--- deliantra/server/common/los.C	2009/01/08 22:35:00	1.58
+++ deliantra/server/common/los.C	2018/12/05 19:03:26	1.78
@@ -1,23 +1,23 @@
 /*
  * 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.
- * 
+ *
+ * Copyright (©) 2017,2018 Marc Alexander Lehmann / the Deliantra team
+ * Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 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 GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- * 
+ *
+ * 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>
  */
 
@@ -35,6 +35,10 @@
   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
@@ -50,7 +54,7 @@
 // one los_info for each lightable map space
 static los_info los[MAP_CLIENT_X][MAP_CLIENT_Y];
 
-struct point
+struct point8
 {
   sint8 x, y;
 };
@@ -59,7 +63,7 @@
 #define QUEUE_LENGTH ((MAP_CLIENT_X + MAP_CLIENT_Y) * 2)
 
 // a queue of spaces to calculate
-static point queue [QUEUE_LENGTH];
+static point8 queue [QUEUE_LENGTH];
 static int q1, q2; // queue start, end
 
 /*
@@ -84,7 +88,7 @@
 
   l.flags |= flags;
 
-  if (l.flags & FLG_QUEUED)
+  if (ecb_expect_false (l.flags & FLG_QUEUED))
     return;
 
   l.flags |= FLG_QUEUED;
@@ -127,7 +131,7 @@
     // 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->observe, -half_x, -half_y, half_x, half_y)
+    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;
@@ -157,13 +161,13 @@
 
       los_info &l = los[x][y];
 
-      if (expect_true (l.flags & (FLG_XI | FLG_YI)))
+      if (ecb_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))
+          if (ecb_expect_true (l.flags & FLG_XI))
             {
               los_info *xi = &los[x - sign (dx)][y];
 
@@ -171,9 +175,9 @@
               l.culled &= !xi->visible;
 
               /* merge input space */
-              if (expect_false (xi->xo || xi->yo))
+              if (ecb_expect_false (xi->xo || xi->yo))
                 {
-	          // The X input can provide two main pieces of information: 
+	          // The X input can provide two main pieces of information:
 	          // 1. Progressive X obscurity.
 	          // 2. Recessive Y obscurity.
 		          
@@ -198,7 +202,7 @@
             }
 		
           // check contributing spaces, last vertical, identical structure
-          if (expect_true (l.flags & FLG_YI))
+          if (ecb_expect_true (l.flags & FLG_YI))
             {
               los_info *yi = &los[x][y - sign (dy)];
 
@@ -206,9 +210,9 @@
               l.culled &= !yi->visible;
 
               /* merge input space */
-              if (expect_false (yi->yo || yi->xo))
+              if (ecb_expect_false (yi->yo || yi->xo))
                 {
-	          // The Y input can provide two main pieces of information: 
+	          // The Y input can provide two main pieces of information:
 	          // 1. Progressive Y obscurity.
 	          // 2. Recessive X obscurity.
 		          
@@ -259,7 +263,7 @@
         }
 
       // 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 
+      // If a component has no direction, then it is expanded in both of its
       // positive and negative directions.
       if (!l.culled)
         {
@@ -290,7 +294,7 @@
           int intensity = min (LOS_MAX, abs (radius) + 1);
 
           // actual intensity
-          intensity = max (0, lerp_rd (distance, 0, abs (radius) + 1, intensity, 0));
+          intensity = max (0, lerp_ru (distance, 0, abs (radius) + 1, intensity, 0));
 
           light_atten [radius + MAX_LIGHT_RADIUS][distance] = radius < 0
             ? min (3, intensity)
@@ -304,17 +308,29 @@
   }
 } los_init;
 
-sint8
-los_brighten (sint8 b, sint8 l)
-{
-  return b == LOS_BLOCKED ? b : min (b, l);
-}
+// 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);
+  }
 
-sint8
-los_darken (sint8 b, sint8 l)
-{
-  return max (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
@@ -338,13 +354,13 @@
         change_it (pl->los[ax][ay], atten_table [idistance (ax - dx, ay - dy)]);
 }
 
-/* add light, by finding all (non-null) nearby light sources, then 
+/* add light, by finding all (non-null) nearby light sources, then
  * mark those squares specially.
  */
 static void
 apply_lights (player *pl)
 {
-  object *op = pl->observe;
+  object *op = pl->viewpoint;
   int darklevel = op->map->darklevel ();
 
   int half_x = pl->ns->mapx / 2;
@@ -352,11 +368,12 @@
 
   int pass2 = 0; // negative lights have an extra pass
 
-  maprect *rects = pl->observe->map->split_to_tiles (
-    pl->observe->x - half_x - MAX_LIGHT_RADIUS,
-    pl->observe->y - half_y - MAX_LIGHT_RADIUS,
-    pl->observe->x + half_x + MAX_LIGHT_RADIUS + 1,
-    pl->observe->y + half_y + MAX_LIGHT_RADIUS + 1
+  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 */
@@ -384,13 +401,13 @@
             ms.update ();
             sint8 light = ms.light;
 
-            if (expect_false (light))
+            if (ecb_expect_false (light))
               if (light < 0)
                 pass2 = 1;
               else
                 {
                   light = clamp (light + bonus, 0, MAX_LIGHT_RADIUS);
-                  apply_light<los_brighten> (pl, dx - pl->observe->x, dy - pl->observe->y, light, light_atten [light + MAX_LIGHT_RADIUS]);
+                  apply_light<los_brighten> (pl, dx - pl->viewpoint->x, dy - pl->viewpoint->y, light, light_atten [light + MAX_LIGHT_RADIUS]);
                 }
           }
 
@@ -405,12 +422,16 @@
         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, 0, MAX_VISION);
+        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
@@ -422,15 +443,15 @@
           ms.update ();
           sint8 light = ms.light;
 
-          if (expect_false (light < 0))
+          if (ecb_expect_false (light < 0))
             {
               light = clamp (light - bonus, 0, MAX_DARKNESS);
-              apply_light<los_darken> (pl, dx - pl->observe->x, dy - pl->observe->y, -light, light_atten [light + MAX_LIGHT_RADIUS]);
+              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 
+/* 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.
@@ -453,7 +474,7 @@
 
   if (ob->flag [FLAG_WIZLOOK])
     clear_los (0);
-  else if (observe->flag [FLAG_BLIND])      /* player is blind */
+  else if (viewpoint->flag [FLAG_BLIND])      /* player is blind */
     {
       clear_los ();
       blinded_sight (this);
@@ -465,7 +486,7 @@
       apply_lights (this);
     }
 
-  if (observe->flag [FLAG_XRAYS])
+  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);
@@ -504,10 +525,6 @@
 void
 update_all_los (const maptile *map, int x, int y)
 {
-  // no need to do anything if we don't have darkness
-  if (map->darklevel () <= 0)
-    return;
-
   map->at (x, y).invalidate ();
 
   for_all_players (pl)
@@ -518,54 +535,12 @@
       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;
-        }
+      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;
     }
 }