Unpack premultiplied alpha?

[deathcap]

Consider enabling premultiplied alpha unpacking before loading the texture atlas into WebGL:

gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, true)

This has many advantages:

https://home.comcast.net/~tom_forsyth/blog.wiki.html#%5B%5BPremultiplied%20alpha%5D%5D
http://blogs.msdn.com/b/shawnhar/archive/2009/11/06/premultiplied-alpha.aspx
http://kriscg.blogspot.co.uk/2009/11/premultiplied-alpha.html
http://stackoverflow.com/questions/11521035/blending-with-html-background-in-webgl

but the blending function in voxel-shader may also have to change:

gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
gl.blendFuncSeparate(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA, gl.ONE, gl.ONE_MINUS_SRC_ALPHA)

also see:

• Inconsistent translucency voxel-shader#7
• Alpha transparency support mikolalysenko/ao-shader#2