/// <summary>
/// Returns a grid point at the given point.
/// Assumes the point is within the bounds of the grid.
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
public GridPoint2d GridPointAtUnsafe(Vec2d point)
{
GridPoint2d result = new GridPoint2d();
GridPointAtUnsafe(point, result);
return(result);
}
/// <summary>
///
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
public Vec2d CoordinateAt(GridPoint2d point)
{
var corners = point.Corners;
var weights = point.Weights;
var sum = new Vec2d();
for (int i = 0; i < 4; i++)
{
sum += CoordinateAt(corners[i]) * weights[i];
}
return(sum);
}
/// <summary>
/// Returns a grid point at the given point.
/// Assumes the point is within the bounds of the grid.
/// </summary>
/// <param name="point"></param>
/// <param name="result"></param>
public void GridPointAtUnsafe(Vec2d point, GridPoint2d result)
{
point = ToGridSpace(point);
result.SetWeights(
zMath.Fract(point.X, out int i0),
zMath.Fract(point.Y, out int j0)
);
j0 *= _nx;
int i1 = i0 + 1;
int j1 = j0 + _nx;
var corners = result.Corners;
corners[0] = i0 + j0;
corners[1] = i1 + j0;
corners[2] = i0 + j1;
corners[3] = i1 + j1;
}
/// <summary>
/// Returns a grid point at the given point.
/// </summary>
/// <param name="point"></param>
/// <param name="result"></param>
public void GridPointAt(Vec2d point, GridPoint2d result)
{
point = ToGridSpace(point);
result.SetWeights(
zMath.Fract(point.X, out int i0),
zMath.Fract(point.Y, out int j0)
);
int i1 = WrapX(i0 + 1);
int j1 = WrapY(j0 + 1) * _nx;
i0 = WrapX(i0);
j0 = WrapY(j0) * _nx;
var corners = result.Corners;
corners[0] = i0 + j0;
corners[1] = i1 + j0;
corners[2] = i0 + j1;
corners[3] = i1 + j1;
}
/// <inheritdoc />
public sealed override double ValueAt(GridPoint2d point)
{
return(FieldUtil.ValueAt(Values, point.Corners, point.Weights));
}
/// <summary>
///
/// </summary>
/// <param name="point"></param>
/// <param name="amount"></param>
public static void IncrementAt(this GridField2d <Vec2d> field, GridPoint2d point, Vec2d amount)
{
FieldUtil.IncrementAt(field, point.Corners, point.Weights, amount);
}
/// <summary>
///
/// </summary>
/// <param name="point"></param>
/// <param name="value"></param>
public static void SetAt(this GridField2d <Vec2d> field, GridPoint2d point, Vec2d value)
{
FieldUtil.SetAt(field, point.Corners, point.Weights, value);
}