tldraw/state/shape-utils/arrow.tsx
2021-07-09 17:15:27 +01:00

644 lines
16 KiB
TypeScript

import vec from 'utils/vec'
import {
getArcLength,
uniqueId,
getSvgPathFromStroke,
rng,
getBoundsFromPoints,
translateBounds,
pointInBounds,
pointInCircle,
circleFromThreePoints,
isAngleBetween,
getPerfectDashProps,
clampToRotationToSegments,
lerpAngles,
clamp,
getFromCache,
} from 'utils'
import {
ArrowShape,
DashStyle,
Decoration,
ShapeHandle,
ShapeType,
} from 'types'
import {
intersectArcBounds,
intersectLineSegmentBounds,
} from 'utils/intersections'
import { defaultStyle, getShapeStyle } from 'state/shape-styles'
import getStroke from 'perfect-freehand'
import React from 'react'
import { registerShapeUtils } from './register'
// A cache for semi-expensive circles calculated from three points
function getCtp(shape: ArrowShape) {
const { start, end, bend } = shape.handles
return circleFromThreePoints(start.point, end.point, bend.point)
}
const arrow = registerShapeUtils<ArrowShape>({
boundsCache: new WeakMap([]),
defaultProps: {
id: uniqueId(),
type: ShapeType.Arrow,
name: 'Arrow',
parentId: 'page1',
childIndex: 0,
point: [0, 0],
rotation: 0,
bend: 0,
handles: {
start: {
id: 'start',
index: 0,
point: [0, 0],
},
end: {
id: 'end',
index: 1,
point: [1, 1],
},
bend: {
id: 'bend',
index: 2,
point: [0.5, 0.5],
},
},
decorations: {
start: null,
middle: null,
end: Decoration.Arrow,
},
style: {
...defaultStyle,
isFilled: false,
},
},
create(props) {
const shape = {
...this.defaultProps,
...props,
decorations: {
...this.defaultProps.decorations,
...props.decorations,
},
style: {
...this.defaultProps.style,
...props.style,
isFilled: false,
},
}
return shape
},
shouldRender(shape, prev) {
return shape.handles !== prev.handles || shape.style !== prev.style
},
render(shape, { isHovered }) {
const { id, bend, handles, style } = shape
const { start, end, bend: _bend } = handles
const isStraightLine =
vec.dist(_bend.point, vec.round(vec.med(start.point, end.point))) < 1
const isDraw = shape.style.dash === DashStyle.Draw
const styles = getShapeStyle(style)
const { strokeWidth } = styles
const arrowDist = vec.dist(start.point, end.point)
const arrowHeadlength = Math.min(arrowDist / 3, strokeWidth * 8)
let shaftPath: JSX.Element
let insetStart: number[]
let insetEnd: number[]
if (isStraightLine) {
const sw = strokeWidth * (isDraw ? 0.618 : 1.618)
const path = isDraw
? renderFreehandArrowShaft(shape)
: 'M' + vec.round(start.point) + 'L' + vec.round(end.point)
const { strokeDasharray, strokeDashoffset } = getPerfectDashProps(
arrowDist,
sw,
shape.style.dash,
2
)
insetStart = vec.nudge(start.point, end.point, arrowHeadlength)
insetEnd = vec.nudge(end.point, start.point, arrowHeadlength)
// Straight arrow path
shaftPath = (
<>
<path
d={path}
fill="none"
stroke="transparent"
strokeWidth={Math.max(8, strokeWidth * 2)}
strokeDasharray="none"
strokeDashoffset="none"
strokeLinecap="round"
/>
<path
d={path}
fill={styles.stroke}
stroke={styles.stroke}
strokeWidth={sw}
strokeDasharray={strokeDasharray}
strokeDashoffset={strokeDashoffset}
strokeLinecap="round"
/>
</>
)
} else {
const circle = getCtp(shape)
const sw = strokeWidth * (isDraw ? 0.618 : 1.618)
const path = isDraw
? renderCurvedFreehandArrowShaft(shape, circle)
: getArrowArcPath(start, end, circle, bend)
const arcLength = getArcLength(
[circle[0], circle[1]],
circle[2],
start.point,
end.point
)
