Set the drawing area for rendering on the current target.
int SDL_RenderSetViewport(SDL_Renderer * renderer, const SDL_Rect * rect);
|renderer||the rendering context|
|rect||the SDL_Rect structure representing the drawing area, or NULL to set the viewport to the entire target|
Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.
When the window is resized, the viewport is reset to fill the entire new window size.
This function is available since SDL 2.0.0.