server/common/los.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * Copyright (©) 2002,2007 Mark Wedel & Crossfire Development Team
 * Copyright (©) 1992,2007 Frank Tore Johansen
 * 
 * Deliantra is free software: you can redistribute it and/or modify
 * it under the terms of the 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 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>
 */

/* Nov 95 - inserted USE_LIGHTING code stuff in here - b.t. */

#include <global.h>
#include <math.h>

/* Distance must be less than this for the object to be blocked.
 * An object is 1.0 wide, so if set to 0.5, it means the object
 * that blocks half the view (0.0 is complete block) will
 * block view in our tables.
 * .4 or less lets you see through walls.  .5 is about right.
 */
#define SPACE_BLOCK     0.5

typedef struct blstr
{
  int x[4], y[4];
  int index;
} blocks;

// 31/32 == a speed hack
// we would like to use 32 for speed, but the code loops endlessly
// then, reason not yet identified, so only make the array use 32,
// not the define's.
blocks block[MAP_CLIENT_X][MAP_CLIENT_Y == 31 ? 32 : MAP_CLIENT_Y];

static void expand_lighted_sight (object *op);

/*
 * Used to initialise the array used by the LOS routines.
 * What this sets if that x,y blocks the view of bx,by
 * This then sets up a relation - for example, something
 * at 5,4 blocks view at 5,3 which blocks view at 5,2
 * etc.  So when we check 5,4 and find it block, we have
 * the data to know that 5,3 and 5,2 and 5,1 should also
 * be blocked.
 */

static void
set_block (int x, int y, int bx, int by)
{
  int index = block[x][y].index, i;

  /* Due to flipping, we may get duplicates - better safe than sorry.
   */
  for (i = 0; i < index; i++)
    {
      if (block[x][y].x[i] == bx && block[x][y].y[i] == by)
        return;
    }

  block[x][y].x[index] = bx;
  block[x][y].y[index] = by;
  block[x][y].index++;
#ifdef LOS_DEBUG
  LOG (llevDebug, "setblock: added %d %d -> %d %d (%d)\n", x, y, bx, by, block[x][y].index);
#endif
}

/*
 * initialises the array used by the LOS routines.
 */

/* since we are only doing the upper left quadrant, only
 * these spaces could possibly get blocked, since these
 * are the only ones further out that are still possibly in the
 * sightline.
 */
void
init_block (void)
{
  static int block_x[3] = { -1, -1, 0 },
             block_y[3] = { -1, 0, -1 }; 

  for (int x = 0; x < MAP_CLIENT_X; x++)
    for (int y = 0; y < MAP_CLIENT_Y; y++)
      block[x][y].index = 0;

  /* The table should be symmetric, so only do the upper left
   * quadrant - makes the processing easier.
   */
  for (int x = 1; x <= MAP_CLIENT_X / 2; x++)
    {
      for (int y = 1; y <= MAP_CLIENT_Y / 2; y++)
        {
          for (int i = 0; i < 3; i++)
            {
              int dx = x + block_x[i];
              int dy = y + block_y[i];

              /* center space never blocks */
              if (x == MAP_CLIENT_X / 2 && y == MAP_CLIENT_Y / 2)
                continue;

              /* If its a straight line, its blocked */
              if ((dx == x && x == MAP_CLIENT_X / 2) || (dy == y && y == MAP_CLIENT_Y / 2))
                {
                  /* For simplicity, we mirror the coordinates to block the other
                   * quadrants.
                   */
                  set_block (x, y, dx, dy);
                  if (x == MAP_CLIENT_X / 2)
                    set_block (x, MAP_CLIENT_Y - y - 1, dx, MAP_CLIENT_Y - dy - 1);
                  else if (y == MAP_CLIENT_Y / 2)
                    set_block (MAP_CLIENT_X - x - 1, y, MAP_CLIENT_X - dx - 1, dy);
                }
              else
                {
                  float d1, r, s, l;

