Sdl2 don't change resolution in raspberry pi

Hi everyone,

I tried a Hello example from Lazy Foo tutorial: 01_hello_SDL.cpp

my raspberry is configurated at video 1080p resolution and when this example start the
resolution not swich to 640x480, remained at 1080p
I tried to change a last flag of SDL_CreateWindow command: SDL_WINDOW_SHOWN with SDL_WINDOW_FULLSCREEN or SDL_WINDOW_FULLSCREEN_DESKTOP but don’t work.

but if I use SDL 1.2 Hello example with:
SDL_Surface* myVideoSurface = SDL_SetVideoMode(SCREEN_WIDTH,SCREEN_HEIGHT,16,SDL_SWSURFACE |SDL_FULLSCREEN);
it’s work very well.

Somebody can Help me?
thanks in advice.
Dak.

/This source code copyrighted by Lazy Foo’ Productions (2004-2015)
and may not be redistributed without written permission.
/

//Using SDL and standard IO
#include <SDL.h>
#include <stdio.h>

//Screen dimension constants
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;

int main( int argc, char* args[] )
{
//The window we’ll be rendering to
SDL_Window* window = NULL;

//The surface contained by the window
SDL_Surface* screenSurface = NULL;

//Initialize SDL
if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
{
	printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
}
else
{
	//Create window
	window = SDL_CreateWindow( "SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN );
	if( window == NULL )
	{
		printf( "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
	}
	else
	{
		//Get window surface
		screenSurface = SDL_GetWindowSurface( window );

		//Fill the surface white
		SDL_FillRect( screenSurface, NULL, SDL_MapRGB( screenSurface->format, 0xFF, 0xFF, 0xFF ) );
		
		//Update the surface
		SDL_UpdateWindowSurface( window );

		//Wait two seconds
		SDL_Delay( 2000 );
	}
}

//Destroy window
SDL_DestroyWindow( window );

//Quit SDL subsystems
SDL_Quit();

return 0;

}