Something went wrong. Try again.
Bluesky app fork with some witchin' additions 💫
Something went wrong. Try again.
2.6 kB · 98 lines
TypeScript
at main
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899import {type Position} from './@types'
export type TransformMatrix = [ number, number, number, number, number, number, number, number, number,]
// These are affine transforms. See explanation of every cell here:// https://en.wikipedia.org/wiki/Transformation_matrix#/media/File:2D_affine_transformation_matrix.svg
export function createTransform(): TransformMatrix { 'worklet' return [1, 0, 0, 0, 1, 0, 0, 0, 1]}
export function applyRounding(t: TransformMatrix) { 'worklet' t[2] = Math.round(t[2]) t[5] = Math.round(t[5]) // For example: 0.985, 0.99, 0.995, then 1: t[0] = Math.round(t[0] * 200) / 200 t[4] = Math.round(t[0] * 200) / 200}
// We're using a limited subset (always scaling and translating while keeping aspect ratio) so// we can assume the transform doesn't encode have skew, rotation, or non-uniform stretching.
// All write operations are applied in-place to avoid unnecessary allocations.
export function readTransform(t: TransformMatrix): [number, number, number] { 'worklet' const scale = t[0] const translateX = t[2] const translateY = t[5] return [translateX, translateY, scale]}
export function prependTranslate(t: TransformMatrix, x: number, y: number) { 'worklet' t[2] += t[0] * x + t[1] * y t[5] += t[3] * x + t[4] * y}
export function prependScale(t: TransformMatrix, value: number) { 'worklet' t[0] *= value t[1] *= value t[3] *= value t[4] *= value}
export function prependTransform(ta: TransformMatrix, tb: TransformMatrix) { 'worklet' // In-place matrix multiplication. const a00 = ta[0], a01 = ta[1], a02 = ta[2] const a10 = ta[3], a11 = ta[4], a12 = ta[5] const a20 = ta[6], a21 = ta[7], a22 = ta[8] ta[0] = a00 * tb[0] + a01 * tb[3] + a02 * tb[6] ta[1] = a00 * tb[1] + a01 * tb[4] + a02 * tb[7] ta[2] = a00 * tb[2] + a01 * tb[5] + a02 * tb[8] ta[3] = a10 * tb[0] + a11 * tb[3] + a12 * tb[6] ta[4] = a10 * tb[1] + a11 * tb[4] + a12 * tb[7] ta[5] = a10 * tb[2] + a11 * tb[5] + a12 * tb[8] ta[6] = a20 * tb[0] + a21 * tb[3] + a22 * tb[6] ta[7] = a20 * tb[1] + a21 * tb[4] + a22 * tb[7] ta[8] = a20 * tb[2] + a21 * tb[5] + a22 * tb[8]}
export function prependPan(t: TransformMatrix, translation: Position) { 'worklet' prependTranslate(t, translation.x, translation.y)}
export function prependPinch( t: TransformMatrix, scale: number, origin: Position, translation: Position,) { 'worklet' prependTranslate(t, translation.x, translation.y) prependTranslate(t, origin.x, origin.y) prependScale(t, scale) prependTranslate(t, -origin.x, -origin.y)}