# Module libreda_db::layout::prelude

Expand description

The `prelude` helps to import most commonly used modules.

## Re-exports

`pub use super::traits::*;`
`pub use super::io::*;`
`pub use super::types::*;`
`pub use super::util;`
`pub use super::util::LayoutEditUtil;`

## Modules

Common traits for geometrical objects.

## Structs

Transformation described by a mirroring at the `x` axis, then a rotation around the origin, then a scaling, then a translation. This transformation allows rotations by arbitrary angles.

An edge (line segment) is represented by its starting point and end point.

Describe a non-equispaced repetition by storing a list of offsets.

Description of a transformation in the euclidean plane by a 2x2 matrix `A`. Transforming a point `p` is computed by the matrix product `A*p`.

Affine transformation represented as a 3x3 matrix like:

A `MultiPolygon` is a list of polygons. There is no restrictions on the polygons (they can be intersecting, empty, etc.).

`Path` is essentially a chain of line segments but with a possibly a non-zero width. It can be thought of the shape resulting by a stroke of a thick pen along the line segments.

A point is defined by a x and y coordinate in the euclidean plane.

A point string is a finite sequence of points. TODO: Implement `Deref` for accessing the list of points.

A polygon possibly with holes. The polygon is defined by a hull and a list of holes which are both `SimplePolygon`s.

An rectilinear edge (horizontal or vertical line segment) is represented by its starting point and end point.

A rectangle which is oriented along the x an y axis and represented by its lower left and upper right corner.

Iterator over edges of a rectangle.

Describe a equi-spaced n*m two-dimensional repetition as a lattice. The offsets are computed as `(i*a, j*b)` for `i` in `0..n` and `j` in `0..m`. `a` and `b` the distance vectors between two neighbouring points.

Transformation that consists only of a rotation by a multiple of 90 degrees around the origin `(0, 0)`.

A `SimplePolygon` is a polygon defined by vertices. It does not contain holes but can be self-intersecting.

A `SimpleRPolygon` is a rectilinear polygon. It does not contain holes but can be self-intersecting. The vertices are stored in an implicit format (one coordinate of two neighbour vertices is always the same for rectilinear polygons). This reduces memory usage but has the drawback that edges must alternate between horizontal and vertical. Vertices between two edges of the same orientation will be dropped.

Describes a geometric transformation that consists of a optional mirroring along the x-axis followed by a rotation by a multiple of 90 degrees followed by a displacement.

A text is a point associated with a string. This struct does not define how the text should be rendered on screen.

`Vector` defines a two dimensional vector with x and y components in the Euclidean plane.

## Enums

Angle expressed as a multiple of 90 degrees.

This is a result type for containment checks.

Return type for the edge-edge intersection functions. Stores all possible results of a edge to edge intersection.

Abstracted geometrical shape.

Return type for the line-line intersection functions. Stores all possible results of a line to line intersection.

Relative orientation of two geometrical objects such as vectors.

Encoding for the type of the beginning and end of the path.

Orientation of a rectilinear edge.

Return type for the line-line intersection functions. Stores all possible results of a line to line intersection.

Describe the regular or irregular repetition of a geometrical object.

Location relative to a directed line or edge. Something can be on the left of the line, right of the line or on top of the line (center).

## Constants

Precision for distance related decisions.

## Traits

Geometric transformation which preserves parallelism. Adds ‘shear’ to the `SimilarityTransform`.

Calculate the area of a geometry.

Calculation of the ‘bounding box’, i.e. the smallest rectangle that contains the geometrical object.

Trait for types that can be used as coordinates in the euclidean plane. In practice this are integers, floats and possible rational numbers.

Used for immutable dereferencing operations, like `*v`.

Geometric transformation which preserves oriented angles and distances (i.e. translation).

Calculate the doubled oriented area of a geometry. Using the doubled area allows to compute the area without using fractions. This is especially helpful when computing in integer coordinates.

Get the endpoints of an edge.

Define the intersection between two edges (i.e. line segments).

Iterate over edges. For an n-gon this would produce n edges.

Geometric transformation which preserves angles and distances (e.g. euclidean transform) but allows only rotations by a multiple of 90 degrees.

Geometric transformation which preserves angles and distances (e.g. euclidean transform).

Transform the geometrical object by transforming each point of it.

Mirror at the x or y axis.

Rotate by a integer multiple of 90 degrees.

Scale the geometrical shape. Scaling center is the origin `(0, 0)`.

Geometric transformation which preserves angles and ratios of distances. Adds resizing by integer numbers to the `IsometricRTransform`.

Geometric transformation which preserves angles and ratios of distances. Adds resizing to the `IsometricTransform`.

Trait for types that can be used as the text of this label. The most simple solution is to use `String`. However, in many cases where the same text is used in many labels it might be desirable to use ‘string interning’ for more efficient memory usage. Then an `Rc<String>` could be used for instance.

Trait for the conversion of a geometric shape to a polygon.

General geometric transformation.

Translate the geometrical object by a vector.

Try the calculation of the ‘bounding box’, i.e. the smallest rectangle that contains the geometrical object. In some cases this is not always possible, so the try might fail. For instance a set of polygons does not have a bounding box if the set is empty.

This trait defines the type-casting of the coordinate types for geometrical objects.

Try to compute the bounding box while consuming the data. This is intended to be used for computing bounding boxes over iterators.

Compute the winding number of a geometrical object around a point. The winding number is used to check if a point is contained in a shape.

Defines an additive identity element for `Self`.

## Type Definitions

Default type for euclidean distances.

Default floating point type.

Return type for the edge-edge intersection functions. Stores all possible results of a edge to edge intersection.