
+ i_alter++;
+ if (i_alter == n_strong_char)
+ {
+ i_alter = 0;
+ i_of_char = !i_of_char;
+ }
+ }
+ else
+ {
+ i_of_char = !i_of_char;
+ }
+
+ dirs[i] = dirchar;
+ }
+ dirs[i] = '\0';
+ return dirs;
+}
+
+
+
+static char * dir_from_delta(uint8_t indent, int16_t diff_y, int16_t diff_x)
+{
+ int16_t double_x = 2 * diff_x;
+ int16_t indent_corrected_double_x_pos = double_x - indent + !indent;
+ int16_t indent_corrected_double_x_neg = -double_x - !indent + indent;
+ if (diff_y > 0)
+ {
+ if (diff_y == double_x || diff_y == indent_corrected_double_x_pos)
+ {
+ return "c";
+ }
+ if (diff_y == -double_x || diff_y == indent_corrected_double_x_neg)
+ {
+ return "x";
+ }
+ if (diff_y < double_x || diff_y < indent_corrected_double_x_pos)
+ {
+ return "dc";
+ }
+ if (diff_y < -double_x || diff_y < indent_corrected_double_x_neg)
+ {
+ return "xs";
+ }
+ return "cx";
+ }
+ if (diff_y < 0)
+ {
+ if (diff_y == double_x || diff_y == indent_corrected_double_x_pos)
+ {
+ return "w";
+ }
+ if (diff_y == -double_x || diff_y == indent_corrected_double_x_neg)
+ {
+ return "e";
+ }
+ if (diff_y > double_x || diff_y > indent_corrected_double_x_pos)
+ {
+ return "sw";
+ }
+ if (diff_y > -double_x || diff_y > indent_corrected_double_x_neg)
+ {
+ return "ed";
+ }
+ return "we";
+ }
+ return 0 > diff_x ? "s" : "d";
+}
+
+
+
+static char * eye_to_cell(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_cell,
+ uint8_t right)
+{
+ int16_t diff_y = yx_cell->y - yx_eye->y;
+ int16_t diff_x = yx_cell->x - yx_eye->x;
+ uint8_t indent = yx_eye->y % 2;
+ char * dir = dir_from_delta(indent, diff_y, diff_x);
+ char * dirs;
+ if (1 == strlen(dir))
+ {
+ return strdup(dir);
+ }
+ else if (!strcmp(dir, "dc"))
+ {
+ dirs = eye_to_cell_dir_ratio(dir, indent, diff_y, diff_x, 0,0,right);
+ }
+ else if (!strcmp(dir, "xs"))
+ {
+ dirs = eye_to_cell_dir_ratio(dir, !indent, diff_y, -diff_x, 0,1,right);
+ }
+ else if (!strcmp(dir, "cx"))
+ {
+ dirs = eye_to_cell_dir_ratio(dir, indent, diff_y, diff_x, 1,0,right);
+ }
+ else if (!strcmp(dir, "sw"))
+ {
+ dirs = eye_to_cell_dir_ratio(dir, !indent, -diff_y, -diff_x, 0,0,right);
+ }
+ else if (!strcmp(dir, "ed"))
+ {
+ dirs = eye_to_cell_dir_ratio(dir, indent, -diff_y, diff_x, 0,1,right);
+ }
+ else if (!strcmp(dir, "we"))
+ {
+ dirs = eye_to_cell_dir_ratio(dir, indent, -diff_y, diff_x, 1,1,right);
+ }
+ return dirs;
+}
+
+
+
+static uint8_t is_top_left_shaded(uint16_t pos_a, uint16_t pos_b,
+ int16_t a_y_on_left)
+{
+ uint16_t start_last_row = world.map.size.x * (world.map.size.y - 1);
+ uint8_t a_on_left_or_bottom = 0 <= a_y_on_left
+ || (pos_a >= start_last_row);
+ uint8_t b_on_top_or_right = pos_b < world.map.size.x
+ || pos_b % world.map.size.x==world.map.size.x-1;
+ return pos_a != pos_b && b_on_top_or_right && a_on_left_or_bottom;
+}
+
+
+
