/// <summary>
/// Gets a random ball direction which does not end up in a hole within the first direction.
/// If no valid direction is found within the defined calculation steps, the last calculated direction is returned.
/// </summary>
/// <param name="window">The window.</param>
/// <param name="ballPosition">The ball position.</param>
/// <param name="maxCalculationSteps">The maximum calculation steps.</param>
/// <returns>
/// The direction
/// </returns>
public static Vector GetRandomBallDirection(Window window, Point ballPosition, int maxCalculationSteps = 2000)
{
if (window == null)
{
throw new ArgumentNullException("window");
}
var directionsCalculated = 0;
var random = new Random(DateTime.Now.GetHashCode());
while (true)
{
var clickPosition = new Point(
random.Next(0, GameConfiguration.GameWindowWidth),
random.Next(0, GameConfiguration.GameWindowHeight));
// Set the direction and negate it, because the ball has to move away from the queue
var direction = new Vector(clickPosition.X, clickPosition.Y)
- new Vector(ballPosition.X, ballPosition.Y);
direction.Negate();
directionsCalculated++;
// The direction is valid if there are no holes in the window
if (!window.Holes.Any())
{
return(direction);
}
// Create a fake point outside of the window in the ball direction
var intersectionTestPoint = ballPosition + (direction * 10);
var intersectionFound = false;
// Check for an intersection between the ball and a hole in the set direction
foreach (var hole in window.Holes)
{
Point?firstIntersection;
Point?secondIntersection;
var intersection = CalculationHelpers.CalculateLineSphereIntersection(
hole.CenterPosition,
hole.Radius,
ballPosition,
intersectionTestPoint,
out firstIntersection,
out secondIntersection);
// Cancel the check because we have an intersection
if (intersection > 0)
{
Tracer.Debug(string.Format("GameHelpers :: GetRandomBallDirection :: Found an intersection between click position {0}, ball position {1}, direction {2} and hole position {3}", clickPosition, ballPosition, direction, hole.CenterPosition));
intersectionFound = true;
break;
}
}
// Return the current direction if there was no valid direction within the defined tries
if (directionsCalculated == maxCalculationSteps)
{
Tracer.Debug(string.Format("GameHelpers :: GetRandomBallDirection :: Returning direction {0} because the amount of tries is reached", direction));
return(direction);
}
// If we have a intersection, we need another try to find a valid direction
if (intersectionFound)
{
continue;
}
Tracer.Debug(string.Format("GameHelpers :: GetRandomBallDirection :: Returning direction {0} after {1} tries", direction, directionsCalculated));
return(direction);
}
}
/// <summary>
/// Calculates the ball animation tasks.
/// </summary>
/// <param name="initialWindow">The initial window.</param>
/// <param name="startPosition">The start position.</param>
/// <param name="initialDirection">The initial direction.</param>
/// <returns>The calculated animation queue</returns>
private Queue <BallAnimationTask> CalculateBallAnimationTasks(Models.Window initialWindow, Point startPosition, Vector initialDirection)
{
var animationQueue = new Queue <BallAnimationTask>();
var isLastAnimation = false;
var currentWindow = initialWindow;
var currentBallPosition = startPosition;
var currentDirection = initialDirection;
var stepCounter = 0;
var currentTask = new BallAnimationTask {
Window = currentWindow
};
var previousIntersection = Intersection.None;
var windowPreviouslyChanged = false;
const double BallRadius = GameConfiguration.BallDiameter / 2;
while (!isLastAnimation)
{
// Ensure an end of the animation
stepCounter++;
if (stepCounter == 30)
{
isLastAnimation = true;
currentTask.IsLastAnimation = true;
currentTask.IntersectsWithHole = false;
}
var borderPositionCorrection = new Point();
// Calculate the ignorable intersection
var ignoredIntersection = Intersection.None;
if (previousIntersection != Intersection.None)
{
if (windowPreviouslyChanged)
{
switch (previousIntersection)
{
case Intersection.TopWall:
ignoredIntersection = Intersection.BottomWall;
break;
case Intersection.LeftWall:
ignoredIntersection = Intersection.RightWall;
break;
case Intersection.RightWall:
ignoredIntersection = Intersection.LeftWall;
break;
case Intersection.BottomWall:
ignoredIntersection = Intersection.TopWall;
break;
}
}
else
{
ignoredIntersection = previousIntersection;
}
}
var currentIntersection = Intersection.None;
Point? intersectionPosition = null;
Models.Window neighbourWindow = null;
// Generate a point outside of the window
var intersectionTestPoint = currentBallPosition + (currentDirection * 1000);
// Check for hole intersection
if (currentWindow.Holes != null)
{
foreach (var hole in currentWindow.Holes)
{
Point?firstIntersection;
Point?secondIntersection;
var intersection = CalculationHelpers.CalculateLineSphereIntersection(