const { strokeDasharray, strokeDashoffset } = getPerfectDashProps(
arcLength - 1,
sw,
shape.style.dash,
2
)
const center = [circle[0], circle[1]]
const radius = circle[2]
const sa = vec.angle(center, start.point)
const ea = vec.angle(center, end.point)
const t = arrowHeadlength / Math.abs(arcLength)
insetStart = vec.nudgeAtAngle(center, lerpAngles(sa, ea, t), radius)
insetEnd = vec.nudgeAtAngle(center, lerpAngles(ea, sa, t), radius)
// Curved arrow path
shaftPath = (
<>
<path
d={path}
fill="none"
stroke="transparent"
strokeWidth={Math.max(8, strokeWidth * 2)}
strokeDasharray="none"
strokeDashoffset="none"
strokeLinecap="round"
/>
<path
d={path}
fill={isDraw ? styles.stroke : 'none'}
stroke={styles.stroke}
strokeWidth={sw}
strokeDasharray={strokeDasharray}
strokeDashoffset={strokeDashoffset}
strokeLinecap="round"
/>
</>
)
}
const sw = strokeWidth * 1.618
return (
<g id={id} filter={isHovered ? 'url(#expand)' : 'none'}>
{shaftPath}
{shape.decorations.start === Decoration.Arrow && (
<path
d={getArrowHeadPath(shape, start.point, insetStart)}
fill="none"
stroke={styles.stroke}
strokeWidth={sw}
strokeDashoffset="none"
strokeDasharray="none"
strokeLinecap="round"
strokeLinejoin="round"
/>
)}
{shape.decorations.end === Decoration.Arrow && (
<path
d={getArrowHeadPath(shape, end.point, insetEnd)}
fill="none"
stroke={styles.stroke}
strokeWidth={sw}
strokeDashoffset="none"
strokeDasharray="none"
strokeLinecap="round"
strokeLinejoin="round"
/>
)}
</g>
)
},
rotateBy(shape, delta) {
const { start, end, bend } = shape.handles
const mp = vec.med(start.point, end.point)
start.point = vec.rotWith(start.point, mp, delta)
end.point = vec.rotWith(end.point, mp, delta)
bend.point = vec.rotWith(bend.point, mp, delta)
this.onHandleChange(shape, shape.handles, {
delta: [0, 0],
shiftKey: false,
})
return this
},
rotateTo(shape, rotation, delta) {
const { start, end, bend } = shape.handles
const mp = vec.med(start.point, end.point)
start.point = vec.rotWith(start.point, mp, delta)
end.point = vec.rotWith(end.point, mp, delta)
bend.point = vec.rotWith(bend.point, mp, delta)
this.onHandleChange(shape, shape.handles, {
delta: [0, 0],
shiftKey: false,
})
return this
},
getBounds(shape) {
const bounds = getFromCache(this.boundsCache, shape, (cache) => {
const { start, bend, end } = shape.handles
cache.set(
shape,
getBoundsFromPoints([start.point, bend.point, end.point])
)
})
return translateBounds(bounds, shape.point)
},
getRotatedBounds(shape) {
const { start, bend, end } = shape.handles
return translateBounds(
getBoundsFromPoints([start.point, bend.point, end.point], shape.rotation),
shape.point
)
},
getCenter(shape) {
const { start, end } = shape.handles
return vec.add(shape.point, vec.med(start.point, end.point))
},
hitTest(shape, point) {
const { start, end } = shape.handles
if (shape.bend === 0) {
return (
vec.distanceToLineSegment(
start.point,
end.point,
vec.sub(point, shape.point)
) < 4
)
}
const [cx, cy, r] = getCtp(shape)
return !pointInCircle(point, vec.add(shape.point, [cx, cy]), r - 4)
},
hitTestBounds(this, shape, brushBounds) {
const { start, end, bend } = shape.handles
const sp = vec.add(shape.point, start.point)
const ep = vec.add(shape.point, end.point)
if (pointInBounds(sp, brushBounds) || pointInBounds(ep, brushBounds)) {
return true
}
if (vec.isEqual(vec.med(start.point, end.point), bend.point)) {
return intersectLineSegmentBounds(sp, ep, brushBounds).length > 0
