/* src/server/field_of_view.c */
-#define _POSIX_C_SOURCE 200809L /* strdup() */
#include "field_of_view.h"
+#include <stdint.h> /* uint8_t, uint16_t, uint32_t, int32_t */
#include <stdlib.h> /* free() */
-#include <stdint.h> /* uint8_t, uint16_t, uint32_t */
-#include <string.h> /* memset(), strchr(), strdup() */
+#include <string.h> /* memset() */
#include "../common/rexit.h" /* exit_trouble() */
#include "../common/try_malloc.h" /* try_malloc() */
#include "map.h" /* yx_to_map_pos() */
#include "things.h" /* Thing */
#include "yx_uint8.h" /* yx_uint8 */
-#include "world.h" /* global world */
+#include "world.h" /* world */
+
+
+
+/* Number of degrees a circle is divided into. */
+#define CIRCLE 36000000
WRAP_W = 0x08
};
+
+
+/* Angle of a shadow. */
+struct shadow_angle
+{
+ struct shadow_angle * next;
+ uint32_t left_angle;
+ uint32_t right_angle;
+};
+
+
+
+/* Move "yx" into hex direction "d". */
+static void mv_yx_in_hex_dir(char d, 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.
+ * "unwrap" of !0 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);
+static 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);
+/* Recalculate angle < 0 or > CIRCLE to a value between these two limits. */
+static uint32_t correct_angle(int32_t angle);
-/* 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.
+/* 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 char * eye_to_cell(struct yx_uint8 * yx_eye, struct yx_uint8 * yx_cell,
- uint8_t right);
+static uint8_t try_merge(struct shadow_angle * shadow,
+ uint32_t left_angle, uint32_t right_angle);
-/* 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.
+/* 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 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 uint8_t try_merging_angles(uint32_t left_angle, uint32_t right_angle,
+ struct shadow_angle ** shadows);
+
+/* If "pos_in_map" in angle between"left_angle" to "right_angle" to the viewing
+ * actor is in a shadow from the shadow list "shadows", mark it as HIDDEN on the
+ * "fov_map"; else, if the world map features a viewing obstacle on the world
+ * map, calculate its shadow angle to the viewer and add it to "shadows".
*/
-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_shadow(uint32_t left_angle, uint32_t right_angle,
+ struct shadow_angle ** shadows, uint16_t pos_in_map,
+ uint8_t * fov_map);
+
+/* 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 cells in "fov_map" and
+ * potentially adding a new shadow to linked shadow angle list "shadows".
*/
-static void set_view_of_cell_and_shadows(struct yx_uint8 * yx_cell,
- struct yx_uint8 * yx_eye,
- uint8_t * fov_map);
+static void eval_position(uint16_t dist, uint16_t hex_i, uint8_t * fov_map,
+ struct yx_uint8 * test_pos,
+ struct shadow_angle ** shadows);
-static uint8_t mv_yx_in_dir_wrap(char d, struct yx_uint8 * yx, uint8_t unwrap)
+static void mv_yx_in_hex_dir(char d, struct yx_uint8 * yx)
{
- 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->x = yx->x - !(yx->y % 2);
yx->y--;
}
- else
+}
+
+
+
+static uint8_t mv_yx_in_dir_wrap(char d, struct yx_uint8 * yx, uint8_t unwrap)
+{
+ static uint8_t wrap = 0;
+ if (unwrap)
{
- exit_trouble(1, "mv_yx_in_dir_wrap()", "illegal direction");
+ wrap = 0;
+ return 0;
}
+ struct yx_uint8 original;
+ original.y = yx->y;
+ original.x = yx->x;
+ mv_yx_in_hex_dir(d, yx);
if (strchr("edc", d) && yx->x < original.x)
{
wrap = wrap & WRAP_W ? wrap ^ WRAP_W : wrap | WRAP_E;
-extern uint8_t mv_yx_in_dir_legal(char dir, struct yx_uint8 * yx)
+static 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.length && yx->y < world.map.length)
-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)
+static uint32_t correct_angle(int32_t angle)
{
- uint8_t dist;
- for (dist = 1; dist <= radius; dist++)
+ while (angle < 0)
{
- mv_yx_in_dir_wrap('w', &yx, 0);
+ angle = angle + CIRCLE;
}
- next_circle_dir(1, radius);
- char dir;
- while ('\0' != (dir = next_circle_dir(0, 0)))
+ while (angle > CIRCLE)
{
- if (mv_yx_in_dir_legal(dir, &yx))
- {
- uint16_t pos = yx_to_map_pos(&yx);
- fov_map[pos] = LIMIT;
- }
+ angle = angle - CIRCLE;
}
- mv_yx_in_dir_wrap(0, NULL, 1);
+ return angle;
}
-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)
+static uint8_t try_merge(struct shadow_angle * shadow,
+ uint32_t left_angle, uint32_t right_angle)
{
- if (vertical)
+ if ( shadow->right_angle <= left_angle + 1
+ && shadow->right_angle >= right_angle)
{
- *n1 = (diff_y / 2) - diff_x + ( indent * (diff_y % 2));
- *n2 = (diff_y / 2) + diff_x + (!indent * (diff_y % 2));
+ shadow->right_angle = right_angle;
}
- else if (!vertical)
+ else if ( shadow->left_angle + 1 >= right_angle
+ && shadow->left_angle <= left_angle)
{
- *n1 = diff_y;
- *n2 = diff_x - (diff_y / 2) - (indent * (diff_y % 2));
+ shadow->left_angle = left_angle;
}
- if (!variant)
+ else
{
- uint8_t tmp = *n1;
- *n1 = *n2;
- *n2 = tmp;
+ return 0;
}
+ return 1;
}
-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)
+static uint8_t try_merging_angles(uint32_t left_angle, uint32_t right_angle,
+ struct shadow_angle ** shadows)
