/// <inheritdoc />
public IList <Tuple <IntVector2, bool> > OverlapAlongLine(TShape movingPolygon, TShape fixedPolygon, OrthogonalLine line)
{
var reverse = line.GetDirection() == OrthogonalLine.Direction.Bottom || line.GetDirection() == OrthogonalLine.Direction.Left;
if (reverse)
{
line = line.SwitchOrientation();
}
var rotation = line.ComputeRotation();
var rotatedLine = line.Rotate(rotation);
var movingDecomposition = GetDecomposition(movingPolygon).Select(x => x.Rotate(rotation)).ToList();
var fixedDecomposition = GetDecomposition(fixedPolygon).Select(x => x.Rotate(rotation)).ToList();
var smallestX = movingDecomposition.Min(x => x.A.X);
var events = new List <Tuple <IntVector2, bool> >();
// Compute the overlap for every rectangle in the decomposition of the moving polygon
foreach (var movingRectangle in movingDecomposition)
{
var newEvents = OverlapAlongLine(movingRectangle, fixedDecomposition, rotatedLine, movingRectangle.A.X - smallestX);
events = MergeEvents(events, newEvents, rotatedLine);
}
if (reverse)
{
events = ReverseEvents(events, rotatedLine);
}
return(events.Select(x => Tuple.Create(x.Item1.RotateAroundCenter(-rotation), x.Item2)).ToList());
}
/// <summary>
/// Computes the overlap along a line of a given moving rectangle and a fixed rectangle.
/// </summary>
/// <param name="movingRectangle"></param>
/// <param name="fixedRectangle"></param>
/// <param name="line"></param>
/// <param name="movingRectangleOffset"></param>
/// <returns></returns>
protected List <Tuple <IntVector2, bool> > OverlapAlongLine(GridRectangle movingRectangle, GridRectangle fixedRectangle, OrthogonalLine line, int movingRectangleOffset = 0)
{
if (line.GetDirection() != OrthogonalLine.Direction.Right)
{
throw new ArgumentException();
}
// The smallest rectangle that covers both the first and the last position on the line of the moving rectangle
var boundingRectangle = new GridRectangle(movingRectangle.A + line.From, movingRectangle.B + line.To);
// They cannot overlap if the bounding rectangle does not overlap with the fixed one
if (!DoOverlap(boundingRectangle, fixedRectangle))
{
return(new List <Tuple <IntVector2, bool> >());
}
var events = new List <Tuple <IntVector2, bool> >();
if (fixedRectangle.A.X - movingRectangle.Width - movingRectangleOffset <= line.From.X)
{
events.Add(Tuple.Create(line.From, true));
}
if (fixedRectangle.A.X > line.From.X + movingRectangle.Width + movingRectangleOffset)
{
events.Add(Tuple.Create(new IntVector2(fixedRectangle.A.X - movingRectangle.Width + 1 - movingRectangleOffset, line.From.Y), true));
}
if (fixedRectangle.B.X - movingRectangleOffset < line.To.X)
{
events.Add(Tuple.Create(new IntVector2(fixedRectangle.B.X - movingRectangleOffset, line.From.Y), false));
}
return(events);
}
public void GetDirection_ReturnsDirection()
{
var top = new OrthogonalLine(new IntVector2(2, 2), new IntVector2(2, 4));
var bottom = new OrthogonalLine(new IntVector2(2, 4), new IntVector2(2, 2));
var right = new OrthogonalLine(new IntVector2(5, 3), new IntVector2(8, 3));
var left = new OrthogonalLine(new IntVector2(8, 3), new IntVector2(5, 3));
Assert.AreEqual(OrthogonalLine.Direction.Top, top.GetDirection());
Assert.AreEqual(OrthogonalLine.Direction.Bottom, bottom.GetDirection());
Assert.AreEqual(OrthogonalLine.Direction.Right, right.GetDirection());
Assert.AreEqual(OrthogonalLine.Direction.Left, left.GetDirection());
}
/// <summary>
/// Computes the overlap along a line of a given moving rectangle and a set o fixed rectangles.
/// </summary>
/// <param name="movingRectangle"></param>
/// <param name="fixedRectangles"></param>
/// <param name="line"></param>
/// <param name="movingRectangleOffset">Specifies the X-axis offset of a given moving rectangle.</param>
/// <returns></returns>
protected List <Tuple <IntVector2, bool> > OverlapAlongLine(GridRectangle movingRectangle, IList <GridRectangle> fixedRectangles, OrthogonalLine line, int movingRectangleOffset = 0)
{
if (line.GetDirection() != OrthogonalLine.Direction.Right)
{
throw new ArgumentException();
}
var events = new List <Tuple <IntVector2, bool> >();
foreach (var fixedRectangle in fixedRectangles)
{
var newEvents = OverlapAlongLine(movingRectangle, fixedRectangle, line, movingRectangleOffset);
events = MergeEvents(events, newEvents, line);
}
return(events);
}