Path2D

Path2D is a two-dimensional geometric path used in computer graphics to represent a sequence of connected shapes and subpaths. It serves as a container for drawing commands such as lines and curves, and can be used for rendering, hit-testing, or clipping. Path2D objects are mutable and can be reused across drawing operations, allowing complex shapes to be built up from simpler components.

In the context of web graphics, Path2D is a JavaScript object in the HTML5 Canvas API. It can be created empty or initialized from an SVG-style path data string. Once created, a Path2D can be built using methods that mirror those on a canvas context, including moving to points, drawing lines and curves, and closing paths. The resulting path can be drawn with fill or stroke operations, or used as a clipping path by calling clip with the path. Path2D also supports combining paths via addPath, optionally applying a transform to the added path.

In Java, Path2D is part of the java.awt.geom package and represents a shape that implements the Shape interface. It provides concrete implementations such as Path2D.Double and Path2D.Float, and is commonly used with Graphics2D for rendering and hit-testing. Typical operations include moveTo, lineTo, quadTo, curveTo, and closePath, as well as append and transform. As a Shape, a Path2D can be filled, stroked, or used as a clipping region. A closely related class is GeneralPath, which is a common concrete implementation of the Path2D concept in Java’s 2D API.

Summary: Path2D functions as a versatile, reusable representation of complex 2D shapes, available in both web canvas and Java 2D environments, enabling drawing, clipping, and geometry calculations through a consistent set of path-building operations.