import Vector from "lib/code/vector" import { getShapeUtils } from "lib/shapes" import React from "react" import { Data, Bounds, TransformEdge, TransformCorner, Shape } from "types" import * as svg from "./svg" import * as vec from "./vec" export function screenToWorld(point: number[], data: Data) { return vec.sub(vec.div(point, data.camera.zoom), data.camera.point) } /** * Get a bounding box that includes two bounding boxes. * @param a Bounding box * @param b Bounding box * @returns */ export function getExpandedBounds(a: Bounds, b: Bounds) { const minX = Math.min(a.minX, b.minX), minY = Math.min(a.minY, b.minY), maxX = Math.max(a.maxX, b.maxX), maxY = Math.max(a.maxY, b.maxY), width = Math.abs(maxX - minX), height = Math.abs(maxY - minY) return { minX, minY, maxX, maxY, width, height } } /** * Get the common bounds of a group of bounds. * @returns */ export function getCommonBounds(...b: Bounds[]) { if (b.length < 2) return b[0] let bounds = b[0] for (let i = 1; i < b.length; i++) { bounds = getExpandedBounds(bounds, b[i]) } return bounds } // export function getBoundsFromPoints(a: number[], b: number[]) { // const minX = Math.min(a[0], b[0]) // const maxX = Math.max(a[0], b[0]) // const minY = Math.min(a[1], b[1]) // const maxY = Math.max(a[1], b[1]) // return { // minX, // maxX, // minY, // maxY, // width: maxX - minX, // height: maxY - minY, // } // } // A helper for getting tangents. export function getCircleTangentToPoint( A: number[], r0: number, P: number[], side: number ) { const B = vec.lrp(A, P, 0.5), r1 = vec.dist(A, B), delta = vec.sub(B, A), d = vec.len(delta) if (!(d <= r0 + r1 && d >= Math.abs(r0 - r1))) { return } const a = (r0 * r0 - r1 * r1 + d * d) / (2.0 * d), n = 1 / d, p = vec.add(A, vec.mul(delta, a * n)), h = Math.sqrt(r0 * r0 - a * a), k = vec.mul(vec.per(delta), h * n) return side === 0 ? vec.add(p, k) : vec.sub(p, k) } export function circleCircleIntersections(a: number[], b: number[]) { const R = a[2], r = b[2] let dx = b[0] - a[0], dy = b[1] - a[1] const d = Math.sqrt(dx * dx + dy * dy), x = (d * d - r * r + R * R) / (2 * d), y = Math.sqrt(R * R - x * x) dx /= d dy /= d return [ [a[0] + dx * x - dy * y, a[1] + dy * x + dx * y], [a[0] + dx * x + dy * y, a[1] + dy * x - dx * y], ] } export function getClosestPointOnCircle( C: number[], r: number, P: number[], padding = 0 ) { const v = vec.sub(C, P) return vec.sub(C, vec.mul(vec.div(v, vec.len(v)), r + padding)) } export function projectPoint(p0: number[], a: number, d: number) { return [Math.cos(a) * d + p0[0], Math.sin(a) * d + p0[1]] } function shortAngleDist(a0: number, a1: number) { const max = Math.PI * 2 const da = (a1 - a0) % max return ((2 * da) % max) - da } export function lerpAngles(a0: number, a1: number, t: number) { return a0 + shortAngleDist(a0, a1) * t } export function getBezierCurveSegments(points: number[][], tension = 0.4) { const len = points.length, cpoints: number[][] = [...points] if (len < 2) { throw Error("Curve must have at least two points.") } for (let i = 1; i < len - 1; i++) { const p0 = points[i - 1], p1 = points[i], p2 = points[i + 1] const pdx = p2[0] - p0[0], pdy = p2[1] - p0[1], pd = Math.hypot(pdx, pdy), nx = pdx / pd, // normalized x ny = pdy / pd, // normalized y dp = Math.hypot(p1[0] - p0[0], p1[1] - p0[1]), // Distance to previous dn = Math.hypot(p1[0] - p2[0], p1[1] - p2[1]) // Distance to next cpoints[i] = [ // tangent start p1[0] - nx * dp * tension, p1[1] - ny * dp * tension, // tangent end p1[0] + nx * dn * tension, p1[1] + ny * dn * tension, // normal