tldraw/state/sessions/draw-session.ts
2021-05-27 21:11:48 +01:00

69 lines
1.8 KiB
TypeScript

import { current } from "immer"
import { Data, DrawShape } from "types"
import BaseSession from "./base-session"
import { getShapeUtils } from "lib/shape-utils"
import { getPage, simplify } from "utils/utils"
import * as vec from "utils/vec"
import commands from "state/commands"
export default class BrushSession extends BaseSession {
origin: number[]
previous: number[]
points: number[][]
snapshot: DrawSnapshot
shapeId: string
constructor(data: Data, id: string, point: number[]) {
super(data)
this.shapeId = id
this.origin = point
this.previous = point
this.points = []
this.snapshot = getDrawSnapshot(data, id)
const page = getPage(data)
const shape = page.shapes[id]
getShapeUtils(shape).translateTo(shape, point)
}
update = (data: Data, point: number[]) => {
const { shapeId } = this
const lp = vec.med(this.previous, point)
this.points.push(vec.sub(lp, this.origin))
this.previous = lp
const page = getPage(data)
const shape = page.shapes[shapeId]
getShapeUtils(shape).setPoints!(shape, [...this.points])
}
cancel = (data: Data) => {
const { shapeId, snapshot } = this
const page = getPage(data)
const shape = page.shapes[shapeId]
getShapeUtils(shape).setPoints!(shape, snapshot.points)
}
complete = (data: Data) => {
commands.draw(
data,
this.shapeId,
this.snapshot.points,
simplify(this.points, 0.1 / data.camera.zoom).map(([x, y]) => [
Math.trunc(x * 100) / 100,
Math.trunc(y * 100) / 100,
])
)
}
}
export function getDrawSnapshot(data: Data, shapeId: string) {
const page = getPage(current(data))
const { points } = page.shapes[shapeId] as DrawShape
return {
points,
}
}
export type DrawSnapshot = ReturnType<typeof getDrawSnapshot>