interface IShape in Tinman.Terrain.Shapes

Base interface for geometric two-dimensional shapes that are defined by a distance field.

interface	IShape	extends	ISerializable
			IShapeInfo
		base of	IShapeGroup
			ShapeBase

Remarks

Shapes can be defined implicitly. In this case, VertexCount returns zero and the implementation class is responsible for computing a proper distance field. Explicit shape definitions make use of vertices (see VertexAt), edges (EdgeAt) and triangles (TriangleAt). Edges can also be used to define polygon contours (see EdgeWalk and EdgeParity). To built an explicit shape, use Geometry.

shape type |   vertex |     edge | triangle |   edge
           |    count |    count |    count | parity
-----------+----------+----------+----------+-------
implicit   |        0 |        0 |        0 |      0
-----------+----------+----------+----------+-------
points     |      > 0 |        0 |        0 |      0
-----------+----------+----------+----------+-------
graph      |      > 0 |      > 0 |        0 |      0
-----------+----------+----------+----------+-------
polygon    |      > 0 |      > 0 |        0 |   != 0
-----------+----------+----------+----------+-------
mesh       |      > 0 |        0 |      > 0 |      0

All other combinations are invalid.

A polygon is made up of one or more contours, where each contour is a connected sequence of edges, usually forming a closed ring. Polygon contours are defined piecewise by the set of edges (see EdgeAt). A contour can either be an outer ring or a hole.

In order to test whether a point p lies in the inside or outside half-space of a contour edge between two vertices v0 and v1, the Winding method can be used:

w       := Winding(v0, v1, p)
inside  := w == Parity
outside := w != Parity
where w != 0

Usually, contours will be closed. Open contours can occur during transformation of shapes from one coordinate system to another (see TransformCoordinateSystem or TransformCubemap) for vertex coordinates which are not defined in the target coordinate system.

Attributes

Bounds

Returns the axis-aligned bounding box of this shape.

property	Bounds { get }
type	Box2D
value		The axis-aligned bounding box.

Remarks:

The bounding box is defined as the smallest possible rectangle that contains all points which have a shape distance of zero or less.

EdgeCount

Returns the number of shape edges.

property	EdgeCount { get }
type	int32
value	[>=0]	The number of shape edges.
inherited	IShapeInfo.EdgeCount

See also:

EdgeAt

EdgeParity

Defines how the vertex winding of polygon contours is interpreted (outer rings vs. holes).

property	EdgeParity { get }
type	int32
value		The parity value: +/- 1 for polygons, 0 for non-polygon shapes.
inherited	IShapeInfo.EdgeParity

Remarks:

A polygon contour is classified as an outer ring or a hole according to the sign of its signed area:

outer := sign(Area(contour)) == Parity
hole  := sign(Area(contour)) != Parity

The default value is -1 (i.e. clockwise orientation in a standard Cartesian coordinate system).

Georef

The coordinate system of the shape.

property	Georef { get }
type	CoordinateSystem
value	[not-null]	The coordinate system.
inherited	IShapeInfo.Georef

Remarks:

The default coordinate system is a local one (see IsLocal) in metres (see Metre).

IsCubemap

Is this a cubemap shape?

property	IsCubemap { get }
type	bool
value		true if this is a cubemap shape, false if not.
inherited	IShapeInfo.IsCubemap

Remarks:

Cubemap shapes have a geographic coordinate system (see IsGeographic) and six separate sub-shapes, one for each cubemap face (see Cubemap)).

See also:

TransformCubemap
Face

IsGeometry

Does this shape consist of plain geometry only?

property	IsGeometry { get }
type	bool
value		true if this shape has plain geometry only, false if not.

Remarks:

Shapes with plain geometry can be rebuilt via Geometry.

SerialType

Returns the serial type of this object.

property	SerialType { get }
type	ISerialTypeInfo
value	[not-null]	The serial type.
inherited	ISerializable.SerialType

SerialVersion

Returns the serial data version.

property	SerialVersion { get }
type	int32
value	[>=1]	The serial data version tag.
inherited	ISerializable.SerialVersion

Remarks:

An ISerializable implementation is required to support all versions up to the one returned by SerialVersion.

