/// <summary>
/// Sets the x and y acceleration of an object or group of objects to move towards a given point.
/// </summary>
/// <param name="objectOrGroup">The object or group of objects to move.</param>
/// <param name="point">The point to move towards.</param>
/// <param name="speed">The acceleration to move the object at.</param>
/// <param name="radius">The radius extending from the point. An object will need to be within this area to accelerate. A value of 0 will not use a radius.</param>
/// <param name="axis">The allowed movement axis of the object.</param>
/// <param name="allowImmovable">A flag used to determine if an object set to immovable will be affected.</param>
public static void AccelerateToPoint(GenBasic objectOrGroup, Vector2 point, float speed, float radius = 0, Axis axis = Axis.Both, bool allowImmovable = false)
{
if (speed != 0)
{
if (objectOrGroup is GenObject)
{
if (allowImmovable || !(objectOrGroup as GenObject).Immovable)
{
// Get a normalized distance vector to calculate the horizontal and vertical speeds.
Vector2 distanceNormal = GetDistanceNormal(objectOrGroup as GenObject, point, axis);
if (radius <= 0)
(objectOrGroup as GenObject).Velocity += distanceNormal * speed * GenG.TimeStep;
else
{
// If the object is within the radius from the point, accelerate the object towards the point.
// The closer the object is to the point, the higher its acceleration will be.
float accelerationFactor = MathHelper.Clamp(radius - Vector2.Distance((objectOrGroup as GenObject).CenterPosition, point), 0, 1);
(objectOrGroup as GenObject).Velocity += distanceNormal * speed * accelerationFactor * GenG.TimeStep;
}
}
}
else if (objectOrGroup is GenGroup)
{
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
AccelerateToPoint(basic, point, speed, radius, axis, allowImmovable);
}
}
}
/// <summary>
/// Adds an object to the group.
/// If the group already contains the object, the object will not be added again.
/// </summary>
/// <param name="basic">The object to add.</param>
/// <returns>The object that was added to the group.</returns>
public GenBasic Add(GenBasic basic)
{
// Do not add the same object twice.
if (Members.Contains(basic))
return basic;
Members.Add(basic);
_updateMembers = true;
if (Quadtree != null)
{
Quadtree.Add(basic);
}
return basic;
}
/// <summary>
/// Sets the x and y acceleration of an object to move in a given angle direction.
/// </summary>
/// <param name="objectOrGroup">The object or group of objects to move.</param>
/// <param name="angle">The angle direction, in degrees, to move the object in. A value of 0 would be up, and 90 would be to the right.</param>
/// <param name="speed">The acceleration to move the object at.</param>
/// <param name="allowImmovable">A flag used to determine if an object set to immovable will be affected.</param>
public static void AccelerateAtAngle(GenBasic objectOrGroup, float angle, float speed, bool allowImmovable = false)
{
if (speed != 0)
{
if (objectOrGroup is GenObject)
{
if (allowImmovable || !(objectOrGroup as GenObject).Immovable)
{
// Convert the angle to a normal vector to calculate the horizontal and vertical speeds.
Vector2 angleVector = AngleToVector(angle);
(objectOrGroup as GenObject).Acceleration = angleVector * speed;
}
}
else if (objectOrGroup is GenGroup)
{
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
AccelerateAtAngle(basic, angle, speed, allowImmovable);
}
}
}
/// <summary>
/// Applies collision detection and response between an object or group of objects and the tiles of the tilemap.
/// Uses an object's position to efficiently find neighboring tiles to check for collision in the tiles two-dimensional array.
/// </summary>
/// <param name="objectOrGroup">The object or group to check for collisions.</param>
/// <param name="callback">The delegate method that will be invoked if a collision occurs.</param>
/// <returns>True is a collision occurs, false if not.</returns>
public bool Collide(GenBasic objectOrGroup, CollideEvent callback)
{
if (objectOrGroup is GenObject)
return CollideObject(objectOrGroup as GenObject, callback);
if (objectOrGroup is GenGroup)
{
bool collided = false;
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
{
if (CollideObject(basic as GenObject, callback))
collided = true;
}
return collided;
}
return false;
}
/// <summary>
/// Removes an object or group of objects from the follow targets list.