nx, ny, ] } // TODO: Reflect the nearest control points, not average them const d0 = Math.hypot(points[0][0] + cpoints[1][0]) cpoints[0][2] = (points[0][0] + cpoints[1][0]) / 2 cpoints[0][3] = (points[0][1] + cpoints[1][1]) / 2 cpoints[0][4] = (cpoints[1][0] - points[0][0]) / d0 cpoints[0][5] = (cpoints[1][1] - points[0][1]) / d0 const d1 = Math.hypot(points[len - 1][1] + cpoints[len - 1][1]) cpoints[len - 1][0] = (points[len - 1][0] + cpoints[len - 2][2]) / 2 cpoints[len - 1][1] = (points[len - 1][1] + cpoints[len - 2][3]) / 2 cpoints[len - 1][4] = (cpoints[len - 2][2] - points[len - 1][0]) / -d1 cpoints[len - 1][5] = (cpoints[len - 2][3] - points[len - 1][1]) / -d1 const results: { start: number[] tangentStart: number[] normalStart: number[] pressureStart: number end: number[] tangentEnd: number[] normalEnd: number[] pressureEnd: number }[] = [] for (let i = 1; i < cpoints.length; i++) { results.push({ start: points[i - 1].slice(0, 2), tangentStart: cpoints[i - 1].slice(2, 4), normalStart: cpoints[i - 1].slice(4, 6), pressureStart: 2 + ((i - 1) % 2 === 0 ? 1.5 : 0), end: points[i].slice(0, 2), tangentEnd: cpoints[i].slice(0, 2), normalEnd: cpoints[i].slice(4, 6), pressureEnd: 2 + (i % 2 === 0 ? 1.5 : 0), }) } return results } export function cubicBezier( tx: number, x1: number, y1: number, x2: number, y2: number ) { // Inspired by Don Lancaster's two articles // http://www.tinaja.com/glib/cubemath.pdf // http://www.tinaja.com/text/bezmath.html // Set start and end point const x0 = 0, y0 = 0, x3 = 1, y3 = 1, // Convert the coordinates to equation space A = x3 - 3 * x2 + 3 * x1 - x0, B = 3 * x2 - 6 * x1 + 3 * x0, C = 3 * x1 - 3 * x0, D = x0, E = y3 - 3 * y2 + 3 * y1 - y0, F = 3 * y2 - 6 * y1 + 3 * y0, G = 3 * y1 - 3 * y0, H = y0, // Variables for the loop below iterations = 5 let i: number, slope: number, x: number, t = tx // Loop through a few times to get a more accurate time value, according to the Newton-Raphson method // http://en.wikipedia.org/wiki/Newton's_method for (i = 0; i < iterations; i++) { // The curve's x equation for the current time value x = A * t * t * t + B * t * t + C * t + D // The slope we want is the inverse of the derivate of x slope = 1 / (3 * A * t * t + 2 * B * t + C) // Get the next estimated time value, which will be more accurate than the one before t -= (x - tx) * slope t = t > 1 ? 1 : t < 0 ? 0 : t } // Find the y value through the curve's y equation, with the now more accurate time value return Math.abs(E * t * t * t + F * t * t + G * t * H) } export function copyToClipboard(string: string) { let textarea: HTMLTextAreaElement let result: boolean try { navigator.clipboard.writeText(string) } catch (e) { try { textarea = document.createElement("textarea") textarea.setAttribute("position", "fixed") textarea.setAttribute("top", "0") textarea.setAttribute("readonly", "true") textarea.setAttribute("contenteditable", "true") textarea.style.position = "fixed" // prevent scroll from jumping to the bottom when focus is set. textarea.value = string document.body.appendChild(textarea) textarea.focus() textarea.select() const range = document.createRange() range.selectNodeContents(textarea) const sel = window.getSelection() sel.removeAllRanges() sel.addRange(range) textarea.setSelectionRange(0, textarea.value.length) result = document.execCommand("copy") } catch (err) { result = null } finally { document.body.removeChild(textarea) } } return !!result } /** * Get a bezier curve data to for a spline that fits an array of points. * @param points An array