I'm trying to figure out how to apply some custom frag shader into a filter. The intented effect is a simple crt warp over a sprite.
Here is what I got so far: https://jsfiddle.net/djq6kjx4/1/ but It should look something like the image in the attachment.
As you can see from the example above the warp effect is mostly visible to one corner. Now I'm starting with shaders but I think the reason is that vTextureCoord is somehow off?
I tried to use the mapCoords and unma