Segment Rectangle Clip

Description

Clip one closed planar segment to an inclusive axis-aligned rectangle using parameter bounds; null means no intersection.

Planar geometry operates on two-coordinate Cartesian points and explicit shape boundaries. A closed rectangle includes its edges, while a segment parameter locates a point along a supporting line. Signed cross products, areas and axis gaps preserve orientation or direction information that a magnitude alone would lose.

Clip one closed planar segment to an inclusive axis-aligned rectangle using parameter bounds; null means no intersection.

When to use this tool

Use this tool to clip one closed planar segment to an inclusive axis-aligned rectangle using parameter bounds; null means no intersection.

How to use the tool and how it works

Enter start, end, rectangle using the input definitions below.
Run the operation. Resolve malformed-input errors before interpreting the result.
Read result.segment. Interpret signs, units, ordering and null values using the rules below.

Start with segment parameter bounds [0,1] and tighten them against all four closed rectangle boundaries. Return interpolated endpoints when the final lower bound does not exceed the upper bound; otherwise return null.^[1]

Input field	Meaning and units	Accepted input
start	Segment start [x,y], corresponding to parameter zero.	Dense list of at most 128 finite numbers, subject to the stated integer/shape rules.
end	Segment end [x,y], corresponding to parameter one.	Dense list of at most 128 finite numbers, subject to the stated integer/shape rules.
rectangle	Closed rectangle [minX,minY,maxX,maxY]; equal bounds are allowed.	Dense list of at most 128 finite numbers, subject to the stated integer/shape rules.

Output field	Interpretation
result	Object containing the fields below.
result.segment	Two clipped endpoint coordinates, or null when the closed segment misses the rectangle.

json

{
  "input": {
    "start": [
      -1,
      1
    ],
    "end": [
      3,
      1
    ],
    "rectangle": [
      0,
      0,
      2,
      2
    ]
  },
  "output": {
    "result": {
      "segment": [
        [
          0,
          1
        ],
        [
          2,
          1
        ]
      ]
    }
  }
}

Limitations and assumptions

Boundary contact and degenerate segments/rectangle axes are retained. Floating comparisons have no robustness tolerance.
Point components and rectangle bounds are finite within ±1,000,000,000. Rectangles use [minX,minY,maxX,maxY] with ordered inclusive bounds. Floating arithmetic is used without an implicit robustness tolerance.
Every declared top-level input is required and unknown fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
Numeric outputs must be finite and within the absolute safe-integer magnitude; exact larger integers use decimal text. Source positions are zero-based UTF-16 offsets and span ends are exclusive unless a different convention is explicitly stated.

Alternative or Complementary methods

Choose the boundary and coordinate convention explicitly. Use robust geometric predicates or a topology-aware library when near-coincidence, holes, invalid polygons or geographic coordinates matter.

References

Tool behavior and example: Segment Rectangle Clip — tool.io

Similar or alternative tools

Polygon Rectangle Clip
Clip an ordered planar polygon against four rectangle half-planes, preserving algorithm order; floating boundary arithmetic, no polygon topology repair.
Polyline Rectangle Clip
Clip each polyline segment independently, retaining source-segment indexes and boundary point intersections instead of inventing path continuity.