effect::is_activateable

http://yugioh-wiki.net/index.php?%A5%C0%A5%E1%A1%BC%A5%B8%A5%B9%A5%C6%A5%C3%A5%D7#v68ee46e
When this card is sent to grave/destroyed
These types of trigger effects can be activated in damage step.

http://yugioh-wiki.net/index.php?%A5%C0%A5%E1%A1%BC%A5%B8%B7%D7%BB%BB%BB%FE
These effects can be activated in PHASE_DAMAGE_CAL.
So these types of trigger effects should be allowed in damage step as default.
Otherwise, we'll need to add EFFECT_FLAG_DAMAGE_STEP and EFFECT_FLAG_DAMAGE_CAL in all EVENT_TO_GRAVE effects one by one.

ocgcore/effect.cpp

@@ -203,7 +203,7 @@ int32 effect::is_activateable(uint8 playerid, const tevent& e, int32 neglect_con
 			if((handler->current.location & (LOCATION_ONFIELD | LOCATION_REMOVED))
 			        && (code != EVENT_FLIP) && (!handler->is_position(POS_FACEUP) || !handler->is_status(STATUS_EFFECT_ENABLED)))
 				return FALSE;
-			if(!(type & (EFFECT_TYPE_FLIP | EFFECT_TYPE_TRIGGER_F))) {
+			if(!(type & (EFFECT_TYPE_FLIP | EFFECT_TYPE_TRIGGER_F)) && !((type & EFFECT_TYPE_SINGLE) && (code == EVENT_TO_GRAVE || code == EVENT_DESTROYED))) {
 				if((code < 1132 || code > 1149) && pduel->game_field->infos.phase == PHASE_DAMAGE && !(flag & EFFECT_FLAG_DAMAGE_STEP))
 					return FALSE;
 				if((code < 1134 || code > 1136) && pduel->game_field->infos.phase == PHASE_DAMAGE_CAL && !(flag & EFFECT_FLAG_DAMAGE_CAL))

script/constant.lua

@@ -509,8 +509,8 @@ EVENT_BE_BATTLE_TARGET			=1131	--被选为攻击对象时
 EVENT_BATTLE_START				=1132	--伤害步骤开始时（反转前）
 EVENT_BATTLE_CONFIRM			=1133	--伤害计算前（反转後）
 EVENT_PRE_DAMAGE_CALCULATE		=1134	--伤害计算时（羽斬）
-EVENT_DAMAGE_CALCULATING		=1135	--伤害计算（摩天樓）
-EVENT_PRE_BATTLE_DAMAGE			=1136	--即将产生战斗伤害(EFFECT_TYPE_CONTINUOUS)
+EVENT_DAMAGE_CALCULATING		=1135	--伤害计算（只能使用EFFECT_TYPE_CONTINUOUS）
+EVENT_PRE_BATTLE_DAMAGE			=1136	--即将产生战斗伤害(只能使用EFFECT_TYPE_CONTINUOUS)
 EVENT_BATTLE_END				=1137	--(N/A)
 EVENT_BATTLED					=1138	--伤害计算后（异女、同反转效果时点）
 EVENT_BATTLE_DESTROYING			=1139	--战斗破坏送去墓地时（BF-苍炎之修罗）