server/common/los.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the Affero GNU General Public License
 * and the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

#include <global.h>
#include <cmath>

#define SEE_IN_DARK_RADIUS 2
#define MAX_VISION 10 // maximum visible radius

// los flags
enum {
  FLG_XI      = 0x01, // we have an x-parent
  FLG_YI      = 0x02, // we have an y-parent
  FLG_BLOCKED = 0x04, // this space blocks the view
  FLG_QUEUED  = 0x80  // already queued in queue, or border
};

// it is important for performance reasons that this structure
// has a size easily computable by the cpu (*8 is perfect).
// it is possible to move culled and visible into flags, at
// some speed loss.
struct los_info
{
  uint8 flags;   // FLG_xxx
  uint8 culled;  // culled from "tree"
  uint8 visible;
  uint8 pad0;

  sint8 xo, yo;  // obscure angle
  sint8 xe, ye;  // angle deviation
};

// temporary storage for the los algorithm,
// one los_info for each lightable map space
static los_info los[MAP_CLIENT_X][MAP_CLIENT_Y];

struct point
{
  sint8 x, y;
};

// minimum size, but must be a power of two
#define QUEUE_LENGTH ((MAP_CLIENT_X + MAP_CLIENT_Y) * 2)

// a queue of spaces to calculate
static point queue [QUEUE_LENGTH];
static int q1, q2; // queue start, end

/*
 * Clears/initialises the los-array associated to the player
 * controlling the object.
 */
void
player::clear_los (sint8 value)
{
  memset (los, value, sizeof (los));
}

// enqueue a single mapspace, but only if it hasn't
// been enqueued yet.
static void
enqueue (sint8 dx, sint8 dy, uint8 flags = 0)
{
  sint8 x = LOS_X0 + dx;
  sint8 y = LOS_Y0 + dy;

  los_info &l = los[x][y];

  l.flags |= flags;

  if (expect_false (l.flags & FLG_QUEUED))
    return;

  l.flags |= FLG_QUEUED;

  queue[q1].x = dx;
  queue[q1].y = dy;

  q1 = (q1 + 1) & (QUEUE_LENGTH - 1);
}

// run the los algorithm
// this is a variant of a spiral los algorithm taken from
// http://www.geocities.com/temerra/los_rays.html
// which has been simplified and changed considerably, but
// still is basically the same algorithm.
static void
calculate_los (player *pl)
{
  {
    memset (los, 0, sizeof (los));

    // we keep one line for ourselves, for the border flag
    // so the client area is actually MAP_CLIENT_(X|Y) - 2
    int half_x = min (LOS_X0 - 1, pl->ns->mapx / 2);
    int half_y = min (LOS_Y0 - 1, pl->ns->mapy / 2);

    // create borders, the corners are not touched
    for (int dx = -half_x; dx <= half_x; ++dx)
      los [dx + LOS_X0][LOS_Y0 - (half_y + 1)].flags =
      los [dx + LOS_X0][LOS_Y0 + (half_y + 1)].flags = FLG_QUEUED;

    for (int dy = -half_y; dy <= half_y; ++dy)
      los [LOS_X0 - (half_x + 1)][dy + LOS_Y0].flags =
      los [LOS_X0 + (half_x + 1)][dy + LOS_Y0].flags = FLG_QUEUED;

    // now reset the los area and also add blocked flags
    // which supposedly is faster than doing it inside the
    // spiral path algorithm below, except when very little
    // area is visible, in which case it is slower. which evens
    // out los calculation times between large and small los maps.
    // apply_lights also iterates over this area, maybe these
    // two passes could be combined somehow.
    unordered_mapwalk (mapwalk_buf, pl->viewpoint, -half_x, -half_y, half_x, half_y)
      {
        los_info &l = los [LOS_X0 + dx][LOS_Y0 + dy];
        l.flags = m->at (nx, ny).flags () & P_BLOCKSVIEW ? FLG_BLOCKED : 0;
      }
  }

  q1 = 0; q2 = 0; // initialise queue, not strictly required
  enqueue (0, 0); // enqueue center

  // treat the origin specially
  los[LOS_X0][LOS_Y0].visible = 1;
  pl->los[LOS_X0][LOS_Y0] = 0;

  // loop over all enqueued points until the queue is empty
  // the order in which this is done ensures that we
  // never touch a mapspace whose input spaces we haven't checked
  // yet.
  while (q1 != q2)
    {
      sint8 dx = queue[q2].x;
      sint8 dy = queue[q2].y;

      q2 = (q2 + 1) & (QUEUE_LENGTH - 1);

      sint8 x = LOS_X0 + dx;
      sint8 y = LOS_Y0 + dy;

      los_info &l = los[x][y];

      if (expect_true (l.flags & (FLG_XI | FLG_YI)))
        {
          l.culled = 1;
          l.xo = l.yo = l.xe = l.ye = 0;

          // check contributing spaces, first horizontal
          if (expect_true (l.flags & FLG_XI))
            {
              los_info *xi = &los[x - sign (dx)][y];

              // don't cull unless obscured
              l.culled &= !xi->visible;

              /* merge input space */
              if (expect_false (xi->xo || xi->yo))
                {
                  // The X input can provide two main pieces of information: 
                  // 1. Progressive X obscurity.
                  // 2. Recessive Y obscurity.
                          
