Make previous commit about fog/shroud variants less config heavy.

Simply scan which images exist as we already do for transitions.

data/game_config.cfg

@@ -98,9 +98,7 @@
     unreachable_image="terrain/darken.png"
 
     fog_prefix="terrain/fog"
-    fog_variants="terrain/fog1.png,terrain/fog2.png,terrain/fog3.png"
     shroud_prefix="terrain/void"
-    shroud_variants="terrain/void.png"
 
     observer_image="misc/eye.png"
     tod_bright_image="misc/tod-bright.png"

src/display.cpp

@@ -107,6 +107,8 @@ display::display(CVideo& video, const gamemap* map, const config& theme_cfg, con
 	mouseover_hex_overlay_(NULL),
 	tod_hex_mask1(NULL),
 	tod_hex_mask2(NULL),
+	fog_images_(),
+	shroud_images_(),
 	selectedHex_(),
 	mouseoverHex_(),
 	keys_(),
@@ -129,6 +131,9 @@ display::display(CVideo& video, const gamemap* map, const config& theme_cfg, con
 		screen_.lock_updates(true);
 	}
 
+	fill_images_list(game_config::fog_prefix, fog_images_);
+	fill_images_list(game_config::shroud_prefix, shroud_images_);
+
 	set_idle_anim_rate(preferences::idle_anim_rate());
 
 	std::fill(reportRects_,reportRects_+reports::NUM_REPORTS,empty_rect);
@@ -140,7 +145,25 @@ display::~display()
 {
 }
 
-const std::string& display::get_variant(const std::vector<std::string>& variants, const map_location &loc)
+void display::fill_images_list(const std::string& prefix, std::vector<std::string>& images)
+{
+	// search prefix.png, prefix1.png, prefix2.png ...
+	for(int i=0; ; ++i){
+		std::ostringstream s;
+		s << prefix;
+		if(i != 0)
+			s << i;
+		s << ".png";
+		if(image::exists(s.str()))
+			images.push_back(s.str());
+		else if(i>0)
+			break;
+	}
+	if (images.empty())
+		images.push_back("");
+}
+
+const std::string& display::get_variant(const std::vector<std::string>& variants, const map_location &loc) const
 {
 	//TODO use better noise function
 	return variants[abs(loc.x + loc.y) % variants.size()];
@@ -1967,11 +1990,11 @@ void display::draw_hex(const map_location& loc) {
 	if(shrouded(loc)) {
 		// We apply void also on off-map tiles
 		// to shroud the half-hexes too
-		const std::string& shroud_image = get_variant(game_config::shroud_variants, loc);
+		const std::string& shroud_image = get_variant(shroud_images_, loc);
 		drawing_buffer_add(LAYER_FOG_SHROUD, loc, tblit(xpos, ypos,
 			image::get_image(shroud_image, image_type)));
 	} else if(fogged(loc)) {
-		const std::string& fog_image = get_variant(game_config::fog_variants, loc);
+		const std::string& fog_image = get_variant(fog_images_, loc);
 		drawing_buffer_add(LAYER_FOG_SHROUD, loc, tblit(xpos, ypos,
 			image::get_image(fog_image, image_type)));
 	}

src/display.hpp

@@ -546,7 +546,9 @@ protected:
 
 	void scroll_to_xy(int screenxpos, int screenypos, SCROLL_TYPE scroll_type,bool force = true);
 
-	const std::string& get_variant(const std::vector<std::string>& variants, const map_location &loc);
+	void fill_images_list(const std::string& prefix, std::vector<std::string>& images);
+
+	const std::string& get_variant(const std::vector<std::string>& variants, const map_location &loc) const;
 
 	CVideo& screen_;
 	const gamemap* map_;
@@ -590,6 +592,8 @@ protected:
 	// If we're transitioning from one time of day to the next,
 	// then we will use these two masks on top of all hexes when we blit.
 	surface tod_hex_mask1, tod_hex_mask2;
+	std::vector<std::string> fog_images_;
+	std::vector<std::string> shroud_images_;
 
 	map_location selectedHex_;
 	map_location mouseoverHex_;

src/game_config.cpp

@@ -66,8 +66,6 @@ namespace game_config
 
 	std::string shroud_prefix;
 	std::string fog_prefix;
-	std::vector<std::string> fog_variants;
-	std::vector<std::string> shroud_variants;
 
 	std::string energy_image = "misc/bar-energy.png";
 	std::string moved_ball_image = "misc/ball-moved.png";
@@ -205,8 +203,6 @@ namespace game_config
 
 		shroud_prefix = v["shroud_prefix"].str();
 		fog_prefix  = v["fog_prefix"].str();
-		fog_variants = utils::split(v["fog_variants"].str());
-		shroud_variants = utils::split(v["shroud_variants"].str());
 
 		observer_image = v["observer_image"].str();
 		tod_bright_image = v["tod_bright_image"].str();

src/game_config.hpp

@@ -82,7 +82,6 @@ namespace game_config
 	extern std::vector<Uint32> red_green_scale;
 	extern std::vector<Uint32> red_green_scale_text;
 
-	extern std::vector<std::string> fog_variants, shroud_variants;
 	extern std::vector<std::string> foot_speed_prefix;
 	extern std::string foot_teleport_enter, foot_teleport_exit;