of points formatted as [x, y] * @param k Tension * @returns An array of points as [cp1x, cp1y, cp2x, cp2y, px, py]. */ export function getSpline(pts: number[][], k = 0.5) { let p0: number[], [p1, p2, p3] = pts const results: number[][] = [] for (let i = 1, len = pts.length; i < len; i++) { p0 = p1 p1 = p2 p2 = p3 p3 = pts[i + 2] ? pts[i + 2] : p2 results.push([ p1[0] + ((p2[0] - p0[0]) / 6) * k, p1[1] + ((p2[1] - p0[1]) / 6) * k, p2[0] - ((p3[0] - p1[0]) / 6) * k, p2[1] - ((p3[1] - p1[1]) / 6) * k, pts[i][0], pts[i][1], ]) } return results } export function getCurvePoints( pts: number[][], tension = 0.5, isClosed = false, numOfSegments = 3 ) { const _pts = [...pts], len = pts.length, res: number[][] = [] // results let t1x: number, // tension vectors t2x: number, t1y: number, t2y: number, c1: number, // cardinal points c2: number, c3: number, c4: number, st: number, st2: number, st3: number // The algorithm require a previous and next point to the actual point array. // Check if we will draw closed or open curve. // If closed, copy end points to beginning and first points to end // If open, duplicate first points to befinning, end points to end if (isClosed) { _pts.unshift(_pts[len - 1]) _pts.push(_pts[0]) } else { //copy 1. point and insert at beginning _pts.unshift(_pts[0]) _pts.push(_pts[len - 1]) // _pts.push(_pts[len - 1]) } // For each point, calculate a segment for (let i = 1; i < _pts.length - 2; i++) { // Calculate points along segment and add to results for (let t = 0; t <= numOfSegments; t++) { // Step st = t / numOfSegments st2 = Math.pow(st, 2) st3 = Math.pow(st, 3) // Cardinals c1 = 2 * st3 - 3 * st2 + 1 c2 = -(2 * st3) + 3 * st2 c3 = st3 - 2 * st2 + st c4 = st3 - st2 // Tension t1x = (_pts[i + 1][0] - _pts[i - 1][0]) * tension t2x = (_pts[i + 2][0] - _pts[i][0]) * tension t1y = (_pts[i + 1][1] - _pts[i - 1][1]) * tension t2y = (_pts[i + 2][1] - _pts[i][1]) * tension // Control points res.push([ c1 * _pts[i][0] + c2 * _pts[i + 1][0] + c3 * t1x + c4 * t2x, c1 * _pts[i][1] + c2 * _pts[i + 1][1] + c3 * t1y + c4 * t2y, ]) } } res.push(pts[pts.length - 1]) return res } export function angleDelta(a0: number, a1: number) { return shortAngleDist(a0, a1) } /** * Rotate a point around a center. * @param x The x-axis coordinate of the point. * @param y The y-axis coordinate of the point. * @param cx The x-axis coordinate of the point to rotate round. * @param cy The y-axis coordinate of the point to rotate round. * @param angle The distance (in radians) to rotate. */ export function rotatePoint(A: number[], B: number[], angle: number) { const s = Math.sin(angle) const c = Math.cos(angle) const px = A[0] - B[0] const py = A[1] - B[1] const nx = px * c - py * s const ny = px * s + py * c return [nx + B[0], ny + B[1]] } export function degreesToRadians(d: number) { return (d * Math.PI) / 180 } export function radiansToDegrees(r: number) { return (r * 180) / Math.PI } export function getArcLength(C: number[], r: number, A: number[], B: number[]) { const sweep = getSweep(C, A, B) return r * (2 * Math.PI) * (sweep / (2 * Math.PI)) } export function getArcDashOffset( C: number[], r: number, A: number[], B: number[], step: number ) { const del0 = getSweep(C, A, B) const len0 = getArcLength(C, r, A, B) const off0 = del0 < 0 ? len0 : 2 * Math.PI * C[2] - len0 return -off0 / 2 + step } export function getEllipseDashOffset(A: number[], step: number) { const c = 2 * Math.PI * A[2] return -c / 2 + -step } export function getSweep(C: number[], A: number[], B: number[]) { return angleDelta(vec.angle(C, A), vec.angle(C, B)) } export function deepCompareArrays(a: T[], b: T[]) { if (a?.length !