implement image prefs using function pointers, for efficiency

src/gui/dialogs/advanced_graphics_options.cpp

@@ -106,6 +106,8 @@ void tadvanced_graphics_options::scale_button_callback(std::string pref_id, SCAL
 		ttoggle_button * b = &find_widget<ttoggle_button>(&window, pref_id + "_" + SCALING_ALGORITHM_to_string(static_cast<SCALING_ALGORITHM>(x)), false);
 		b->set_value(x == me);
 	}
+
+	image::update_from_preferences();
 }
 
 void tadvanced_graphics_options::setup_scale_case(const std::string & i, twindow & window)

src/image.cpp

@@ -42,6 +42,7 @@
 
 #include "SDL_image.h"
 
+#include <boost/bind.hpp>
 #include <boost/functional/hash.hpp>
 #include <boost/foreach.hpp>
 
@@ -172,6 +173,11 @@ std::vector<std::string> team_colors;
 int zoom = tile_size;
 int cached_zoom = 0;
 
+/** Algorithm choices */
+typedef boost::function<surface(const surface &, int, int)> scaling_function;
+scaling_function scale_to_zoom_func;
+scaling_function scale_to_hex_func;
+
 } // end anon namespace
 
 namespace image {
@@ -801,12 +807,7 @@ static surface get_scaled_to_hex(const locator& i_locator)
 	//return scale_surface(img, zoom, zoom);
 
 	if (!img.null()) {
-		gui2::tadvanced_graphics_options::SCALING_ALGORITHM algo = gui2::tadvanced_graphics_options::LINEAR;
+		return scale_to_hex_func(img, zoom, zoom);
-		try {
-			algo = gui2::tadvanced_graphics_options::string_to_SCALING_ALGORITHM(preferences::get("scale_hex"));
-		} catch (bad_enum_cast &) {}
-
-		return scale_surface_algorithm(img, zoom, zoom, algo);
 	} else {
 		return surface(NULL);
 	}
@@ -826,12 +827,7 @@ static surface get_scaled_to_zoom(const locator& i_locator)
 	surface res(get_image(i_locator, UNSCALED));
 	// For some reason haloes seems to have invalid images, protect against crashing
 	if(!res.null()) {
-		gui2::tadvanced_graphics_options::SCALING_ALGORITHM algo = gui2::tadvanced_graphics_options::LINEAR;
+		return scale_to_zoom_func(res, ((res.get()->w * zoom) / tile_size), ((res.get()->h * zoom) / tile_size));
-		try {
-			algo = gui2::tadvanced_graphics_options::string_to_SCALING_ALGORITHM(preferences::get("scale_zoom"));
-		} catch (bad_enum_cast &) {}
-
-		return scale_surface_algorithm(res, ((res.get()->w * zoom) / tile_size), ((res.get()->h * zoom) / tile_size), algo);
 	} else {
 		return surface(NULL);
 	}
@@ -1298,5 +1294,24 @@ std::string describe_versions()
 	return ss.str();
 }
 
+bool update_from_preferences()
+{
+	gui2::tadvanced_graphics_options::SCALING_ALGORITHM algo = gui2::tadvanced_graphics_options::LINEAR;
+	try {
+		algo = gui2::tadvanced_graphics_options::string_to_SCALING_ALGORITHM(preferences::get("scale_hex"));
+	} catch (bad_enum_cast &) {}
+
+	scale_to_hex_func = boost::bind(& scale_surface_algorithm, _1, _2, _3, algo);
+
+	algo = gui2::tadvanced_graphics_options::LINEAR;
+	try {
+		algo = gui2::tadvanced_graphics_options::string_to_SCALING_ALGORITHM(preferences::get("scale_zoom"));
+	} catch (bad_enum_cast &) {}
+
+	scale_to_zoom_func = boost::bind(& scale_surface_algorithm, _1, _2, _3, algo);
+
+	return true;
+}
+
 } // end namespace image
 

src/image.hpp

@@ -248,6 +248,9 @@ namespace image {
 
 	std::string describe_versions();
 
+	/// initialize any private data, e.g. algorithm choices from preferences
+	bool update_from_preferences();
+
 	void save_image(const locator& i_locator, const std::string& outfile);
 	void save_image(const surface& surf, const std::string& outfile);
 }

src/wesnoth.cpp

@@ -572,6 +572,12 @@ static int do_gameloop(const std::vector<std::string>& args)
 		return 1;
 	}
 
+	res = image::update_from_preferences();
+	if(res == false) {
+		std::cerr << "could not initialize image preferences\n";
+		return 1;
+	}
+
 	if(preferences::joystick_support_enabled()) {
 		res = game->init_joystick();
 		if(res == false) {