/*
* This method detects collision between a cannonball and a point on the string
* If a collision is detected, the string moves away from the cannonball
* NOTE: If the segment length of the string is larger than the collision radius of the cannonball,
* than a collision may not be detected
*/
private void DetectAndMoveOnStringCollision()
{
foreach (GameObject cannonball in OperateCannons.activeCannonballs) // For each active cannonball
{
if (cannonball == null)
{
continue;
}
CannonballMotion motion = cannonball.GetComponent <CannonballMotion>(); // Get the CannonballMotion component of the cannonball
Vector3 cannonballCenter = new Vector3(motion.GetXPosition(), motion.GetYPosition(), 0f);
Vector3 centerToPoint; // The vector from the center of the cannonball to a point on the string
float distance; // The distance between the center and the point
// For each point of the string, except the point connected to the body
for (int i = 1; i < NUM_STRING_POINTS; i++)
{
centerToPoint = cannonballCenter - currentStringPoints[i];
distance = centerToPoint.magnitude;
// If the distance from the center of the cannonball to the point is less than or equal to the collision radius of the cannonball
if (System.Math.Abs(distance) <= CannonballCollisionDetection.collisionRadius + COLLISION_BUFFER_ZONE)
{
// The point is inside the cannonball
float error = CannonballCollisionDetection.collisionRadius + COLLISION_BUFFER_ZONE - distance;
float direction; // The direction in which to correct the position of the string points
// Set the direction to the direction the cannonball is moving
if (motion.GetXVelocity() > 0)
{
direction = 1f; // Right direction
}
else
{
direction = -1f; // Left direction
}
// For the string point and every string point below it
for (int j = i; j < NUM_STRING_POINTS; j++)
{
currentStringPoints[j].x += 2f * error * direction; // Correct the x position of the point
currentStringPoints[j].y += 2f * error; // Correct the y position of the point (always upward)
}
}
}
}
}
// Returns true if a cannonball has collided with the body
private bool DetectBodyCollision()
{
foreach (GameObject cannonball in OperateCannons.activeCannonballs) // For each active cannonball
{
if (cannonball == null)
{
continue; // Do nothing if the cannonball is not active
}
CannonballMotion motion = cannonball.GetComponent <CannonballMotion>(); // Get the CannonballMotion component of the cannonball
Vector3 cannonballCenter = new Vector3(motion.GetXPosition(), motion.GetYPosition(), 0f);
Vector3 centerToCenter = cannonballCenter - bodyCenterPoint; // The vector from the center of the cannonball to the center for the body
float distance = centerToCenter.magnitude; // The distance between the centers
// If the distance is less or equal to the radius of collision of the cannonball combined with the radius of the biggest circle inscribed within a hexagon
if (System.Math.Abs(distance) < CannonballCollisionDetection.collisionRadius + COLLISION_BUFFER_ZONE + BODY_SEGMENT_LENGTH * System.Math.Cos(System.Math.PI / 6))
{
// The cannonball is inside the body
return(true); // A collision occured
}
// For each point of the body
for (int i = 0; i < NUM_BODY_POINTS; i++)
{
centerToCenter = cannonballCenter - currentBodyPoints[i];
distance = centerToCenter.magnitude;
// If the distance from the center of the cannonball to the point is less than or equal to the collision radius of the cannonball
if (System.Math.Abs(distance) <= CannonballCollisionDetection.collisionRadius + COLLISION_BUFFER_ZONE)
{
// The point is inside the cannonball
return(true); // A collision occured
}
}
}
return(false); // No collision occured
}
private CannonballMotion cannonballMotion; // The instance of the CannonballMotion class that is linked to the current cannonball game object
// Start is called before the first frame update
void Start()
{
cannonballMotion = gameObject.GetComponent <CannonballMotion>(); // Get the instance of the CannonballMotion class from the current cannonball game object
}