== b?.length) return false return deepCompare(a, b) } export function deepCompare(a: T, b: T) { return a === b || JSON.stringify(a) === JSON.stringify(b) } /** * Get outer tangents of two circles. * @param x0 * @param y0 * @param r0 * @param x1 * @param y1 * @param r1 * @returns [lx0, ly0, lx1, ly1, rx0, ry0, rx1, ry1] */ export function getOuterTangents( C0: number[], r0: number, C1: number[], r1: number ) { const a0 = vec.angle(C0, C1) const d = vec.dist(C0, C1) // Circles are overlapping, no tangents if (d < Math.abs(r1 - r0)) return const a1 = Math.acos((r0 - r1) / d), t0 = a0 + a1, t1 = a0 - a1 return [ [C0[0] + r0 * Math.cos(t1), C0[1] + r0 * Math.sin(t1)], [C1[0] + r1 * Math.cos(t1), C1[1] + r1 * Math.sin(t1)], [C0[0] + r0 * Math.cos(t0), C0[1] + r0 * Math.sin(t0)], [C1[0] + r1 * Math.cos(t0), C1[1] + r1 * Math.sin(t0)], ] } export function arrsIntersect( a: T[], b: K[], fn?: (item: K) => T ): boolean export function arrsIntersect(a: T[], b: T[]): boolean export function arrsIntersect( a: T[], b: unknown[], fn?: (item: unknown) => T ) { return a.some((item) => b.includes(fn ? fn(item) : item)) } // /** // * Will mutate an array to remove items. // * @param arr // * @param item // */ // export function pull(arr: T[], ...items: T[]) { // for (let item of items) { // arr.splice(arr.indexOf(item), 1) // } // return arr // } // /** // * Will mutate an array to remove items, based on a function // * @param arr // * @param fn // * @returns // */ // export function pullWith(arr: T[], fn: (item: T) => boolean) { // pull(arr, ...arr.filter((item) => fn(item))) // return arr // } // export function rectContainsRect( // x0: number, // y0: number, // x1: number, // y1: number, // box: { x: number; y: number; width: number; height: number } // ) { // return !( // x0 > box.x || // x1 < box.x + box.width || // y0 > box.y || // y1 < box.y + box.height // ) // } export function getTouchDisplay() { return ( "ontouchstart" in window || navigator.maxTouchPoints > 0 || navigator.msMaxTouchPoints > 0 ) } const rounds = [1, 10, 100, 1000] export function round(n: number, p = 2) { return Math.floor(n * rounds[p]) / rounds[p] } /** * Linear interpolation betwen two numbers. * @param y1 * @param y2 * @param mu */ export function lerp(y1: number, y2: number, mu: number) { mu = clamp(mu, 0, 1) return y1 * (1 - mu) + y2 * mu } /** * Modulate a value between two ranges. * @param value * @param rangeA from [low, high] * @param rangeB to [low, high] * @param clamp */ export function modulate( value: number, rangeA: number[], rangeB: number[], clamp = false ) { const [fromLow, fromHigh] = rangeA const [v0, v1] = rangeB const result = v0 + ((value - fromLow) / (fromHigh - fromLow)) * (v1 - v0) return clamp ? v0 < v1 ? Math.max(Math.min(result, v1), v0) : Math.max(Math.min(result, v0), v1) : result } /** * Clamp a value into a range. * @param n * @param min */ export function clamp(n: number, min: number): number export function clamp(n: number, min: number, max: number): number export function clamp(n: number, min: number, max?: number): number { return Math.max(min, typeof max !