Collision detection for an arc of a circle [closed]

Question

So how do I implement the collision detection for an arc of a circle? Will I have to use the Box 2D collision or can I do it some other way using Rectangle or stuff like that?

BTW I hate box2d because I don't understand most of the things in it, so if there is a solution that excludes the box2d, it will be very much appreciated.

The yellow arc keeps on rotating over the black circle. How do I implement collision detection in here?

Answer 1

I answered this question already Collision detection for an arc of a circle however I will sum it up here:

You can create a polygon that represents the area you want to detect collisions for using code similar to:

    polya = new Polygon();

    // create vertices
    float section = 15f;
    float[] newVerts = new float[200];
    for(int i = 0; i < 50; i++){
        newVerts[i*2] = (float)Math.sin(i/section); //x 0 to 98 even
        newVerts[i*2+1] = (float)Math.cos(i/section); //y 1 to 99  odd

        newVerts[199-i*2] = (float)Math.cos(i/section); //x 100 to 108
        newVerts[198-i*2] = (float)Math.sin(i/section) + 0.2f; //y 101 to 199

    }

    polya.setVertices(newVerts);
    polya.scale(50);

Then you use the polygon.contains(x,y) method to check if the point x,y is inside. This will return a boolean value true if the point is inside the polygon which equates to a collision.

if(polya.contains(mp.x,mp.y)){
      //point has collided with polygon do something
}