hole.CenterPosition,
hole.Radius,
currentBallPosition,
intersectionTestPoint,
out firstIntersection,
out secondIntersection);
if (intersection > 0 && firstIntersection != null)
{
currentIntersection = Intersection.Hole;
// This hole intersection is only relevant, if the distance between this intersection and the ball is the shortest
if (intersectionPosition == null ||
currentBallPosition.DistanceTo((Point)firstIntersection)
< currentBallPosition.DistanceTo((Point)intersectionPosition))
{
intersectionPosition = firstIntersection;
}
}
}
}
// Check for top wall hit
if (intersectionPosition == null && ignoredIntersection != Intersection.TopWall)
{
intersectionPosition = CalculationHelpers.GetLineIntersection(
currentBallPosition,
intersectionTestPoint,
new Point(0, 0),
new Point(GameConfiguration.GameWindowWidth, 0));
if (intersectionPosition != null)
{
previousIntersection = currentIntersection = Intersection.TopWall;
var upperWindow = this.CurrentGame.Map.Windows.FirstOrDefault(w => w.X == currentWindow.X && w.Y == currentWindow.Y - 1);
if (upperWindow != null)
{
neighbourWindow = upperWindow;
}
else
{
borderPositionCorrection.Y += BallRadius;
}
}
}
if (intersectionPosition == null && ignoredIntersection != Intersection.LeftWall)
{
// Check for left wall hit
intersectionPosition = CalculationHelpers.GetLineIntersection(
currentBallPosition,
intersectionTestPoint,
new Point(0, 0),
new Point(0, GameConfiguration.GameWindowWidth));
if (intersectionPosition != null)
{
previousIntersection = currentIntersection = Intersection.LeftWall;
var leftWindow = this.CurrentGame.Map.Windows.FirstOrDefault(w => w.X == currentWindow.X - 1 && w.Y == currentWindow.Y);
if (leftWindow != null)
{
neighbourWindow = leftWindow;
}
else
{
borderPositionCorrection.X += BallRadius;
}
}
}
if (intersectionPosition == null && ignoredIntersection != Intersection.RightWall)
{
// Check for right wall hit
intersectionPosition = CalculationHelpers.GetLineIntersection(
currentBallPosition,
intersectionTestPoint,
new Point(GameConfiguration.GameWindowWidth, 0),
new Point(GameConfiguration.GameWindowWidth, GameConfiguration.GameWindowWidth));
if (intersectionPosition != null)
{
previousIntersection = currentIntersection = Intersection.RightWall;
var rightWindow = this.CurrentGame.Map.Windows.FirstOrDefault(w => w.X == currentWindow.X + 1 && w.Y == currentWindow.Y);
if (rightWindow != null)
{
neighbourWindow = rightWindow;
}
else
{
borderPositionCorrection.X -= BallRadius;
}
}
}
if (intersectionPosition == null && ignoredIntersection != Intersection.BottomWall)
{
// Check for bottom wall hit
intersectionPosition = CalculationHelpers.GetLineIntersection(
currentBallPosition,
intersectionTestPoint,
new Point(0, GameConfiguration.GameWindowWidth),
new Point(GameConfiguration.GameWindowWidth, GameConfiguration.GameWindowWidth));
if (intersectionPosition != null)
{
previousIntersection = currentIntersection = Intersection.BottomWall;
var bottomWindow = this.CurrentGame.Map.Windows.FirstOrDefault(w => w.X == currentWindow.X && w.Y == currentWindow.Y + 1);
if (bottomWindow != null)
{
neighbourWindow = bottomWindow;
}
else
{
borderPositionCorrection.Y -= BallRadius;
}
}
}
if (currentIntersection != Intersection.None && intersectionPosition != null)
{
var newPosition = (Point)intersectionPosition;
// Apply correction
newPosition.X += borderPositionCorrection.X;
newPosition.Y += borderPositionCorrection.Y;
currentTask.Steps.Add(AnimationHelpers.GetPointAnimation(currentBallPosition, newPosition));
// If the ball intersects a hole, end the calculation after this step
if (currentIntersection == Intersection.Hole)
{
currentTask.IsLastAnimation = true;
currentTask.IntersectsWithHole = true;
animationQueue.Enqueue(currentTask);
return(animationQueue);
}
currentBallPosition = newPosition;
// Ball will leave the window
if (neighbourWindow != null)
{
animationQueue.Enqueue(currentTask);
currentWindow = neighbourWindow;
currentTask = new BallAnimationTask {
Window = currentWindow
};
windowPreviouslyChanged = true;
// Set new initial position for the next window
switch (currentIntersection)
{
case Intersection.TopWall:
currentBallPosition.Y = GameConfiguration.GameWindowWidth;
break;
case Intersection.LeftWall:
currentBallPosition.X = GameConfiguration.GameWindowWidth;
break;
case Intersection.RightWall:
currentBallPosition.X = 0;
break;
case Intersection.BottomWall:
currentBallPosition.Y = 0;
break;
}
}
else
{
// Change ball direction within the current window
if (currentIntersection == Intersection.TopWall || currentIntersection == Intersection.BottomWall)
{
currentDirection.Y *= -1;
}
else
{
currentDirection.X *= -1;
}
windowPreviouslyChanged = false;
}
}
}
// Add the last animation task to the queue because we had no wall hit (timeout)
if (currentTask.Steps.Count > 0)
{
animationQueue.Enqueue(currentTask);
}
return(animationQueue);
}