== "undefined" ? Math.min(n, max) : n) } // CURVES // Mostly adapted from https://github.com/Pomax/bezierjs export function computePointOnCurve(t: number, points: number[][]) { // shortcuts if (t === 0) { return points[0] } const order = points.length - 1 if (t === 1) { return points[order] } const mt = 1 - t let p = points // constant? if (order === 0) { return points[0] } // linear? if (order === 1) { return [mt * p[0][0] + t * p[1][0], mt * p[0][1] + t * p[1][1]] } // quadratic/cubic curve? if (order < 4) { const mt2 = mt * mt, t2 = t * t let a: number, b: number, c: number, d = 0 if (order === 2) { p = [p[0], p[1], p[2], [0, 0]] a = mt2 b = mt * t * 2 c = t2 } else if (order === 3) { a = mt2 * mt b = mt2 * t * 3 c = mt * t2 * 3 d = t * t2 } return [ a * p[0][0] + b * p[1][0] + c * p[2][0] + d * p[3][0], a * p[0][1] + b * p[1][1] + c * p[2][1] + d * p[3][1], ] } // higher order curves: use de Casteljau's computation } function distance2(p: DOMPoint, point: number[]) { const dx = p.x - point[0], dy = p.y - point[1] return dx * dx + dy * dy } /** * Find the closest point on a path to an off-path point. * @param pathNode * @param point * @returns */ export function getClosestPointOnPath( pathNode: SVGPathElement, point: number[] ) { const pathLen = pathNode.getTotalLength() let p = 8, best: DOMPoint, bestLen: number, bestDist = Infinity, bl: number, al: number // linear scan for coarse approximation for ( let scan: DOMPoint, scanLen = 0, scanDist: number; scanLen <= pathLen; scanLen += p ) { if ( (scanDist = distance2( (scan = pathNode.getPointAtLength(scanLen)), point )) < bestDist ) { ;(best = scan), (bestLen = scanLen), (bestDist = scanDist) } } // binary search for precise estimate p /= 2 while (p > 0.5) { let before: DOMPoint, after: DOMPoint, bd: number, ad: number if ( (bl = bestLen - p) >= 0 && (bd = distance2((before = pathNode.getPointAtLength(bl)), point)) < bestDist ) { ;(best = before), (bestLen = bl), (bestDist = bd) } else if ( (al = bestLen + p) <= pathLen && (ad = distance2((after = pathNode.getPointAtLength(al)), point)) < bestDist ) { ;(best = after), (bestLen = al), (bestDist = ad) } else { p /= 2 } } return { point: [best.x, best.y], distance: bestDist, length: (bl + al) / 2, t: (bl + al) / 2 / pathLen, } } export function det( a: number, b: number, c: number, d: number, e: number, f: number, g: number, h: number, i: number ) { return a * e * i + b * f * g + c * d * h - a * f * h - b * d * i - c * e * g } /** * Get a circle from three points. * @param p0 * @param p1 * @param center * @returns */ export function circleFromThreePoints(A: number[], B: number[], C: number[]) { const a = det(A[0], A[1], 1, B[0], B[1], 1, C[0], C[1], 1) const bx = -det( A[0] * A[0] + A[1] * A[1], A[1], 1, B[0] * B[0] + B[1] * B[1], B[1], 1, C[0] * C[0] + C[1] * C[1], C[1], 1 ) const by = det( A[0] * A[0] + A[1] * A[1], A[0], 1, B[0] * B[0] + B[1] * B[1], B[0], 1, C[0] * C[0] + C[1] * C[1], C[0], 1 ) const c = -det( A[0] * A[0] + A[1] * A[1], A[0], A[1], B[0] * B[0] + B[1] * B[1], B[0], B[1], C[0] * C[0] + C[1] * C[1], C[0], C[1] ) return [ -bx / (2 * a), -by / (2 * a), Math.sqrt(bx * bx + by * by - 4 * a * c) / (2 * Math.abs(a)), ] } // eslint-disable-next-line @typescript-eslint/no-explicit-any export function throttle

any>( fn: T, wait: number, preventDefault?: boolean ) { // eslint-disable-next-line @typescript-eslint/no-explicit-any let inThrottle: boolean, lastFn: any, lastTime: number return function (...args: P) { if (preventDefault) args[0].preventDefault() // eslint-disable-next-line @typescript-eslint/no-this-alias const context = this if (!inThrottle) { fn.apply(context, args) lastTime = Date.now() inThrottle = true } else { clearTimeout(lastFn) lastFn = setTimeout(function () { if (Date.now() - lastTime >= wait) { fn.apply(context, args) lastTime = Date.now() } }, Math.max(wait - (Date.now() - lastTime), 0)) } } } export function pointInRect( point: number[], minX: number, minY: number, maxX: number, maxY: number ) { return !