public static CollisionInfo?GetVerticalCollision(this int[,] map, Vector2 position, float directionInDegrees, float maxDistance)
{
if (directionInDegrees == 90 || directionInDegrees == 270)
{
return(null);
}
int firstXCoordinateToCheck = 0;
int lastXCoordinateToCheck = 0;
var directionInRadian = MathHelper.ToRadians(directionInDegrees);
Vector2 directionAsVector = directionInRadian.AngleAsVector();
float angleOfCollisionInDegrees = angleOfCollisionInDegrees = Math.Abs(((directionInDegrees + 360) % 180) - 90);
if (directionAsVector.X < 0)
{
firstXCoordinateToCheck = (int)Math.Floor(position.X);
lastXCoordinateToCheck = 0;
}
else
{
firstXCoordinateToCheck = (int)Math.Ceiling(position.X);
lastXCoordinateToCheck = map.GetLength(0) - 1;
}
int deltaX = Math.Sign(lastXCoordinateToCheck - firstXCoordinateToCheck);
var line = LineFormula.FromCoordinateAndDirection(position, directionInRadian);
bool done = false;
for (int x = firstXCoordinateToCheck; !done; x += deltaX)
{
float?y = 0;
if (directionInDegrees == 0 || directionInDegrees == 180)
{
y = position.Y;
}
else
{
y = line.GetInterSectWithVerticalLine(x);
}
var realX = x - (deltaX < 0 ? 1 : 0);
if (!y.HasValue || !map.Contains(realX, (int)y.Value))
{
return(null);
}
if (map[realX, (int)y.Value] != 0)
{
var fraction = y.Value - (int)y.Value;
if (deltaX < 0)
{
fraction = 1 - fraction;
}
var collisionPoint = new Vector2(x, y.Value);
return(new CollisionInfo()
{
CollisionPoint = collisionPoint,
PositionOnWall = fraction,
TileHit = new Point(realX, (int)y.Value),
TileHitValue = map[realX, (int)y.Value],
DistanceToCollision = Vector2.Distance(position, collisionPoint),
ViewAngleOnWall = angleOfCollisionInDegrees
});
}
if (x == lastXCoordinateToCheck)
{
done = true;
}
}
return(null);
}
public static CollisionInfo?GetHorizontalCollision(this int[,] map, Vector2 position, float directionInDegrees, float maxDistance)
{
int firstYCoordinateToCheck = 0;
int lastYCoordinateToCheck = 0;
if (directionInDegrees == 0 || directionInDegrees == 180)
{
return(null);
}
float directionInRadian = (float)MathHelper.ToRadians(directionInDegrees);
Vector2 directionAsVector = new Vector2((float)Math.Cos(directionInRadian), (float)Math.Sin(directionInRadian));
float angleOfCollisionInDegrees = angleOfCollisionInDegrees = (directionInDegrees + 360) % 180;
if (directionAsVector.Y < 0)
{
firstYCoordinateToCheck = (int)Math.Floor(position.Y);
lastYCoordinateToCheck = 0;
}
else
{
firstYCoordinateToCheck = (int)Math.Ceiling(position.Y);
lastYCoordinateToCheck = map.GetLength(1) - 1;
}
int deltaY = Math.Sign(lastYCoordinateToCheck - firstYCoordinateToCheck);
var line = LineFormula.FromCoordinateAndDirection(position, directionInRadian);
bool done = false;
for (int y = firstYCoordinateToCheck; !done; y += deltaY)
{
float?x = 0;
if (directionInDegrees == 90 || directionInDegrees == 270)
{
x = position.X;
}
else
{
x = line.GetInterSectWithHorizontalLine(y);
}
var realY = y - (deltaY < 0 ? 1 : 0);
if (!x.HasValue || !map.Contains((int)x.Value, realY))
{
return(null);
}
if (map[(int)x.Value, realY] != 0)
{
var fraction = x.Value - (int)x.Value;
if (deltaY > 0)
{
fraction = 1 - fraction;
}
var collisionPoint = new Vector2(x.Value, y);
return(new CollisionInfo()
{
CollisionPoint = collisionPoint,
PositionOnWall = fraction,
TileHit = new Point((int)x.Value, realY),
TileHitValue = map[(int)x.Value, realY],
DistanceToCollision = Vector2.Distance(position, collisionPoint),
ViewAngleOnWall = angleOfCollisionInDegrees
});
}
if (y == lastYCoordinateToCheck)
{
done = true;
}
}
return(null);
}
