OK. Another question is about this equation: (x + 0.5) / tex_width. Why you are always using + 0.5? From your picture it looks like you need to use + 0.5 for e.g. left side of textured object and - 0.5 right side. Like in this answer. Could you please clarify this a bit?

For some reason I thought that this half-pixel padding for texture coordinates is already made for us by OpenGL automatically and we need to make this padding by hand only in Direct3D. The link in the post is also about Direct3D. Here is another post saying that OpenGL and Direct3D > 9 already solve this proving my point. Not sure if I can believe it or not.

From the first glance it looks like Charles is a kind of HTTP proxy, so it can't shape plain TCP or UDP traffic. Am I missing something?