MakePicture methods always create new TargetPicture

[gwttk]

Look at batch.go#L82 and canvas.go#L73
All MakePicture methods return new TargetPicture instances.
Also every Sprite caches a TargetPicture.
So, does that means, for 10k Sprites created from a single Picture, pixel creates 10k TargetPictures?
That sounds very inefficient!

[faiface]

Yep, means exactly that! This can be efficient or inefficient based on what target you're using. If you're drawing directly to the window, then yes, this will be rather inefficient, because a new OpenGL texture will be allocated for each picture. However, if you use Batch, it will be very efficient because TargetPicture for Batch is just a struct of two pointers and the Batch only makes one TargetPicture from its own target (e.g. window).

[gwttk]

Hmmm, that makes sense.
How about... instead of creating new batchPicture everytime, just reuse it, since every Batch uses only one Picture?

[faiface]

Looking at it, yeah, that could be done. Feel free to make a PR :)