Lines from geojsonToBinary are rendered "wobbly"

[ffendt]

Hi everyone,

I am trying to render binary geojson data, which I create with the geojsonToBinary functionality from @loaders.gl/gis. But for some reason, the LineStrings from the original geojson are rendered "wobbly", when in binary format.

This is the original geojson:

While this the binary version of the geojson:

I also created a CodePen for this: https://codepen.io/Flo-Flindt/pen/XWGMMWm

Does anyone have a clue if this is related rather to deck.gl or to the geojsonToBinary function? Did this happen to anyone before? Any help is highly appreciated! Thanks in advance.

Side Note: This only seems to be a problem on "diagonal" LineStrings. Straight vertical or horizontal coordinates don't seem to cause this issue.

[ffendt]

Just found out the problem after further debugging: The used Float32Array for the coordinates, created by geojsonToBinary, does not have enough precision for the coordinates used in my example:

const f32 = new Float32Array(1)
const f64 = new Float64Array(1)
f32.set([4.3678157])
f64.set([4.3678157])

f32[0] // -> 4.3678154945373535
f64[0] // -> 4.3678157

This can be fixed by changing the position data type when creating the binary geojson via geojsonToBinary:

const binaryGeojson = geojsonToBinary(geojson.features, { PositionDataType: Float64Array });