Reset the viewport when we reset the other D3D state.

From Sythical:

Hello, I've created a simple SDL2 application which draws a texture on the screen. The problem I'm having is that if I launch another program which loads the UAC popup or if I lock my PC and then login again, the application stops drawing the texture. I tried adding SDL_Delay(10000) after SDL_RenderPresent(renderer). This made the texture stay on the screen for a little bit but the texture wasn't drawn again after the delay. Here's my code:

#include "SDL.h"

int main(int argc, char *argv[])
{
    SDL_Renderer *renderer;
    SDL_Window *window;
    SDL_Surface *surface;
    SDL_Texture *rect_texture;
    SDL_Event main_event;
    SDL_Rect rect_data;
    int enable_vsync = 1;

    if(SDL_Init(SDL_INIT_VIDEO) < 0) return 1;

    window = SDL_CreateWindow("SDL2 Application", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 600, 600, SDL_WINDOW_RESIZABLE);

    renderer = SDL_CreateRenderer(window, -1, enable_vsync ? SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC : SDL_RENDERER_ACCELERATED);
    SDL_SetRenderDrawColor(renderer, 20, 20, 30, 255);

    surface = SDL_LoadBMP("icon.bmp");
    rect_texture = SDL_CreateTextureFromSurface(renderer, surface);

    rect_data.w = 32; rect_data.h = 32;
    rect_data.x = 300; rect_data.y = 300;

    while(main_event.type != SDL_QUIT)
    {
        SDL_PollEvent(&main_event);

        SDL_RenderClear(renderer);
        SDL_RenderCopy(renderer, rect_texture, NULL, &rect_data);
        SDL_RenderPresent(renderer);
    }

    SDL_DestroyTexture(rect_texture);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}