server/common/los.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009 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
};

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 (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 (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 (
    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 (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:	1.66
Committed:	Fri Nov 6 13:03:34 2009 UTC (14 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_90
Changes since 1.65:	+21 -18 lines
Log Message:	make effectively static symbols actually static, part 2
#	User	Rev	Content
1	elmex	1.1	/*
2	root	1.29	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	pippijn	1.19	*
4	root	1.60	* Copyright (©) 2005,2006,2007,2008,2009 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	pippijn	1.19	*
6	root	1.62	* 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	pippijn	1.19	*
11	root	1.28	* 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	pippijn	1.19	*
16	root	1.62	* 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	root	1.26	*
20	root	1.29	* The authors can be reached via e-mail to <support@deliantra.net>
21	pippijn	1.19	*/
22	elmex	1.1
23			#include <global.h>
24	root	1.41	#include <cmath>
25	elmex	1.1
26	root	1.56	#define SEE_IN_DARK_RADIUS 2
27	root	1.57	#define MAX_VISION 10 // maximum visible radius
28	root	1.51
29	root	1.49	// los flags
30	root	1.41	enum {
31	root	1.49	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	root	1.41	};
36
37			struct los_info
38			{
39	root	1.49	uint8 flags; // FLG_xxx
40			uint8 culled; // culled from "tree"
41			uint8 visible;
42			uint8 pad0;
43
44	root	1.43	sint8 xo, yo; // obscure angle
45			sint8 xe, ye; // angle deviation
46	root	1.41	};
47
48			// temporary storage for the los algorithm,
49			// one los_info for each lightable map space
50			static los_info los[MAP_CLIENT_X][MAP_CLIENT_Y];
51
52			struct point
53			{
54			sint8 x, y;
55			};
56
57			// minimum size, but must be a power of two
58			#define QUEUE_LENGTH ((MAP_CLIENT_X + MAP_CLIENT_Y) * 2)
59
60			// a queue of spaces to calculate
61			static point queue [QUEUE_LENGTH];
62			static int q1, q2; // queue start, end
63	elmex	1.1
64			/*
65	root	1.41	* Clears/initialises the los-array associated to the player
66			* controlling the object.
67	elmex	1.1	*/
68	root	1.41	void
69	root	1.42	player::clear_los (sint8 value)
70	root	1.41	{
71	root	1.42	memset (los, value, sizeof (los));
72	root	1.41	}
73	elmex	1.1
74	root	1.41	// enqueue a single mapspace, but only if it hasn't
75			// been enqueued yet.
76	root	1.4	static void
77	root	1.41	enqueue (sint8 dx, sint8 dy, uint8 flags = 0)
78	root	1.4	{
79	root	1.41	sint8 x = LOS_X0 + dx;
80			sint8 y = LOS_Y0 + dy;
81
82			los_info &l = los[x][y];
83
84			l.flags \|= flags;
85
86	root	1.49	if (l.flags & FLG_QUEUED)
87	root	1.41	return;
88	elmex	1.1
89	root	1.49	l.flags \|= FLG_QUEUED;
90	root	1.41
91			queue[q1].x = dx;
92			queue[q1].y = dy;
93	elmex	1.1
94	root	1.41	q1 = (q1 + 1) & (QUEUE_LENGTH - 1);
95	elmex	1.1	}
96
97	root	1.41	// run the los algorithm
98			// this is a variant of a spiral los algorithm taken from
99			// http://www.geocities.com/temerra/los_rays.html
100			// which has been simplified and changed considerably, but
101			// still is basically the same algorithm.
102			static void
103	root	1.48	calculate_los (player *pl)
104	root	1.4	{
105	root	1.49	{
106	root	1.52	memset (los, 0, sizeof (los));
107
108	root	1.49	// we keep one line for ourselves, for the border flag
109			// so the client area is actually MAP_CLIENT_(X\|Y) - 2
110			int half_x = min (LOS_X0 - 1, pl->ns->mapx / 2);
111			int half_y = min (LOS_Y0 - 1, pl->ns->mapy / 2);
112
113			// create borders, the corners are not touched
114			for (int dx = -half_x; dx <= half_x; ++dx)
115			los [dx + LOS_X0][LOS_Y0 - (half_y + 1)].flags =
116			los [dx + LOS_X0][LOS_Y0 + (half_y + 1)].flags = FLG_QUEUED;
117
118			for (int dy = -half_y; dy <= half_y; ++dy)
119			los [LOS_X0 - (half_x + 1)][dy + LOS_Y0].flags =
120			los [LOS_X0 + (half_x + 1)][dy + LOS_Y0].flags = FLG_QUEUED;
121
122			// now reset the los area and also add blocked flags
123			// which supposedly is faster than doing it inside the
124			// spiral path algorithm below, except when very little
125	root	1.54	// area is visible, in which case it is slower. which evens
126	root	1.49	// out los calculation times between large and small los maps.
