Tracers for cloud spells for both players (#2491) and monsters.

This updates the beam code to check for the impact of a cloud forming at
the beam's endpoint, and updates the player implementations of the cloud
spells to fire a tracer cloud at that endpoint; thus players will be
warned for targetting themself and/or allies, and monsters will take
allies into consideration when using cloud spells.

1 files changed, 31 insertions, 0 deletions

diff --git a/crawl-ref/source/spl-clouds.cc b/crawl-ref/source/spl-clouds.cc
index de14fa00d3..7c218ef543 100644
--- a/crawl-ref/source/spl-clouds.cc
+++ b/crawl-ref/source/spl-clouds.cc
@@ -182,6 +182,37 @@ spret_type cast_big_c(int pow, cloud_type cty, const actor *caster, bolt &beam,
         return SPRET_ABORT;
     }
 
+    //XXX: there should be a better way to specify beam cloud types
+    switch(cty)
+    {
+        case CLOUD_POISON:
+            beam.flavour = BEAM_POISON;
+            beam.name = "blast of poison";
+            break;
+        case CLOUD_HOLY_FLAMES:
+            beam.flavour = BEAM_HOLY;
+            beam.origin_spell = SPELL_HOLY_BREATH;
+            break;
+        case CLOUD_COLD:
+            beam.flavour = BEAM_COLD;
+            beam.name = "freezing blast";
+            break;
+        default:
+            mpr("That kind of cloud doesn't exist!");
+            return SPRET_ABORT;
+    }
+
+    beam.thrower           = KILL_YOU;
+    beam.hit               = AUTOMATIC_HIT;
+    beam.damage            = INSTANT_DEATH; // just a convenient non-zero
+    beam.is_big_cloud      = true;
+    beam.is_tracer         = true;
+    beam.use_target_as_pos = true;
+    beam.affect_endpoint();
+    if (beam.beam_cancelled)
+        return SPRET_ABORT;
+
+
     fail_check();
 
     big_cloud(cty, caster, beam.target, pow, 8 + random2(3), -1);