                  /* We use the algorithm that found out how close the point
                   * (x,y) is to the line from dx,dy to the center of the viewable
                   * area. l is the distance from x,y to the line.
                   * r is more a curiosity - it lets us know what direction (left/right)
                   * the line is off
                   */

                  d1 = (powf (MAP_CLIENT_X / 2 - dx, 2.f) + powf (MAP_CLIENT_Y / 2 - dy, 2.f));
                  r = ((dy - y) * (dy - MAP_CLIENT_Y / 2) - (dx - x) * (MAP_CLIENT_X / 2 - dx)) / d1;
                  s = ((dy - y) * (MAP_CLIENT_X / 2 - dx) - (dx - x) * (MAP_CLIENT_Y / 2 - dy)) / d1;
                  l = fabs (sqrtf (d1) * s);

                  if (l <= SPACE_BLOCK)
                    {
                      /* For simplicity, we mirror the coordinates to block the other
                       * quadrants.
                       */
                      set_block (x, y, dx, dy);
                      set_block (MAP_CLIENT_X - x - 1, y, MAP_CLIENT_X - dx - 1, dy);
                      set_block (x, MAP_CLIENT_Y - y - 1, dx, MAP_CLIENT_Y - dy - 1);
                      set_block (MAP_CLIENT_X - x - 1, MAP_CLIENT_Y - y - 1, MAP_CLIENT_X - dx - 1, MAP_CLIENT_Y - dy - 1);
                    }
                }
            }
        }
    }
}

/*
 * Used to initialise the array used by the LOS routines.
 * x,y are indexes into the blocked[][] array.
 * This recursively sets the blocked line of sight view.
 * From the blocked[][] array, we know for example
 * that if some particular space is blocked, it blocks
 * the view of the spaces 'behind' it, and those blocked
 * spaces behind it may block other spaces, etc.  
 * In this way, the chain of visibility is set.
 */
static void
set_wall (object *op, int x, int y)
{
  for (int i = 0; i < block[x][y].index; i++)
    {
      int dx = block[x][y].x[i], dy = block[x][y].y[i], ax, ay;

      /* ax, ay are the values as adjusted to be in the
       * socket look structure.
       */
      ax = dx - (MAP_CLIENT_X - op->contr->ns->mapx) / 2;
      ay = dy - (MAP_CLIENT_Y - op->contr->ns->mapy) / 2;

      if (ax < 0 || ax >= op->contr->ns->mapx || ay < 0 || ay >= op->contr->ns->mapy)
        continue;
#if 0
      LOG (llevDebug, "blocked %d %d -> %d %d\n", dx, dy, ax, ay);
#endif
      /* we need to adjust to the fact that the socket
       * code wants the los to start from the 0,0
       * and not be relative to middle of los array.
       */
      op->contr->blocked_los[ax][ay] = LOS_BLOCKED;
      set_wall (op, dx, dy);
    }
}

/*
 * Used to initialise the array used by the LOS routines.
 * op is the object, x and y values based on MAP_CLIENT_X and Y.
 * this is because they index the blocked[][] arrays.
 */
static void
check_wall (object *op, int x, int y)
{
  int ax, ay;

  if (!block[x][y].index)
    return;

  /* ax, ay are coordinates as indexed into the look window */
  ax = x - (MAP_CLIENT_X - op->contr->ns->mapx) / 2;
  ay = y - (MAP_CLIENT_Y - op->contr->ns->mapy) / 2;

  /* If the converted coordinates are outside the viewable
   * area for the client, return now.
   */
  if (ax < 0 || ay < 0 || ax >= op->contr->ns->mapx || ay >= op->contr->ns->mapy)
    return;

#if 0
  LOG (llevDebug, "check_wall, ax,ay=%d, %d  x,y = %d, %d  blocksview = %d, %d\n",
       ax, ay, x, y, op->x + x - MAP_CLIENT_X / 2, op->y + y - MAP_CLIENT_Y / 2);
#endif

  /* If this space is already blocked, prune the processing - presumably
   * whatever has set this space to be blocked has done the work and already
   * done the dependency chain.
   */
  if (op->contr->blocked_los[ax][ay] == LOS_BLOCKED)
    return;

  if (get_map_flags (op->map, NULL, op->x + x - MAP_CLIENT_X / 2, op->y + y - MAP_CLIENT_Y / 2, NULL, NULL) & (P_BLOCKSVIEW | P_OUT_OF_MAP))
    set_wall (op, x, y);
}