                  // Progressive X obscurity, favouring recessive input angle
                  if (xi->xe > 0 && l.xo == 0)
                    {
                      l.xe = xi->xe - xi->yo;
                      l.ye = xi->ye + xi->yo;
                      l.xo = xi->xo;
                      l.yo = xi->yo;
                    }

                  // Recessive Y obscurity
                  if (xi->ye <= 0 && xi->yo > 0 && xi->xe > 0)
                    {
                      l.ye = xi->yo + xi->ye;
                      l.xe = xi->xe - xi->yo;
                      l.xo = xi->xo;
                      l.yo = xi->yo;
                    }
                }
            }
                
          // check contributing spaces, last vertical, identical structure
          if (expect_true (l.flags & FLG_YI))
            {
              los_info *yi = &los[x][y - sign (dy)];

              // don't cull unless obscured
              l.culled &= !yi->visible;

              /* merge input space */
              if (expect_false (yi->yo || yi->xo))
                {
                  // The Y input can provide two main pieces of information: 
                  // 1. Progressive Y obscurity.
                  // 2. Recessive X obscurity.
                          
                  // Progressive Y obscurity, favouring recessive input angle
                  if (yi->ye > 0 && l.yo == 0)
                    {
                      l.ye = yi->ye - yi->xo;
                      l.xe = yi->xe + yi->xo;
                      l.yo = yi->yo;
                      l.xo = yi->xo;
                    }

                  // Recessive X obscurity
                  if (yi->xe <= 0 && yi->xo > 0 && yi->ye > 0)
                    {
                      l.xe = yi->xo + yi->xe;
                      l.ye = yi->ye - yi->xo;
                      l.yo = yi->yo;
                      l.xo = yi->xo;
                    }
                }
            }

          if (l.flags & FLG_BLOCKED)
            {
              l.xo = l.xe = abs (dx);
              l.yo = l.ye = abs (dy);

              // we obscure dependents, but might be visible
              // copy the los from the square towards the player,
              // so outward diagonal corners are lit.
              pl->los[x][y] = los[x - sign0 (dx)][y - sign0 (dy)].visible ? 0 : LOS_BLOCKED;

              l.visible = false;
            }
          else
            {
              // we are not blocked, so calculate visibility, by checking
              // whether we are inside or outside the shadow
              l.visible = (l.xe <= 0 || l.xe > l.xo)
                       && (l.ye <= 0 || l.ye > l.yo);

              pl->los[x][y] = l.culled  ? LOS_BLOCKED
                            : l.visible ? 0
                                        : 3;
            }

        }

      // Expands by the unit length in each component's current direction.
      // If a component has no direction, then it is expanded in both of its 
      // positive and negative directions.
      if (!l.culled)
        {
          if (dx >= 0) enqueue (dx + 1, dy, FLG_XI);
          if (dx <= 0) enqueue (dx - 1, dy, FLG_XI);
          if (dy >= 0) enqueue (dx, dy + 1, FLG_YI);
          if (dy <= 0) enqueue (dx, dy - 1, FLG_YI);
        }
    }
}

/* radius, distance => lightness adjust */
static sint8 light_atten[MAX_LIGHT_RADIUS * 2 + 1][MAX_LIGHT_RADIUS * 3 / 2 + 1];
static sint8 vision_atten[MAX_VISION + 1][MAX_VISION * 3 / 2 + 1];

static struct los_init
{
  los_init ()
  {
    assert (("QUEUE_LENGTH, MAP_CLIENT_X and MAP_CLIENT_Y *must* be powers of two",
             !(QUEUE_LENGTH & (QUEUE_LENGTH - 1))));

    /* for lights */
    for (int radius = -MAX_LIGHT_RADIUS; radius <= MAX_LIGHT_RADIUS; ++radius)
      for (int distance = 0; distance <= MAX_LIGHT_RADIUS * 3 / 2; ++distance)
        {
          // max intensity
          int intensity = min (LOS_MAX, abs (radius) + 1);

          // actual intensity
          intensity = max (0, lerp_ru (distance, 0, abs (radius) + 1, intensity, 0));

          light_atten [radius + MAX_LIGHT_RADIUS][distance] = radius < 0
            ? min (3, intensity)
            : LOS_MAX - intensity;
        }

    /* for general vision */
    for (int radius = 0; radius <= MAX_VISION; ++radius)
      for (int distance = 0; distance <= MAX_VISION * 3 / 2; ++distance)
        vision_atten [radius][distance] = distance <= radius ? clamp (lerp (radius, 0, MAX_DARKNESS, 3, 0), 0, 3) : 4;
  }
} los_init;

// the following functions cannot be static, due to c++ stupidity :/
namespace {
  // brighten area, ignore los
  sint8
  los_brighten_nolos (sint8 b, sint8 l)
  {
    return min (b, l);
  }

  // brighten area, but respect los
  sint8
  los_brighten (sint8 b, sint8 l)
  {
    return b == LOS_BLOCKED ? b : min (b, l);
  }

  // darken area, respect los
  sint8
  los_darken (sint8 b, sint8 l)
  {
    return max (b, l);
  }
};

template<sint8 change_it (sint8, sint8)>
static void
apply_light (player *pl, int dx, int dy, int light, const sint8 *atten_table)
{
  // min or max the circular area around basex, basey
  dx += LOS_X0;
  dy += LOS_Y0;

  int hx = pl->ns->mapx / 2;
  int hy = pl->ns->mapy / 2;

  int ax0 = max (LOS_X0 - hx, dx - light);
  int ay0 = max (LOS_Y0 - hy, dy - light);
  int ax1 = min (dx + light, LOS_X0 + hx);
  int ay1 = min (dy + light, LOS_Y0 + hy);

  for (int ax = ax0; ax <= ax1; ax++)
    for (int ay = ay0; ay <= ay1; ay++)
      pl->los[ax][ay] =
        change_it (pl->los[ax][ay], atten_table [idistance (ax - dx, ay - dy)]);
}

