public static IEnumerable<Pair<Point, Point>> WallsUnderRay(Point a, Point b, Model m)
{
var tiles = TilesUnderRay(a, b);
var prev = a.ToSquare();
foreach (var t in tiles)
{
var i = MakeDirMask(Math.Sign(t.X - prev.X), Math.Sign(t.Y - prev.Y));
var mask = m.Cache.Value.GetWallMask(prev.X, prev.Y);
if (i != 0 && mask != null)
if ((mask.Value & i) != ((mask.Value >> 2) & i))
yield return new Pair<Point, Point>(t, prev);
prev = t;
}
}
public static IEnumerable<Point> TilesUnderRay(Point a, Point b)
{
if (a == b)
{
yield return a;
yield break;
}
var dist = Math.Sqrt(a.DistanceSqTo(b));
var frac = 1.0f / (float)dist;
var p = a.ToSquare();
yield return p;
for (var f = 0.0f; f <= 1.0f; f += frac)
{
var q = Lerp(f, a, b).ToSquare();
if (p != q) yield return p = q;
}
}