See also:

ISerializable.Serialize
ISerializable.Deserialize

TriangleCount

Returns the number of shape triangles.

property	TriangleCount { get }
type	int32
value	[>=0]	The number of shape triangles.
inherited	IShapeInfo.TriangleCount

Type

The shape type.

property	Type { get }
type	ShapeType
value		The shape type.
inherited	IShapeInfo.Type

VertexCount

Returns the number of shape vertices.

property	VertexCount { get }
type	int32
value	[>=0]	The number of shape vertices.
inherited	IShapeInfo.VertexCount

Remarks:

When the vertex count is zero, the shape is defined implicitly. If the vertex count is greater than zero, the shape is explicitly defined by its vertices.

See also:

VertexAt

Methods

Absolute

Returns a shape that returns the absolute distance value (i.e. the outline of this shape).

method	Absolute ()
type	IShape
returns		[not-null]	The resulting shape.

Accept

Accepts the given IShapeVisitor object.

method	Accept (IShapeVisitor visitor, object userData = null)
params	visitor	[not-null]	The shape visitor object.
	userData		Optional user data. Defaults to null.

CheckIntersection

Checks the intersection between this shape and the given bounds.

[ThreadSafe]
method	CheckIntersection (Box2D box, float64 offset = 0)
type	int32
params	box		The box bounds.
	offset		Optional distance offset to apply to this shape for the intersection test. Defaults to 0.
returns			-1 if this shape and box are disjoint. 0 if this shape and box intersect. 1 if box fully contains this shape. 2 if this shape fully contains box.

Compile

Compiles this shape into the most compact form.

method	Compile ()
type	IShape
returns		[not-null]	The resulting shape.

Remarks:

Calling this method will not modify the geometry of a shape, only the object model structure.

Deserialize

Initializes the state of this object from the given data stream.

method	Deserialize (int32 serialVersion, ISerializer data)
type	ISerializable
params	serialVersion	[>=1]	The serial data version.
	data	[not-null]	The serial data stream.
returns		[not-null]	The deserialized object. This will typically be this, but in some circumstances, another instance may be returned (e.g. singletons).
inherited	ISerializable.Deserialize

Remarks:

The Deserialize method will be called immediately after the object has been instantiated via its default constructor.

The provided serialVersion number is guaranteed to be equal to or less than the SerialVersion returned by this object (i.e. ISerializable object must provide backwards compatibility).

See also:

ISerializable.Serialize
ISerializable.SerialVersion

DistanceTo

Computes the smallest distance from the given point to the shape.

[ThreadSafe]
method	DistanceTo (float64 x, float64 y, float64 maximum = Maths.MaxDouble)
type	float64
params	x		X-coordinate of point.
	y		Y-coordinate of point.
	maximum		The maximum relevant distance. This is a hint for the implementing class which can be exploited in order to optimize performance.
returns			Smallest distance to the shape.

Remarks:

If the point lies outside of the shape, the returned distance will be greater than zero. If the point is inside of the shape, the returned distance will be negative. The returned distance will be zero if the point exactly lies on the shape boundary.

---

Computes the smallest distance from the given point to the shape, additionally returning the corresponding nearest feature point on the shape.

[ThreadSafe]
method	DistanceTo (float64 x, float64 y, out Vec3I vertices, out Vec3D weights, float64 maximum = Maths.MaxDouble)
type	float64
params	x		X-coordinate of point.
	y		Y-coordinate of point.
	vertices		Shape vertex indices (see VertexAt) that describe the location of the nearest shape feature.
	weights		Location of the nearest shape feature, given as relative weights (i.e. the weight sum is 1) of vertices. The weights are sorted in descending order, i.e. X always holds the greatest weight and Z always holds the smallest weight.
	maximum		The maximum relevant distance. This is a hint for the implementing class which can be exploited in order to optimize performance.
returns			Smallest distance to the shape. All results greater than maximum are considered irrelevant. Implementing methods are free to discard those results.

Remarks:

If the point lies outside of the shape, the returned distance will be greater than zero. If the point is inside of the shape, the returned distance will be negative. The returned distance will be zero if the point exactly lies on the shape boundary.

EdgeAt

Returns a shape edge.

method	EdgeAt (int32 index)
type	Vec2I
params	index	[0..EdgeCount-1]	The edge index.
returns			The shape edge.

Remarks:

Each edge connects two vertices (see VertexAt), in the direction from X to Y.

All points that lie on an edge have a shape distance of zero.

See also:

IShapeInfo.EdgeCount

EdgeWalk

Returns the neighbouring edges for walking along a polygon contour.

method	EdgeWalk (int32 index)
type	Vec2I
params	index	[0..EdgeCount-1]	The edge index.
returns			Index of neighbouring edge (see IShape): X points to previous edge, Y points to next edge. The component will be -1 if there is no neighbouring edge (i.e. the contour is not closed). Both components will be -1 for non-polygon shapes.

