Fix explosions through walls (patch 1777426, zelgadis).

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@2040 c06c8d41-db1a-0410-9941-cceddc491573

4 files changed, 95 insertions, 5 deletions

diff --git a/crawl-ref/source/beam.cc b/crawl-ref/source/beam.cc
index 3fdcc52fe9..cd1ae2acd2 100644
--- a/crawl-ref/source/beam.cc
+++ b/crawl-ref/source/beam.cc
@@ -4248,8 +4248,90 @@ static void explosion1(bolt &pbolt)
 
 // for each cell affected by the explosion, affect() is called.
 
-void explosion( bolt &beam, bool hole_in_the_middle )
+void explosion( bolt &beam, bool hole_in_the_middle,
+                bool explode_in_wall, bool stop_at_statues,
+                bool stop_at_walls)
 {
+    if (in_bounds(beam.source_x, beam.source_y)
+        && !(beam.source_x == beam.target_x
+             && beam.source_y == beam.target_y)
+        && (!explode_in_wall || stop_at_statues || stop_at_walls))
+    {
+        ray_def ray;
+        int     max_dist = grid_distance(beam.source_x, beam.source_y,
+                                     beam.target_x, beam.target_y);
+
+        ray.fullray_idx = -1; // to quiet valgrind
+        find_ray( beam.source_x, beam.source_y, beam.target_x, beam.target_y,
+                  true, ray, 0, true );
+
+        // Can cast explosions out from statues or walls.
+        if (ray.x() == beam.source_x && ray.y() == beam.source_y)
+        {
+            max_dist--;
+            ray.advance(true); 
+        }
+
+        int dist = 0;
+        while (dist++ <= max_dist && !(ray.x()    == beam.target_x
+                                       && ray.y() == beam.target_y))
+        {
+            if (grid_is_solid(ray.x(), ray.y()))
+            {
+                bool is_wall = grid_is_wall(grd[ray.x()][ray.y()]);
+                if (!stop_at_statues && !is_wall)
+                {
+#if DEBUG_DIAGNOSTICS
+                    mpr("Explosion beam passing over a statue or other "
+                        "non-wall solid feature.", MSGCH_DIAGNOSTICS);
+#endif
+                    continue;
+                }
+                else if (!stop_at_walls && is_wall)
+                {
+#if DEBUG_DIAGNOSTICS
+                    mpr("Explosion beam passing through a wall.",
+                        MSGCH_DIAGNOSTICS);
+#endif
+                    continue;
+                }
+
+#if DEBUG_DIAGNOSTICS
+                if (!is_wall && stop_at_statues)
+                    mpr("Explosion beam stopped by a statue or other "
+                        "non-wall solid feature.", MSGCH_DIAGNOSTICS);
+                else if (is_wall && stop_at_walls)
+                    mpr("Explosion beam stopped by a by wall.",
+                        MSGCH_DIAGNOSTICS);
+                else
+                    mpr("Explosion beam stopped by someting buggy.",
+                        MSGCH_DIAGNOSTICS);
+#endif
+
+                break;
+            }
+            ray.advance(true);
+        } // while (dist++ <= max_dist)
+
+        // Backup so we don't explode inside the wall.
+        if (!explode_in_wall && grid_is_wall(grd[ray.x()][ray.y()]))
+        {
+#if DEBUG_DIAGNOSTICS
+            int old_x = ray.x();
+            int old_y = ray.y();
+#endif
+            ray.regress();
+#if DEBUG_DIAGNOSTICS
+            mprf(MSGCH_DIAGNOSTICS,
+                 "Can't explode in a solid wall, backing up a step "
+                 "along the beam path from (%d, %d) to (%d, %d)",
+                 old_x, old_y, ray.x(), ray.y());
+#endif
+        }
+        beam.target_x = ray.x();
+        beam.target_y = ray.y();
+    } // if (!explode_in_wall)
+
     int r = beam.ex_size;
 
     // beam is now an explosion;  set in_explosion_phase
diff --git a/crawl-ref/source/beam.h b/crawl-ref/source/beam.h
index 2db36672fe..e9ac9efa84 100644
--- a/crawl-ref/source/beam.h
+++ b/crawl-ref/source/beam.h
@@ -39,8 +39,10 @@ bool nasty_beam( struct monsters *mon, struct bolt &beam );
  * called from: ability - it_use3 - item_use - mstuff2 - religion -
  *              spells - spells4
  * *********************************************************************** */
-void explosion( struct bolt &pbolt, bool hole_in_the_middle = false );
-
+void explosion( struct bolt &pbolt, bool hole_in_the_middle = false,
+                bool explode_in_wall = false,
+                bool stop_at_statues = true,
+                bool stop_at_walls   = true);
 
 // last updated 22jan2001 {gdl}
 /* ***********************************************************************
diff --git a/crawl-ref/source/dat/descript/spells.txt b/crawl-ref/source/dat/descript/spells.txt
index 8c687d7310..fcc109002e 100644
--- a/crawl-ref/source/dat/descript/spells.txt
+++ b/crawl-ref/source/dat/descript/spells.txt
@@ -363,6 +363,10 @@ Iskenderun's Mystic Blast
 
 This spell throws a crackling sphere of destructive energy. 
 %%%%
+Lee's Rapid Deconstruction
+
+This spells fragments a wall into an explosion of deadly shrapnel.  It can also be used directly on monsters made of wall-like substances.
+%%%%
 Lehudib's Crystal Spear
 
 This spell hurls a lethally sharp bolt of crystal. 
diff --git a/crawl-ref/source/spells4.cc b/crawl-ref/source/spells4.cc
index 7773c3efda..082d435ed7 100644
--- a/crawl-ref/source/spells4.cc
+++ b/crawl-ref/source/spells4.cc
@@ -2346,7 +2346,7 @@ void cast_fragmentation(int pow)        // jmf: ripped idea from airstrike
     bool hole = true;
     const char *what = NULL;
 
-    mpr("Fragment what (e.g. a wall)?", MSGCH_PROMPT);
+    mpr("Fragment what (e.g. a wall or monster)?", MSGCH_PROMPT);
     direction( beam, DIR_TARGET, TARG_ENEMY );
 
     if (!beam.isValid)
@@ -2363,6 +2363,8 @@ void cast_fragmentation(int pow)        // jmf: ripped idea from airstrike
     blast.type = '#';
     blast.colour = 0;
     blast.set_target(beam);
+    blast.source_x = you.x_pos;
+    blast.source_y = you.y_pos;
     blast.is_tracer = false;
     blast.flavour = BEAM_FRAG;
     blast.hit = AUTOMATIC_HIT;
@@ -2680,7 +2682,7 @@ void cast_fragmentation(int pow)        // jmf: ripped idea from airstrike
         if (what != NULL)
             mprf("The %s explodes!", what);
 
-        explosion( blast, hole );
+        explosion( blast, hole, true );
     }
     else if (blast.damage.num == 0)
     {