/// <summary>
/// Check if the bounding rectangle intersects this bounding rectangle.
/// </summary>
/// <param name="otherRect"></param>
/// <returns></returns>
public bool Intersects( BoundingRect otherRect )
{
// Generate the potential seperating axis vectors between our bounding rect
// and the provided rect. We avoid the use of arrays here so we can avoid
// garbage collection
Vector2 v0 = UpperRight - UpperLeft;
Vector2 v1 = UpperRight - LowerRight;
Vector2 v2 = otherRect.UpperLeft - otherRect.LowerLeft;
Vector2 v3 = otherRect.UpperLeft - otherRect.UpperRight;
return ( IsAxisCollision( otherRect, v0 ) &&
IsAxisCollision( otherRect, v1 ) &&
IsAxisCollision( otherRect, v2 ) &&
IsAxisCollision( otherRect, v3 ) );
}
private bool IsAxisCollision( BoundingRect otherRect, Vector2 axis )
{
// Project the four corners of the bounding box we are checking onto the axis,
// and get a scalar value of that projection for comparison.
Vector2 axisNormalized = Vector2.Normalize( axis );
float a0 = Vector2.Dot( otherRect.UpperLeft, axisNormalized );
float a1 = Vector2.Dot( otherRect.UpperRight, axisNormalized );
float a2 = Vector2.Dot( otherRect.LowerLeft, axisNormalized );
float a3 = Vector2.Dot( otherRect.LowerRight, axisNormalized );
// Project the four corners of our bounding rect onto the requested axis, and
// get scalar values for those projections
float b0 = Vector2.Dot( UpperLeft, axisNormalized );
float b1 = Vector2.Dot( UpperRight, axisNormalized );
float b2 = Vector2.Dot( LowerLeft, axisNormalized );
float b3 = Vector2.Dot( LowerRight, axisNormalized );
// Get the maximum and minimum scalar values for each of the rectangles
float aMin = Math.Min( Math.Min( a0, a1 ), Math.Min( a2, a3 ) );
float aMax = Math.Max( Math.Min( a0, a1 ), Math.Max( a2, a3 ) );
float bMin = Math.Min( Math.Min( b0, b1 ), Math.Min( b2, b3 ) );
float bMax = Math.Max( Math.Min( b0, b1 ), Math.Max( b2, b3 ) );
// Test if there is an overlap between the minimum of a and the maximum
// values of the two rectangles
return ( bMin <= aMax && bMax >= aMax ) ||
( aMin <= bMax && aMax >= bMax );
}
/// <summary>
/// Draws a hit box for the game
/// </summary>
private void DrawHitBox( GameTime gameTime )
{
double currentTime = gameTime.TotalGameTime.TotalSeconds;
double startedAt = mTimeStarted.TotalSeconds + WAIT_TIME;
double finishedAt = startedAt + ACTION_TIME - WAIT_TIME;
double weightedAmount = Utils.FindOneZeroWeighting( currentTime, startedAt, finishedAt );
float angleDeg = MathHelper.Lerp( 170.0f, 10.0f, (float) weightedAmount );
float radians = MathHelper.ToRadians( angleDeg );
Vector2 actorPosition = mGameObject.Position;
Vector2 weaponOffset = new Vector2( 32, 32 );
Vector2 weaponSize = new Vector2( 55, 10 );
Vector2 weaponPivot = new Vector2( 0, 5 );
Vector2 weaponWorldPos = actorPosition + weaponOffset;
Rectangle weaponRect = new Rectangle( (int) weaponWorldPos.X,
(int) weaponWorldPos.Y,
(int) weaponSize.X,
(int) weaponSize.Y );
BoundingRect bounds = new BoundingRect( weaponRect, radians, weaponPivot + weaponWorldPos );
// new Vector2( 0.0f, 10.0f / 2.0f ) );
GameRoot.Debug.DrawBoundingBox( bounds, Color.HotPink );
// Test all the other skeletons out there
List<GameObject> collisions = new List<GameObject>();
for ( int i = 0; i < GameRoot.Enemies.Count; ++i )
{
GameObject obj = GameRoot.Enemies[i];
Vector2 pos = obj.Position;
Rectangle staticInnerRect = new Rectangle( (int) pos.X, (int) pos.Y, 64, 64 );
BoundingRect staticRect = new BoundingRect( staticInnerRect );
GameRoot.Debug.DrawBoundingBox( staticRect, Color.PowderBlue );
// lets see what happens
if ( bounds.Intersects( staticRect ) )
{
collisions.Add( obj );
GameRoot.Debug.DrawFilledRect( staticInnerRect, Color.White );
}
}
// Delete the other colliding game objects
for ( int i = 0; i < collisions.Count; ++i )
{
GameRoot.Enemies.Remove( collisions[i] );
}
}