+static void fill_shadow(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_cell,
+ uint8_t * fov_map, uint16_t pos_a, uint16_t pos_b)
+{
+ int16_t a_y_on_left = !(pos_a%world.map.size.x)? pos_a/world.map.size.x :-1;
+ int16_t b_y_on_left = !(pos_b%world.map.size.x)? pos_b/world.map.size.x :-1;
+ uint8_t top_left_shaded = is_top_left_shaded(pos_a, pos_b, a_y_on_left);
+ uint16_t pos;
+ uint8_t y, x, in_shade;
+ for (y = 0; y < world.map.size.y; y++)
+ {
+ in_shade = (top_left_shaded || (b_y_on_left >= 0 && y > b_y_on_left))
+ && (a_y_on_left < 0 || y < a_y_on_left);
+ for (x = 0; x < world.map.size.x; x++)
+ {
+ pos = (y * world.map.size.x) + x;
+ if (yx_eye->y == yx_cell->y && yx_eye->x < yx_cell->x)
+ {
+ uint8_t val = fov_map[pos] & (SHADOW_LEFT | SHADOW_RIGHT);
+ in_shade = 0 < val ? 1 : in_shade;
+ }
+ else if (yx_eye->y == yx_cell->y && yx_eye->x > yx_cell->x)
+ {
+ uint8_t val = fov_map[pos] & (SHADOW_LEFT | SHADOW_RIGHT);
+ in_shade = 0 < val ? 0 : in_shade;
+ }
+ else if (yx_eye->y > yx_cell->y && y <= yx_cell->y)
+ {
+ in_shade = 0 < (fov_map[pos] & SHADOW_LEFT) ? 1 : in_shade;
+ in_shade = (fov_map[pos] & SHADOW_RIGHT) ? 0 : in_shade;
+ }
+ else if (yx_eye->y < yx_cell->y && y >= yx_cell->y)
+ {
+ in_shade = 0 < (fov_map[pos] & SHADOW_RIGHT) ? 1 : in_shade;
+ in_shade = (fov_map[pos] & SHADOW_LEFT) ? 0 : in_shade;
+ }
+ if (!(fov_map[pos] & (SHADOW_LEFT | SHADOW_RIGHT))
+ && in_shade)
+ {
+ fov_map[pos] = fov_map[pos] | HIDDEN;
+ }
+ }
+ }
+}
+
+
+
+static uint16_t shadow_arm(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_start,
+ uint8_t * fov_map, char dir, uint8_t flag,
+ uint8_t shift_right)
+{
+ struct yx_uint8 yx_border = *yx_start;
+ uint16_t pos;
+ if (mv_yx_in_dir_legal(dir, &yx_border))
+ {
+ uint8_t met_limit = 0;
+ uint8_t i_dirs = 0;
+ char * dirs = eye_to_cell(yx_eye, &yx_border, shift_right);
+ yx_border = *yx_start;
+ while (!met_limit && mv_yx_in_dir_legal(dirs[i_dirs], &yx_border))
+ {
+ pos = yx_to_pos(&yx_border);
+ met_limit = fov_map[pos] & LIMIT;
+ fov_map[pos] = fov_map[pos] | flag;
+ i_dirs = dirs[i_dirs + 1] ? i_dirs + 1 : 0;
+ }
+ free(dirs);
+ }
+ mv_yx_in_dir_wrap(0, NULL, 1);
+ return pos;
+}
+
+
+
+static void shadow(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_start,
+ uint8_t * fov_map, char dir_left, char dir_right)
+{
+ uint16_t pos_a, pos_b, pos_start, i;
+ pos_a = shadow_arm(yx_eye, yx_start, fov_map, dir_left, SHADOW_LEFT, 0);
+ pos_b = shadow_arm(yx_eye, yx_start, fov_map, dir_right, SHADOW_RIGHT, 1);
+ pos_start = yx_to_pos(yx_start);
+ fov_map[pos_start] = fov_map[pos_start] | SHADOW_LEFT | SHADOW_RIGHT;
+ fill_shadow(yx_eye, yx_start, fov_map, pos_a, pos_b);
+ for (i = 0; i < world.map.size.y * world.map.size.x; i++)
+ {
+ if (fov_map[i] & (SHADOW_LEFT | SHADOW_RIGHT) && i != pos_start)
+ {
+ fov_map[i] = fov_map[i] | HIDE_LATER;
+ }