( point[0] < minX || point[0] > maxX || point[1] < minY || point[1] > maxY ) } /** * Get the intersection of two rays, with origin points p0 and p1, and direction vectors n0 and n1. * @param p0 The origin point of the first ray * @param n0 The direction vector of the first ray * @param p1 The origin point of the second ray * @param n1 The direction vector of the second ray * @returns */ export function getRayRayIntersection( p0: number[], n0: number[], p1: number[], n1: number[] ) { const p0e = vec.add(p0, n0), p1e = vec.add(p1, n1), m0 = (p0e[1] - p0[1]) / (p0e[0] - p0[0]), m1 = (p1e[1] - p1[1]) / (p1e[0] - p1[0]), b0 = p0[1] - m0 * p0[0], b1 = p1[1] - m1 * p1[0], x = (b1 - b0) / (m0 - m1), y = m0 * x + b0 return [x, y] } export async function postJsonToEndpoint( endpoint: string, data: { [key: string]: unknown } ) { const d = await fetch( `${process.env.NEXT_PUBLIC_BASE_API_URL}/api/${endpoint}`, { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify(data), } ) return await d.json() } export function getKeyboardEventInfo(e: KeyboardEvent | React.KeyboardEvent) { const { shiftKey, ctrlKey, metaKey, altKey } = e return { key: e.key, shiftKey, ctrlKey, metaKey: isDarwin() ? metaKey : ctrlKey, altKey, } } export function isDarwin() { return /Mac|iPod|iPhone|iPad/.test(window.navigator.platform) } export function metaKey(e: KeyboardEvent | React.KeyboardEvent) { return isDarwin() ? e.metaKey : e.ctrlKey } export function getTransformAnchor( type: TransformEdge | TransformCorner, isFlippedX: boolean, isFlippedY: boolean ) { let anchor: TransformCorner | TransformEdge = type // Change corner anchors if flipped switch (type) { case TransformCorner.TopLeft: { if (isFlippedX && isFlippedY) { anchor = TransformCorner.BottomRight } else if (isFlippedX) { anchor = TransformCorner.TopRight } else if (isFlippedY) { anchor = TransformCorner.BottomLeft } break } case TransformCorner.TopRight: { if (isFlippedX && isFlippedY) { anchor = TransformCorner.BottomLeft } else if (isFlippedX) { anchor = TransformCorner.TopLeft } else if (isFlippedY) { anchor = TransformCorner.BottomRight } break } case TransformCorner.BottomRight: { if (isFlippedX && isFlippedY) { anchor = TransformCorner.TopLeft } else if (isFlippedX) { anchor = TransformCorner.BottomLeft } else if (isFlippedY) { anchor = TransformCorner.TopRight } break } case TransformCorner.BottomLeft: { if (isFlippedX && isFlippedY) { anchor = TransformCorner.TopRight } else if (isFlippedX) { anchor = TransformCorner.BottomRight } else if (isFlippedY) { anchor = TransformCorner.TopLeft } break } } return anchor } export function vectorToPoint(point: number[] | Vector | undefined) { if (typeof point === "undefined") { return [0, 0] } if (point instanceof Vector) { return [point.x, point.y] } return point } export function getBoundsFromPoints(points: number[][]): Bounds { let minX = Infinity let minY = Infinity let maxX = -Infinity let maxY = -Infinity for (let [x, y] of points) { minX = Math.min(x, minX) minY = Math.min(y, minY) maxX = Math.max(x, maxX) maxY = Math.max(y, maxY) } return { minX, minY, maxX, maxY, width: maxX - minX, height: maxY - minY, } } /** * Move a bounding box without recalculating it. * @param bounds * @param delta * @returns */ export function translateBounds(bounds: Bounds, delta: number[]) { return { minX: bounds.minX + delta[0], minY: bounds.minY + delta[1], maxX: