Azmyth.Mono.Game1.CreateCircle C# (CSharp) Method

        public Texture2D CreateCircle(int radius)
        {
            int outerRadius = radius * 2 + 2; // So circle doesn't go out of bounds
            Texture2D texture = new Texture2D(GraphicsDevice, outerRadius, outerRadius);

            Color[] data = new Color[outerRadius * outerRadius];

            // Colour the entire texture transparent first.
            for (int i = 0; i < data.Length; i++)
                data[i] = Color.Transparent;

            // Work out the minimum step necessary using trigonometry + sine approximation.
            double angleStep = 1f / radius;

            for (double angle = 0; angle < Math.PI * 2; angle += angleStep)
            {
                // Use the parametric definition of a circle: http://en.wikipedia.org/wiki/Circle#Cartesian_coordinates
                int x = (int)Math.Round(radius + radius * Math.Cos(angle));
                int y = (int)Math.Round(radius + radius * Math.Sin(angle));

                data[y * outerRadius + x + 1] = Color.White;
            }

            texture.SetData(data);
            return texture;
        }