+ fov_map[i] = fov_map[i] ^ (fov_map[i] & SHADOW_LEFT);
+ fov_map[i] = fov_map[i] ^ (fov_map[i] & SHADOW_RIGHT);
+ }
+ return;
+}
+
+
+
+static void set_view_of_cell_and_shadows(struct yx_uint8 * yx_cell,
+ struct yx_uint8 * yx_eye,
+ uint8_t * fov_map)
+{
+ char * dirs = "dcxswe";
+ uint16_t pos = yx_to_pos(yx_cell);
+ if (!(fov_map[pos] & HIDDEN))
+ {
+ fov_map[pos] = fov_map[pos] | VISIBLE;
+ if ('X' == world.map.cells[pos])
+ {
+ uint8_t last_pos = strlen(dirs) - 1;
+ int16_t diff_y = yx_cell->y - yx_eye->y;
+ int16_t diff_x = yx_cell->x - yx_eye->x;
+ uint8_t indent = yx_eye->y % 2;
+ char * dir = dir_from_delta(indent, diff_y, diff_x);
+ uint8_t start_pos = strchr(dirs, dir[0]) - dirs;
+ char prev = start_pos > 0 ? dirs[start_pos - 1] : dirs[last_pos];
+ char next = start_pos < last_pos ? dirs[start_pos + 1] : dirs[0];
+ if (dir[1])
+ {
+ uint8_t end_pos = strchr(dirs, dir[1]) - dirs;
+ next = end_pos < last_pos ? dirs[end_pos + 1] : dirs[0];
+ }
+ shadow(yx_eye, yx_cell, fov_map, prev, next);
+ }
+ }
+}
+
+
+
+static uint8_t * build_fov_map()
+{
+ char * f_name = "build_fov_map()";
+ uint8_t radius = 2 * world.map.size.y;
+ uint32_t map_size = world.map.size.y * world.map.size.x;
+ struct MapObj * player = get_player();
+ struct yx_uint8 yx = player->pos;
+ uint8_t * fov_map = try_malloc(map_size, f_name);
+ memset(fov_map, 0, map_size);
+ draw_border_circle(yx, radius, fov_map);
+ fov_map[yx_to_pos(&yx)] = VISIBLE;
+ uint8_t dist;
+ for (dist = 1; dist <= radius; dist++)
+ {
+ uint8_t first_round = 1;
+ char dir;
+ next_circle_dir(1, dist);
+ while ('\0' != (dir = next_circle_dir(0, 0)))
+ {
+ char i_dir = first_round ? 'e' : dir;
+ first_round = 0;
+ if (mv_yx_in_dir_legal(i_dir, &yx))
+ {
+ set_view_of_cell_and_shadows(&yx, &player->pos, fov_map);
+ }
+ }
+ }
+ uint16_t i;
+ for (i = 0; i < world.map.size.y * world.map.size.x; i++)
+ {
+ if (fov_map[i] & HIDE_LATER)
+ {
+ fov_map[i] = fov_map[i] ^ (fov_map[i] & VISIBLE);
+ }
+ }
+ return fov_map;
+}
+
+
+
+extern char * build_visible_map()
+{
+ char * f_name = "build_visible_map()";
+ uint8_t * fov_map = build_fov_map();
+ uint32_t map_size = world.map.size.y * world.map.size.x;
+ char * visible_map = try_malloc(map_size, f_name);
+ memset(visible_map, ' ', map_size);
+ uint16_t pos_i;
+ for (pos_i = 0; pos_i < map_size; pos_i++)
+ {
+ if (fov_map[pos_i] & VISIBLE)
+ {
+ visible_map[pos_i] = world.map.cells[pos_i];
+ }
+ }
+ struct MapObj * o;
+ struct MapObjDef * d;
+ char c;
+ uint8_t i;
+ for (i = 0; i < 2; i++)
+ {
+ for (o = world.map_objs; o != 0; o = o->next)
+ {
+ if ( fov_map[yx_to_pos(&o->pos)] & VISIBLE
+ && ( (0 == i && 0 == o->lifepoints)
+ || (1 == i && 0 < o->lifepoints)))
+ {
+ d = get_map_object_def(o->type);
+ c = d->char_on_map;
+ visible_map[yx_to_pos(&o->pos)] = c;
+ }
+ }
+ }
+ free(fov_map);
+ return visible_map;
+}