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feat: BREAKING CHANGE: Express zoom factor always in actual factor value (1, 2, 128, ...) instead of 0.0-1.0 scale (#306)

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* Make `zoom` go on "factor" scale

* Clean up `zoom` code

* fix float conversion

* fix zoom interpretation

* Update docs for new zoom scale

* fix float conversion
This commit is contained in:
Marc Rousavy
2021-07-29 11:44:22 +02:00
committed by GitHub
parent 6e2dc4e73b
commit 445af943c3
10 changed files with 46 additions and 41 deletions
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docs/docs/guides/ZOOMING.mdx
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@@ -90,9 +90,11 @@ A Camera device has different minimum, maximum and neutral zoom values. Those va
<img src="https://developer.android.com/images/training/camera/multi-camera-4.gif" width="45%" />
</div>
The Camera's `zoom` property expects values to be in the same "factor" scale as the `minZoom`, `neutralZoom` and `maxZoom` values - so if you pass `zoom={device.minZoom}` it is at the minimum available zoom, where as if you pass `zoom={device.maxZoom}` the maximum zoom value possible is zoomed in. It is recommended that you start at `device.neutralZoom` and let the user manually zoom out to the fish-eye camera on demand (if available).
### Logarithmic scale
A Camera's `zoom` property is represented in a **logarithmic scale**. That means, increasing from `0` to `0.1` will appear to be a much larger offset than increasing from `0.9` to `1`. If you want to implement a zoom gesture (`<PinchGestureHandler>`, `<PanGestureHandler>`), try to flatten the `zoom` property to a **linear scale** by raising it **exponentially**. (`zoom.value ** 2`)
A Camera's `zoom` property is represented in a **logarithmic scale**. That means, increasing from `1` to `2` will appear to be a much larger offset than increasing from `127` to `128`. If you want to implement a zoom gesture (`<PinchGestureHandler>`, `<PanGestureHandler>`), try to flatten the `zoom` property to a **linear scale** by raising it **exponentially**. (`zoom.value ** 2`)
### Pinch-to-zoom