C++ Drawing to the screen

Creating A Window

The code below will create a window, and also provides a loop to keep the window open and to check for window events:

#include <SFML/Graphics.hpp>

int main()
{
	sf::RenderWindow window{{ 800, 800 }, "Window Title"};
	window.setFramerateLimit(60);

	while (window.isOpen())
	{
		sf::Event event;
		while (window.pollEvent(event))
		{
			if (event.type == sf:: Event::Closed)
			{
				window.close();
			}
		}
		window.clear();
		window.display();
	}
}

if you declare a namespace, you can remove references to 'sf' in the code:

#include <SFML/Graphics.hpp>

using namespace sf;

int main()
{
	RenderWindow window{ { 800, 800 }, "Window Title" };
	window.setFramerateLimit(60);

	while (window.isOpen())
	{
		Event event;
		while (window.pollEvent(event))
		{
			if (event.type == Event::Closed)
			{
				window.close();
			}
		}
		window.clear();
		window.display();
	}
}

Drawing a Rectangle

We can declare a rectangle, so after the 'window.setFramerateLimit(60)' line add:

		sf::RectangleShape rectangle{ { 220.f, 160.f } }; 
		rectangle.setFillColor(sf::Color::White);
		rectangle.setPosition({ 150.f, 20.f }); 
		rectangle.rotate(20.f);

Now in between the 'window.clear()' and the 'window.display()' enter the following line to draw the rectangle:

window.draw(rectangle);

Drawing a Circle

We can declare a circle, so after the 'window.setFramerateLimit(60)' line add:

		sf::CircleShape circle{ {100.f } }; 
		circle.setFillColor(sf:: Color{ 0x006495FF }); //another way to set a color
		circle.setOutlineColor(sf:: Color{ 224, 160, 37, 255 }); //yet another way to set a color
		circle.setPosition({ 300.f, 395.f }); 
		circle.setOutlineThickness(5.f);

Now in between the 'window.clear()' and the 'window.display()' enter the following line to draw the circle:

window.draw(circle);

Drawing a Polygon

In SFML, this is called a Convex Shape. You provide it with the number of points and then define each point:

sf::ConvexShape polygon{ {4 } }; //this is the number of points which make up the shape
polygon.setPoint (0, { 100.f, 0.f }); 
polygon.setPoint (1, { 0.f, 200.f }); 
polygon.setPoint (2, { 600.f, 200.f }); 
polygon.setPoint (3, { 500.f, 0.f }); 
polygon.setFillColor(sf::Color{ 0xF2635FFF }); 
polygon.setOutlineColor(sf:: Color{ 224, 160, 37, 255 }); 
polygon.setPosition({ 100.f, 600.f }); 
polygon.setOutlineThickness(5.f);

Now in between the 'window.clear()' and the 'window.display()' enter the following line to draw the polygon:

window.draw(polygon);

Drawing an Image

One obvious feature is to draw images to the screen. You will need to have a texture, and a sprite to use the texture:

		sf::Texture texture;
		texture.loadFromFile("player.png");

		sf::Sprite player{ texture };
		player.setPosition({ 300.f,300.f });

The image will need to be added to the 'Resource Files' in 'Solution Explorer'.

Drawing Part of an Image

This can be used to create a texture for a whole sprite sheet or a tilesheet, and then use just section of it for a character or a tile.

		sf::Texture tileset;
		tileset.loadFromFile("tileset.png");

		sf::Sprite tile{ tileset };
		int x = 8;
		int y = 5;
		tile.setTextureRect({ x *32, y*32, 32, 32 });
		tile.setPosition({ 200.f,200.f });

This could be used for animation and also for drawing maps.