bounds.maxX + delta[0], maxY: bounds.maxY + delta[1], width: bounds.width, height: bounds.height, } } export function rotateBounds( bounds: Bounds, center: number[], rotation: number ) { const [minX, minY] = vec.rotWith([bounds.minX, bounds.minY], center, rotation) const [maxX, maxY] = vec.rotWith([bounds.maxX, bounds.maxY], center, rotation) return { minX, minY, maxX, maxY, width: bounds.width, height: bounds.height, } } export function getRotatedCorners(b: Bounds, rotation: number) { const center = [b.minX + b.width / 2, b.minY + b.height / 2] return [ [b.minX, b.minY], [b.maxX, b.minY], [b.maxX, b.maxY], [b.minX, b.maxY], ].map((point) => vec.rotWith(point, center, rotation)) } export function getTransformedBoundingBox( bounds: Bounds, handle: TransformCorner | TransformEdge, delta: number[], rotation = 0 ) { // Create top left and bottom right corners. let [ax0, ay0] = [bounds.minX, bounds.minY] let [ax1, ay1] = [bounds.maxX, bounds.maxY] // Create a second set of corners for the result. let [bx0, by0] = [bounds.minX, bounds.minY] let [bx1, by1] = [bounds.maxX, bounds.maxY] // Counter rotate the delta. This lets us make changes as if // the (possibly rotated) boxes were axis aligned. const [dx, dy] = vec.rot(delta, -rotation) // Depending on the dragging handle (an edge or corner of // the bounding box), find the anchor corner and use the delta // to adjust the result's corners. let anchor: TransformCorner | TransformEdge switch (handle) { case TransformEdge.Top: { anchor = TransformCorner.BottomRight by0 += dy break } case TransformEdge.Right: { anchor = TransformCorner.TopLeft bx1 += dx break } case TransformEdge.Bottom: { anchor = TransformCorner.TopLeft by1 += dy break } case TransformEdge.Left: { anchor = TransformCorner.BottomRight bx0 += dx break } case TransformCorner.TopLeft: { anchor = TransformCorner.BottomRight bx0 += dx by0 += dy break } case TransformCorner.TopRight: { anchor = TransformCorner.BottomLeft bx1 += dx by0 += dy break } case TransformCorner.BottomRight: { anchor = TransformCorner.TopLeft bx1 += dx by1 += dy break } case TransformCorner.BottomLeft: { anchor = TransformCorner.TopRight bx0 += dx by1 += dy break } } // If the bounds are rotated, get a vector from the rotated anchor // corner in the inital bounds to the rotated anchor corner in the // result's bounds. Subtract this vector from the result's corners, // so that the two anchor points (initial and result) will be equal. if (rotation % (Math.PI * 2) !== 0) { let cv = [0, 0] const c0 = vec.med([ax0, ay0], [ax1, ay1]) const c1 = vec.med([bx0, by0], [bx1, by1]) switch (anchor) { case TransformCorner.TopLeft: { cv = vec.sub( vec.rotWith([bx0, by0], c1, rotation), vec.rotWith([ax0, ay0], c0, rotation) ) break } case TransformCorner.TopRight: { cv = vec.sub( vec.rotWith([bx1, by0], c1, rotation), vec.rotWith([ax1, ay0], c0, rotation) ) break } case TransformCorner.BottomRight: { cv = vec.sub( vec.rotWith([bx1, by1], c1, rotation), vec.rotWith([ax1, ay1], c0, rotation) ) break } case TransformCorner.BottomLeft: { cv = vec.sub( vec.rotWith([bx0, by1], c1, rotation), vec.rotWith([ax0, ay1], c0, rotation) ) break } } ;[bx0, by0] = vec.sub([bx0, by0], cv) ;[bx1, by1] = vec.sub([bx1, by1], cv) } // If the axes are flipped (e.g. if the right edge has been dragged // left past the initial left edge) then swap points on that axis. if (bx1 < bx0) { ;[bx1, bx0] = [bx0, bx1] } if (by1 < by0) { ;[by1, by0] = [by0, by1] } return { minX: bx0, minY: by0, maxX: bx1, maxY: by1, width: bx1 - bx0, height: by1 - by0, } }