127			// apply_lights also iterates over this area, maybe these
128			// two passes could be combined somehow.
129	root	1.64	unordered_mapwalk (pl->viewpoint, -half_x, -half_y, half_x, half_y)
130	root	1.52	{
131			los_info &l = los [LOS_X0 + dx][LOS_Y0 + dy];
132			l.flags = m->at (nx, ny).flags () & P_BLOCKSVIEW ? FLG_BLOCKED : 0;
133			}
134	root	1.49	}
135	root	1.4
136	root	1.41	q1 = 0; q2 = 0; // initialise queue, not strictly required
137			enqueue (0, 0); // enqueue center
138	root	1.4
139	root	1.41	// treat the origin specially
140			los[LOS_X0][LOS_Y0].visible = 1;
141			pl->los[LOS_X0][LOS_Y0] = 0;
142
143			// loop over all enqueued points until the queue is empty
144			// the order in which this is done ensures that we
145			// never touch a mapspace whose input spaces we haven't checked
146			// yet.
147			while (q1 != q2)
148			{
149			sint8 dx = queue[q2].x;
150			sint8 dy = queue[q2].y;
151	root	1.4
152	root	1.41	q2 = (q2 + 1) & (QUEUE_LENGTH - 1);
153	root	1.4
154	root	1.41	sint8 x = LOS_X0 + dx;
155			sint8 y = LOS_Y0 + dy;
156	elmex	1.1
157	root	1.41	los_info &l = los[x][y];
158	elmex	1.1
159	root	1.49	if (expect_true (l.flags & (FLG_XI \| FLG_YI)))
160	root	1.41	{
161			l.culled = 1;
162	root	1.49	l.xo = l.yo = l.xe = l.ye = 0;
163	elmex	1.1
164	root	1.41	// check contributing spaces, first horizontal
165	root	1.49	if (expect_true (l.flags & FLG_XI))
166	root	1.41	{
167			los_info *xi = &los[x - sign (dx)][y];
168	elmex	1.1
169	root	1.41	// don't cull unless obscured
170			l.culled &= !xi->visible;
171	elmex	1.1
172	root	1.41	/* merge input space */
173			if (expect_false (xi->xo \|\| xi->yo))
174			{
175			// The X input can provide two main pieces of information:
176			// 1. Progressive X obscurity.
177			// 2. Recessive Y obscurity.
178
179			// Progressive X obscurity, favouring recessive input angle
180			if (xi->xe > 0 && l.xo == 0)
181			{
182			l.xe = xi->xe - xi->yo;
183			l.ye = xi->ye + xi->yo;
184			l.xo = xi->xo;
185			l.yo = xi->yo;
186			}
187	root	1.4
188	root	1.41	// Recessive Y obscurity
189			if (xi->ye <= 0 && xi->yo > 0 && xi->xe > 0)
190			{
191			l.ye = xi->yo + xi->ye;
192			l.xe = xi->xe - xi->yo;
193			l.xo = xi->xo;
194			l.yo = xi->yo;
195			}
196			}
197			}
198
199			// check contributing spaces, last vertical, identical structure
200	root	1.49	if (expect_true (l.flags & FLG_YI))
201	root	1.41	{
202			los_info *yi = &los[x][y - sign (dy)];
203	elmex	1.1
204	root	1.41	// don't cull unless obscured
205			l.culled &= !yi->visible;
206	elmex	1.1
207	root	1.41	/* merge input space */
208			if (expect_false (yi->yo \|\| yi->xo))
209			{
210			// The Y input can provide two main pieces of information:
211			// 1. Progressive Y obscurity.
212			// 2. Recessive X obscurity.
