feat: Android Camera v2 API

[dpa99c]

This PR contains a rewrite of the Android implementation to use the Camera v2 API instead of the deprecated Camera API.

The main reason for this change is to fix issues I was encountering with the existing implementation where the camera preview/captured image from this plugin did not correspond the camera preview/captured image from the default Camera app. i.e. this fixes #275

It also opens the way to fetch the device's camera details and select a specific camera/lens based on these [see #256].
While the fetch side is implemented by this PR (getCameraCharacteristics()), the selection of a specific camera/lens is not (as I didn't need it for my use case).

I also implements getZoom(), setZoom() and getMaxZoom() on both Android & iOS, reworking my previous PR #326 on Android to work with Camera v2 API.

[forgr-owner]

Hey @dpa99c feel free to propose your PR here: Cap-go/camera-preview#61
There is bounty of $100

[varshith257]

@dpa99c Is this changes works? Maybe a demo video demonstrating this changes could be good to add in PR description.

It could get easy for @pbowyer or @arielhernandezmusa to get quick reviewed. Hope this get merged soon. I am waiting for the Camera2 API to be integrated in the capacitor soon :)

[eggbeard]

This is a huge step in the right direction and deserves some attention to get it merged.
I am struggling to get the preview to display with the correct aspect ratio, with this PR

[dpa99c]

I am using this test project to validate the plugin functionality:
https://github.com/dpa99c/capacitor-camera-preview-test

[eggbeard]

@dpa99c Thanks for the test project. I believe that using a square preview in the test project is camouflaging a bug in computing the transformation matrix for the preview, since width and height are often the same and many aspect ratios collapse out to 1.

If you make the width, twice the height, then it becomes apparent that, in landscape mode the preview looks stretched vertically, while in portrait the opposite happens (the preview is squashed in Y)

I took a look through configureTransform, but to be honest did not understand it very well. It seems likely that scaleY is calculated wrongly, but trying to work out what it should be hurts my brain.

I have only tested on Android. I don't have access to an apple device

[eggbeard]

I still haven't pinned this one down, but something like:

private void configureTransform(int viewWidth, int viewHeight) {
        if (cameraDevice == null || !textureView.isAvailable() || mPreviewSize == null) {
            return;
        }
        int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
        Matrix matrix = new Matrix();
        RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
        RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
        float centerX = viewRect.centerX();
        float centerY = viewRect.centerY();
        if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
            bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max(
                    (float) viewHeight / mPreviewSize.getHeight(),
                    (float) viewWidth / mPreviewSize.getWidth());
            matrix.postScale(scale, scale, centerX, centerY);
            matrix.postRotate(90 * (rotation - 2), centerX, centerY);
        } else if (Surface.ROTATION_180 == rotation) {
            matrix.postRotate(180, centerX, centerY);
        }
        textureView.setTransform(matrix);
    }