rotate-neg-90-about
function rotateNeg90About(ps: number[][], center: number[]): number[][]
Defined in transformation/affine/rotate-neg-90-about.ts:15
Returns the given bezier curve rotated anti-clockwise about the given point by exactly -90 degrees (i.e. clockwise by 90 degrees).
This is an exact special case of rotateAbout that avoids the floating point error introduced by evaluating sin/cos of a rounded Math.PI/2. The rotation reduces to (x,y) -> (y,-x) (about the origin) which is exact.
Note!
Green circles are draggable!
Parameters:
| Name | Type | Description |
|---|---|---|
ps | number[][] | an order 0,1,2 or 3 bezier curve given as an ordered array of its control point coordinates, e.g. [[0,0], [1,1], [2,1], [2,0]] |
center | number[] | the point to rotate about, e.g. [1,2] |