nuget
IsoCell is used to describe properties of data cells, in particular, indicating whether neighbors are above or below a threshold value. Other methods also help the caller follow isolines from cell to cell in a counter-clockwise manner. That is useful when converting the isolines to GeneralPaths.
IsoCell
01 Syntax
Microsoft.VisualBasic.Imaging.Drawing2D.Math2D.MarchingSquares.IsoCell
02 Methods
| Name | Overloads | Summary |
|---|---|---|
| normalizedPointCCW | 1 | After Marching Squares determines what kind of crossings go through each cell, this method can be used to save linearly interpolated values that more closely follow data values. |
| firstSideCCW | 1 | Depending on this cell's neighbor info, which is an integer in [0, 15], this method determines the first side that would used in a counter- clockwise traversal of an isoline. |
| secondSideCCW | 1 | Depending on this cell's neighbor info, which is an integer in [0, 15], this method determines the second side of a cell that would used in a counter-clockwise traversal of an is… |
| nextCellCCW | 1 | Find the next cell to use in a CCW traversal of an isoline. |
| clearIso | 1 | Clear neighbor info in this cell. |
03 Properties
04 Members
normalizedPointCCW(
Side)After Marching Squares determines what kind of crossings go through each cell, this method can be used to save linearly interpolated values that more closely follow data values. So rather than using cell crossing values of, e.g., (0.5, 0), plotting is better if the data indicated, say, (0.83, 0) should be used.
Parameters
| Name | Type | Description |
|---|---|---|
cellSide | Side | which side crossing is wanted. |
Returns
crossing based on data and normalized to [0, 1].
firstSideCCW(
Side)Depending on this cell's neighbor info, which is an integer in [0, 15], this method determines the first side that would used in a counter- clockwise traversal of an isoline.
Parameters
| Name | Type | Description |
|---|---|---|
prev | Side | previous side, used only for ambiguous cases of 5 and 10. |
Returns
side to start with in a CCW traversal.
secondSideCCW(
Side)Depending on this cell's neighbor info, which is an integer in [0, 15], this method determines the second side of a cell that would used in a counter-clockwise traversal of an isoline.
Parameters
| Name | Type | Description |
|---|---|---|
prev | Side | previous side, used only for ambiguous cases of 5 and 10. |
Returns
side to finish with in a call during a CCW traversal.
nextCellCCW(
Side)Find the next cell to use in a CCW traversal of an isoline.
Parameters
| Name | Type | Description |
|---|---|---|
prev | Side | previous side, used only for ambiguous cases of 5 and 10. |
Returns
next cell to use in a CCW traversal.
clearIso(
Side)Clear neighbor info in this cell. When building up shapes, it is possible to have disjoint isoshapes and holes in them. An easy way to build up a new shape from neighborInfo is to build sub-paths for one isoline at a time. As the shape is built up, it is necessary to erase the line afterward so that subsequent searches for isolines will not loop infinitely.
Parameters
| Name | Type | Description |
|---|---|---|
prev | Side | - |
flipped
Determine is this cell is one of tow ambiguous cases in Marching Squares and, if so, whether or not it must be "flipped" to the other case.
Returns
Indication whether this cell is or isn't flipped.
neighborInfo
Retrieve the neighbor info of this cell. Each of its neighbors is given a value of 1, 2, 4 or 8 depending on whether or not each is above or below a threshold. These values are the foundation of the Marching Squares algorithm.
@return
left
Returns
Get interpolated crossing on left edge of cell.
right
Returns
Get interpolated crossing on right edge of cell.
top
Returns
Get interpolated crossing on top edge of cell.
bottom
Returns
Get interpolated crossing on bottom edge of cell.