Block for get closest and farthest of kind

[UnsignedArduino]

Hi!

First off, I would like to say that this is an amazing extension. It really simplifies the math needed in complex games!

Anyways, so the main reason I use this block:

is to find the closest or farthest sprite of a certain kind from a sprite. I was thinking of a block like:

closest sprite of kind [kind] from [sprite] with a minimum distance of [number]

and it would return a sprite, or null if there aren't any sprites of that kind. number could be hidden behind a + sign or you could pass in null in TypeScript to not have a minimum distance. And also maybe the farthest sprite like this:

farthest sprite of kind [kind] from [sprite] with a maximum distance of [number]

[jwunderl]

Hmm @UnsignedArduino could you point me to some examples of doing this real quick? I can see the value in it, just want to see use cases where you'd use it, in case there are other options / factors we can consider; e.g. I could see some use cases could benefit from having 'n' nearest sprites (in which case I'd want to use https://github.com/jwunderl/pxt-heap to find the closest / furthest sprites, which can be done quite efficiently), but that makes the block a little more tedious to use if someone is looking for only one sprite.

[UnsignedArduino]

In my tower defense game, I could find the closest enemy or the farthest enemy, or maybe even just checking if there is something within a certain range by checking if a sprite is returned. Or maybe a shark that is trying to eat the closest fish, which wouldn't need a range anyway, so we could pass in null or a number less than or equal to 0.

I could see some use cases could benefit from having 'n' nearest sprites

This is also a great idea too, but having a get all sprites within [number] pixels from [sprite] seems to be more useful to me, like for instance getting which enemy has the most health within a certain distance, or destroying all the sprites within a certain radius because of an explosion. You probably would want the closest sprite as element 0 in the array returned and the farthest sprite in the radius as the last element in the array.

[jwunderl]

(get all sprites within [number] pixels from [sprite] implemented by @livcheerful as of v0.1.0:

)