/* add light, by finding all (non-null) nearby light sources, then 
 * mark those squares specially.
 */
static void
apply_lights (player *pl)
{
  object *op = pl->viewpoint;
  int darklevel = op->map->darklevel ();

  int half_x = pl->ns->mapx / 2;
  int half_y = pl->ns->mapy / 2;

  int pass2 = 0; // negative lights have an extra pass

  maprect *rects = pl->viewpoint->map->split_to_tiles (
    mapwalk_buf,
    pl->viewpoint->x - half_x - MAX_LIGHT_RADIUS,
    pl->viewpoint->y - half_y - MAX_LIGHT_RADIUS,
    pl->viewpoint->x + half_x + MAX_LIGHT_RADIUS + 1,
    pl->viewpoint->y + half_y + MAX_LIGHT_RADIUS + 1
  );

  /* If the player can see in the dark, increase light/vision radius */
  int bonus = op->flag [FLAG_SEE_IN_DARK] ? SEE_IN_DARK_RADIUS : 0;

  if (!darklevel)
    pass2 = 1;
  else
    {
      /* first, make everything totally dark */
      for (int dx = -half_x; dx <= half_x; dx++)
        for (int dy = -half_x; dy <= half_y; dy++)
          max_it (pl->los[dx + LOS_X0][dy + LOS_Y0], LOS_MAX);

      /*
       * Only process the area of interest.
       * the basex, basey values represent the position in the op->contr->los
       * array. Its easier to just increment them here (and start with the right
       * value) than to recalculate them down below.
       */
      for (maprect *r = rects; r->m; ++r)
        rect_mapwalk (r, 0, 0)
          {
            mapspace &ms = m->at (nx, ny);
            ms.update ();
            sint8 light = ms.light;

            if (expect_false (light))
              if (light < 0)
                pass2 = 1;
              else
                {
                  light = clamp (light + bonus, 0, MAX_LIGHT_RADIUS);
                  apply_light<los_brighten> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, light, light_atten [light + MAX_LIGHT_RADIUS]);
                }
          }

      /* grant some vision to the player, based on outside, outdoor, and darklevel */
      {
        int light;

        if (!op->map->outdoor) // not outdoor, darkness becomes light radius
          light = MAX_DARKNESS - op->map->darkness;
        else if (op->map->darkness > 0) // outdoor and darkness > 0 => use darkness as max radius
          light = lerp_rd (maptile::outdoor_darkness + 0, 0, MAX_DARKNESS, MAX_DARKNESS - op->map->darkness, 0);
        else // outdoor and darkness <= 0 => start wide and decrease quickly
          light = lerp (maptile::outdoor_darkness + op->map->darkness, 0, MAX_DARKNESS, MAX_VISION, 2);

        light = clamp (light + bonus, 0, MAX_VISION);

        apply_light<los_brighten> (pl, 0, 0, light, vision_atten [light]);
      }
    }

  // when we fly high, we have some minimum viewable area around us, like x-ray
  if (op->move_type & MOVE_FLY_HIGH)
    apply_light<los_brighten_nolos> (pl, 0, 0, 9, vision_atten [9]);

  // possibly do 2nd pass for rare negative glow radii
  // for effect, those are always considered to be stronger than anything else
  // but they can't darken a place completely
  if (pass2)
    for (maprect *r = rects; r->m; ++r)
      rect_mapwalk (r, 0, 0)
        {
          mapspace &ms = m->at (nx, ny);
          ms.update ();
          sint8 light = ms.light;

          if (expect_false (light < 0))
            {
              light = clamp (light - bonus, 0, MAX_DARKNESS);
              apply_light<los_darken> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, -light, light_atten [light + MAX_LIGHT_RADIUS]);
            }
        }
}

/* blinded_sight() - sets all viewable squares to blocked except 
 * for the one the central one that the player occupies.  A little
 * odd that you can see yourself (and what your standing on), but
 * really need for any reasonable game play.
 */
static void
blinded_sight (player *pl)
{
  pl->los[LOS_X0][LOS_Y0] = 1;
}

/*
 * update_los() recalculates the array which specifies what is
 * visible for the given player-object.
 */
void
player::update_los ()
{
  if (ob->flag [FLAG_REMOVED])//D really needed?
    return;

  if (ob->flag [FLAG_WIZLOOK])
    clear_los (0);
  else if (viewpoint->flag [FLAG_BLIND])      /* player is blind */
    {
      clear_los ();
      blinded_sight (this);
    }
  else
    {
      clear_los ();
      calculate_los (this);
      apply_lights (this);
    }

  if (viewpoint->flag [FLAG_XRAYS])
    for (int dx = -2; dx <= 2; dx++)
      for (int dy = -2; dy <= 2; dy++)
        min_it (los[dx + LOS_X0][dy + LOS_Y0], 1);
}

/* update all_map_los is like update_all_los below,
 * but updates everyone on the map, no matter where they
 * are. This generally should not be used, as a per
 * specific map change doesn't make much sense when tiling
 * is considered (lowering darkness would certainly be a
 * strange effect if done on a tile map, as it makes
 * the distinction between maps much more obvious to the
 * players, which is should not be.
 * Currently, this function is called from the
 * change_map_light function
 */
void
update_all_map_los (maptile *map)
{
  for_all_players_on_map (pl, map)
    pl->do_los = 1;
}

