public RayHitResult ShootRay(Ray ray)
{
var result = new RayHitResult(false, 1, ray.Start + ray.Direction, Vector2.Zero);
foreach (var wall in this.Walls)
{
var wS = wall.StartPoint;
var wD = wall.EndPoint - wS;
var denominator = ray.Direction.Y * wD.X - ray.Direction.X * wD.Y;
// disregard backfacing and parallel walls
// (denominator is dot product of non-unit normal and ray)
if (denominator >= 0)
{
continue;
}
var numerator = (wS.Y - ray.Start.Y) * wD.X + (ray.Start.X - wS.X) * wD.Y;
var f = numerator / denominator;
// disregard behind and further than previous result
if (f < -0.001f || f > result.RayFactor)
{
continue;
}
var point = ray.Start + f * ray.Direction;
var wF = wD.X != 0
? (point.X - wS.X) / wD.X
: (point.Y - wS.Y) / wD.Y;
// disregard outside of line segment
if (wF < 0 || wF > 1)
{
continue;
}
result = new RayHitResult(true, f, point, wall.Normal);
}
return(result);
}
public TiledRayHitResult(Tile <TileInfo> tile, RayHitResult results, Vector2 tileOffset)
{
this.Tile = tile;
this.GlobalPoint = results.Point + tileOffset;
this.Results = results;
}