/*
 * Clears/initialises the los-array associated to the player
 * controlling the object.
 */

void
clear_los (player *pl)
{
  /* This is safer than using the ns->mapx, mapy because
   * we index the blocked_los as a 2 way array, so clearing
   * the first z spaces may not not cover the spaces we are
   * actually going to use
   */
  memset (pl->blocked_los, 0, MAP_CLIENT_X * MAP_CLIENT_Y);
}

/*
 * expand_sight goes through the array of what the given player is
 * able to see, and expands the visible area a bit, so the player will,
 * to a certain degree, be able to see into corners.
 * This is somewhat suboptimal, would be better to improve the formula.
 */
static void
expand_sight (object *op)
{
  for (int x = 1; x < op->contr->ns->mapx - 1; x++)      /* loop over inner squares */
    for (int y = 1; y < op->contr->ns->mapy - 1; y++)
      if (!op->contr->blocked_los[x][y] &&
          !(get_map_flags (op->map, NULL,
                           op->x - op->contr->ns->mapx / 2 + x,
                           op->y - op->contr->ns->mapy / 2 + y, NULL, NULL) & (P_BLOCKSVIEW | P_OUT_OF_MAP)))
        {
          for (int i = 1; i <= 8; i += 1)
            {                 /* mark all directions */
              int dx = x + freearr_x[i];
              int dy = y + freearr_y[i];

              if (op->contr->blocked_los[dx][dy] > 0) /* for any square blocked */
                op->contr->blocked_los[dx][dy] = -1;
            }
        }

  expand_lighted_sight (op);

  /* clear mark squares */
  for (int x = 0; x < op->contr->ns->mapx; x++)
    for (int y = 0; y < op->contr->ns->mapy; y++)
      if (op->contr->blocked_los[x][y] < 0)
        op->contr->blocked_los[x][y] = 0;
}

/* returns true if op carries one or more lights
 * This is a trivial function now days, but it used to
 * be a bit longer.  Probably better for callers to just
 * check the op->glow_radius instead of calling this.
 */
int
has_carried_lights (const object *op)
{
  /* op may glow! */
  if (op->glow_radius > 0)
    return 1;

  return 0;
}

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

static struct darkness_init
{
  darkness_init ()
  {
    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_rd (distance, 0, abs (radius) + 1, intensity, 0));

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

sint8
los_brighten (sint8 b, sint8 l)
{
  return b == LOS_BLOCKED ? b : min (b, l);
}

sint8
los_darken (sint8 b, sint8 l)
{
  return max (b, l);
}

template<sint8 change_it (sint8, sint8)>
static void
apply_light (object *op, int basex, int basey, int light, const sint8 *darkness_table)
{
  // min or max the ciruclar area around basex, basey
  player *pl = op->contr;

  int ax0 = max (0, basex - light);
  int ay0 = max (0, basey - light);
  int ax1 = min (basex + light, pl->ns->mapx - 1);
  int ay1 = min (basey + light, pl->ns->mapy - 1);

  for (int ax = ax0; ax <= ax1; ax++)
    for (int ay = ay0; ay <= ay1; ay++)
      pl->blocked_los[ax][ay] =
        change_it (pl->blocked_los[ax][ay], darkness_table [idistance (ax - basex, ay - basey)]);
}

/* add light, by finding all (non-null) nearby light sources, then 
 * mark those squares specially.
 */
static void
expand_lighted_sight (object *op)
{
  int darklevel, mflags, light, x1, y1;
  maptile *m = op->map;
  sint16 nx, ny;

  darklevel = m->darkness;

  /* If the player can see in the dark, lower the darklevel for him */
  if (QUERY_FLAG (op, FLAG_SEE_IN_DARK))
    darklevel -= LOS_MAX / 2;

  /* Do a sanity check.  If not valid, some code below may do odd
   * things.
   */
  if (darklevel > MAX_DARKNESS)
    {
      LOG (llevError, "Map darkness for %s on %s is too high (%d)\n", &op->name, &op->map->path, darklevel);
      darklevel = MAX_DARKNESS;
    }

