add new distance functions to formula AI, patch 1033 by Alesis Novik

data/core/about.cfg

@@ -624,6 +624,10 @@
 
 [about]
     title = _"Miscellaneous contributors"
+
+    [entry]
+        name = "Alesis Novik"
+    [/entry]
     [entry]
         name = "Andrea Palmatè (afxgroup)"
     [/entry]

src/formula_ai.cpp

@@ -148,6 +148,33 @@ private:
 	const formula_ai& ai_;
 };
 
+class close_enemies_function : public function_expression {
+public:
+	close_enemies_function(const args_list& args, const formula_ai& ai)
+	  : function_expression("close_enemies", args, 2, 2), ai_(ai) {
+	}
+
+private:
+	variant execute(const formula_callable& variables) const {
+		std::vector<variant> vars;
+		const gamemap::location loc = convert_variant<location_callable>(args()[0]->evaluate(variables))->loc();
+		int range = args()[1]->evaluate(variables).as_int();
+		unit_map::const_iterator un = ai_.get_info().units.begin();
+		unit_map::const_iterator end = ai_.get_info().units.end();
+		while (un != end) {
+			if (distance_between(loc, un->first) <= range) {
+				if (un->second.side() != ai_.get_info().team_num) {
+					vars.push_back(variant(new unit_callable(*un, ai_.current_team(), un->second.side())));
+				}
+			}
+			++un;			
+		}
+		return variant(&vars);
+	}
+
+	const formula_ai& ai_;
+};
+
 class outcomes_function : public function_expression {
 public:
 	outcomes_function(const args_list& args, const formula_ai& ai)
@@ -563,6 +590,8 @@ class ai_function_symbol_table : public function_symbol_table {
 			return expression_ptr(new distance_to_nearest_unowned_village_function(args, ai_));
 		} else if(fn == "nearest_keep") {
 			return expression_ptr(new nearest_keep_function(args, ai_));
+		} else if(fn == "close_enemies") {
+			return expression_ptr(new close_enemies_function(args, ai_));
 		} else if(fn == "distance_between") {
 			return expression_ptr(new distance_between_function(args));
 		} else {

src/pathutils.cpp

@@ -57,6 +57,30 @@ void get_adjacent_tiles(const gamemap::location& a, gamemap::location* res)
 	res->y = a.y - (is_even(a.x) ? 1:0);
 }
 
+void get_tile_ring(const gamemap::location& a, const int r, std::vector<gamemap::location>& res)
+{
+	if(r <= 0) {
+		return;
+	}
+
+	gamemap::location loc = a.get_direction(gamemap::location::SOUTH_WEST, r);
+
+	for(int n = 0; n != 6; ++n) {
+		const gamemap::location::DIRECTION dir = static_cast<gamemap::location::DIRECTION>(n);
+		for(int i = 0; i != r; ++i) {
+			res.push_back(loc);
+			loc = loc.get_direction(dir, 1);
+		}
+	}
+}
+
+void get_tiles_in_radius(const gamemap::location& a, const int r, std::vector<gamemap::location>& res)
+{
+	for(int n = 0; n <= r; ++n) {
+		get_tile_ring(a, n, res);
+	}
+}
+
 bool tiles_adjacent(const gamemap::location& a, const gamemap::location& b)
 {
 	// Two tiles are adjacent:

src/pathutils.hpp

@@ -27,6 +27,15 @@ bool tiles_adjacent(const gamemap::location& a, const gamemap::location& b);
 //! res must point to an array of 6 location objects.
 void get_adjacent_tiles(const gamemap::location& a, gamemap::location* res);
 
+
+//! Function which, given a location, will place all locations in a ring of
+//! distance r in res. res must be a std::vector of location
+void get_tile_ring(const gamemap::location& a, const int r, std::vector<gamemap::location>& res);
+
+//! Function which, given a location, will place all locations in the radius of r in res
+//! res must be a std::vector of location
+void get_tiles_in_radius(const gamemap::location& a, const int r, std::vector<gamemap::location>& res);
+
 //! Function which gives the number of hexes between two tiles
 //! (i.e. the minimum number of hexes that have to be traversed
 //! to get from one hex to the other).