/*
 * This function makes sure that update_los() will be called for all
 * players on the given map within the next frame.
 * It is triggered by removal or inserting of objects which blocks
 * the sight in the map.
 * Modified by MSW 2001-07-12 to take a coordinate of the changed
 * position, and to also take map tiling into account.  This change
 * means that just being on the same map is not sufficient - the
 * space that changes must be withing your viewable area.
 *
 * map is the map that changed, x and y are the coordinates.
 */
void
update_all_los (const maptile *map, int x, int y)
{
  map->at (x, y).invalidate ();

  for_all_players (pl)
    {
      /* Player should not have a null map, but do this
       * check as a safety
       */
      if (!pl->ob || !pl->ob->map || !pl->ns)
        continue;

      rv_vector rv;

      get_rangevector_from_mapcoord (pl->ob->map, x, y, pl->ob, &rv);
      
      if ((abs (rv.distance_x) <= pl->ns->mapx / 2) && (abs (rv.distance_y) <= pl->ns->mapy / 2))
        pl->do_los = 1;
    }
}

static const int season_darkness[5][HOURS_PER_DAY] = {
  /*0  1  2  3  4  5  6  7  8  9 10 11 12 13 14  1  2  3  4  5  6  7  8  9 10 11 12 13 */
  { 5, 5, 4, 4, 4, 4, 4, 3, 3, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 1, 2, 2, 2, 3, 3, 4, 4, 5 },
  { 5, 5, 4, 4, 4, 4, 3, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4 },
  { 5, 4, 4, 4, 4, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 4, 4 },
  { 4, 4, 4, 4, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 4 },
  { 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4 }
};

/*
 * Tell players the time and compute the darkness level for all maps in the game.
 * MUST be called exactly once per hour.
 */
void
maptile::adjust_daylight ()
{
  timeofday_t tod;

  get_tod (&tod);

  // log the time to log-1 every hour, and to chat every day
  {
    char todbuf[512];

    format_tod (todbuf, sizeof (todbuf), &tod);

    for_all_players (pl)
      pl->ns->send_msg (NDI_GREY, tod.hour == 15 ? CHAT_CHANNEL : LOG_CHANNEL, todbuf);
  }

  /* If the light level isn't changing, no reason to do all
   * the work below.
   */
  sint8 new_darkness = season_darkness[tod.season][tod.hour];

  if (new_darkness == maptile::outdoor_darkness)
    return;

  new_draw_info (NDI_GREY | NDI_UNIQUE | NDI_ALL, 1, 0,
                 new_darkness > maptile::outdoor_darkness
                 ? "It becomes darker."
                 : "It becomes brighter.");

  maptile::outdoor_darkness = new_darkness;

  // we simply update the los for all players, which is unnecessarily
  // costly, but should do for the moment.
  for_all_players (pl)
    pl->do_los = 1;
}

/*
 * make_sure_seen: The object is supposed to be visible through walls, thus
 * check if any players are nearby, and edit their LOS array.
 */
void
make_sure_seen (const object *op)
{
  for_all_players (pl)
    if (pl->ob->map == op->map &&
        pl->ob->y - pl->ns->mapy / 2 <= op->y &&
        pl->ob->y + pl->ns->mapy / 2 >= op->y && pl->ob->x - pl->ns->mapx / 2 <= op->x && pl->ob->x + pl->ns->mapx / 2 >= op->x)
      pl->los[op->x - pl->ob->x + LOS_X0][op->y - pl->ob->y + LOS_Y0] = 0;
}

/*
 * make_sure_not_seen: The object which is supposed to be visible through
 * walls has just been removed from the map, so update the los of any
 * players within its range
 */
void
make_sure_not_seen (const object *op)
{
  for_all_players (pl)
    if (pl->ob->map == op->map &&
        pl->ob->y - pl->ns->mapy / 2 <= op->y &&
        pl->ob->y + pl->ns->mapy / 2 >= op->y && pl->ob->x - pl->ns->mapx / 2 <= op->x && pl->ob->x + pl->ns->mapx / 2 >= op->x)
      pl->do_los = 1;
}

