https://github.com/ishape-swift/ioverlay
Boolean Operations for 2D Polygons: Supports intersection, union, difference, xor, and self-intersections for all polygon varieties.
https://github.com/ishape-swift/ioverlay
boolean-operations clipper clipping difference intersection poly-bool polygon polygon-clipping self-intersection union vatti-clipping xor
Last synced: 3 months ago
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Boolean Operations for 2D Polygons: Supports intersection, union, difference, xor, and self-intersections for all polygon varieties.
- Host: GitHub
- URL: https://github.com/ishape-swift/ioverlay
- Owner: iShape-Swift
- License: mit
- Created: 2023-07-10T12:25:00.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2024-11-27T18:52:56.000Z (about 1 year ago)
- Last Synced: 2025-09-27T17:46:35.180Z (4 months ago)
- Topics: boolean-operations, clipper, clipping, difference, intersection, poly-bool, polygon, polygon-clipping, self-intersection, union, vatti-clipping, xor
- Language: Swift
- Homepage: https://ishape-rust.github.io/iShape-js/overlay/stars_demo.html
- Size: 824 KB
- Stars: 8
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# iOverlay
The iOverlay is a fast poly-bool library supporting main operations like union, intersection, difference, and xor, governed by either the even-odd or non-zero rule.
This library is optimized for different scenarios, ensuring high performance across various use cases. For detailed performance benchmarks, check out the [Performance Comparison](https://ishape-rust.github.io/iShape-js/overlay/performance/performance.html)
## [Documentation](https://ishape-rust.github.io/iShape-js/overlay/stars_demo.html)
Try out iOverlay with an interactive demo. The demo covers operations like union, intersection, difference and exclusion
- [Stars Rotation](https://ishape-rust.github.io/iShape-js/overlay/stars_demo.html)
- [Shapes Editor](https://ishape-rust.github.io/iShape-js/overlay/shapes_editor.html)
## Features
- **Operations**: union, intersection, difference, and exclusion.
- **Polygons**: with holes, self-intersections, and multiple paths.
- **Simplification**: removes degenerate vertices and merges collinear edges.
- **Fill Rules**: even-odd and non-zero.
## Working Range and Precision
The iOverlay library operates within the following ranges and precision levels:
Extended Range: From -1,000,000 to 1,000,000 with a precision of 0.001.
Recommended Range: From -100,000 to 100,000 with a precision of 0.01 for more accurate results.
Utilizing the library within the recommended range ensures optimal accuracy in computations and is advised for most use cases.
## Installation
Installing iOverlay is simple and easy using Swift Package Manager. Just follow these steps:
- Open your Xcode project.
- Select your project and open tab Package Dependencies.
- Click on the "+" button.
- In search bar enter ```https://github.com/iShape-Swift/iOverlay```
- Click the "Add" button.
- Wait for the package to be imported.
- In your Swift code, add the following using statement to access the library:
```swift
import iOverlay
```
## Usage
Here's an example of how you can create a square with a hole and *union / differnce / intersect / xor* with other polygon:
```swift
var overlay = CGOverlay()
// add shape
overlay.add(path: [
CGPoint(x:-20, y:-16),
CGPoint(x:-20, y: 16),
CGPoint(x: 20, y: 16),
CGPoint(x: 20, y:-16)
], type: ShapeType.subject)
// add hole
overlay.add(path: [
CGPoint(x:-12, y:-8),
CGPoint(x:-12, y: 8),
CGPoint(x: 12, y: 8),
CGPoint(x: 12, y:-8)
], type: ShapeType.subject)
// add clip
overlay.add(path: [
CGPoint(x:-4, y:-24),
CGPoint(x:-4, y: 24),
CGPoint(x: 4, y: 24),
CGPoint(x: 4, y:-24)
], type: ShapeType.clip)
// make overlay graph
let graph = overlay.buildGraph()
// get union shapes
let union = graph.extractShapes(overlayRule: OverlayRule.union)
// get difference shapes
let difference = graph.extractShapes(overlayRule: OverlayRule.difference)
// get intersect shapes
let intersect = graph.extractShapes(overlayRule: OverlayRule.intersect)
// get exclusion shapes
let xor = graph.extractShapes(overlayRule: OverlayRule.xor)
// get clean shapes from subject, self intersections will be removed
let subject = graph.extractShapes(overlayRule: OverlayRule.subject)
```
### Shapes result
The output of the `extractShapes` function is a `[[[CGPoint]]]`, where:
- The outer `[CGShape]` represents a set of shapes.
- Each shape `[CGPath]` represents a collection of paths, where the first path is the outer boundary, and all subsequent paths are holes in this boundary.
- Each path `[CGPoint]` is a sequence of points, forming a closed path.
**Note**: Outer boundary paths have a clockwise order, and holes have a counterclockwise order.
### Union
### Difference
### Intersection
### Exclusion (xor)
### Self-intersection