} else {
const [cx, cy, r] = getCtp(shape)
const cp = vec.add(shape.point, [cx, cy])
return intersectArcBounds(sp, ep, cp, r, brushBounds).length > 0
}
},
transform(shape, bounds, { initialShape, scaleX, scaleY }) {
const initialShapeBounds = this.getBounds(initialShape)
// let nw = initialShape.point[0] / initialShapeBounds.width
// let nh = initialShape.point[1] / initialShapeBounds.height
// shape.point = [
// bounds.width * (scaleX < 0 ? 1 - nw : nw),
// bounds.height * (scaleY < 0 ? 1 - nh : nh),
// ]
shape.point = [bounds.minX, bounds.minY]
const handles = ['start', 'end']
handles.forEach((handle) => {
const [x, y] = initialShape.handles[handle].point
const nw = x / initialShapeBounds.width
const nh = y / initialShapeBounds.height
shape.handles[handle].point = [
bounds.width * (scaleX < 0 ? 1 - nw : nw),
bounds.height * (scaleY < 0 ? 1 - nh : nh),
]
})
const { start, bend, end } = shape.handles
const dist = vec.dist(start.point, end.point)
const midPoint = vec.med(start.point, end.point)
const bendDist = (dist / 2) * initialShape.bend
const u = vec.uni(vec.vec(start.point, end.point))
const point = vec.add(midPoint, vec.mul(vec.per(u), bendDist))
bend.point = Math.abs(bendDist) < 10 ? midPoint : point
return this
},
onDoublePointHandle(shape, handle) {
switch (handle) {
case 'bend': {
shape.bend = 0
shape.handles.bend.point = getBendPoint(shape)
break
}
case 'start': {
shape.decorations.start = shape.decorations.start
? null
: Decoration.Arrow
break
}
case 'end': {
shape.decorations.end = shape.decorations.end ? null : Decoration.Arrow
break
}
}
return this
},
onHandleChange(shape, handles, { shiftKey }) {
// Apple changes to the handles
for (const id in handles) {
const handle = handles[id]
shape.handles[handle.id] = handle
}
// If the user is holding shift, we want to snap the handles to angles
for (const id in handles) {
if ((id === 'start' || id === 'end') && shiftKey) {
const point = handles[id].point
const other = id === 'start' ? shape.handles.end : shape.handles.start
const angle = vec.angle(other.point, point)
const distance = vec.dist(other.point, point)
const newAngle = clampToRotationToSegments(angle, 24)
shape.handles[id].point = vec.nudgeAtAngle(
other.point,
newAngle,
distance
)
}
}
// If the user is moving the bend handle, we want to move the bend point
if ('bend' in handles) {
const { start, end, bend } = shape.handles
const distance = vec.dist(start.point, end.point)
const midPoint = vec.med(start.point, end.point)
const angle = vec.angle(start.point, end.point)
const u = vec.uni(vec.vec(start.point, end.point))
// Create a line segment perendicular to the line between the start and end points
const ap = vec.add(midPoint, vec.mul(vec.per(u), distance / 2))
const bp = vec.sub(midPoint, vec.mul(vec.per(u), distance / 2))
const bendPoint = vec.nearestPointOnLineSegment(ap, bp, bend.point, true)
// Find the distance between the midpoint and the nearest point on the
// line segment to the bend handle's dragged point
const bendDist = vec.dist(midPoint, bendPoint)
// The shape's "bend" is the ratio of the bend to the distance between
// the start and end points. If the bend is below a certain amount, the
// bend should be zero.
shape.bend = clamp(bendDist / (distance / 2), -0.99, 0.99)
// If the point is to the left of the line segment, we make the bend
// negative, otherwise it's positive.