Face

Returns the shape on the given cubemap face.

method	Face (CubemapFace face)
type	IShape
params	face		The cubemap face.
returns			The shape or null if there are no shape parts on the given cubemap face.

Remarks:

Passing NegZ to an ordinary shape will return this. Cubemap shapes (see TransformCubemap) will return an aggregated shape for each cubemap face, or null.

Cubemap shapes are used by IHeightmapShape and IPixelPyramidShape objects.

Invert

Inverts this shape.

method	Invert ()
type	IShape
returns		[not-null]	The inverted shape.

Maximum

Returns a composite shape that returns the maximum distance value (i.e. intersection of this shape and the given one).

method	Maximum (IShape shape)
type	IShape
params	shape	[not-null]	The other shape.
returns		[not-null]	The resulting shape.

Minimum

Returns a composite shape that returns the minimum distance value (i.e. the union of this shape and the given one).

method	Minimum (IShape shape)
type	IShape
params	shape	[not-null]	The other shape.
returns		[not-null]	The resulting shape.

Offset

Applies a distance offset to this shape.

method	Offset (float64 offset)
type	IShape
params	offset		The distance offset to apply.
returns		[not-null]	The resulting shape.

Serialize

Serializes the current state of this object to the given data stream.

method	Serialize (ISerializer data)
params	data	[not-null]	The serial data stream.
inherited	ISerializable.Serialize

See also:

ISerializable.Deserialize
ISerializable.SerialVersion

ToConfig

Returns the configuration value that describes this object.

method	ToConfig ()
type	ConfigValue
returns		[not-null]	The configuration value.
inherited	IConfigurable.ToConfig

Remarks:

All configurable objects need to implement this interface. For simple types, it is preferable to delegate to ToValue.

The returned value may be of type Invalid, which means that this object in its current state cannot be described with the configuration API.

Before returning the resulting configuration value, Cache must be called on it, passing this IConfigurable object as parameter.

TransformCoordinates

Transforms this shape using the given 2D homogeneous matrix.

method	TransformCoordinates (Mat3D matrix)
type	IShape
params	matrix		The 2D homogeneous matrix.
returns		[not-null]	The transforming shape.

Remarks:

Shape coordinates of this shape are multiplied with matrix using Mul2 (w = 1) in order to produce shape coordinates of the returned shape.

TransformCoordinateSystem

Transforms this shape to the given coordinate system.

method	TransformCoordinateSystem (CoordinateSystem target, float64 accuracy = 0)
type	IShape
params	target	[not-null]	The target coordinate system.
	accuracy	[>=0]	Optional accuracy to use for subdivision of edges. Given as a maximum error in the target coordinate system (see target. HorizontalUnit). Set to 0 to disable edge subdivision. Defaults to 0.
returns		[not-null]	The transforming shape.

Remarks:

Transformation cannot be performed from resp. to a local coordinate system (see IsLocal). A transformation between two local coordinate system is possible, but only a conversion regarding unit of measure (see LocalUnit) and coordinate system flags (see CoordinateSystemFlags) is done.

Implicit shapes cannot be transformed (see IShape).

TransformCubemap

Transforms this shape to a geographic cubemap coordinate system.

method	TransformCubemap (float64 accuracy = 0)
type	IShape
params	accuracy	[>=0]	Optional accuracy to use for subdivision of edges. Given as a maximum error in the target coordinate system (see Face). Set to 0 to disable edge subdivision. Defaults to 0.
returns		[not-null]	The transforming cubemap shape.

See also:

CoordinateSystem.ToCubemapFace

TransformGeometry

Transforms this shape to the given coordinate system.

method	TransformGeometry (CoordinateSystemTransform transform, float64 accuracy = 0)
type	IShape
params	transform	[not-null]	The coordinate system transformation to apply.
	accuracy	[>=0]	Optional accuracy to use for subdivision of edges. Given as a maximum error in the target coordinate system (see transform. Target. HorizontalUnit). Set to 0 to disable edge subdivision. Defaults to 0.
returns			The transformed shape or null if the transformed shape is empty or if the transformation is not possible (see remarks).

Remarks:

Transformation cannot be performed from resp. to a local coordinate system (see IsLocal). A transformation between two local coordinate system is possible, but only a conversion regarding unit of measure (see LocalUnit) and coordinate system flags (see CoordinateSystemFlags) is done.