213
214			// Progressive Y obscurity, favouring recessive input angle
215			if (yi->ye > 0 && l.yo == 0)
216			{
217			l.ye = yi->ye - yi->xo;
218			l.xe = yi->xe + yi->xo;
219			l.yo = yi->yo;
220			l.xo = yi->xo;
221			}
222	elmex	1.1
223	root	1.41	// Recessive X obscurity
224			if (yi->xe <= 0 && yi->xo > 0 && yi->ye > 0)
225			{
226			l.xe = yi->xo + yi->xe;
227			l.ye = yi->ye - yi->xo;
228			l.yo = yi->yo;
229			l.xo = yi->xo;
230			}
231			}
232			}
233	elmex	1.1
234	root	1.49	if (l.flags & FLG_BLOCKED)
235	root	1.41	{
236			l.xo = l.xe = abs (dx);
237			l.yo = l.ye = abs (dy);
238	elmex	1.1
239	root	1.41	// we obscure dependents, but might be visible
240			// copy the los from the square towards the player,
241			// so outward diagonal corners are lit.
242			pl->los[x][y] = los[x - sign0 (dx)][y - sign0 (dy)].visible ? 0 : LOS_BLOCKED;
243	root	1.49
244	root	1.41	l.visible = false;
245			}
246			else
247			{
248			// we are not blocked, so calculate visibility, by checking
249			// whether we are inside or outside the shadow
250			l.visible = (l.xe <= 0 \|\| l.xe > l.xo)
251			&& (l.ye <= 0 \|\| l.ye > l.yo);
252
253			pl->los[x][y] = l.culled ? LOS_BLOCKED
254	root	1.49	: l.visible ? 0
255	root	1.41	: 3;
256	root	1.37	}
257	root	1.41
258	root	1.37	}
259	root	1.4
260	root	1.41	// Expands by the unit length in each component's current direction.
261			// If a component has no direction, then it is expanded in both of its
262			// positive and negative directions.
263			if (!l.culled)
264			{
265	root	1.49	if (dx >= 0) enqueue (dx + 1, dy, FLG_XI);
266			if (dx <= 0) enqueue (dx - 1, dy, FLG_XI);
267			if (dy >= 0) enqueue (dx, dy + 1, FLG_YI);
268			if (dy <= 0) enqueue (dx, dy - 1, FLG_YI);
269	root	1.41	}
270			}
271	elmex	1.1	}
272
273	root	1.32	/* radius, distance => lightness adjust */
274	root	1.44	static sint8 light_atten[MAX_LIGHT_RADIUS * 2 + 1][MAX_LIGHT_RADIUS * 3 / 2 + 1];
275	root	1.57	static sint8 vision_atten[MAX_VISION + 1][MAX_VISION * 3 / 2 + 1];
276	root	1.32
277	root	1.44	static struct los_init
278	root	1.32	{
279	root	1.44	los_init ()
280	root	1.32	{
281	root	1.49	assert (("QUEUE_LENGTH, MAP_CLIENT_X and MAP_CLIENT_Y must be powers of two",
282			!(QUEUE_LENGTH & (QUEUE_LENGTH - 1))));
283
284	root	1.45	/* for lights */
285	root	1.32	for (int radius = -MAX_LIGHT_RADIUS; radius <= MAX_LIGHT_RADIUS; ++radius)
286	root	1.35	for (int distance = 0; distance <= MAX_LIGHT_RADIUS * 3 / 2; ++distance)
287	root	1.32	{
288			// max intensity
289	root	1.36	int intensity = min (LOS_MAX, abs (radius) + 1);
290	root	1.32
291			// actual intensity
292	root	1.61	intensity = max (0, lerp_ru (distance, 0, abs (radius) + 1, intensity, 0));
293	root	1.32
294	root	1.44	light_atten [radius + MAX_LIGHT_RADIUS][distance] = radius < 0
295	root	1.35	? min (3, intensity)
296	root	1.36	: LOS_MAX - intensity;
297	root	1.32	}
298	root	1.45
299			/* for general vision */
300	root	1.57	for (int radius = 0; radius <= MAX_VISION; ++radius)
301			for (int distance = 0; distance <= MAX_VISION * 3 / 2; ++distance)
