public static Texture2D CircleWireFrame(Circle circle)
{
if (GraphicsDevice == null)
{
throw new MissingFieldException("Must set the GraphicsDevice field on WireFrames before any wire frames can be generated.");
}
int diameter = circle.Radius * 2;
Color[] data = new Color[diameter * diameter];
double delta = Math.Atan((double)1 / circle.Radius);
for (double t = 0; t < 2 * Math.PI + delta; t += delta)
{
double y = circle.Radius * (1 - Math.Sin(t));
int y_int = (int)AxisMath.Clamp(y, 0, diameter);
double x = circle.Radius * (1 + Math.Cos(t));
int x_int = (int)AxisMath.Clamp(x, 0, diameter);
int i = y_int * diameter + x_int;
data[i] = Color;
}
Texture2D result = new Texture2D(GraphicsDevice, diameter, diameter);
result.SetData(data);
return(result);
}
public static bool Collides(Rectangle r, Circle c)
{
// check if the center of the circle is in the rectangle
if (r.Contains(c.Center))
{
return(true);
}
// check if the circle's "outer box" doesn't intersect the rectangle
Rectangle outerBounds = new Rectangle(new Point(c.Left, c.Top), new Point(c.Radius * 2));
if (!r.Intersects(outerBounds))
{
return(false);
}
// check if the circle contains any of the rectangle's corners
Point corner = new Point(r.Left, r.Top);
if (c.Contains(corner))
{
return(true);
}
corner.X = r.Right;
if (c.Contains(corner))
{
return(true);
}
corner.Y = r.Bottom;
if (c.Contains(corner))
{
return(true);
}
corner.X = r.Left;
if (c.Contains(corner))
{
return(true);
}
// check for a top/bottom rectangle edge collision
if (AxisMath.Between(c.Center.X, r.Left, r.Right))
{
// check top edge
if (c.Bottom >= r.Top)
{
return(true);
}
// check bottom edge
if (c.Top <= r.Bottom)
{
return(true);
}
}
// check for a left/right rectangle edge collision
if (AxisMath.Between(c.Center.Y, r.Top, r.Bottom))
{
// check left edge
if (c.Right >= r.Left)
{
return(true);
}
// check right edge
if (c.Left <= r.Right)
{
return(true);
}
}
// if all else fails, return false
return(false);
}