Revision:	1.72
Committed:	Tue Jan 3 11:25:31 2012 UTC (12 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.71:	+1 -1 lines
Log Message:	update copyrights to 2012
#	Content
1	/*
2	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	*
4	* Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	*
6	* Deliantra is free software: you can redistribute it and/or modify it under
7	* the terms of the Affero GNU General Public License as published by the
8	* Free Software Foundation, either version 3 of the License, or (at your
9	* option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the Affero GNU General Public License
17	* and the GNU General Public License along with this program. If not, see
18	* <http://www.gnu.org/licenses/>.
19	*
20	* The authors can be reached via e-mail to <support@deliantra.net>
21	*/
22
23	#include <global.h>
24	#include <cmath>
25
26	#define SEE_IN_DARK_RADIUS 2
27	#define MAX_VISION 10 // maximum visible radius
28
29	// los flags
30	enum {
31	FLG_XI = 0x01, // we have an x-parent
32	FLG_YI = 0x02, // we have an y-parent
33	FLG_BLOCKED = 0x04, // this space blocks the view
34	FLG_QUEUED = 0x80 // already queued in queue, or border
35	};
36
37	// it is important for performance reasons that this structure
38	// has a size easily computable by the cpu (*8 is perfect).
39	// it is possible to move culled and visible into flags, at
40	// some speed loss.
41	struct los_info
42	{
43	uint8 flags; // FLG_xxx
44	uint8 culled; // culled from "tree"
45	uint8 visible;
46	uint8 pad0;
47
48	sint8 xo, yo; // obscure angle
49	sint8 xe, ye; // angle deviation
50	};
51
52	// temporary storage for the los algorithm,
53	// one los_info for each lightable map space
54	static los_info los[MAP_CLIENT_X][MAP_CLIENT_Y];
55
56	struct point
57	{
58	sint8 x, y;
59	};
60
61	// minimum size, but must be a power of two
62	#define QUEUE_LENGTH ((MAP_CLIENT_X + MAP_CLIENT_Y) * 2)
63
64	// a queue of spaces to calculate
65	static point queue [QUEUE_LENGTH];
66	static int q1, q2; // queue start, end
67
68	/*
69	* Clears/initialises the los-array associated to the player
70	* controlling the object.
71	*/
72	void
73	player::clear_los (sint8 value)
74	{
75	memset (los, value, sizeof (los));
76	}
77
78	// enqueue a single mapspace, but only if it hasn't
79	// been enqueued yet.
80	static void
81	enqueue (sint8 dx, sint8 dy, uint8 flags = 0)
82	{
83	sint8 x = LOS_X0 + dx;
84	sint8 y = LOS_Y0 + dy;
85
86	los_info &l = los[x][y];
87
88	l.flags \|= flags;
89
90	if (expect_false (l.flags & FLG_QUEUED))
91	return;
92
93	l.flags \|= FLG_QUEUED;
94
95	queue[q1].x = dx;
96	queue[q1].y = dy;
97
98	q1 = (q1 + 1) & (QUEUE_LENGTH - 1);
99	}
100
101	// run the los algorithm
102	// this is a variant of a spiral los algorithm taken from
103	// http://www.geocities.com/temerra/los_rays.html
104	// which has been simplified and changed considerably, but
105	// still is basically the same algorithm.
106	static void
107	calculate_los (player *pl)
108	{
109	{
110	memset (los, 0, sizeof (los));
111
112	// we keep one line for ourselves, for the border flag
113	// so the client area is actually MAP_CLIENT_(X\|Y) - 2
114	int half_x = min (LOS_X0 - 1, pl->ns->mapx / 2);
115	int half_y = min (LOS_Y0 - 1, pl->ns->mapy / 2);
116
117	// create borders, the corners are not touched
118	for (int dx = -half_x; dx <= half_x; ++dx)
119	los [dx + LOS_X0][LOS_Y0 - (half_y + 1)].flags =
120	los [dx + LOS_X0][LOS_Y0 + (half_y + 1)].flags = FLG_QUEUED;
121
122	for (int dy = -half_y; dy <= half_y; ++dy)
123	los [LOS_X0 - (half_x + 1)][dy + LOS_Y0].flags =
124	los [LOS_X0 + (half_x + 1)][dy + LOS_Y0].flags = FLG_QUEUED;
125
126	// now reset the los area and also add blocked flags
127	// which supposedly is faster than doing it inside the
128	// spiral path algorithm below, except when very little
129	// area is visible, in which case it is slower. which evens
130	// out los calculation times between large and small los maps.
131	// apply_lights also iterates over this area, maybe these
132	// two passes could be combined somehow.
133	unordered_mapwalk (mapwalk_buf, pl->viewpoint, -half_x, -half_y, half_x, half_y)
134	{
135	los_info &l = los [LOS_X0 + dx][LOS_Y0 + dy];
136	l.flags = m->at (nx, ny).flags () & P_BLOCKSVIEW ? FLG_BLOCKED : 0;
137	}
138	}
139
140	q1 = 0; q2 = 0; // initialise queue, not strictly required
141	enqueue (0, 0); // enqueue center
142
143	// treat the origin specially
144	los[LOS_X0][LOS_Y0].visible = 1;
145	pl->los[LOS_X0][LOS_Y0] = 0;
146
147	// loop over all enqueued points until the queue is empty
148	// the order in which this is done ensures that we
149	// never touch a mapspace whose input spaces we haven't checked
150	// yet.
151	while (q1 != q2)
152	{
153	sint8 dx = queue[q2].x;
