Class TriangleBinsGrid2d

This class is a spatial data structure for 2D triangles. It is intended for point-containment and box-overlap queries. It does not store the triangles, only indices, so you must pass in the triangle vertices to add/remove functions, similar to PointHashGrid2d.

However, unlike the hash classes, this one is based on a grid of "bins" which has a fixed size, so you must provide a bounding box on construction. Each triangle is inserted into every bin that it overlaps.

[TODO] currently each triangle is inserted into every bin that it's bounding box overlaps. Need conservative rasterization to improve this. Can implement by testing each bin bbox for intersection w/ triangle

Inheritance
Object
TriangleBinsGrid2d
Inherited Members
Namespace: g3
Assembly: cs.temp.dll.dll
Syntax
public class TriangleBinsGrid2d

Constructors

TriangleBinsGrid2d(AxisAlignedBox2d, Int32)

"invalid" value will be returned by queries if no valid result is found (eg bounded-distance query)

Declaration
public TriangleBinsGrid2d(AxisAlignedBox2d bounds, int numCells)
Parameters
Type Name Description
AxisAlignedBox2d bounds
Int32 numCells

Properties

Bounds

Declaration
public AxisAlignedBox2d Bounds { get; }
Property Value
Type Description
AxisAlignedBox2d

Methods

FindContainingTriangle(Vector2d, Func<Int32, Vector2d, Boolean>, Func<Int32, Boolean>)

Find triangle that contains point. Not thread-safe. You provide containsF(), which does the containment check. If you provide ignoreF(), then tri is skipped if ignoreF(tid) == true

Declaration
public int FindContainingTriangle(Vector2d query_pt, Func<int, Vector2d, bool> containsF, Func<int, bool> ignoreF = null)
Parameters
Type Name Description
Vector2d query_pt
Func<Int32, Vector2d, Boolean> containsF
Func<Int32, Boolean> ignoreF
Returns
Type Description
Int32

FindTrianglesInRange(AxisAlignedBox2d, HashSet<Int32>)

find all triangles that overlap range

Declaration
public void FindTrianglesInRange(AxisAlignedBox2d range, HashSet<int> triangles)
Parameters
Type Name Description
AxisAlignedBox2d range
HashSet<Int32> triangles

InsertTriangle(Int32, ref Vector2d, ref Vector2d, ref Vector2d)

Insert triangle. This function is thread-safe, uses a SpinLock internally

Declaration
public void InsertTriangle(int triangle_id, ref Vector2d a, ref Vector2d b, ref Vector2d c)
Parameters
Type Name Description
Int32 triangle_id
Vector2d a
Vector2d b
Vector2d c

InsertTriangleUnsafe(Int32, ref Vector2d, ref Vector2d, ref Vector2d)

Insert triangle without locking / thread-safety

Declaration
public void InsertTriangleUnsafe(int triangle_id, ref Vector2d a, ref Vector2d b, ref Vector2d c)
Parameters
Type Name Description
Int32 triangle_id
Vector2d a
Vector2d b
Vector2d c

RemoveTriangle(Int32, ref Vector2d, ref Vector2d, ref Vector2d)

Remove triangle. This function is thread-safe, uses a SpinLock internally

Declaration
public void RemoveTriangle(int triangle_id, ref Vector2d a, ref Vector2d b, ref Vector2d c)
Parameters
Type Name Description
Int32 triangle_id
Vector2d a
Vector2d b
Vector2d c

RemoveTriangleUnsafe(Int32, ref Vector2d, ref Vector2d, ref Vector2d)

Remove triangle without locking / thread-safety

Declaration
public void RemoveTriangleUnsafe(int triangle_id, ref Vector2d a, ref Vector2d b, ref Vector2d c)
Parameters
Type Name Description
Int32 triangle_id
Vector2d a
Vector2d b
Vector2d c