/// <summary>
/// checks for the weapon firing collision.
/// When collision check succeeds, returns a result report.
/// If not, returns null.
/// </summary>
/// <param name="position">the start position of firing</param>
/// <param name="direction">the direction of firing</param>
/// <param name="distance">the range of firing</param>
/// <param name="targetCollisionLayer">target collision layer</param>
/// <param name="worldCollisionLayer">world collision layer</param>
/// <returns>result report</returns>
protected static CollisionResult FireHitTest(Vector3 position,
Vector3 direction,
float distance,
ref CollisionLayer targetCollisionLayer,
ref CollisionLayer worldCollisionLayer)
{
bool doHit = false;
CollideRay collideRay = new CollideRay(position, direction);
// checks with enemies.
CollisionResult fireResult = FrameworkCore.CollisionContext.HitTest(
collideRay,
ref targetCollisionLayer,
ResultType.NearestOne);
if (fireResult != null)
{
if (fireResult.distance <= distance)
{
// Hit unit
doHit = true;
}
}
// checks with world.
CollisionResult worldResult = FrameworkCore.CollisionContext.HitTest(
collideRay,
ref worldCollisionLayer,
ResultType.NearestOne);
if (worldResult != null)
{
// Hit world
if (worldResult.distance <= distance)
{
if (doHit)
{
// closer world
if (worldResult.distance < fireResult.distance)
{
return(worldResult);
}
}
else
{
return(worldResult);
}
}
}
if (doHit)
{
return(fireResult);
}
return(null);
}
public CollisionResult MoveHitTestWithWorld(Vector3 velocityAmount)
{
CollideSphere playerSphere = Collide as CollideSphere;
float radius = playerSphere.Radius;
// calculate simulated position for collision.
Matrix transformSimulate = TransformedMatrix *
Matrix.CreateTranslation(velocityAmount);
// first, check using sphere.
{
CollideSphere simulateSphere =
new CollideSphere(playerSphere.LocalCenter, radius);
simulateSphere.Transform(transformSimulate);
simulateSphere.Id = playerSphere.Id;
CollisionResult result = FrameworkCore.CollisionContext.HitTest(
simulateSphere,
ref colLayerMoveWorld,
ResultType.NearestOne);
if (result != null)
{
return(result);
}
}
// second, check using ray.
{
Vector3 direction = velocityAmount;
direction.Normalize();
CollideRay simulateRay =
new CollideRay(playerSphere.BoundingSphere.Center, direction);
simulateRay.Id = playerSphere.Id;
CollisionResult result = FrameworkCore.CollisionContext.HitTest(
simulateRay,
ref colLayerMoveWorld,
ResultType.NearestOne);
if (result != null)
{
if (result.distance <= radius)
{
return(result);
}
}
}
return(null);
}
public CollisionResult HitTestWithWorld(Vector3 start, Vector3 direction)
{
CollideRay simulateRay = new CollideRay(start, direction);
simulateRay.Id = Collide.Id;
// Test collision
CollisionResult result =
FrameworkCore.CollisionContext.HitTest(simulateRay,
ref colLayerMoveWorld,
ResultType.NearestOne);
return(result);
}