154	sint8 dy = queue[q2].y;
155
156	q2 = (q2 + 1) & (QUEUE_LENGTH - 1);
157
158	sint8 x = LOS_X0 + dx;
159	sint8 y = LOS_Y0 + dy;
160
161	los_info &l = los[x][y];
162
163	if (expect_true (l.flags & (FLG_XI \| FLG_YI)))
164	{
165	l.culled = 1;
166	l.xo = l.yo = l.xe = l.ye = 0;
167
168	// check contributing spaces, first horizontal
169	if (expect_true (l.flags & FLG_XI))
170	{
171	los_info *xi = &los[x - sign (dx)][y];
172
173	// don't cull unless obscured
174	l.culled &= !xi->visible;
175
176	/* merge input space */
177	if (expect_false (xi->xo \|\| xi->yo))
178	{
179	// The X input can provide two main pieces of information:
180	// 1. Progressive X obscurity.
181	// 2. Recessive Y obscurity.
182
183	// Progressive X obscurity, favouring recessive input angle
184	if (xi->xe > 0 && l.xo == 0)
185	{
186	l.xe = xi->xe - xi->yo;
187	l.ye = xi->ye + xi->yo;
188	l.xo = xi->xo;
189	l.yo = xi->yo;
190	}
191
192	// Recessive Y obscurity
193	if (xi->ye <= 0 && xi->yo > 0 && xi->xe > 0)
194	{
195	l.ye = xi->yo + xi->ye;
196	l.xe = xi->xe - xi->yo;
197	l.xo = xi->xo;
198	l.yo = xi->yo;
199	}
200	}
201	}
202
203	// check contributing spaces, last vertical, identical structure
204	if (expect_true (l.flags & FLG_YI))
205	{
206	los_info *yi = &los[x][y - sign (dy)];
207
208	// don't cull unless obscured
209	l.culled &= !yi->visible;
210
211	/* merge input space */
212	if (expect_false (yi->yo \|\| yi->xo))
213	{
214	// The Y input can provide two main pieces of information:
215	// 1. Progressive Y obscurity.
216	// 2. Recessive X obscurity.
217
218	// Progressive Y obscurity, favouring recessive input angle
219	if (yi->ye > 0 && l.yo == 0)
220	{
221	l.ye = yi->ye - yi->xo;
222	l.xe = yi->xe + yi->xo;
223	l.yo = yi->yo;
224	l.xo = yi->xo;
225	}
226
227	// Recessive X obscurity
228	if (yi->xe <= 0 && yi->xo > 0 && yi->ye > 0)
229	{
230	l.xe = yi->xo + yi->xe;
231	l.ye = yi->ye - yi->xo;
232	l.yo = yi->yo;
233	l.xo = yi->xo;
234	}
235	}
236	}
237
238	if (l.flags & FLG_BLOCKED)
239	{
240	l.xo = l.xe = abs (dx);
241	l.yo = l.ye = abs (dy);
242
243	// we obscure dependents, but might be visible
244	// copy the los from the square towards the player,
245	// so outward diagonal corners are lit.
246	pl->los[x][y] = los[x - sign0 (dx)][y - sign0 (dy)].visible ? 0 : LOS_BLOCKED;
247
248	l.visible = false;
249	}
250	else
251	{
252	// we are not blocked, so calculate visibility, by checking
253	// whether we are inside or outside the shadow
254	l.visible = (l.xe <= 0 \|\| l.xe > l.xo)
255	&& (l.ye <= 0 \|\| l.ye > l.yo);
256
257	pl->los[x][y] = l.culled ? LOS_BLOCKED
258	: l.visible ? 0
259	: 3;
260	}
261
262	}
263
264	// Expands by the unit length in each component's current direction.
265	// If a component has no direction, then it is expanded in both of its
266	// positive and negative directions.
267	if (!l.culled)
268	{
269	if (dx >= 0) enqueue (dx + 1, dy, FLG_XI);
270	if (dx <= 0) enqueue (dx - 1, dy, FLG_XI);
271	if (dy >= 0) enqueue (dx, dy + 1, FLG_YI);
272	if (dy <= 0) enqueue (dx, dy - 1, FLG_YI);
273	}
274	}
275	}
276
277	/* radius, distance => lightness adjust */
278	static sint8 light_atten[MAX_LIGHT_RADIUS * 2 + 1][MAX_LIGHT_RADIUS * 3 / 2 + 1];
279	static sint8 vision_atten[MAX_VISION + 1][MAX_VISION * 3 / 2 + 1];
280
281	static struct los_init
282	{
283	los_init ()
284	{
285	assert (("QUEUE_LENGTH, MAP_CLIENT_X and MAP_CLIENT_Y must be powers of two",
286	!(QUEUE_LENGTH & (QUEUE_LENGTH - 1))));
287
288	/* for lights */
289	for (int radius = -MAX_LIGHT_RADIUS; radius <= MAX_LIGHT_RADIUS; ++radius)
290	for (int distance = 0; distance <= MAX_LIGHT_RADIUS * 3 / 2; ++distance)
291	{
292	// max intensity
293	int intensity = min (LOS_MAX, abs (radius) + 1);
294
295	// actual intensity
296	intensity = max (0, lerp_ru (distance, 0, abs (radius) + 1, intensity, 0));
297
298	light_atten [radius + MAX_LIGHT_RADIUS][distance] = radius < 0
299	? min (3, intensity)
300	: LOS_MAX - intensity;
301	}
302
303	/* for general vision */
304	for (int radius = 0; radius <= MAX_VISION; ++radius)
305	for (int distance = 0; distance <= MAX_VISION * 3 / 2; ++distance)
306	vision_atten [radius][distance] = distance <= radius ? clamp (lerp (radius, 0, MAX_DARKNESS, 3, 0), 0, 3) : 4;
307	}
308	} los_init;
309
310	// the following functions cannot be static, due to c++ stupidity :/
311	namespace {
312	// brighten area, ignore los
313	sint8
314	los_brighten_nolos (sint8 b, sint8 l)
315	{
316	return min (b, l);
317	}
318
319	// brighten area, but respect los
320	sint8
321	los_brighten (sint8 b, sint8 l)
322	{
323	return b == LOS_BLOCKED ? b : min (b, l);
324	}
325
326	// darken area, respect los
327	sint8
328	los_darken (sint8 b, sint8 l)
329	{
330	return max (b, l);
331	}
332	};
333
