问题
I'am trying to rotate Leaflet Rectangle using code from this question.
rotatePoints (center, points, yaw) {
const res = []
const angle = yaw * (Math.PI / 180)
for (let i = 0; i < points.length; i++) {
const p = points[i]
// translate to center
const p2 = new LatLng(p.lat - center.lat, p.lng - center.lng)
// rotate using matrix rotation
const p3 = new LatLng(Math.cos(angle) * p2.lat - Math.sin(angle) * p2.lng, Math.sin(angle) * p2.lat + Math.cos(angle) * p2.lng)
// translate back to center
const p4 = new LatLng(p3.lat + center.lat, p3.lng + center.lng)
// done with that point
res.push(p4)
}
return res
}
The problem is that the rectangle is skewed while rotating. Any ideas how to optimize this function?
Fixed Final code:
rotatePoints (center, points, yaw) {
const res = []
const centerPoint = map.latLngToLayerPoint(center)
const angle = yaw * (Math.PI / 180)
for (let i = 0; i < points.length; i++) {
const p = map.latLngToLayerPoint(points[i])
// translate to center
const p2 = new Point(p.x - centerPoint.x, p.y - centerPoint.y)
// rotate using matrix rotation
const p3 = new Point(Math.cos(angle) * p2.x - Math.sin(angle) * p2.y, Math.sin(angle) * p2.x + Math.cos(angle) * p2.y)
// translate back to center
let p4 = new Point(p3.x + centerPoint.x, p3.y + centerPoint.y)
// done with that point
p4 = map.layerPointToLatLng(p4)
res.push(p4)
}
return res
}
回答1:
What is "rectangle" on sphere? It is result of applying of current projection to such coordinates that their image on the map/screen form rectangle. Note that lat-long coordinates are not ought to be equal for every rectangle side (for example, longitude for equator-aligned rectangle will differ for top and bottom point in the most of usual projections)
So to to get good-looking rectangle in map, you need to rotate vertices in screen coordinates, and make back-projection into lat-long space.
来源:https://stackoverflow.com/questions/60615163/rotate-leaflet-polyline-rectangle