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".
+/* 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 HIDDEN. If the whole
+ * angle and not just "middle_angle" is captured, return 1. Any other case: 0.
*/
-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);
+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, uint8_t * fov_map);
+
+/* 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 HIDDEN. 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, 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
+ * 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, uint8_t * fov_map,
-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)
+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, uint8_t * fov_map)
{
struct shadow_angle * shadow_i;
if (fov_map[pos_in_map] & VISIBLE)
&& right_angle >= shadow_i->right_angle)
{
fov_map[pos_in_map] = HIDDEN;
- return;
+ return 1;
+ }
+ if ( middle_angle < shadow_i->left_angle
+ && middle_angle > shadow_i->right_angle)
+ {
+ fov_map[pos_in_map] = HIDDEN;
}
}
}
- if ('X' == world.map.cells[pos_in_map])
+ return 0;
+}
+
+
+
+/* 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)
+{
+ struct shadow_angle * shadow_i;
+ if (!try_merging_angles(left_angle, right_angle, shadows))
{
- 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)
{
- 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)
{
- for (shadow_i = *shadows; shadow_i; shadow_i = shadow_i->next)
+ if (!shadow_i->next)
{
- if (!shadow_i->next)
- {
- shadow_i->next = shadow;
- return;
- }
+ shadow_i->next = shadow;
+ return;
}
}
- *shadows = shadow;
}
+ *shadows = shadow;
}
}
struct shadow_angle ** shadows)
{
int32_t left_angle_uncorrected = ((CIRCLE / 12) / dist)
- - ((hex_i * (CIRCLE / 6)) / 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;
- set_shadow(left_angle, right_angle_1st, shadows, pos_in_map, fov_map);
- if (right_angle_1st != right_angle)
+ 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])
{
- left_angle = CIRCLE;
- set_shadow(left_angle, right_angle, shadows, pos_in_map, fov_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);
+ }
}
}