29 lines
708 B
TypeScript
29 lines
708 B
TypeScript
import React, { useEffect } from "react"
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import state from "state"
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/**
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* When the state's camera changes, update the transform of
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* the SVG group to reflect the correct zoom and pan.
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* @param ref
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*/
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export default function useCamera(ref: React.MutableRefObject<SVGGElement>) {
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useEffect(() => {
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let { camera } = state.data
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return state.onUpdate(({ data }) => {
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const g = ref.current
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if (!g) return
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const { point, zoom } = data.camera
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if (point !== camera.point || zoom !== camera.zoom) {
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g.setAttribute(
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"transform",
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`scale(${zoom}) translate(${point[0]} ${point[1]})`
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)
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}
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camera = data.camera
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})
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}, [state])
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}
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