Description
Return upper/lower from positive/negative y and right/left from positive/negative x inside result.
Polygon formulas combine edge, angle, and area contributions under a stated shape model. A single shoelace term or turning-angle ratio is only part of a full polygon computation and does not independently validate its boundary.
Return upper/lower from positive/negative y and right/left from positive/negative x inside result.
When to use this tool
Use Geometry: Rectangle Corner Sign Label when you need a polygon dimension, angle, or local accumulation term.
How to use the tool and how it works
- Enter xSign, ySign. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read result. Expand result to inspect the returned fields.
Require xSign and ySign each +1 or -1. Return upper/lower from positive/negative y and right/left from positive/negative x inside result.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| xSign | X Sign | Required. Safe integer. |
| ySign | Y Sign | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| result | Object containing the calculated members; expand to inspect the fields below. | Required. Object. |
| result.corner | Corner | Calculated result member: string. |
{
"input": {
"xSign": -1,
"ySign": 1
},
"output": {
"result": {
"corner": "upper-left"
}
}
}Limitations and assumptions
- This assumes a Cartesian y-up frame; screen y-down coordinates need a different convention and no actual rectangle, point, or bounds are inspected.
- Outputs are nested inside result. Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Evaluate the complete ordered boundary for area, winding, and validity. Use a general polygon method when regularity, simplicity, convexity, or uniform shape assumptions do not hold.
References
Similar or alternative tools
- Polygon Boundary Turn Sum
Sum supplied signedTurnsRadians and divide by 2π for winding.
- Polygon Signed Area Edge Term
Return (firstX × secondY-secondX × firstY)/2 as signedAreaContribution.