334	template<sint8 change_it (sint8, sint8)>
335	static void
336	apply_light (player pl, int dx, int dy, int light, const sint8 atten_table)
337	{
338	// min or max the circular area around basex, basey
339	dx += LOS_X0;
340	dy += LOS_Y0;
341
342	int hx = pl->ns->mapx / 2;
343	int hy = pl->ns->mapy / 2;
344
345	int ax0 = max (LOS_X0 - hx, dx - light);
346	int ay0 = max (LOS_Y0 - hy, dy - light);
347	int ax1 = min (dx + light, LOS_X0 + hx);
348	int ay1 = min (dy + light, LOS_Y0 + hy);
349
350	for (int ax = ax0; ax <= ax1; ax++)
351	for (int ay = ay0; ay <= ay1; ay++)
352	pl->los[ax][ay] =
353	change_it (pl->los[ax][ay], atten_table [idistance (ax - dx, ay - dy)]);
354	}
355
356	/* add light, by finding all (non-null) nearby light sources, then
357	* mark those squares specially.
358	*/
359	static void
360	apply_lights (player *pl)
361	{
362	object *op = pl->viewpoint;
363	int darklevel = op->map->darklevel ();
364
365	int half_x = pl->ns->mapx / 2;
366	int half_y = pl->ns->mapy / 2;
367
368	int pass2 = 0; // negative lights have an extra pass
369
370	maprect *rects = pl->viewpoint->map->split_to_tiles (
371	mapwalk_buf,
372	pl->viewpoint->x - half_x - MAX_LIGHT_RADIUS,
373	pl->viewpoint->y - half_y - MAX_LIGHT_RADIUS,
374	pl->viewpoint->x + half_x + MAX_LIGHT_RADIUS + 1,
375	pl->viewpoint->y + half_y + MAX_LIGHT_RADIUS + 1
376	);
377
378	/* If the player can see in the dark, increase light/vision radius */
379	int bonus = op->flag [FLAG_SEE_IN_DARK] ? SEE_IN_DARK_RADIUS : 0;
380
381	if (!darklevel)
382	pass2 = 1;
383	else
384	{
385	/* first, make everything totally dark */
386	for (int dx = -half_x; dx <= half_x; dx++)
387	for (int dy = -half_x; dy <= half_y; dy++)
388	max_it (pl->los[dx + LOS_X0][dy + LOS_Y0], LOS_MAX);
389
390	/*
391	* Only process the area of interest.
392	* the basex, basey values represent the position in the op->contr->los
393	* array. Its easier to just increment them here (and start with the right
394	* value) than to recalculate them down below.
395	*/
396	for (maprect *r = rects; r->m; ++r)
397	rect_mapwalk (r, 0, 0)
398	{
399	mapspace &ms = m->at (nx, ny);
400	ms.update ();
401	sint8 light = ms.light;
402
403	if (expect_false (light))
404	if (light < 0)
405	pass2 = 1;
406	else
407	{
408	light = clamp (light + bonus, 0, MAX_LIGHT_RADIUS);
409	apply_light<los_brighten> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, light, light_atten [light + MAX_LIGHT_RADIUS]);
410	}
411	}
412
413	/* grant some vision to the player, based on outside, outdoor, and darklevel */
414	{
415	int light;
416
417	if (!op->map->outdoor) // not outdoor, darkness becomes light radius
418	light = MAX_DARKNESS - op->map->darkness;
419	else if (op->map->darkness > 0) // outdoor and darkness > 0 => use darkness as max radius
420	light = lerp_rd (maptile::outdoor_darkness + 0, 0, MAX_DARKNESS, MAX_DARKNESS - op->map->darkness, 0);
421	else // outdoor and darkness <= 0 => start wide and decrease quickly
422	light = lerp (maptile::outdoor_darkness + op->map->darkness, 0, MAX_DARKNESS, MAX_VISION, 2);
423
424	light = clamp (light + bonus, 0, MAX_VISION);
425
426	apply_light<los_brighten> (pl, 0, 0, light, vision_atten [light]);
427	}
428	}
429
430	// when we fly high, we have some minimum viewable area around us, like x-ray
431	if (op->move_type & MOVE_FLY_HIGH)
432	apply_light<los_brighten_nolos> (pl, 0, 0, 9, vision_atten [9]);
433
434	// possibly do 2nd pass for rare negative glow radii
435	// for effect, those are always considered to be stronger than anything else
436	// but they can't darken a place completely
437	if (pass2)
438	for (maprect *r = rects; r->m; ++r)
439	rect_mapwalk (r, 0, 0)
440	{
441	mapspace &ms = m->at (nx, ny);
442	ms.update ();
443	sint8 light = ms.light;
444
445	if (expect_false (light < 0))
446	{
447	light = clamp (light - bonus, 0, MAX_DARKNESS);
448	apply_light<los_darken> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, -light, light_atten [light + MAX_LIGHT_RADIUS]);
449	}
450	}
451	}
452
453	/* blinded_sight() - sets all viewable squares to blocked except
454	* for the one the central one that the player occupies. A little
455	* odd that you can see yourself (and what your standing on), but
456	* really need for any reasonable game play.
457	*/
458	static void
459	blinded_sight (player *pl)
460	{
461	pl->los[LOS_X0][LOS_Y0] = 1;
462	}
463
464	/*
465	* update_los() recalculates the array which specifies what is
466	* visible for the given player-object.
467	*/
468	void
469	player::update_los ()
470	{
471	if (ob->flag [FLAG_REMOVED])//D really needed?
472	return;
473
474	if (ob->flag [FLAG_WIZLOOK])
475	clear_los (0);
476	else if (viewpoint->flag [FLAG_BLIND]) /* player is blind */
477	{
478	clear_los ();
479	blinded_sight (this);
