Don't miscast when the spell can still be aborted (#4281).

This is a significant refactoring. All the spells now return a spret_type and
take a boolean which tells if the spell has actually failed.
Also some code clean up in _do_cast(). All spells have their own function now.

Also fix the following bugs:
* Properly abort fire storm if forced casting on a wall with '!'.
  Also put a message for forced out of range casting (like cloud spells).
* Casting summon elemental on an invisible monster aborted with no cost.
* if a summoning spell aborts because create_monster fails, you don't lose a
  turn. You still get a chance of miscast in this rare case.
* s2s, tukima and branding spells abort properly instead of consuming turn and
MP when player is not wielding appropriate object.
* s2s abort message when wielding a non-snakable.

1 files changed, 18 insertions, 13 deletions

diff --git a/crawl-ref/source/spl-selfench.h b/crawl-ref/source/spl-selfench.h
index 02fb7b0b9a..4f479456b6 100644
--- a/crawl-ref/source/spl-selfench.h
+++ b/crawl-ref/source/spl-selfench.h
@@ -1,25 +1,30 @@
 #ifndef SPL_SELFENCH_H
 #define SPL_SELFENCH_H
 
+#include "spl-cast.h"
+
 int allowed_deaths_door_hp(void);
-bool cast_deaths_door(int pow);
+spret_type cast_deaths_door(int pow, bool fail);
 void remove_ice_armour();
-bool ice_armour(int pow);
-void missile_prot(int pow);
-void deflection(int pow);
+spret_type ice_armour(int pow, bool fail);
+spret_type missile_prot(int pow, bool fail);
+spret_type deflection(int pow, bool fail);
 
 void remove_regen(bool divine_ability = false);
-void cast_regen(int pow, bool divine_ability = false);
+spret_type cast_regen(int pow, bool divine_ability = false, bool fail = false);
+spret_type cast_revivification(int pow, bool fail);
 
-bool cast_swiftness(int power);
-void cast_fly(int power);
-void cast_insulation(int power);
+spret_type cast_swiftness(int power, bool fail = false);
+spret_type cast_levitation(int power, bool fail);
+spret_type cast_fly(int power, bool fail = false);
+spret_type cast_insulation(int power, bool fail);
 
-void cast_teleport_control(int power);
+spret_type cast_teleport_control(int power, bool fail);
 int cast_selective_amnesia(std::string *pre_msg = NULL);
-void cast_see_invisible(int pow);
-void cast_silence(int pow);
-void cast_liquefaction(int pow);
-void cast_shroud_of_golubria(int pow);
+spret_type cast_see_invisible(int pow, bool fail);
+spret_type cast_silence(int pow, bool fail = false);
+spret_type cast_liquefaction(int pow, bool fail);
+spret_type cast_shroud_of_golubria(int pow, bool fail);
+spret_type cast_transform(int pow, transformation_type which_trans, bool fail);
 
 #endif