{
- 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++)
+ uint8_t angle_merge = 0;
+ struct shadow_angle * shadow;
+ for (shadow = *shadows; shadow; shadow = shadow->next)
{
- char dirchar = available_dirs[i_of_char];
- if (more_char1 != i_of_char)
+ if (try_merge(shadow, left_angle, right_angle))
{
- i_alter++;
- if (i_alter == n_strong_char)
- {
- i_alter = 0;
- i_of_char = !i_of_char;
- }
+ angle_merge = 1;
}
- 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 (angle_merge)
{
- 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)
+ struct shadow_angle * shadow1;
+ for (shadow1 = *shadows; shadow1; shadow1 = shadow1->next)
{
- 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";
+ 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 "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 = NULL;
- 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.length * (world.map.length - 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.length
- || pos_b % world.map.length==world.map.length-1;
- return pos_a != pos_b && b_on_top_or_right && a_on_left_or_bottom;
+ return angle_merge;
}
-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)
+static void set_shadow(uint32_t left_angle, uint32_t right_angle,
+ struct shadow_angle ** shadows, uint16_t pos_in_map,
+ uint8_t * fov_map)
{
- int16_t a_y_on_left = !(pos_a%world.map.length)? pos_a/world.map.length :-1;
- int16_t b_y_on_left = !(pos_b%world.map.length)? pos_b/world.map.length :-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.length; y++)
+ char * f_name = "set_shadow()";
+ struct shadow_angle * shadow_i;
+ if (fov_map[pos_in_map] & VISIBLE)
{
- 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.length; x++)
+ for (shadow_i = *shadows; shadow_i; shadow_i = shadow_i->next)
{
- pos = (y * world.map.length) + 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)
+ if ( left_angle <= shadow_i->left_angle
+ && right_angle >= shadow_i->right_angle)
{
- fov_map[pos] = fov_map[pos] | HIDDEN;
+ fov_map[pos_in_map] = HIDDEN;
+ return;
}
}
}
-}
-
-
-
-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 = yx_to_map_pos(&yx_border);
- if (mv_yx_in_dir_legal(dir, &yx_border))
+ if ('X' == world.map.cells[pos_in_map])
{
- 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))
+ if (!try_merging_angles(left_angle, right_angle, shadows))
{
- pos = yx_to_map_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;
+ struct shadow_angle * shadow;
+ shadow = try_malloc(sizeof(struct shadow_angle), f_name);
+ 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;
}
- 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)
+static void free_angles(struct shadow_angle * angles)
{
- 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_map_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.length * world.map.length; i++)
+ if (angles->next)
{
- 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);
+ free_angles(angles->next);
}
- return;
+ free(angles);
}
-static void set_view_of_cell_and_shadows(struct yx_uint8 * yx_cell,
- struct yx_uint8 * yx_eye,
- uint8_t * fov_map)
+static void eval_position(uint16_t dist, uint16_t hex_i, uint8_t * fov_map,
+ struct yx_uint8 * test_pos,
+ struct shadow_angle ** shadows)
{
- char * dirs = "dcxswe";
- uint16_t pos = yx_to_map_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);
- }
+ 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;
+ uint16_t pos_in_map = yx_to_map_pos(test_pos);
+ set_shadow(left_angle, right_angle_1st, shadows, pos_in_map, fov_map);
+ if (right_angle_1st != right_angle)
+ {
+ left_angle = CIRCLE;
+ set_shadow(left_angle, right_angle, shadows, pos_in_map, fov_map);
}
}
extern uint8_t * build_fov_map(struct Thing * eye)
{
char * f_name = "build_fov_map()";
- uint8_t radius = 2 * world.map.length;
uint32_t map_size = world.map.length * world.map.length;
- struct yx_uint8 yx = eye->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_map_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)))
+ memset(fov_map, VISIBLE, map_size);
+ struct yx_uint8 test_pos = eye->pos;
+ struct shadow_angle * shadows = NULL;
+ char * circle_dirs = "xswedc";
+ uint16_t dist;
+ uint8_t first_round, circle_on_map;
+ for (first_round = 1, dist = 1, circle_on_map = 1; circle_on_map; dist++)
+ {
+ if (!first_round)
{
- 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, &eye->pos, fov_map);
- }
+ mv_yx_in_dir_legal('c', &test_pos);
}
- }
- uint16_t i;
- for (i = 0; i < world.map.length * world.map.length; i++)
- {
- if (fov_map[i] & HIDE_LATER)
+ char dir = 'd';
+ uint8_t i_dir = first_round = circle_on_map = 0;
+ uint16_t i_dist, hex_i;
+ for (hex_i = 0, i_dist = 1; hex_i < 6 * dist; i_dist++, hex_i++)
{
- fov_map[i] = fov_map[i] ^ (fov_map[i] & VISIBLE);
+ if (mv_yx_in_dir_legal(dir, &test_pos))
+ {
+ eval_position(dist, hex_i, fov_map, &test_pos, &shadows);
+ circle_on_map = 1;
+ }
+ dir = circle_dirs[i_dir];
+ if (dist == i_dist)
+ {
+ i_dist = 0;
+ i_dir++;
+ }
}
}
+ mv_yx_in_dir_wrap(0, NULL, 1);
+ free_angles(shadows);
return fov_map;
}
projects / plomrogue / commitdiff