SDL2 Wont draw Rectangles Correctly - c++

Question

I'm creating a window and drawing a box but for some reason instead of drawing a box, the screen is just changed to that color. I have attached a photo of how the window looks and I will attach the source code.
#include <iostream>
#include <SDL.h>
#undef main
using namespace std;
int SCREEN_WIDTH = 650;
int SCREEN_HEIGHT = 650;
int main() {
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
std::cout << "SDL_Init Error: " << SDL_GetError() << std::endl;
return 1;
}
SDL_Window *window = SDL_CreateWindow("Cells", 100, 100, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
if (window == nullptr) {
std::cout << "SDL_CreateWindow Error: " << SDL_GetError() << std::endl;
SDL_Quit();
return 1;
}
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
if (renderer == nullptr) {
std::cout << "SDL_CreateRenderer Error: " << SDL_GetError() << std::endl;
SDL_DestroyWindow(window);
SDL_Quit();
return 1;
}
SDL_Event event;
bool quit = false;
while (!quit) {
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT) {
quit = true;
}
}
SDL_RenderClear(renderer);
// renderTextures
SDL_Rect fillRect = { 122, 122, 122, 122};
SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
SDL_RenderFillRect(renderer, &fillRect);
SDL_RenderPresent(renderer);
}
return 0;
}
Doesn't Draw Correctly

Answer 1

SDL_RenderClear uses current draw colour, which you modified, so your clear and rectangle colour is the same. Set different clear colour (the one you want at background where nothing else is drawn) with e.g.
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
SDL_RenderClear(renderer);
// now draw your rectangles with different col