480	}
481	else
482	{
483	clear_los ();
484	calculate_los (this);
485	apply_lights (this);
486	}
487
488	if (viewpoint->flag [FLAG_XRAYS])
489	for (int dx = -2; dx <= 2; dx++)
490	for (int dy = -2; dy <= 2; dy++)
491	min_it (los[dx + LOS_X0][dy + LOS_Y0], 1);
492	}
493
494	/* update all_map_los is like update_all_los below,
495	* but updates everyone on the map, no matter where they
496	* are. This generally should not be used, as a per
497	* specific map change doesn't make much sense when tiling
498	* is considered (lowering darkness would certainly be a
499	* strange effect if done on a tile map, as it makes
500	* the distinction between maps much more obvious to the
501	* players, which is should not be.
502	* Currently, this function is called from the
503	* change_map_light function
504	*/
505	void
506	update_all_map_los (maptile *map)
507	{
508	for_all_players_on_map (pl, map)
509	pl->do_los = 1;
510	}
511
512	/*
513	* This function makes sure that update_los() will be called for all
514	* players on the given map within the next frame.
515	* It is triggered by removal or inserting of objects which blocks
516	* the sight in the map.
517	* Modified by MSW 2001-07-12 to take a coordinate of the changed
518	* position, and to also take map tiling into account. This change
519	* means that just being on the same map is not sufficient - the
520	* space that changes must be withing your viewable area.
521	*
522	* map is the map that changed, x and y are the coordinates.
523	*/
524	void
525	update_all_los (const maptile *map, int x, int y)
526	{
527	map->at (x, y).invalidate ();
528
529	for_all_players (pl)
530	{
531	/* Player should not have a null map, but do this
532	* check as a safety
533	*/
534	if (!pl->ob \|\| !pl->ob->map \|\| !pl->ns)
535	continue;
536
537	rv_vector rv;
538
539	get_rangevector_from_mapcoord (pl->ob->map, x, y, pl->ob, &rv);
540
541	if ((abs (rv.distance_x) <= pl->ns->mapx / 2) && (abs (rv.distance_y) <= pl->ns->mapy / 2))
542	pl->do_los = 1;
543	}
544	}
545
546	static const int season_darkness[5][HOURS_PER_DAY] = {
547	/0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5 6 7 8 9 10 11 12 13 /
548	{ 5, 5, 4, 4, 4, 4, 4, 3, 3, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 1, 2, 2, 2, 3, 3, 4, 4, 5 },
549	{ 5, 5, 4, 4, 4, 4, 3, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4 },
550	{ 5, 4, 4, 4, 4, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 4, 4 },
551	{ 4, 4, 4, 4, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 4 },
552	{ 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4 }
553	};
554
555	/*
556	* Tell players the time and compute the darkness level for all maps in the game.
557	* MUST be called exactly once per hour.
558	*/
559	void
560	maptile::adjust_daylight ()
561	{
562	timeofday_t tod;
563
564	get_tod (&tod);
565
566	// log the time to log-1 every hour, and to chat every day
567	{
568	char todbuf[512];
569
570	format_tod (todbuf, sizeof (todbuf), &tod);
571
572	for_all_players (pl)
573	pl->ns->send_msg (NDI_GREY, tod.hour == 15 ? CHAT_CHANNEL : LOG_CHANNEL, todbuf);
574	}
575
576	/* If the light level isn't changing, no reason to do all
577	* the work below.
578	*/
579	sint8 new_darkness = season_darkness[tod.season][tod.hour];
580
581	if (new_darkness == maptile::outdoor_darkness)
582	return;
583
584	new_draw_info (NDI_GREY \| NDI_UNIQUE \| NDI_ALL, 1, 0,
585	new_darkness > maptile::outdoor_darkness
586	? "It becomes darker."
587	: "It becomes brighter.");
588
589	maptile::outdoor_darkness = new_darkness;
590
591	// we simply update the los for all players, which is unnecessarily
592	// costly, but should do for the moment.
593	for_all_players (pl)
594	pl->do_los = 1;
595	}
596
597	/*
598	* make_sure_seen: The object is supposed to be visible through walls, thus
599	* check if any players are nearby, and edit their LOS array.
600	*/
601	void
602	make_sure_seen (const object *op)
603	{
604	for_all_players (pl)
605	if (pl->ob->map == op->map &&
606	pl->ob->y - pl->ns->mapy / 2 <= op->y &&
607	pl->ob->y + pl->ns->mapy / 2 >= op->y && pl->ob->x - pl->ns->mapx / 2 <= op->x && pl->ob->x + pl->ns->mapx / 2 >= op->x)
608	pl->los[op->x - pl->ob->x + LOS_X0][op->y - pl->ob->y + LOS_Y0] = 0;
609	}
610
611	/*
612	* make_sure_not_seen: The object which is supposed to be visible through
613	* walls has just been removed from the map, so update the los of any
614	* players within its range
615	*/
616	void
617	make_sure_not_seen (const object *op)
618	{
619	for_all_players (pl)
620	if (pl->ob->map == op->map &&
621	pl->ob->y - pl->ns->mapy / 2 <= op->y &&
622	pl->ob->y + pl->ns->mapy / 2 >= op->y && pl->ob->x - pl->ns->mapx / 2 <= op->x && pl->ob->x + pl->ns->mapx / 2 >= op->x)
623	pl->do_los = 1;
624	}
625