From 56340c3e0560dd4791617784e5f09363bfe06373 Mon Sep 17 00:00:00 2001
From: Robert Vollmert <rvollmert@gmx.net>
Date: Sat, 14 Nov 2009 15:55:47 +0100
Subject: Implement blink_range and blink_away.

This is done by generalizing random_close_space to
random_space weighted.

Also tweak the weights a little. These might still need work.
---
 crawl-ref/source/teleport.cc | 89 ++++++++++++++++++++++++++++++--------------
 1 file changed, 61 insertions(+), 28 deletions(-)

(limited to 'crawl-ref/source/teleport.cc')

diff --git a/crawl-ref/source/teleport.cc b/crawl-ref/source/teleport.cc
index eb59fe06ad..d1f8aeb077 100644
--- a/crawl-ref/source/teleport.cc
+++ b/crawl-ref/source/teleport.cc
@@ -21,33 +21,6 @@
 #include "state.h"
 #include "terrain.h"
 
-typedef std::pair<coord_def, int> coord_weight;
-
-// Try to find a "safe" place for the victim close to the target.
-static coord_def random_close_space(actor* victim, actor* target)
-{
-    std::vector<std::pair<coord_def, int> > dests;
-    const coord_def tpos = target->pos();
-
-    // XXX: should use actor::see_cell_no_trans.
-    const los_def* vlos = &victim->get_los_no_trans();
-    const los_def* tlos = &target->get_los_no_trans();
-    for (radius_iterator ri(vlos); ri; ++ri)
-    {
-        if (!tlos->see_cell(*ri) || !victim->is_habitable(*ri)
-            || actor_at(*ri))
-        {
-            continue;
-        }
-        int weight = (LOS_RADIUS+1)*(LOS_RADIUS+1) - (tpos - *ri).abs();
-        if (weight < 0)
-            weight = 1;
-        dests.push_back(coord_weight(*ri, weight));
-    }
-    coord_def* choice = random_choose_weighted(dests);
-    return (choice ? *choice : coord_def(0, 0));
-}
-
 bool player::blink_to(const coord_def& dest, bool quiet)
 {
     // We rely on the non-generalized move_player_to_cell.
@@ -90,6 +63,40 @@ bool monsters::blink_to(const coord_def& dest, bool quiet)
     return (true);
 }
 
+
+typedef std::pair<coord_def, int> coord_weight;
+
+// Try to find a "safe" place for moved close or far from the target.
+// keep_los indicates that the destination should be in view of the target.
+static coord_def random_space_weighted(actor* moved, actor* target,
+                                       bool close, bool keep_los = true)
+{
+    std::vector<coord_weight> dests;
+    const coord_def tpos = target->pos();
+
+    const los_def* mlos = &moved->get_los_no_trans();
+    const los_def* tlos = &target->get_los_no_trans();
+    for (radius_iterator ri(mlos); ri; ++ri)
+    {
+        if (!moved->is_habitable(*ri) || actor_at(*ri)
+            || keep_los && !tlos->see_cell(*ri))
+        {
+            continue;
+        }
+        int weight;
+        int dist = (tpos - *ri).rdist();
+        if (close)
+            weight = (LOS_RADIUS - dist) * (LOS_RADIUS - dist);
+        else
+            weight = dist;
+        if (weight < 0)
+            weight = 0;
+        dests.push_back(coord_weight(*ri, weight));
+    }
+    coord_def* choice = random_choose_weighted(dests);
+    return (choice ? *choice : coord_def(0, 0));
+}
+
 // Blink the victim closer to the monster at target.
 void blink_closer(actor* victim, const coord_def &target)
 {
@@ -98,13 +105,39 @@ void blink_closer(actor* victim, const coord_def &target)
         return;
     if (is_sanctuary(you.pos()))
         return;
-    coord_def dest = random_close_space(victim, caster);
+    coord_def dest = random_space_weighted(victim, caster, true);
     if (dest.origin())
         return;
     bool success = victim->blink_to(dest);
     ASSERT(success);
 }
 
+// Blink the monster away from its foe.
+void blink_away(monsters* mon)
+{
+    actor* foe = mon->get_foe();
+    if (!foe || !mon->can_see(foe))
+        return;
+    coord_def dest = random_space_weighted(mon, foe, false, false);
+    if (dest.origin())
+        return;
+    bool success = mon->blink_to(dest);
+    ASSERT(success);
+}
+
+// Blink the monster within range but at distance to its foe.
+void blink_range(monsters* mon)
+{
+    actor* foe = mon->get_foe();
+    if (!foe || !mon->can_see(foe))
+        return;
+    coord_def dest = random_space_weighted(mon, foe, false, true);
+    if (dest.origin())
+        return;
+    bool success = mon->blink_to(dest);
+    ASSERT(success);
+}
+
 bool random_near_space(const coord_def& origin, coord_def& target,
                        bool allow_adjacent, bool restrict_los,
                        bool forbid_dangerous, bool forbid_sanctuary)
-- 
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