LibGDX collision with rectangle and circle

Question

I have 2 objects, A and B, both are classes with only values, so positions and dimensions are only values (float posX,posY).

I have a render class which render A and B with shapeRenderer; A is rendered as a rectangle and B as a circle, how could check if there is a collision ?

edit: I have a rectangle coming from up, when it hits the circle I have to stop the game

Answer 1

This is what I use to check collision between circle / rectangle. Note that this doesn't do continuous collision detection. Which means that if both of the shapes are unproportionally small or the objects are colliding with really high speeds (because you have too low fps and you use Delta Time to calculate the velocity for example), then the collision won't be detected.

static public Boolean CircleRectCollision(Vector2 circleCenter, Vector2 rectCenter, 
    float radius, float width, float height)
{
    float distanceY = Math.Abs(circleCenter.Y - rectCenter.Y);
    if (distanceY > (height / 2 + radius)) return false;

    float distanceX = Math.Abs(circleCenter.X - rectCenter.X);
    if (distanceX > (width / 2 + radius)) return false;

    if (distanceX <= (width / 2)) return true;
    if (distanceY <= (height / 2)) return true;

    float a = distanceX - width / 2;
    float b = distanceY - height / 2;
    float cSqr = a * a + b * b;
    return (cSqr <= (radius * radius));
}