add support for detectRetina display

[DanialV]

there is an option in original leaflet js library which is used for retina display(high pixel density) however I couldn't find such feature in FlutterMap widget. this feature will prevent map images render blurry in devices with high pixel density
here is the github issue about this problem Blurry Maps
here is leaflet document description about this option

If true and user is on a retina display, it will request four tiles of half the specified size and a bigger zoom level in place of one to utilize the high resolution.

[sky93]

I really need this feature too.

[johnpryan]

Some tiles providers allow you to append @2x on the end of the tile url. Does that fix your issue?

[DanialV]

@johnpryan yes but not all of them provide this feature, unfortunately, my tile provider doesn't provide this feature but it can be easily achieved if the number of tile on screen increased.

[johnpryan]

I see. thanks for the clarification - this will take some effort to figure out

[sky93]

I think we should change tileSize from 256.0 to 128.0 and then somehow resize the image when showing in tiles. And add the whole thing as an option called Retina Display.

[songfei]

use 512x512 png tile or 768x768 png tile and set tileSize to 256

[sky93]

use 512x512 png tile or 768x768 png tile and set tileSize to 256

Unfortunately our tile server only supports 256px.

[HugoHeneault]

Hey there! Thanks for this awesome flutter map plugin 🍻

Is it in your schedule to support retina? It is blurring my maps on almost every design for providers without @2x support...

Thanks a lot!

[maRci002]

Hello, checkout PR #585 it adds support for retina mode.