Implicit shapes cannot be transformed (see IShape).

TriangleAt

Returns a shape triangle.

method	TriangleAt (int32 index)
type	Vec3I
params	index	[0..TriangleCount-1]	The triangle index.
returns			The shape triangle.

Remarks:

Each triangle connects three vertices (see IShape), in the order X, Y, Z, where X <Y and X < Z. The vertex winding is chosen so that the signed triangle area is positive (see Area).

VertexAt

Returns a shape vertex.

method	VertexAt (int32 index)
type	Vec2D
params	index	[0..VertexCount-1]	The vertex index.
returns			The shape vertex.

Remarks:

All vertices have a shape distance of zero.

See also:

IShapeInfo.VertexCount

Extensions

Contains

method	Contains (LatLon latLon)
type	bool
params	latLon

---

method	Contains (float64 latitude, float64 longitude)
type	bool
params	latitude
	longitude

ConvexHull

Computes the convex hull of vertices of this shape.

method	ConvexHull ()
type	IShape
returns			The convex hull or null if this shape does not have any vertices.

DistanceTo

Computes the shortest distance from the given point to the shape.

method	DistanceTo (Vec2D point, float64 maximum = Maths.MaxDouble)
type	float64
params	point		The point coordinates.
	maximum		The maximum relevant distance. This is a hint for the implementing class which can be exploited in order to optimize performance.
returns			Shortest distance to the shape.

Remarks:

If the point lies outside of the shape, the returned distance will be greater than zero. If the point is inside of the shape, the returned distance will be negative. The returned distance will be zero if the point exactly lies on the shape boundary.

ImportCSH

Imports this shape into a CSH file (Compressed SHape).

[OwnerReturn]
method	ImportCSH (Path output)
type	IOperation
params	output	[not-null]	Path to output CSH file.

Outline

Returns a shape that covers the outline of this shape.

method	Outline (float64 width = 0)
type	IShape
params	width	[>=0]	Width of outline shape. Defaults to 0.
returns		[not-null]	The resulting shape.

Rasterizer

Returns a ShapeRasterizer object that rasterizes distance values into the given sample buffer.

method	Rasterizer (IColorRamp colorRamp)
type	IShapeRasterizer<ColorBuffer>
params	colorRamp	[not-null]	The color ramp to use.
returns		[not-null]	The shape rasterizer.

Remarks:

Distance values are converted into color values by performing a color ramp lookup.

See also:

IColorRamp
ColorBuffer

---

Returns a ShapeRasterizer object that rasterizes distance values into the given sample buffer.

method	Rasterizer (HeightmapSamples samples, float64 falloff)
type	IShapeRasterizer<HeightmapRegion>
params	samples	[not-null]	Heightmap sample values per shape vertex.
	falloff	[>=0]	Distance falloff at shape boundary.
returns		[not-null]	The shape rasterizer.

Remarks:

The shape interior is rasterized by interpolating the shape vertices: Each vertex (see VertexAt) has a corresponding heightmap value in samples.

See also:

HeightmapRegion

---

Returns a ShapeRasterizer object that rasterizes distance values into the given sample buffer.

method	Rasterizer (HeightmapSample sample, float64 falloff)
type	IShapeRasterizer<HeightmapRegion>
params	sample		The uniform heightmap sample of the shape.
	falloff	[>=0]	Distance falloff at shape boundary.
returns		[not-null]	The shape rasterizer.

Remarks:

The shape interior is rasterized using the given uniform heightmap sample value.

See also:

HeightmapRegion

TransformCoordinates

Transforms this shape using the center of its bounds as the origin.

method	TransformCoordinates (Transform transform)
type	IShape
params	transform		The transform to apply.
returns		[not-null]	The resulting shape.

See also:

Transforms.TransformPointD

---

Transforms this shape using the given homogeneous matrix.

method	TransformCoordinates (Mat2D matrix)
type	IShape
params	matrix		The homogeneous transformation matrix.
returns		[not-null]	The resulting shape.

---

Transforms this shape.

method	TransformCoordinates (Transform transform, Vec2D center)
type	IShape
params	transform		The transform to apply.
	center		The transformation center.
returns		[not-null]	The resulting shape.

See also:

Transforms.TransformPointD

WriteCSH

Writes this shape to a CSH file (Compressed SHape).

method	WriteCSH (IDataStream stream)
params	stream	[not-null]	The output data stream.