Getting started

This guide will show you how to get started with the Apos.Camera library.

Before you start, make sure that you have a valid MonoGame project. You can create a new project by following this other guide.

Install

Install using the following dotnet command:

dotnet add package Apos.Camera

For KNI, use Apos.Camera.KNI instead.

The library depends on MonoGame.Extended for RectangleF, which needs MonoGame 3.8.4 or later.

Setup

Import the library with:

using Apos.Camera;

In your game’s LoadContent(), create a viewport and give it to a camera. A DefaultViewport covers the whole window:

protected override void LoadContent() {
    _spriteBatch = new SpriteBatch(GraphicsDevice);

    _viewport = new DefaultViewport(GraphicsDevice, Window);
    _camera = new Camera(_viewport);
}

SpriteBatch _spriteBatch;
IVirtualViewport _viewport;
Camera _camera;

The viewport listens to the window so that it follows its size. Dispose it once you’re done with it:

protected override void UnloadContent() {
    _viewport.Dispose();
}

Drawing

In your game’s draw loop, set the viewport, then give the camera’s view matrix to the SpriteBatch:

protected override void Draw(GameTime gameTime) {
    GraphicsDevice.Clear(Color.Black);

    _camera.SetViewport();
    _spriteBatch.Begin(transformMatrix: _camera.View);

    // Your draw code.

    _spriteBatch.End();
    _camera.ResetViewport();

    base.Draw(gameTime);
}

SetViewport puts the viewport on the GraphicsDevice and ResetViewport puts back the one that was there before.

Anything that takes a view matrix works the same way. With Apos.Shapes, it’s _sb.Begin(_camera.View).

With the default settings, the camera looks at (0, 0) and one world unit is one pixel. The white dot is (0, 0), in the middle of the window:

Moving the camera

XY is the point the camera looks at. It’s always in the middle of the viewport. Scale zooms in and out, and Rotation turns the view around XY. The angle is in radians.

_camera.XY = new Vector2(100, 50);
_camera.Scale = new Vector2(2f, 2f);
_camera.Rotation = MathHelper.PiOver4;

At a scale of 2, everything is twice as big. A positive rotation turns the world clockwise on the screen.

Follow up

Camera, a guide that shows how to go between screen and world coordinates and how to find what the camera sees.