New targetting code; for now for reaching and Fire Storm.

directn.cc tried to assume everything is a beam, this make it impossible
to properly visualise spells/effects with different rules, like reaching,
clouds, IOOD, shotgun-targetted spells, cones, etc.  This interface lets
every spell come with an object that answers the question: if I aim at X,
will location Y be affected?

There are three levels of aiming effect now:
* tracer only
* might be affected
* will be affected unless you miss

This means we can show spells that have randomized area: Freezing Cloud,
Fire Storm's radius, etc.

TODO: display in tiles.

The old targetter has a great number of special cases, I did not replace
it yet since it would be a large amount of work.  The new code allows for
showing explosions and bounces, but I'd start with clouds and such first.
Fire Storm is a good sample.

Also, this commit fixes the targetter not allowing you to reach sqrt(8) via
'f' or '.'; you had to use '!' to do that.  A number of places in the code
assumed that, with a special distinction for two modes of reaching.

1 files changed, 4 insertions, 0 deletions

diff --git a/crawl-ref/source/directn.h b/crawl-ref/source/directn.h
index faea2c1fc1..344edb7c91 100644
--- a/crawl-ref/source/directn.h
+++ b/crawl-ref/source/directn.h
@@ -13,6 +13,7 @@
 #include "enum.h"
 #include "ray.h"
 #include "state.h"
+#include "target.h"
 
 class range_view_annotator
 {
@@ -69,6 +70,7 @@ public:
 
 struct direction_chooser_args
 {
+    targetter *hitfunc;
     targeting_type restricts;
     targ_mode_type mode;
     int range;
@@ -83,6 +85,7 @@ struct direction_chooser_args
     bool show_floor_desc;
 
     direction_chooser_args() :
+        hitfunc(NULL),
         restricts(DIR_NONE),
         mode(TARG_ANY),
         range(-1),
@@ -232,6 +235,7 @@ private:
     targeting_behaviour *behaviour; // Can be NULL for default
     bool cancel_at_self;        // Disallow self-targeting?
     bool show_floor_desc;       // Describe the floor of the current target
+    targetter *hitfunc;         // Determine what would be hit.
 
     // Internal data.
     ray_def beam;               // The (possibly invalid) beam.