Trying to draw a circle

SDL Development
1

I’ve been trying to draw a circle and so far I have the following, that wont render for some reason that I can’t figure out. I’d appreciate any help.

Particle.cpp:

void Particle::DrawParticle(SDL_Renderer* renderer, int x0, int y0, int radius) {
	Radius = radius;
	float pi = 3.14159265358979323846264338327950288419716939937510;
	float pih = pi / 2.0;

	const int prec = 27;
	float theta = 0;

	int x = (float)Radius * cos(theta);
	int y = (float)Radius * sin(theta);
	int x1 = x;
	int y1 = y;

	float step = pih / (float)prec;
	for (theta = step; theta <= pih; theta += step)
	{
		x1 = (float)Radius * cosf(theta) + 0.5;
		y1 = (float)Radius * sinf(theta) + 0.5;

		if ((x != x1) || (y != y1))
		{
			SDL_RenderDrawLine(renderer, x0 + x, y0 - y, x0 + x1, y0 - y1);
			SDL_RenderDrawLine(renderer, x0 - x, y0 - y, x0 - x1, y0 - y1);
			SDL_RenderDrawLine(renderer, x0 - x, y0 + y, x0 - x1, y0 + y1);
			SDL_RenderDrawLine(renderer, x0 + x, y0 + y, x0 + x1, y0 + y1);
		}

		x = x1;
		y = y1;
	}

	if (x != 0)
	{
		x = 0;
		SDL_RenderDrawLine(renderer, x0 + x, y0 - y, x0 + x1, y0 - y1);
		SDL_RenderDrawLine(renderer, x0 - x, y0 - y, x0 - x1, y0 - y1);
		SDL_RenderDrawLine(renderer, x0 - x, y0 + y, x0 - x1, y0 + y1);
		SDL_RenderDrawLine(renderer, x0 + x, y0 + y, x0 + x1, y0 + y1);
	}
}

SDLmain.cpp:

#include "SDLmain.h"

SDLMain::SDLMain(){}
SDLMain::~SDLMain(){}

Particle* particle = nullptr;

void SDLMain::Init(const char* TITLE, int XPOS, int YPOS, int WIDTH, int HEIGHT, bool FULLSCREEN){

	int FLAGS = 0;

	if (FULLSCREEN) {
		FLAGS = SDL_WINDOW_FULLSCREEN;
	}

	if (SDL_Init(SDL_INIT_EVERYTHING) == 0) {
		
		window = SDL_CreateWindow(TITLE, XPOS, YPOS, WIDTH, HEIGHT, FLAGS);
		if (window) {
			std::cout << "SDL Window was successfully created!" << std::endl;
		}
		else {
			std::cout << "SDL Window failed. SDL Error: " << SDL_GetError() << std::endl;
		}

		renderer = SDL_CreateRenderer(window, -1, 0);
		if (renderer) {
			SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
			std::cout << "SDL Renderer was successfully created!" << std::endl;
		}
		else {
			std::cout << "SDL Renderer failed. SDL Error: " << SDL_GetError() << std::endl;
		}

		isOnline = true;
	}
	else {
		isOnline = false;
	}

	particle = new Particle();
	particle->Init();
}

void SDLMain::handleEvents() {
	SDL_Event event;
	SDL_PollEvent(&event);

	switch (event.type) {
	case SDL_QUIT:
		isOnline = false;
		break;

	default:
		break;
	}
}

void SDLMain::Update(){
	particle->Update();
}

void SDLMain::Render(){
	SDL_RenderClear(renderer);
	
	particle->DrawParticle(renderer, 150, 100, 50);

	SDL_RenderPresent(renderer);
}
void SDLMain::Clean(){
	SDL_DestroyWindow(window);
	SDL_DestroyRenderer(renderer);

	particle->Clean();

	SDL_Quit();
	std::cout << "SDL System cleaned!" << std::endl;
}

EDIT:
Figured it out, the drawing & window rendering was using the same color and therefor making it impossible to see the drawing, just changed the colors and it worked.