Relegate some unneeded Bpp-related functions to SDL1

src/game_launcher.cpp

@@ -433,7 +433,9 @@ bool game_launcher::init_video()
 
 	std::cerr << "Setting mode to " << resolution.first << "x" << resolution.second << "x" << bpp << "\n";
 	const int res = video_.setMode(resolution.first,resolution.second,bpp,video_flags);
+#if !SDL_VERSION_ATLEAST(2, 0, 0)
 	video_.setBpp(bpp);
+#endif
 	if(res == 0) {
 		std::cerr << "Required video mode, " << resolution.first << "x"
 		          << resolution.second << "x" << bpp << " is not supported\n";

src/preferences_display.cpp

@@ -85,8 +85,12 @@ bool detect_video_settings(CVideo& video, std::pair<int,int>& resolution, int& b
 		res_list.push_back(res_t(1920, 1080));
 	}
 
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+	bpp = DefaultBPP;
+#else
 	bpp = video.modePossible(resolution.first, resolution.second,
 		DefaultBPP, video_flags, true);
+#endif
 
 	BOOST_REVERSE_FOREACH(const res_t &res, res_list)
 	{
@@ -96,8 +100,12 @@ bool detect_video_settings(CVideo& video, std::pair<int,int>& resolution, int& b
 			<< " is not supported; attempting " << res.first
 			<< 'x' << res.second << 'x' << DefaultBPP << "...\n";
 		resolution = res;
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+		bpp = DefaultBPP;
+#else
 		bpp = video.modePossible(resolution.first, resolution.second,
 			DefaultBPP, video_flags);
+#endif
 	}
 
 	return bpp != 0;
@@ -158,7 +166,11 @@ bool set_resolution(CVideo& video
 	}
 
 	const int flags = fullscreen() ? SDL_FULLSCREEN : 0;
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+	int bpp = 32;
+#else
 	int bpp = video.bppForMode(width, height, flags);
+#endif
 
 	if(bpp != 0) {
 		//video.setMode(width, height, bpp, flags);

src/video.cpp

@@ -511,6 +511,7 @@ void CVideo::make_test_fake(const unsigned width,
 
 }
 
+#if !SDL_VERSION_ATLEAST(2, 0, 0)
 int CVideo::bppForMode( int x, int y, int flags)
 {
 	int test_values[3] = {getBpp(), 32, 16};
@@ -522,6 +523,7 @@ int CVideo::bppForMode( int x, int y, int flags)
 
 	return 0;
 }
+#endif
 
 int CVideo::modePossible( int x, int y, int bits_per_pixel, int flags, bool current_screen_optimal )
 {
@@ -847,6 +849,7 @@ surface& CVideo::getSurface()
 
 bool CVideo::isFullScreen() const { return fullScreen; }
 
+#if !SDL_VERSION_ATLEAST(2, 0, 0)
 void CVideo::setBpp( int bpp )
 {
 	bpp_ = bpp;
@@ -856,6 +859,7 @@ int CVideo::getBpp()
 {
 	return bpp_;
 }
+#endif
 
 int CVideo::set_help_string(const std::string& str)
 {

src/video.hpp

@@ -129,8 +129,10 @@ class CVideo : private boost::noncopyable {
 	};
 
 	//functions to allow changing video modes when 16BPP is emulated
+#if !SDL_VERSION_ATLEAST(2, 0, 0)
 	void setBpp( int bpp );
 	int getBpp();
+#endif
 
 	void make_fake();
 	/**