302			vision_atten [radius][distance] = distance <= radius ? clamp (lerp (radius, 0, MAX_DARKNESS, 3, 0), 0, 3) : 4;
303	root	1.32	}
304	root	1.44	} los_init;
305	root	1.32
306	root	1.66	// the following functions cannot be static, due to c++ stupidity :/
307			namespace {
308			// brighten area, ignore los
309			sint8
310			los_brighten_nolos (sint8 b, sint8 l)
311			{
312			return min (b, l);
313			}
314	root	1.64
315	root	1.66	// brighten area, but respect los
316			sint8
317			los_brighten (sint8 b, sint8 l)
318			{
319			return b == LOS_BLOCKED ? b : min (b, l);
320			}
321	root	1.39
322	root	1.66	// darken area, respect los
323			sint8
324			los_darken (sint8 b, sint8 l)
325			{
326			return max (b, l);
327			}
328			};
329	root	1.39
330			template<sint8 change_it (sint8, sint8)>
331			static void
332	root	1.48	apply_light (player pl, int dx, int dy, int light, const sint8 atten_table)
333	root	1.39	{
334	root	1.41	// min or max the circular area around basex, basey
335			dx += LOS_X0;
336			dy += LOS_Y0;
337
338	root	1.48	int hx = pl->ns->mapx / 2;
339			int hy = pl->ns->mapy / 2;
340	root	1.41
341			int ax0 = max (LOS_X0 - hx, dx - light);
342			int ay0 = max (LOS_Y0 - hy, dy - light);
343			int ax1 = min (dx + light, LOS_X0 + hx);
344			int ay1 = min (dy + light, LOS_Y0 + hy);
345	root	1.39
346			for (int ax = ax0; ax <= ax1; ax++)
347			for (int ay = ay0; ay <= ay1; ay++)
348	root	1.41	pl->los[ax][ay] =
349	root	1.44	change_it (pl->los[ax][ay], atten_table [idistance (ax - dx, ay - dy)]);
350	root	1.39	}
351
352			/* add light, by finding all (non-null) nearby light sources, then
353			* mark those squares specially.
354			*/
355	root	1.4	static void
356	root	1.48	apply_lights (player *pl)
357	root	1.4	{
358	root	1.64	object *op = pl->viewpoint;
359	root	1.48	int darklevel = op->map->darklevel ();
360	root	1.4
361	root	1.48	int half_x = pl->ns->mapx / 2;
362			int half_y = pl->ns->mapy / 2;
363	root	1.32
364			int pass2 = 0; // negative lights have an extra pass
365
366	root	1.64	maprect *rects = pl->viewpoint->map->split_to_tiles (
367			pl->viewpoint->x - half_x - MAX_LIGHT_RADIUS,
368			pl->viewpoint->y - half_y - MAX_LIGHT_RADIUS,
369			pl->viewpoint->x + half_x + MAX_LIGHT_RADIUS + 1,
370			pl->viewpoint->y + half_y + MAX_LIGHT_RADIUS + 1
371	root	1.52	);
372
373	root	1.57	/* If the player can see in the dark, increase light/vision radius */
374			int bonus = op->flag [FLAG_SEE_IN_DARK] ? SEE_IN_DARK_RADIUS : 0;
375
376	root	1.48	if (!darklevel)
377	root	1.39	pass2 = 1;
378			else
379			{
380			/* first, make everything totally dark */
381	root	1.41	for (int dx = -half_x; dx <= half_x; dx++)
382			for (int dy = -half_x; dy <= half_y; dy++)
383	root	1.49	max_it (pl->los[dx + LOS_X0][dy + LOS_Y0], LOS_MAX);
384	root	1.39
385			/*
386			* Only process the area of interest.
387	root	1.41	* the basex, basey values represent the position in the op->contr->los
388			* array. Its easier to just increment them here (and start with the right
389	root	1.39	* value) than to recalculate them down below.