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

  int min_x = op->x - half_x - MAX_LIGHT_RADIUS;
  int min_y = op->y - half_y - MAX_LIGHT_RADIUS;
  int max_x = op->x + half_x + MAX_LIGHT_RADIUS;
  int max_y = op->y + half_y + MAX_LIGHT_RADIUS;

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

  if (darklevel < 1)
    pass2 = 1;
  else
    {
      /* first, make everything totally dark */
      for (int x = 0; x < op->contr->ns->mapx; x++)
        for (int y = 0; y < op->contr->ns->mapy; y++)
          if (op->contr->blocked_los[x][y] != LOS_BLOCKED)
            op->contr->blocked_los[x][y] = LOS_MAX;

      /*
       * Only process the area of interest.
       * the basex, basey values represent the position in the op->contr->blocked_los
       * array.  Its easier to just increment them here (and start with the right
       * value) than to recalculate them down below.
       */
      for (int x = min_x, basex = -MAX_LIGHT_RADIUS; x <= max_x; x++, basex++)
        for (int y = min_y, basey = -MAX_LIGHT_RADIUS; y <= max_y; y++, basey++)
          {
            maptile *m = op->map;
            sint16 nx = x;
            sint16 ny = y;

            if (!xy_normalise (m, nx, ny))
              continue;

            mapspace &ms = m->at (nx, ny);
            ms.update ();
            sint8 light = ms.light;

            if (expect_false (light))
              if (light < 0)
                pass2 = 1;
              else
                apply_light<los_brighten> (op, basex, basey, light, darkness [light + MAX_LIGHT_RADIUS]);
          }

      /* grant some vision to the player, based on the darklevel */
      /* for outdoor maps, ensure some mininum visibility radius */
      {
        int light = clamp (MAX_DARKNESS - darklevel, op->map->outdoor ? 2 : 0, MAX_LIGHT_RADIUS);

        apply_light<los_brighten> (op, half_x, half_y, light, darkness [light + MAX_LIGHT_RADIUS]);
      }
    }

  // 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 (int x = min_x, basex = -MAX_LIGHT_RADIUS; x <= max_x; x++, basex++)
      for (int y = min_y, basey = -MAX_LIGHT_RADIUS; y <= max_y; y++, basey++)
        {
          maptile *m = op->map;
          sint16 nx = x;
          sint16 ny = y;

          if (!xy_normalise (m, nx, ny))
            continue;

          mapspace &ms = m->at (nx, ny);
          ms.update ();
          sint8 light = ms.light;

          if (expect_false (light < 0))
            apply_light<los_darken> (op, basex, basey, -light, darkness [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 (object *op)
{
  int x, y;

  for (x = 0; x < op->contr->ns->mapx; x++)
    for (y = 0; y < op->contr->ns->mapy; y++)
      op->contr->blocked_los[x][y] = LOS_BLOCKED;

  op->contr->blocked_los[op->contr->ns->mapx / 2][op->contr->ns->mapy / 2] = 0;
}

/*
 * update_los() recalculates the array which specifies what is
 * visible for the given player-object.
 */
void
update_los (object *op)
{
  int dx = op->contr->ns->mapx / 2, dy = op->contr->ns->mapy / 2, x, y;

  if (QUERY_FLAG (op, FLAG_REMOVED))
    return;

  clear_los (op->contr);

  if (QUERY_FLAG (op, FLAG_WIZ) /* ||XRAYS(op) */ )
    return;

  /* For larger maps, this is more efficient than the old way which
   * used the chaining of the block array.  Since many space views could
   * be blocked by different spaces in front, this mean that a lot of spaces
   * could be examined multile times, as each path would be looked at.
   */
  for (x = (MAP_CLIENT_X - op->contr->ns->mapx) / 2 - 1; x < (MAP_CLIENT_X + op->contr->ns->mapx) / 2 + 1; x++)
    for (y = (MAP_CLIENT_Y - op->contr->ns->mapy) / 2 - 1; y < (MAP_CLIENT_Y + op->contr->ns->mapy) / 2 + 1; y++)
      check_wall (op, x, y);

