Android Vector pixelating on zoom-in

Question

I'm trying to create a zoomable ImageView that can display vector images (SVG converted to Vector Drawable) that doesn't loose it's sharpness when zooming in.

I've used multiple Zooming approaches like this or this to handle the zooming, pinching and dragging. This resulted in a blurry mess when trying to zoom in, as seen below.

As I understand it from this article, these approaches don't work because the vector is drawn to bitmap , therefore pixelating when zooming in.

Is there any workaround to redraw the vector for each zoom step? Or should I try to draw the vector in a bigger size before displaying it?

Any Help is appreciated.

Redraw on zoom? Draw bigger Canvas, then zoom?

Answer 1

This is happening to conserve memory.

The Solution:

You should do subsampling scaling, which is to zoom in on stages.

for example: After zooming to 300% make a new bitmap from the vector which have the rectangle you are in only then start to zoom in the new image (see GIF below)

coding this will take some time, but I recommend using subsampling-scale-image-view library as an interface to do this. you can with a few changes make it for vector scaling.