added the option to draw overlays on terrains filter by location,

...selected and mouseover hex

changelog

@@ -35,6 +35,8 @@ Version 1.3-svn:
    * star shaped "ellipses" for leaders and hero units
    * crown icons for heros and expendable allied leaders.
    * item graphic improvements including animate-able campfire.
+   * added the option to draw overlays on terrains filter by
+     location, selected and mouseover hex
    * terrain
      * added peaks to the impassable mountains
      * added bridges crossing swamp and deep water

src/display.cpp

@@ -1551,6 +1551,25 @@ void display::draw_tile(const gamemap::location &loc, const SDL_Rect &clip_rect)
 		}
 	}
 
+	// Add the top layer overlay surfaces
+	if(! hex_overlay_.empty()) {
+		std::map<gamemap::location, surface>::const_iterator itor = hex_overlay_.find(loc);
+		if(itor != hex_overlay_.end()) {
+			SDL_Rect dstrect = { xpos, ypos, 0, 0 };
+			SDL_BlitSurface(itor->second,NULL,dst,&dstrect);
+		}
+	}
+
+    if(loc == selectedHex_ && map_.on_board(selectedHex_) && selected_hex_overlay_ != NULL) {
+		SDL_Rect dstrect = { xpos, ypos, 0, 0 };
+		SDL_BlitSurface(selected_hex_overlay_,NULL,dst,&dstrect);
+	}
+
+    if(loc == mouseoverHex_ && map_.on_board(mouseoverHex_) && mouseover_hex_overlay_ != NULL) {
+		SDL_Rect dstrect = { xpos, ypos, 0, 0 };
+		SDL_BlitSurface(mouseover_hex_overlay_,NULL,dst,&dstrect);
+	}
+
 	update_rect(xpos,ypos,zoom_,zoom_);
 }
 
@@ -2003,6 +2022,16 @@ void display::float_label(const gamemap::location& loc, const std::string& text,
 	                         0,-2,60,screen_area(),font::CENTER_ALIGN,NULL,0,font::ANCHOR_LABEL_MAP);
 }
 
+void display::clear_hex_overlay(const gamemap::location& loc)
+{
+	if(! hex_overlay_.empty()) {
+		std::map<gamemap::location, surface>::iterator itor = hex_overlay_.find(loc);
+		if(itor != hex_overlay_.end()) {
+			hex_overlay_.erase(itor);
+		}
+	}
+}
+
 void display::draw_unit(int x, int y, surface image,
 		bool upside_down, fixed_t alpha, Uint32 blendto, double blend_ratio, double submerged,
 		surface ellipse_back, surface ellipse_front)

src/display.hpp

@@ -195,6 +195,24 @@ public:
 	                 int red, int green, int blue);
 
 	const gamemap& get_map()const { return map_;}
+
+	// The last action in drawing a tile is adding the overlays
+	// these overlays are drawn in the following order
+	// hex_overlay_ 			if the drawn location is in the map
+	// selected_hex_overlay_	if the drawn location is selected
+	// mouseover_hex_overlay_	if the drawn location is underneath the mouse
+	//
+	// These functions require a prerendered surface since they are
+	// drawn at the top, they are not influenced by TOD, shroud etc
+	void set_hex_overlay(const gamemap::location& loc, surface image) { hex_overlay_[loc] = image; }
+	void clear_hex_overlay(const gamemap::location& loc);
+	
+	void set_selected_hex_overlay(const surface& image) { selected_hex_overlay_ = image; }
+	void clear_selected_hex_overlay() { selected_hex_overlay_ = NULL; }
+
+	void set_mouseover_hex_overlay(const surface& image) { mouseover_hex_overlay_ = image; }
+	void clear_mouseover_hex_overlay() { mouseover_hex_overlay_ = NULL; }
+	
 private:
 	enum ADJACENT_TERRAIN_TYPE { ADJACENT_BACKGROUND, ADJACENT_FOREGROUND, ADJACENT_FOGSHROUD };
 
@@ -419,6 +437,10 @@ private:
 	int xpos_, ypos_, zoom_;
 	const gamemap& map_;
 
+	std::map<gamemap::location, surface> hex_overlay_;
+	surface selected_hex_overlay_;
+	surface mouseover_hex_overlay_;
+
 	gamemap::location selectedHex_;
 	gamemap::location mouseoverHex_;
 
@@ -457,7 +479,7 @@ private:
 	struct overlay {
 		overlay(const std::string& img, const std::string& halo_img,
 		        int handle) : image(img), halo(halo_img),
-		                           halo_handle(handle) {}
+				halo_handle(handle) {}
 		std::string image;
 		std::string halo;
 		int halo_handle;