Clearing the SDL renderer

After the initialization is complete, we will need to clear out the renderer. We can clear our renderer with any color we choose. To do this, we will make a call to the SDL_RenderDrawColor function:

SDL_SetRenderDrawColor( renderer, 0, 0, 0, 255 );
SDL_RenderClear( renderer );

That sets the drawing color for the renderer to black with full opacity. 0, 0, 0 are the RGB color values, and 255 is the alpha opacity. These numbers all range from 0 to 255, where 255 is the full color on the color spectrum. We set this up so that when we call the SDL_RenderClear function in the next line, it will clear the renderer with the color black. If we wanted the color to clear red instead of black, we would have to modify the call in the following way:

SDL_SetRenderDrawColor( renderer, 255, 0, 0, 255 );

That is not what we want, so we will not make that change. I just wanted to point out that we could clear the renderer with any color we like.