Add a fix for the renamed field in SDL2.

The unused field in SDL_Color has been renamed to a.

src/font.hpp

@@ -136,7 +136,11 @@ class floating_label
 	void set_color(const SDL_Color& color) {color_ = color;}
 	void set_bg_color(const SDL_Color& bg_color) {
 		bgcolor_ = bg_color;
+#if SDL_VERSION_ATLEAST(2,0,0)
+		bgalpha_ = bg_color.a;
+#else
 		bgalpha_ = bg_color.unused;
+#endif
 	}
 	void set_border_size(int border) {border_ = border;}
 	// set width for word wrapping (use -1 to disable it)

src/image_modifications.cpp

@@ -451,8 +451,13 @@ surface darken_modification::operator()(const surface &src) const
 surface background_modification::operator()(const surface &src) const
 {
 	surface ret = make_neutral_surface(src);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	SDL_FillRect(ret, NULL, SDL_MapRGBA(ret->format, color_.r, color_.g,
+					    color_.b, color_.a));
+#else
 	SDL_FillRect(ret, NULL, SDL_MapRGBA(ret->format, color_.r, color_.g,
 					    color_.b, color_.unused));
+#endif
 	SDL_SetAlpha(src, SDL_SRCALPHA, SDL_ALPHA_OPAQUE);
 	SDL_BlitSurface(src, NULL, ret, NULL);
 	return ret;

src/map_label.cpp

@@ -408,7 +408,11 @@ std::string terrain_label::cfg_color() const
 	const unsigned int red = static_cast<unsigned int>(color_.r);
 	const unsigned int green = static_cast<unsigned int>(color_.g);
 	const unsigned int blue = static_cast<unsigned int>(color_.b);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	const unsigned int alpha = static_cast<unsigned int>(color_.a);
+#else
 	const unsigned int alpha = static_cast<unsigned int>(color_.unused);
+#endif
 	buf << red << "," << green << "," << blue << "," << alpha;
 	return buf.str();
 }

src/sdl_utils.cpp

@@ -62,7 +62,11 @@ SDL_Color int_to_color(const Uint32 rgb)
 	result.r = (0x00FF0000 & rgb )>> 16;
 	result.g = (0x0000FF00 & rgb) >> 8;
 	result.b = (0x000000FF & rgb);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	result.a = 0;
+#else
 	result.unused = 0;
+#endif
 	return result;
 }
 
@@ -75,7 +79,11 @@ SDL_Color create_color(const unsigned char red
 	result.r = red;
 	result.g = green;
 	result.b = blue;
+#if SDL_VERSION_ATLEAST(2,0,0)
+	result.a = alpha;
+#else
 	result.unused = alpha;
+#endif
 
 	return result;
 }
@@ -2197,7 +2205,11 @@ SDL_Color inverse(const SDL_Color& color) {
 	inverse.r = 255 - color.r;
 	inverse.g = 255 - color.g;
 	inverse.b = 255 - color.b;
+#if SDL_VERSION_ATLEAST(2,0,0)
+	inverse.a = 0;
+#else
 	inverse.unused = 0;
+#endif
 	return inverse;
 }
 
@@ -2279,7 +2291,11 @@ void draw_centered_on_background(surface surf, const SDL_Rect& rect, const SDL_C
 {
 	clip_rect_setter clip_setter(target, &rect);
 
+#if SDL_VERSION_ATLEAST(2,0,0)
+	Uint32 col = SDL_MapRGBA(target->format, color.r, color.g, color.b, color.a);
+#else
 	Uint32 col = SDL_MapRGBA(target->format, color.r, color.g, color.b, color.unused);
+#endif
 	//TODO: only draw background outside the image
 	SDL_Rect r = rect;
 	sdl_fill_rect(target, &r, col);

src/tests/test_image_modifications.cpp

@@ -898,7 +898,11 @@ BOOST_AUTO_TEST_CASE(test_bg_modification_decoding_no_args)
 	BOOST_CHECK_EQUAL(mod->get_color().r, 0);
 	BOOST_CHECK_EQUAL(mod->get_color().g, 0);
 	BOOST_CHECK_EQUAL(mod->get_color().b, 0);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	BOOST_CHECK_EQUAL(mod->get_color().a, 255);
+#else
 	BOOST_CHECK_EQUAL(mod->get_color().unused, 255);
+#endif
 
 	delete mod;
 }
@@ -920,7 +924,11 @@ BOOST_AUTO_TEST_CASE(test_bg_modification_decoding_1_arg)
 	BOOST_CHECK_EQUAL(mod->get_color().r, 1);
 	BOOST_CHECK_EQUAL(mod->get_color().g, 0);
 	BOOST_CHECK_EQUAL(mod->get_color().b, 0);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	BOOST_CHECK_EQUAL(mod->get_color().a, 255);
+#else
 	BOOST_CHECK_EQUAL(mod->get_color().unused, 255);
+#endif
 
 	delete mod;
 }
@@ -942,7 +950,11 @@ BOOST_AUTO_TEST_CASE(test_bg_modification_decoding_2_args)
 	BOOST_CHECK_EQUAL(mod->get_color().r, 1);
 	BOOST_CHECK_EQUAL(mod->get_color().g, 2);
 	BOOST_CHECK_EQUAL(mod->get_color().b, 0);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	BOOST_CHECK_EQUAL(mod->get_color().a, 255);
+#else
 	BOOST_CHECK_EQUAL(mod->get_color().unused, 255);
+#endif
 
 	delete mod;
 }
@@ -964,7 +976,11 @@ BOOST_AUTO_TEST_CASE(test_bg_modification_decoding_3_args)
 	BOOST_CHECK_EQUAL(mod->get_color().r, 1);
 	BOOST_CHECK_EQUAL(mod->get_color().g, 2);
 	BOOST_CHECK_EQUAL(mod->get_color().b, 3);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	BOOST_CHECK_EQUAL(mod->get_color().a, 255);
+#else
 	BOOST_CHECK_EQUAL(mod->get_color().unused, 255);
+#endif
 
 	delete mod;
 }
@@ -986,7 +1002,11 @@ BOOST_AUTO_TEST_CASE(test_bg_modification_decoding_4_args)
 	BOOST_CHECK_EQUAL(mod->get_color().r, 1);
 	BOOST_CHECK_EQUAL(mod->get_color().g, 2);
 	BOOST_CHECK_EQUAL(mod->get_color().b, 3);
+#if SDL_VERSION_ATLEAST(2,0,0)
+	BOOST_CHECK_EQUAL(mod->get_color().a, 4);
+#else
 	BOOST_CHECK_EQUAL(mod->get_color().unused, 4);
+#endif
 
 	delete mod;
 }