Rotate Origin Offset Effect Note
Actual2D rotation about independently resolved transform-origin coordinates (radians), not center assumed from element dimensions. Explicit supplied computed/layout context only; not a browser cascade/layout engine or cross-browser guarantee.
Description
Rotation about an offset origin first expresses the point relative to that origin.
Rotation about an offset origin first expresses the point relative to that origin.1
Translating the rotated vector back changes the final coordinates while preserving the chosen pivot. Use Rotate Origin Offset Effect Note to evaluate the supplied inputs under the specific model below.
When to use Rotate Origin Offset Effect Note
Use Rotate Origin Offset Effect Note to evaluate the supplied inputs under the specific model below. Define the supplied layout, token or rendering scenario and establish the relevant units and browser context independently.
How to use Rotate Origin Offset Effect Note and understand its results
- Define the supplied layout, token or rendering scenario and establish the relevant units and browser context independently.
- Enter Point x, Point y, Origin x, Origin y, Rotation radians using the field table and validation rules below, then run the tool.
- Read Rotated point and interpret units, signs, ordering and placeholders as explained below.
- If the tool reports an input error, correct that field and rerun. A successful false result, empty match list or unknown-evidence placeholder has the specific meaning described here; check the limitations before applying the result.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| pointX | Point x | number | Required; constraints below |
| pointY | Point y | number | Required; constraints below |
| originX | Origin x | number | Required; constraints below |
| originY | Origin y | number | Required; constraints below |
| rotationRadians | Rotation radians | number | Required; constraints below |
Enter a finite point, finite rotation origin and angle in radians. Subtract the origin, rotate with the 2D matrix and add the origin back. The result is a planar coordinate calculation and does not include 3D transforms, perspective or an inferred CSS reference box.
rotatedPoint = origin+R(θ)×(point−origin) Field order, units and branch conditions follow the implementation explanation above.
| Output field | Meaning | Value type |
|---|---|---|
| rotatedPoint | Rotated point | array of number |
{
"input": {
"pointX": 2,
"pointY": 0,
"originX": 1,
"originY": 0,
"rotationRadians": 3.141592653589793
},
"output": {
"rotatedPoint": [
0,
1.2246467991473532e-16
]
}
}Limitations and assumptions
Translating the rotated vector back changes the final coordinates while preserving the chosen pivot. Apply the exact scope and assumptions described above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are stated above; extremely large inputs or outputs can also be rejected. These errors differ from successful results such as false, no matches or unknown evidence.
Alternative or Complementary methods
Use Transform Function Order Matters Note for a related task: Rotation and translation generally do not commute.
Use outline-offset Negative Inset Ring for a related task: Outline offset locates a drawing relative to an element's border edge.
References
-
Rotate Origin Offset Effect Note — tool.io
Similar or alternative tools
- Transform Function Order Matters Note
Rotation and translation generally do not commute.
- outline-offset Negative Inset Ring
Outline offset locates a drawing relative to an element's border edge.