const angleToBend = vec.angle(start.point, bendPoint)
if (isAngleBetween(angle, angle + Math.PI, angleToBend)) {
shape.bend *= -1
}
}
shape.handles.start.point = vec.round(shape.handles.start.point)
shape.handles.end.point = vec.round(shape.handles.end.point)
shape.handles.bend.point = getBendPoint(shape)
return this
},
onSessionComplete(shape) {
const bounds = this.getBounds(shape)
const offset = vec.sub([bounds.minX, bounds.minY], shape.point)
this.translateTo(shape, vec.add(shape.point, offset))
const { start, end, bend } = shape.handles
start.point = vec.round(vec.sub(start.point, offset))
end.point = vec.round(vec.sub(end.point, offset))
bend.point = vec.round(vec.sub(bend.point, offset))
shape.handles = { ...shape.handles }
return this
},
applyStyles(shape, style) {
Object.assign(shape.style, style)
shape.style.isFilled = false
return this
},
canStyleFill: false,
})
export default arrow
function getArrowArcPath(
start: ShapeHandle,
end: ShapeHandle,
circle: number[],
bend: number
) {
return [
'M',
start.point[0],
start.point[1],
'A',
circle[2],
circle[2],
0,
0,
bend < 0 ? 0 : 1,
end.point[0],
end.point[1],
].join(' ')
}
function getBendPoint(shape: ArrowShape) {
const { start, end } = shape.handles
const dist = vec.dist(start.point, end.point)
const midPoint = vec.med(start.point, end.point)
const bendDist = (dist / 2) * shape.bend
const u = vec.uni(vec.vec(start.point, end.point))
const point = vec.round(
Math.abs(bendDist) < 10
? midPoint
: vec.add(midPoint, vec.mul(vec.per(u), bendDist))
)
return point
}
function renderFreehandArrowShaft(shape: ArrowShape) {
const { style, id } = shape
const { start, end } = shape.handles
const getRandom = rng(id)
const strokeWidth = +getShapeStyle(style).strokeWidth * 2
const st = Math.abs(getRandom())
const stroke = getStroke(
[
...vec.pointsBetween(start.point, end.point),
end.point,
end.point,
end.point,
end.point,
],
{
size: strokeWidth / 2,
thinning: 0.5 + getRandom() * 0.3,
easing: (t) => t * t,
end: { taper: 1 },
start: { taper: 1 + 32 * (st * st * st) },
simulatePressure: true,
last: true,
}
)
const path = getSvgPathFromStroke(stroke)
return path
}
function renderCurvedFreehandArrowShaft(shape: ArrowShape, circle: number[]) {
const { style, id } = shape
const { start, end } = shape.handles
const getRandom = rng(id)
const strokeWidth = +getShapeStyle(style).strokeWidth * 2
const st = Math.abs(getRandom())
const center = [circle[0], circle[1]]
const radius = circle[2]
const startAngle = vec.angle(center, start.point)
const endAngle = vec.angle(center, end.point)
const points: number[][] = []
for (let i = 0; i < 21; i++) {
const t = i / 20
const angle = lerpAngles(startAngle, endAngle, t)
points.push(vec.round(vec.nudgeAtAngle(center, angle, radius)))
}
const stroke = getStroke([...points, end.point, end.point], {
size: strokeWidth / 2,
thinning: 0.5 + getRandom() * 0.3,
easing: (t) => t * t,
end: {
taper: shape.decorations.end ? 1 : 1 + strokeWidth * 5 * (st * st * st),
},
start: {
taper: shape.decorations.start ? 1 : 1 + strokeWidth * 5 * (st * st * st),
},
simulatePressure: true,
streamline: 0.01,
last: true,
})
const path = getSvgPathFromStroke(stroke)
return path
}
function getArrowHeadPath(shape: ArrowShape, point: number[], inset: number[]) {
const { left, right } = getArrowHeadPoints(shape, point, inset)
return ['M', left, 'L', point, right].join(' ')
}
function getArrowHeadPoints(
shape: ArrowShape,
point: number[],
inset: number[]
) {
// Use the shape's random seed to create minor offsets for the angles
const getRandom = rng(shape.id)
return {
left: vec.rotWith(inset, point, Math.PI / 6 + (Math.PI / 12) * getRandom()),
right: vec.rotWith(
inset,
point,
-Math.PI / 6 + (Math.PI / 12) * getRandom()
),
}
}