pub trait Buffer {
type Scalar: BoolOpsNum + 'static;
// Required method
fn buffer_with_style(
&self,
style: BufferStyle<Self::Scalar>,
) -> MultiPolygon<Self::Scalar>;
// Provided method
fn buffer(&self, distance: Self::Scalar) -> MultiPolygon<Self::Scalar> { ... }
}Expand description
Create a new geometry whose boundary is offset the specified distance from the input.
The buffer operation creates polygons which represent all points within a specified distance from the input geometry. For example, buffering a point creates a circle, buffering a line creates a “pill” shape, and buffering a polygon creates a larger polygon (or a smaller one if a negative distance is requested).
§Examples
Basic buffering with default style:
use geo::{Point, Buffer, MultiPolygon};
let point = Point::new(0.0, 0.0);
// Creates an approximated circle with radius 2.0
let buffered: MultiPolygon = point.buffer(2.0);Default buffering rounds the point where geometries meet and where lines end. Use a custom style for more control:
use geo::{wkt, MultiPolygon, Buffer};
use geo::algorithm::buffer::{BufferStyle, LineCap, LineJoin};
let lines = wkt! {
MULTILINESTRING(
(0. 0.,2. 0.,1. 2.),
(0. -1.,2. 1.,3. 3.)
)
};
let style = BufferStyle::new(0.5)
.line_cap(LineCap::Square)
.line_join(LineJoin::Miter(1.0));
let buffered: MultiPolygon = lines.buffer_with_style(style);Required Associated Types§
type Scalar: BoolOpsNum + 'static
Required Methods§
Sourcefn buffer_with_style(
&self,
style: BufferStyle<Self::Scalar>,
) -> MultiPolygon<Self::Scalar>
fn buffer_with_style( &self, style: BufferStyle<Self::Scalar>, ) -> MultiPolygon<Self::Scalar>
Create a new geometry whose boundary is offset the specified distance from the input using
the specific styling options where lines intersect (line joins) and end (end caps).
For default (rounded) styling, see buffer.
This method allows control over the buffer appearance through the BufferStyle parameter.
§Arguments
style- ABufferStylethat specifies the distance, line caps, and line joins.
§Returns
A MultiPolygon representing the buffered geometry.
§Examples
use geo::{wkt, Buffer};
use geo::algorithm::buffer::{BufferStyle, LineCap, LineJoin};
let line_string = wkt! { LINESTRING (0. 0.,2. 0.,1. 2.) };
let style = BufferStyle::new(1.5)
.line_cap(LineCap::Square)
.line_join(LineJoin::Bevel);
let buffered = line_string.buffer_with_style(style);Provided Methods§
Sourcefn buffer(&self, distance: Self::Scalar) -> MultiPolygon<Self::Scalar>
fn buffer(&self, distance: Self::Scalar) -> MultiPolygon<Self::Scalar>
Create a new geometry whose boundary is offset the specified distance from the input.
By default, buffering uses rounded joins and end caps.
See buffer_with_style for more control.
§Arguments
distance- The buffer distance. Positive values create an outward buffer, negative values create an inward buffer (for polygons).
§Returns
A MultiPolygon representing the buffered geometry.
§Examples
use geo::{Point, Buffer, MultiPolygon};
let point = Point::new(5.0, 5.0);
let circle: MultiPolygon = point.buffer(3.0);
use geo::algorithm::Area;
// Creates an approximately circular polygon centered at (5, 5) with radius 30
assert_relative_eq!(circle.unsigned_area(), std::f64::consts::PI * 3.0f64.powi(2), epsilon = 2e-1);