Polyline Distance Point Lookup
Interpolate a point by Euclidean cumulative polyline distance without extrapolation; zero-length segments are skipped for interpolation.
Description
Interpolate a point by Euclidean cumulative polyline distance without extrapolation; zero-length segments are skipped for interpolation.
A point at a specified polyline distance can lie inside a segment rather than at a vertex.
When to use this tool
Interpolate a point by Euclidean cumulative polyline distance without extrapolation; zero-length segments are skipped for interpolation.
- Prepare the supplied points, distance fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter points, distance. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.point. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Compute consecutive Euclidean lengths, require distance from zero through total length, find the first positive-length segment reaching it and linearly interpolate. If no positive segment qualifies, return the final point.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| points | points. | Numeric rows; at most 128 rows and 128 values per row |
| distance | distance. | Finite number |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.point | The point list in the ordering and representation described above. |
{
"input": {
"points": [
[
0,
0
],
[
3,
0
],
[
3,
4
]
],
"distance": 5
},
"output": {
"result": {
"point": [
3,
2
]
}
}
}Limitations and assumptions
- No extrapolation is allowed and at least two points are required. Entirely zero-length polylines accept only distance zero and return the final point.
- Point pairs use [x,y], rectangles and viewBox use [x,y,width,height], and all coordinate units must be consistent. This tool does not read, render or modify an SVG document.
- Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
- String lists have at most 128 entries of at most 128 code units; matrices have at most 128 rows and columns. Larger numeric lists and parsed JSON have separate bounded budgets. Nonfinite results and excessively large serialized outputs are rejected.
- Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.
Alternative or Complementary methods
Use a full SVG parser or rendering engine when the task includes commands and CSS values outside the documented branch. Compare coordinates and transforms under the same units and viewport convention.
References
Similar or alternative tools
- Polyline Uniform Distance Resampler
Resample a finite polyline at regular arc-distance spacing with an explicit optional final vertex, bounded to 10,000 samples.
- Polygon Close Point Policy
Add or remove one exact repeated endpoint under an explicit polygon closure policy; no geometric simplification.