390			*/
391	root	1.52	for (maprect *r = rects; r->m; ++r)
392			rect_mapwalk (r, 0, 0)
393	root	1.39	{
394			mapspace &ms = m->at (nx, ny);
395			ms.update ();
396			sint8 light = ms.light;
397
398			if (expect_false (light))
399			if (light < 0)
400			pass2 = 1;
401			else
402	root	1.57	{
403			light = clamp (light + bonus, 0, MAX_LIGHT_RADIUS);
404	root	1.64	apply_light<los_brighten> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, light, light_atten [light + MAX_LIGHT_RADIUS]);
405	root	1.57	}
406	root	1.39	}
407
408	root	1.57	/* grant some vision to the player, based on outside, outdoor, and darklevel */
409	root	1.32	{
410	root	1.57	int light;
411	root	1.39
412	root	1.57	if (!op->map->outdoor) // not outdoor, darkness becomes light radius
413	root	1.58	light = MAX_DARKNESS - op->map->darkness;
414	root	1.57	else if (op->map->darkness > 0) // outdoor and darkness > 0 => use darkness as max radius
415			light = lerp_rd (maptile::outdoor_darkness + 0, 0, MAX_DARKNESS, MAX_DARKNESS - op->map->darkness, 0);
416			else // outdoor and darkness <= 0 => start wide and decrease quickly
417			light = lerp (maptile::outdoor_darkness + op->map->darkness, 0, MAX_DARKNESS, MAX_VISION, 2);
418
419	root	1.59	light = clamp (light + bonus, 0, MAX_VISION);
420	root	1.51
421	root	1.48	apply_light<los_brighten> (pl, 0, 0, light, vision_atten [light]);
422	root	1.32	}
423	root	1.39	}
424	root	1.4
425	root	1.64	// when we fly high, we have some minimum viewable area around us, like x-ray
426			if (op->move_type & MOVE_FLY_HIGH)
427			apply_light<los_brighten_nolos> (pl, 0, 0, 9, vision_atten [9]);
428
429	root	1.38	// possibly do 2nd pass for rare negative glow radii
430	root	1.39	// for effect, those are always considered to be stronger than anything else
431			// but they can't darken a place completely
432			if (pass2)
433	root	1.52	for (maprect *r = rects; r->m; ++r)
434			rect_mapwalk (r, 0, 0)
435			{
436			mapspace &ms = m->at (nx, ny);
437			ms.update ();
438			sint8 light = ms.light;
439
440			if (expect_false (light < 0))
441	root	1.57	{
442			light = clamp (light - bonus, 0, MAX_DARKNESS);
443	root	1.64	apply_light<los_darken> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, -light, light_atten [light + MAX_LIGHT_RADIUS]);
444	root	1.57	}
445	root	1.52	}
446	elmex	1.1	}
447
448	root	1.31	/* blinded_sight() - sets all viewable squares to blocked except
449	elmex	1.1	* for the one the central one that the player occupies. A little
450			* odd that you can see yourself (and what your standing on), but
451			* really need for any reasonable game play.
452			*/
453	root	1.4	static void
454	root	1.48	blinded_sight (player *pl)
455	root	1.4	{
456	root	1.48	pl->los[LOS_X0][LOS_Y0] = 1;
457	elmex	1.1	}
458
459			/*
460			* update_los() recalculates the array which specifies what is
461			* visible for the given player-object.
462			*/
463	root	1.4	void
464	root	1.48	player::update_los ()
465	root	1.4	{
466	root	1.48	if (ob->flag [FLAG_REMOVED])//D really needed?
467	root	1.4	return;
468	elmex	1.1
469	root	1.48	if (ob->flag [FLAG_WIZLOOK])
470	root	1.49	clear_los (0);
471	root	1.64	else if (viewpoint->flag [FLAG_BLIND]) /* player is blind */
472	root	1.49	{
473			clear_los ();
474			blinded_sight (this);
475			}
476	root	1.4	else
477	root	1.41	{
478	root	1.49	clear_los ();
479	root	1.48	calculate_los (this);
480			apply_lights (this);
481	root	1.41	}
482	root	1.4
483	root	1.64	if (viewpoint->flag [FLAG_XRAYS])
484	root	1.41	for (int dx = -2; dx <= 2; dx++)
485			for (int dy = -2; dy <= 2; dy++)
486	root	1.49	min_it (los[dx + LOS_X0][dy + LOS_Y0], 1);
487	elmex	1.1	}
488
489			/* update all_map_los is like update_all_los below,
490			* but updates everyone on the map, no matter where they
491	root	1.12	* are. This generally should not be used, as a per
492	elmex	1.1	* specific map change doesn't make much sense when tiling
493			* is considered (lowering darkness would certainly be a
494			* strange effect if done on a tile map, as it makes
495			* the distinction between maps much more obvious to the
496			* players, which is should not be.
497			* Currently, this function is called from the
498			* change_map_light function
499			*/
500	root	1.4	void
501	root	1.6	update_all_map_los (maptile *map)
502	root	1.4	{
503	root	1.46	for_all_players_on_map (pl, map)
504			pl->do_los = 1;
505	elmex	1.1	}
506
507			/*
508			* This function makes sure that update_los() will be called for all
509			* players on the given map within the next frame.