/// </summary>
/// <param name="objectOrGroup">The object or group of objects to remove from the follow targets list.</param>
public void RemoveTarget(GenBasic objectOrGroup)
{
if (objectOrGroup is GenObject)
{
_followTargets.Remove(objectOrGroup as GenObject);
}
else if (objectOrGroup is GenGroup)
{
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
RemoveTarget(basic);
}
}
/// <summary>
/// Adds an object or group of objects as targets that the camera will follow.
/// Adding multiple targets will cause the camera to follow a point within the center of all targets.
/// Adding the same object twice is useful for zooming in on the target.
/// </summary>
/// <param name="objectOrGroup">The object or group of objects to set as a target.</param>
public void AddTarget(GenBasic objectOrGroup = null)
{
if (objectOrGroup is GenObject)
_followTargets.Add(objectOrGroup as GenObject);
else if (objectOrGroup is GenGroup)
{
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
AddTarget(basic);
}
}
/// <summary>
/// Replaces an existing object in the members list with a new object.
/// </summary>
/// <param name="oldMember">The existing object to replace.</param>
/// <param name="newMember">The new object that will replace the existing object.</param>
/// <returns>The new object that replaced the existing object. Null if the object was not found in the members list.</returns>
public GenBasic Replace(GenBasic oldMember, GenBasic newMember)
{
// Attempt to replace the existing object in the members list.
int index = Members.IndexOf(oldMember);
if (index == -1)
return null;
Members[index] = newMember;
_updateMembers = true;
return newMember;
}
/// <summary>
/// Removes a specified object from the members list.
/// </summary>
/// <param name="basic">The object to remove.</param>
/// <returns>The object removed from the members list. Null if the object was not found in the members list.</returns>
public GenBasic Remove(GenBasic basic)
{
// Attempt to remove the object from the members list.
if (Members.Contains(basic))
{
Members.Remove(basic);
_updateMembers = true;
// TODO: Remove from the quadtree.
return basic;
}
return null;
}
/// <summary>
/// Adds an object or group of objects to the quadtree.
/// Added objects will be inserted into the quadtree nodes during the next update, and added to the active objects list.
/// </summary>
/// <param name="objectOrGroup">The object or group of objects to add.</param>
public void Add(GenBasic objectOrGroup)
{
if (objectOrGroup is GenObject)
{
// If the object has already been added to the quadtree, do not add the same object twice.
if (!Objects.Contains(objectOrGroup as GenObject))
{
Objects.Add(objectOrGroup as GenObject);
_updateObjects = true;
}
}
else if (objectOrGroup is GenGroup)
{
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
Add(basic);
}
}
/// <summary>
/// Sets the x and y velocities of an object or group of objects to move towards a given point.
/// </summary>
/// <param name="objectOrGroup">The object or group of objects to move.</param>
/// <param name="point">The point to move towards.</param>
/// <param name="speed">The velocity to move the object at.</param>
/// <param name="axis">A bit field of flags to determine the allowed movement axis of the object.</param>
/// <param name="allowImmovable">A flag used to determine if an object set to immovable will be affected.</param>
public static void MoveToPoint(GenBasic objectOrGroup, Vector2 point, float speed, Axis axis = Axis.Both, bool allowImmovable = false)
{
if (speed != 0)
{
if (objectOrGroup is GenObject)
{
if (allowImmovable || !(objectOrGroup as GenObject).Immovable)
{
// Get a normalized distance vector to calculate the horizontal and vertical speeds.
Vector2 distanceNormal = GetDistanceNormal(objectOrGroup as GenObject, point, axis);
(objectOrGroup as GenObject).Velocity = distanceNormal * speed;
}
}
else if (objectOrGroup is GenGroup)
{
foreach (GenBasic basic in (objectOrGroup as GenGroup).Members)
MoveToPoint(basic, point, speed, axis, allowImmovable);
}
}
}