  /* do the los of the player. 3 (potential) cases */
  if (QUERY_FLAG (op, FLAG_BLIND))      /* player is blind */
    blinded_sight (op);
  else
    expand_sight (op);

  //TODO: no range-checking whatsoever :(
  if (QUERY_FLAG (op, FLAG_XRAYS))
    for (int x = -2; x <= 2; x++)
      for (int y = -2; y <= 2; y++)
        op->contr->blocked_los[dx + x][dy + y] = 0;
}

/* 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 (pl)
    if (pl->ob && pl->ob->map == 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)
{
  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;

      /* Same map is simple case - see if pl is close enough.
       * Note in all cases, we did the check for same map first,
       * and then see if the player is close enough and update
       * los if that is the case.  If the player is on the
       * corresponding map, but not close enough, then the
       * player can't be on another map that may be closer,
       * so by setting it up this way, we trim processing
       * some.
       */
      if (pl->ob->map == map)
        {
          if ((abs (pl->ob->x - x) <= pl->ns->mapx / 2) && (abs (pl->ob->y - y) <= pl->ns->mapy / 2))
            pl->do_los = 1;
        }

      /* Now we check to see if player is on adjacent
       * maps to the one that changed and also within
       * view.  The tile_maps[] could be null, but in that
       * case it should never match the pl->ob->map, so
       * we want ever try to dereference any of the data in it.
       *
       * The logic for 0 and 3 is to see how far the player is
       * from the edge of the map (height/width) - pl->ob->(x,y)
       * and to add current position on this map - that gives a
       * distance.
       * For 1 and 2, we check to see how far the given
       * coordinate (x,y) is from the corresponding edge,
       * and then add the players location, which gives
       * a distance.
       */
      else if (pl->ob->map == map->tile_map[0])
        {
          if ((abs (pl->ob->x - x) <= pl->ns->mapx / 2) && (abs (y + map->tile_map[0]->height - pl->ob->y) <= pl->ns->mapy / 2))
            pl->do_los = 1;
        }
      else if (pl->ob->map == map->tile_map[2])
        {
          if ((abs (pl->ob->x - x) <= pl->ns->mapx / 2) && (abs (pl->ob->y + map->height - y) <= pl->ns->mapy / 2))
            pl->do_los = 1;
        }
      else if (pl->ob->map == map->tile_map[1])
        {
          if ((abs (pl->ob->x + map->width - x) <= pl->ns->mapx / 2) && (abs (pl->ob->y - y) <= pl->ns->mapy / 2))
            pl->do_los = 1;
        }
      else if (pl->ob->map == map->tile_map[3])
        {
          if ((abs (x + map->tile_map[3]->width - pl->ob->x) <= pl->ns->mapx / 2) && (abs (pl->ob->y - y) <= pl->ns->mapy / 2))
            pl->do_los = 1;
        }
    }
}

/*
 * Debug-routine which dumps the array which specifies the visible
 * area of a player.  Triggered by the z key in DM mode.
 */
void
print_los (object *op)
{
  int x, y;
  char buf[50], buf2[10];

  strcpy (buf, "   ");

  for (x = 0; x < op->contr->ns->mapx; x++)
    {
      sprintf (buf2, "%2d", x);
      strcat (buf, buf2);
    }

  new_draw_info (NDI_UNIQUE, 0, op, buf);

  for (y = 0; y < op->contr->ns->mapy; y++)
    {
      sprintf (buf, "%2d:", y);

      for (x = 0; x < op->contr->ns->mapx; x++)
        {
          sprintf (buf2, " %1d", op->contr->blocked_los[x][y]);
          strcat (buf, buf2);
        }

      new_draw_info (NDI_UNIQUE, 0, op, buf);
    }
}

/*
 * 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->blocked_los[pl->ns->mapx / 2 + op->x - pl->ob->x][pl->ns->mapy / 2 + op->y - pl->ob->y] = 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:	1.40
Committed:	Fri Dec 19 17:52:50 2008 UTC (15 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.39:	+1 -7 lines
Log Message:	* empty log message *