510			* It is triggered by removal or inserting of objects which blocks
511			* the sight in the map.
512			* Modified by MSW 2001-07-12 to take a coordinate of the changed
513			* position, and to also take map tiling into account. This change
514			* means that just being on the same map is not sufficient - the
515			* space that changes must be withing your viewable area.
516			*
517			* map is the map that changed, x and y are the coordinates.
518			*/
519	root	1.4	void
520	root	1.6	update_all_los (const maptile *map, int x, int y)
521	root	1.4	{
522	root	1.46	map->at (x, y).invalidate ();
523
524	root	1.11	for_all_players (pl)
525	root	1.4	{
526			/* Player should not have a null map, but do this
527			* check as a safety
528			*/
529	root	1.12	if (!pl->ob \|\| !pl->ob->map \|\| !pl->ns)
530	root	1.4	continue;
531
532	root	1.61	rv_vector rv;
533
534			get_rangevector_from_mapcoord (map, x, y, pl->ob, &rv);
535
536			if ((abs (rv.distance_x) <= pl->ns->mapx / 2) && (abs (rv.distance_y) <= pl->ns->mapy / 2))
537			pl->do_los = 1;
538	elmex	1.1	}
539			}
540
541	root	1.48	static const int season_darkness[5][HOURS_PER_DAY] = {
542			/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 /
543			{ 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 },
544			{ 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 },
545			{ 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 },
546			{ 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 },
547			{ 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 }
548	root	1.47	};
549
550	root	1.48	/*
551			* Tell players the time and compute the darkness level for all maps in the game.
552			* MUST be called exactly once per hour.
553			*/
554	root	1.47	void
555	root	1.48	maptile::adjust_daylight ()
556	root	1.47	{
557			timeofday_t tod;
558
559			get_tod (&tod);
560
561	root	1.48	// log the time to log-1 every hour, and to chat every day
562			{
563			char todbuf[512];
564	root	1.47
565	root	1.48	format_tod (todbuf, sizeof (todbuf), &tod);
566	root	1.47
567	root	1.48	for_all_players (pl)
568			pl->ns->send_msg (NDI_GREY, tod.hour == 15 ? CHAT_CHANNEL : LOG_CHANNEL, todbuf);
569			}
570	root	1.47
571			/* If the light level isn't changing, no reason to do all
572			* the work below.
573			*/
574	root	1.48	sint8 new_darkness = season_darkness[tod.season][tod.hour];
575
576			if (new_darkness == maptile::outdoor_darkness)
577	root	1.47	return;
578
579	root	1.48	new_draw_info (NDI_GREY \| NDI_UNIQUE \| NDI_ALL, 1, 0,
580			new_darkness > maptile::outdoor_darkness
581			? "It becomes darker."
582			: "It becomes brighter.");
583	root	1.47
584	root	1.48	maptile::outdoor_darkness = new_darkness;
585	root	1.47
586	root	1.48	// we simply update the los for all players, which is unnecessarily
587			// costly, but should do for the moment.
588			for_all_players (pl)
589			pl->do_los = 1;
590	root	1.47	}
591
592	elmex	1.1	/*
593			* make_sure_seen: The object is supposed to be visible through walls, thus
594			* check if any players are nearby, and edit their LOS array.
595			*/
596	root	1.4	void
597			make_sure_seen (const object *op)
598			{
599	root	1.11	for_all_players (pl)
600	root	1.4	if (pl->ob->map == op->map &&
601	root	1.10	pl->ob->y - pl->ns->mapy / 2 <= op->y &&
602			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)
603	root	1.49	pl->los[op->x - pl->ob->x + LOS_X0][op->y - pl->ob->y + LOS_Y0] = 0;
604	elmex	1.1	}
605
606			/*
607			* make_sure_not_seen: The object which is supposed to be visible through
608			* walls has just been removed from the map, so update the los of any
609			* players within its range
610			*/
611	root	1.4	void
612			make_sure_not_seen (const object *op)
613			{
614	root	1.11	for_all_players (pl)
615	root	1.4	if (pl->ob->map == op->map &&
616	root	1.10	pl->ob->y - pl->ns->mapy / 2 <= op->y &&
617			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)
618	root	1.4	pl->do_los = 1;
619	elmex	1.1	}
620	root	1.52