public GridPoint2D(EDirection2D direction, int length = 1)
{
X = 0;
Y = 0;
switch (direction)
{
case EDirection2D.Up:
Y = length;
break;
case EDirection2D.Down:
Y = -length;
break;
case EDirection2D.Left:
X = -length;
break;
case EDirection2D.Right:
X = length;
break;
default:
throw new NotImplementedException();
}
}
public GridPoint2D Translate(EDirection2D direction, int distance)
{
switch (direction)
{
case EDirection2D.Up:
return(new GridPoint2D(X, Y + distance));
case EDirection2D.Down:
return(new GridPoint2D(X, Y - distance));
case EDirection2D.Right:
return(new GridPoint2D(X + distance, Y));
case EDirection2D.Left:
return(new GridPoint2D(X - distance, Y));
default:
throw new NotImplementedException();
}
}
public static EGridAxis2D ToAxis(this EDirection2D direction)
{
return(m_Axes[(int)direction]);
}
public static EDirection2D GetOpposite(this EDirection2D direction)
{
return(m_Opposite[(int)direction]);
}
public static int Raycast(float startX, float startY, float directionX, float directionY, GridHit2D[] hitBuffer)
{
int stepX = Math.Sign(directionX);
int stepY = Math.Sign(directionY);
if (stepX == 0 && stepY == 0)
{
return(0);
}
int bufferSize = hitBuffer.Length;
int currentX = (int)Math.Floor(startX);
int currentY = (int)Math.Floor(startY);
currentX = Math.Max(currentX, 0);
currentY = Math.Max(currentY, 0);
float nextBoundX = CalculateBound(currentX, startX, stepX);
float nextBoundY = CalculateBound(currentY, startY, stepY);
float deltaX = (1f / directionX) * stepX;
float deltaY = (1f / directionY) * stepY;
float travelX = nextBoundX / directionX;
float travelY = nextBoundY / directionY;
int iterator = 0;
EDirection2D xExitFace = (stepX > 0 ? EDirection2D.Left : EDirection2D.Right);
EDirection2D yExitFace = (stepY > 0 ? EDirection2D.Down : EDirection2D.Up);
EDirection2D selectedFace;
float startDecimalX = startX - (float)Math.Truncate(startX);
float startDecimalY = startY - (float)Math.Truncate(startY);
if (startDecimalX < startDecimalY)
{
selectedFace = (directionX > 0 ? EDirection2D.Left : EDirection2D.Right);
}
else
{
selectedFace = (directionY > 0 ? EDirection2D.Down : EDirection2D.Up);
}
while (iterator < bufferSize)
{
GridPoint2D point = new GridPoint2D(currentX, currentY);
if (travelX < travelY)
{
hitBuffer[iterator++] = new GridHit2D(point, selectedFace);
selectedFace = xExitFace;
currentX += stepX;
travelX += deltaX;
}
else
{
hitBuffer[iterator++] = new GridHit2D(point, selectedFace);
selectedFace = yExitFace;
currentY += stepY;
travelY += deltaY;
}
}
return(iterator);
}
public GridHit2D(GridPoint2D point, EDirection2D face)
{
Point = point;
Face = face;
}
