Add [terrain_type] max_light= and min_light=.

The defaults for these attributes fix bug #19250.

changelog

@@ -28,6 +28,7 @@ Version 1.11.0+svn:
    * Sighted events should be reliable, provided the player does not activate
      delayed shroud updates (which is still a major caveat).
    * Added [effect] apply_to=overlay
+   * Added [terrain_type] max_light= and min_light=.
  * Miscellaneous and bug fixes:
    * Fix invalid memory access crash resulting from deleting all saved games
      in the Load Game dialog

data/core/terrain.cfg

@@ -1017,6 +1017,7 @@
     string=Ql
     aliasof=Qt
     light=25
+    max_light=35
     editor_group=cave, obstacle
 [/terrain_type]
 
@@ -1027,6 +1028,7 @@
     string=Qlf
     aliasof=Qt
     light=25
+    max_light=35
     editor_group=cave, obstacle
 [/terrain_type]
 
@@ -1038,6 +1040,7 @@
     string=Mv
     aliasof=Qt
     light=25
+    max_light=35
     editor_group=rough, obstacle
 [/terrain_type]
 

src/terrain.cpp

@@ -48,6 +48,8 @@ terrain_type::terrain_type() :
 		submerge_(0.0),
 		submerge_set_(false),
 		light_modification_(0),
+		max_light_(0),
+		min_light_(0),
 		heals_(0),
 		income_description_(),
 		income_description_ally_(),
@@ -80,6 +82,8 @@ terrain_type::terrain_type(const config& cfg) :
 		submerge_(cfg["submerge"].to_double()),
 		submerge_set_(!cfg["submerge"].empty()),
 		light_modification_(cfg["light"]),
+		max_light_(cfg["max_light"].to_int(light_modification_)),
+		min_light_(cfg["min_light"].to_int(light_modification_)),
 		heals_(cfg["heals"]),
 		income_description_(),
 		income_description_ally_(),
@@ -98,7 +102,7 @@ terrain_type::terrain_type(const config& cfg) :
  *  @todo reenable these validations. The problem is that all MP
  *  scenarios/campaigns share the same namespace and one rogue scenario
  *  can avoid the player to create a MP game. So every scenario/campaign
- *  should get it's own namespace to be safe.
+ *  should get its own namespace to be safe.
  */
 #if 0
 	VALIDATE(number_ != t_translation::NONE_TERRAIN,
@@ -189,6 +193,8 @@ terrain_type::terrain_type(const terrain_type& base, const terrain_type& overlay
 	submerge_(base.submerge_),
 	submerge_set_(base.submerge_set_),
 	light_modification_(base.light_modification_ + overlay.light_modification_),
+	max_light_(std::max(base.max_light_, overlay.max_light_)),
+	min_light_(std::min(base.min_light_, overlay.min_light_)),
 	heals_(std::max<int>(base.heals_, overlay.heals_)),
 	income_description_(),
 	income_description_ally_(),
@@ -272,6 +278,8 @@ bool terrain_type::operator==(const terrain_type& other) const {
 		&& submerge_              == other.submerge_
 		&& submerge_set_          == other.submerge_set_
 		&& light_modification_    == other.light_modification_
+		&& max_light_             == other.max_light_
+		&& min_light_             == other.min_light_
 		&& heals_                 == other.heals_
 		&& village_               == other.village_
 		&& castle_                == other.castle_

src/terrain.hpp

@@ -17,6 +17,7 @@
 
 #include "config.hpp"
 #include "terrain_translation.hpp"
+#include "util.hpp"
 
 class terrain_type
 {
@@ -46,7 +47,10 @@ public:
 
 	bool is_nonnull() const { return  (number_ != t_translation::NONE_TERRAIN) &&
 		(number_ != t_translation::VOID_TERRAIN ); }
-	int light_modification() const { return light_modification_; }
+	/// Returns the light (lawful) bonus for this terrain when the time of day
+	/// gives a @a base bonus.
+	int light_bonus(int base) const
+		{ return bounded_add(base, light_modification_, max_light_, min_light_); }
 
 	int unit_height_adjust() const { return height_adjust_; }
 	double unit_submerge() const { return submerge_; }
@@ -103,7 +107,10 @@ private:
 	double submerge_;
 	bool submerge_set_;
 
-	int light_modification_, heals_;
+	int light_modification_;
+	int max_light_;
+	int min_light_;
+	int heals_;
 
 	t_string income_description_;
 	t_string income_description_ally_;

src/tod_manager.cpp

@@ -129,9 +129,8 @@ const time_of_day tod_manager::get_illuminated_time_of_day(const map_location& l
 
 	if ( map.on_board_with_border(loc) )
 	{
-		// now add illumination
-		const int terrain_light = map.get_terrain_info(loc).light_modification()
-		                          + tod.lawful_bonus;
+		// Now add terrain illumination.
+		const int terrain_light = map.get_terrain_info(loc).light_bonus(tod.lawful_bonus);
 
 		std::vector<int> mod_list;
 		std::vector<int> max_list;